Draft Assessment Report On Uncaria Tomentosa (Willd. Ex Schult.) Dc., Cortex
o
EUROPEAN MEDICINES AGENCY
SCIENCE MEDICINES HEALTH
10 March 2015
EMA/HM PC/259598/2014
Committee on Herbal Medicinal Products (HMPC)
Assessment report on Uncaria tomentosa (Willd. ex Schult.) DC., cortex
Based on Article 10a of Directive 2001/83/EC as amended (well-established use)
Based on Article 16d(1), Article 16f and Article 16h of Directive 2001/83/EC as amended (traditional use)
Draft
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Herbal substance(s) (binomial scientific name of the plant, including plant part) |
Uncaria tomentosa, cortex |
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Herbal preparation(s) | |
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Pharmaceutical form(s) | |
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Rapporteur(s) |
Z. Biró-Sándor |
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Assessor(s) |
O. Roza |
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Peer-reviewer |
R. Länger |
Note: This draft assessment report is published to support the public consultation of the draft public statement on Uncaria tomentosa, cortex. It is a working document, not yet edited, and shall be further developed after the release for consultation of the public statement. Interested parties are welcome to submit comments to the HMPC secretariat, which will be taken into consideration but no 'overview of comments received during the public consultation' will be prepared on comments that will be received on this assessment report. The publication of this draft assessment report has been agreed to facilitate the understanding by Interested Parties of the assessment that has been carried out so far and led to the preparation of the draft public statement.
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© European Medicines Agency, 2015. Reproduction is authorised provided the source is acknowledged.
Table of contents...................................................................................................................2
1.1. Description of the herbal substance(s), herbal preparation(s) or combinations thereof ..4
2.1.1. Information about products on the market in the EU/EEA Member States.................7
2.1.2. Information on products on the market outside the EU/EEA....................................9
2.2. Information on documented medicinal use and historical data from literature..............9
3.1. Overview of available pharmacological data regarding the herbal substance(s), herbal
3.2. Overview of available pharmacokinetic data regarding the herbal substance(s), herbal
3.3. Overview of available toxicological data regarding the herbal substance(s)/herbal
4.1.1. Overview of pharmacodynamic data regarding the herbal substance(s)/preparation(s)
4.1.2. Overview of pharmacokinetic data regarding the herbal substance(s)/preparation(s)
5.5.7. Effects on ability to drive or operate machinery or impairment of mental ability......77
1. Introduction
1.1. Description of the herbal substance(s), herbal preparation(s) or combinations thereof
• Herbal substance(s)
Different definitions regarding the plant part used can be found in literature:
According to the WHO monograph Uncariae cortex consists of the dried stem bark of Uncaria tomentosa (Willd.) DC. (Rubiaceae) (WHO monograph 2007).
According to the definition of USP, cat's claw consists of the inner bark of the stems of Uncaria tomentosa (Willd.) DC. (Rubiaceae). It contains > 0.3% pentacyclic oxindole alkaloids as isopteropodine, calculated on the dried basis, as the sum of speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine and isopteropodine. The tetracyclic alkaloids contant is < 0.05% (USP 37).
According to Hagers Handbuch the herbal substance is the root bark (Blaschek et al. 1998).
Uncaria tomentosa is a scrambling liana, up to 20-30 meters long, main stem up to 25 cm in diameter. It grows as high as altitudes of 500-600 meters above sea level, in high forests with abundant insolation and reaches 18-19 m in height (Roth and Lindorf, 2002; WHO, 2007). The plant, also known as the "life-giving vine of Peru", "cat's claw", "saventaro", or "uña de gato", is a thick woody vine indigenous to the Amazon rain forest and other tropical areas of South and Central America. The plant has hook-like thorns, growing largely along the vine in a leafy pattern, which resembles the claws of a cat.
The vernacular names 'cat's claw' and 'uña de gato' in Spanish may lead to confusion because they are used for several plant species in tropical America.
From the genus Uncaria the two most common species used and marketed interchangeably for their various properties are Uncaria tomentosa and Uncaria guianensis. Uncaria tomentosa is evidently the preferred species partly because of its higher alkaloid content (Erowele and Kalejaiye, 2009).
Main constituents
Major classes of compounds (Table 1) identified in Uncaria tomentosa include oxindole and indole alkaloids (0.15-4.60%), pyroquinovic acid glycosides, organic acids, proanthocyanidins, sterols, and polyoxygenated triterpenes (WHO, 2007; Gonzales and Valerio, 2006).
Table 1: Constituents identified from Uncaria tomentosa (all plant parts) (Gonzales and Valerio, 2006)
|
Oxindole alkaloids |
Pentacvclic: Formosanine (uncarine B), Pteropodine (uncarine C), Isopteropodine (uncarine E), Speciophylline (uncarine D), Speciophylline N-oxide, Uncarine F N-oxide, Mitraphylline, Isomitraphylline. |
|
Tetracvclic: Rhynchophylline, Rhynchophylline N-oxide, Isorhynchophylline, Isorhynchophylline N-oxide, Rotundifoline, Isorotundifoline, Corynoxeine, Isocorynoxeine |
|
Indole alkaloids |
Pentacyclic: Akuammigine, Tetrahydroalstonine, Isoajimalicine. Tetracyclic: Hirsutine, Hirsutine N-oxide, Dihydrocorynantheine, Hirsuteine, Corynantheine |
|
Quinovic acid glycosides |
Approximately 9 compounds (e.g. quinovic acid (28-1)-b-D-glucopyranosyl ester |
|
Pyroquinovic acid glycosides: |
Tomentoside A, Tomentoside B |
|
Organic acids |
Oleanolic acid |
|
Proanthocyanidines |
(-)-Epicatechin, cinchonain 1a, cinchonain 1b |
|
Sterols |
p-Sitosterol, stigmasterol, campesterol |
|
Triterpenes |
Ursolic acid derivatives, oleanan-type triterpenes, cincholic acid glycosides |
About 50 different components have been isolated from Uncaria tomentosa (considering all plant parts), 35 of which have been identified in only a couple of other species (Heitzman et al. 2005). There are three classes of compounds that are thought to play an important role in the activity of cat's claw. These compounds are the alkaloids, quinovic acid glycosides and polyhydroxylated triterpenes (Valerio and Gonzales,. 2005).
Quinovic acid glycosides having a C-3, a C-27, a C-28, a C-3, -28 or a C-3, 27 glycosylation patterns are characteristic to the family Rubiaceae (Aquino et al. 1991, Aquino 1997). Tomentoside A and B were the first reported naturally occurring pyroquinovic acid glycosides (Kitajima et al. 2003), hence these compounds can be considered as markers of the species.
The alkaloid content can vary 10- to 40-fold depending on cultivation techniques and the season when the plant is harvested (Kemper, 1999; Laus and Keplinger, 1994). Uncaria tomentosa occurs in two chemotypes, each varies greatly in its alkaloid content. One predominantly contains pentacyclic oxindole alkaloids, while the other is rich in the tetracyclic oxindoles. The alkaloid composition of Uncaria tomentosa is changing significantly over time period and plant generations. Laus and Keplinger reported that the total alkaloid content varied from 0.036 to 3.83% (w/w) of the dried root bark of Uncaria tomentosa, depending on harvestings; and individual plants switched from one alkaloid pattern to the other over time (Laus and Keplinger, 1994). Based on the study of Wurm et al. (1998), it has been stated, that the mixture of the two chemotypes of cat's claw are unsuitable for therapeutic use, unless certified to contain less than 0.02% tetracyclic oxindole alkaloids (Laus and Keplinger, 1997; Barnes et al. 2007).
• Herbal preparation(s)
Herbal preparations obtained from the stem bark:
Powdered herbal substance (according to WHO): It consists of finely broken pieces of wood, bast and bark, and clear, crystallinus particles of dried sap (WHO, 2007).
Powdered Cat's Claw (according to USP 37) is cat's claw reduced to a powder or very fine powder. It contains no less than 0.3% of pentacyclic oxindole alkaloids, calculated on the dried basis, as the sum of speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, and isopteropodine (USP 37)
Powdered Cat's Claw Extract (according to USP 37) is prepared from Cat's Claw by extraction with hydroalcoholic mixtures or other suitable solvents. The ratio of plant material to extract is between 4:1 and 6:1. It contains no less than 90.0% and not more than 110.0% of the labelled amount of pentacyclic oxindole alkaloids, calculated on the dried basis, as the sum of speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, and isopteropodine. It may contain suitable added substances (USP 37).
Cat's Claw Capsules (according to USP 37) contain Powdered Cat's Claw Extract. Capsules contain no less than 90.0% and not more than 110.0% of the labelled amount of Powdered Extract, calculated as pentacyclic oxindole alkaloids (USP, 37).
Cat's Claw Tablets (according to USP 37) contain Powdered Cat's Claw Extract. Tablets contain no less than 90.0% and no more than 110.0% of the labelled amount of Powdered Extract, calculated as pentacyclic oxindole alkaloids (USP 37).
There is a Brasilian product, 50 mg/g herbarium gel cream which contains 50 mg Uncaria tomentosa bark extract/g cream. The 50 mg extract is equivalent of 0.03 to 0.045 mg of the oxindole alkaloids (no more details regarding extraction solvent and DER available)(Caldas et al. 2010).
Herbal preparations obtained from the root bark:
PTI-00703: proprietary extract of the root or the inner bark of Uncaria tomentosa (Cummings et al. 2000, Quinn et al. 2004, Snow et al. 2000). Herein after referred to as 'a proprietary extract of the root or the inner bark of Uncaria tomentosa (PE) '.
Herbal preparations lacking information regarding the plant part used:
Batch-2: aqueous extract from of Uncaria tomentosa (Shi et al. 2010). Herein after referred to as a 'novel aqueous extract from of Uncaria tomentosa (NAE)'.
There is a commercially available, patented water-soluble filtered Uncaria tomentosa aqueous extract, standardized to 8-10% CAEs (carboxy alkyl esthers) and almost free from oxindole alkaloids (<0.05%). It can be found in several food supplements. Herein after referred to as 'a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE)'
(Akesson et al. 2003a, Guthrie et al. 2011, Lamm et al., Mammone et al. 2006, Sheng et al., 1998, 2000a, 2000b, 2001, 2005).
Herbal preparations from the entire root:
20 mg dry extract from Uncaria tomentosae radix/capsule (DER 8-12:1, extraction solvent acidified water) 14.7 mg/g POA, no TOA. Contains 0.93% pteropodine, 0.53% speciophylline, 0.34% mitraphylline, 0.25% isopteropodine, 0.16% Uncarine F and 0.05% isomitraphylline (Winkler et al. 2004). Herein after referred to as 'HE'.
• Combinations of herbal substance(s) and/or herbal preparation(s) including a description of vitamin(s) and/or mineral(s) as ingredients of traditional combination herbal medicinal products assessed, where applicable.
1.2. Search and assessment methodology
The assessment of Uncariae tomentsae cortex is based on the following literature:
- Articles and references retrieved from databases (PubMed, ToxNet, SciFinder) or internet sources (e.g. Google, Google scholar) until March 2014. The databases were searched using the terms [Uncaria tomentosa], [Una de gato] and [cat's claw].
- Monographs on Uncaria tomentosa: Hagers Handbuch (Blaschek, 1998), WHO (2007).
- Handbooks, textbooks and review articles were also used.
2. Data on medicinal use
2.1. Information about products on the market
2.1.1. Information about products on the market in the EU/EEA Member States
Information on medicinal products marketed in the EU/EEA
Table 2: Overview of data obtained from marketed medicinal products containing bark/root
|
Active substance |
Indication |
Pharmaceutical form Strength (where relevant) Posology Duration of use |
Regulatory Status (date, Member State) |
|
Powdered herbal substance |
Relief of minor articular pain associated to inflammatory processes |
Capsules 150 mg twice a day |
Traditional use 1998 Spain |
|
Powdered herbal substance |
Capsules 380 mg four times daily |
Traditional use 2000 Spain | |
|
Powdered herbal substance Tablet |
Tablets 500 mg three times daily |
Traditional use 2002 Spain | |
|
Dry extract (entire root is extracted, not the bark separately), DER 8-12:1, extraction solvent acidified water. Minimum 13 mg/g pentacyclic oxindole alkaloids, maximum 0.5 mg/g tetracyclic oxindole alkaloids |
Adjuvant therapy to an antirheumatic standard therapy in patients with rheumatoid arthritis. |
20 mg/capsule Oral; adults: 3 x 20 mg daily. Duration of use: onset of clinical efficacy within 3-4 months. Clinical trials provide evidence of safe use over a period of 12 months. |
Full marketing authorization May 2000 Austria |
|
Powdered herbal substance |
To relieve the symptoms of disorders of the locomotor system As adjuvant therapy to enhance the protective capacity of the body |
150 mg/capsule Adults an adolescent: 300 mg three times daily Children between the age of 3-12: Up to 150 mg three times daily |
Healing product 2000 Hungary |
|
Powdered herbal substance |
To relieve the symptoms of inflammation of locomotor disorders as adjunct to medicinal and physico-therapial treatment As adjuvant therapy to enhance the protective capacity of the body |
330 mg/capsule Adults an adolescent: 330-660 mg three times daily Children between the age of 3-12: 330 mg once a day |
Healing product 2001 Hungary |
|
Uncariae tomentosae corticis ethanolic ext. sicc. (DER: 8:1): 100 mg [with 5 mg pentacyclic oxindole alkaloid (POA) content at least] Extraction solvent ethanolum 80% |
For the treatment of disorders of the locomotor system - rheumatism, inflammation of the joints, arthritis- alone or as adjuvant of medicinal or physiotherapeutic treatment. For strengthening the immuno-system, for improvement of protective power of the body, as an adjuvant therapy of medicinal treatment in acute and recurrent infectious diseases |
100 mg/tablet Adults: Generally 100 mg daily, up to 100 mg three times daily Children above 12 years of age: according to recommendation of the therapist |
Healing product 2001 Hungary |
|
20 mg Uncariae tomentosae corticis ethanolic ext. sicc. (15:1) [with 5mg pentacyclic-oxindol alcaloide (POA) content at least]/g extraction solvent : ethanolum 80% |
Acute and chronic inflammation of the skin. For cuts, bruises to promote epithelisation. Alleviation of inflammation in case of burn (I. grade) solar erythema, insect bite. |
Apply the gel in thin layer to the affected area of the skin 2-3 times daily |
Healing product 2006 Hungary |
|
Uncariae tomentosae corticis sine pericarpii pulvis with 0.2% total alkaloid content expressed in mitrofilline at least and up to 0.07% tetracyclic oxindole alkaloid content |
For the treatment of disorders of the locomotor system -rheumatism, inflammation of the joints, arthritis-alone or as adjuvant of medicinal or physiotherapeutic treatment. For strengthening the immuno-system, for improvement of protective power of the body, as an adjuvant therapy of medicinal treatment in acute and recurrent infectious diseases. |
Tea 700.0 mg/tea bag Adolescent: tea infusion prepared from 700 mg-1400 mg three times daily. Maximum daily doses: 2100 mg three times Children above 12 years of age: tea prepared from 700 mg twice a day 700 mg should be poured with 2-2.5 dl of boiling water, to keep covered for 10 minutes In case of use of 1400 mg or 2100 mg the quantity of water should be increased for 6-7 dl |
Healing product 2001 Hungary |
This overview is not exhaustive. It is provided for information only and reflects the situation at the time when it was established.
Information on relevant combination medicinal products marketed in the EU/EEA
Not applicable
Information on other products marketed in the EU/EEA (where relevant)
Food-supplements in the literature:
A patented hot water extract (90-100°C), which is 100% water soluble containing 8-10% carboxy alkyl esters, almost free from oxindole alkaloids (<0.05%). It is produced from heating 150 g of bark in 5 L of tap water for 18-24 hours at 95 °C, until the hot water extract is concentrated to about 900-1000 milliliters by evaporation. The dark brown extract then adjusted to exactly 1000 milliliters. After decanting the soluble fraction and ultra-filtrating the resulting water extract to remove all components >10,000 MW and larger, it is dried according to U.S. Patent 6,039,949. Quantification of the extract was performed by Sheng et al. (2000b). The amount of alkaloids in 100 g C-MED-100tm: Uncarine F (2.39 mg), speciophylline (13.75 mg), mitraphylline (4.34 mg), isomitraphylline (1.73 mg), pteropodine (20.17 mg), isopteropodine (5.96 mg) (Åkesson et al. 2003a, Guthrie et al. 2011,Lamm et al., Mammone et al. 2006, Sheng et al., 1998, 2000a, 2000b, 2001, 2005).
• 150 mg Uncaria tomentosa dry extract/capsule containing product (Castaneda et al. 1998).
2.1.2. Information on products on the market outside the EU/EEA
Uncaria tomentosa is considered a dietary supplement by the US Food and Drug Administration. In the USA Uncaria tomentosa is available in 300 mg capsules to be taken three times daily, 1000 mg timerelease capsules to be taken once daily, liquid concentrate (8:1 in a 20% alcohol) to be diluted in water and taking 1 to 3 times daily, and bark to be used for tea (No more information regarding the herbal preparations available; Cupp et al., 2000).
There is a Brasilian product, 50 mg/g herbarium gel cream which contains 50 mg Uncaria tomentosa bark extract/g cream. The 50 mg extract is an equivalent of 0.03 to 0.045 mg of the oxindole alkaloids (No more information regarding the herbal preparations available) (Caldas et al. 2010).
Two products are reported from Peru: one of them contains Uncaria tomentosa hydroalcoholic, (80% of ethanol) spray-dried extract (drug extract ratio 8:1) with 5.61% of total oxindole alkaloids, the other an aqueous freeze-dried extract with a total 0.26% oxindol alkaloids (Aguliar et al. 2002).
2.2. Information on documented medicinal use and historical data from literature
Peruvian tribes (longest recorded history of use: Ashaninka indians) have used cat's claw (Uncaria tomentosa) as an anti-inflammatory agent, contraceptive, emmenagogue; for cancer, gastric ulcer, diarrhoea, asthma, wounds, gonorrhoea, arthritis, rheumatism, acne, diabetes, diseases of the urinary tract, menstrual irregularity; to recover from childbirth, but also as a tonic to ward off disease or as abortifacient. Sometimes cat's claw is used in combination with other local herbs (such as chuchuhuasi (Maytenus krukovii) bark) to treat arthritis. It has been traditionally contraindicated in pregnancy, during lactation and for children. A related species (Uncaria guianensis) has been used in South America for wound healing, as a sedative and to treat intestinal ailments, but is not considered as strong as Uncaria tomentosa. Cat's claw has been used in Peru and Europe since the early 1990s as an adjunctive treatment for cancer and AIDS, as well as other diseases targeting the immunological system (Kemper, 1999; Taylor, 2002).
Uncaria tomentosa was first described in 1830 and first studied in Peru by the German biologist Brell in 1950 (Cabieses, 1994). Scientific studies with cat's claw began in the early 1970s when Klaus Keplinger from Austria organised the first work on Uncaria tomentosa. Keplinger's work in the 1970s and 1980s led to several extracts of cat's claw being sold in Austria and Germany as well as four US patents describing extraction procedures for a group of chemicals, oxindole alkaloids and the immunostimulating actions of these alkaloids found in Uncaria tomentosa. These novel oxindole alkaloids fuelled research and business worldwide. Hence, the presence of Uncaria tomentosa has declined in Peruvian rainforests by overharvesting. The lower growing and easier to find Uncaria guianensis is thus a common adulterant in many cat's claw products.
Referring to an article in Suriname Bulletin (1962) Hagers Handbuch (Blaschek, 1998) mentions that the root bark and the stem bark as well has been used in Peru in the form of aqueous or alcoholic infusion for arthritis, gastritis and other disturbances of the gastro-intestinal system, treatment of cancer and for different skin disorders.
According to Roth and Lindorf (2002) traditionally in Peru two spoonful's of the bark (plant part not specified) of Uncaria tomentosa are boiled in 1,5 L water for 30 minutes and left to cool. Half a glass of this liquid is taken three times a day before meals.
In Peru the root bark is applied as decoction (20 g sliced material in 1 L water for 45 min). The liquid is decanted and losses due to evaporization are replenished. This bitter decoction is said to be a 10-day dose. From HPLC analyses using a previously published method (Laus and Keplinger, 1994) of similarly prepared decoctions the daily dose was estimated at 4 mg oxindole alkaloids (Keplinger et al. 1999).
According to Cabieses, Uncaria tomentosa was traditionally used in massive concentrations as a contraceptive and in lower concentrations to dissolve tumours, but not as an abortive. It is said, that women in Campa tribe boil six kilograms of the root in one litre of water, until it is reduced to about 250 cc. They filter it and drink the fluid during the menstrual period for three consecutive months in order to avoid pregnancy for three or four years. It is said that to dissolve tumours, the dosage is much less, 0.5 kilogram root in 5 litres of water for 30 minutes (Cabieses, 1994).
Table 3: Overview of historical data
|
Herbal preparation |
Documented Use / Traditional Use |
Pharmaceutical form Strength (where relevant) Posology Duration of use |
Reference |
|
Root, root bark, stem bark and leaves |
Traditionally to treat gonorrhoea, dysentery, arthritis, rheumatism, gastric ulcers and various tumours, reputed to be contraceptive |
Commercial products (tablets, capsules) contain varying amounts of material, ranging from 25 to 300 mg standardised extract and from 400 mg to 5 g of plant material |
Barnes J et al. 2002 |
|
Root bark or steam bark |
Arthritis, gastritis or other disturbance in the gastro-intestinal system, treatment of cancer and for different skin disorders |
in Peru in the form of aqueous or alcoholic infusion 20 g sliced material in 1 L water for 45 min as a decoction |
Blaschek W et al. 1998 |
|
Vine bark (not specified), root |
as an immune stimulant and an adjunctive therapy for cancer (to reduce side effects of chemotherapy and protect cells) as a bowel cleanser and antiinflammatory for Crohn's, colitis, diverticulitis, irritable bowel syndrome (IBS), and other bowel problems as an anti-inflammatory for arthritis (all kinds) and muscle pains/strains/injuries as a general daily tonic (to tone, balance, and strengthen all body functions) for stomach ulcers and ulcerative colitis and as an ulcer preventative/ stomach and bowel protector) |
Decoction: 1 cup twice daily Powder: 1-2 g 2-3 times daily Fluid Extract: 2-4 ml twice daily Tincture: 2-4 ml twice daily |
Rain-tree tropical database 2004 |
|
Herbal preparation |
Documented Use / Traditional Use |
Pharmaceutical form Strength (where relevant) Posology Duration of use |
Reference |
|
Dried steam bark |
Uses described in pharmacopoeias and well-established documents: symptomatic treatment of arthritis, rheumatism and gastric ulcers. Uses described in traditional medicine: Treatment of abscesses, asthma, fevers, urinary tract infection, viral infections and wounds. As emmenagouge. The efficacy of Uncaria extract was examined in patients with immunodeficiency (cancer, HIV), |
Average daily dose: extracts, 20.0-350.0 mg. capsules and tablets: 300.0-500.0 mg, one capsule or tablet two to three times. Herpes simplex labialis increased mutagenic potential (smoker), rheumatoid arthritis |
WHO monograph 2007 |
|
Root |
Traditional use: "Dissolve" tumours |
Decoction (0.5 kg drug + 5 L water, boiling for 30 mins), per os One cup of decoction three times a day |
Cabieses 1994 Peru |
|
Root |
Traditional use: Contraception |
Decoction (5-6 kg drug+1 L water, boiling until 250 cc) During menstruation for three consecutive months, per os |
Cabieses 1994 Peru |
|
Bark |
Traditional use: prostatitis, antiinflammatory, tumours, AIDS, rheumatism, diabetes, arthritis, contraceptive |
Decoction, per os |
Taylor 2002 Peru |
|
Bark |
Traditional use: Anti-inflammatory |
Infusion, per os |
Klinar et al. 1995 Peru |
|
Vine |
Traditional use: Gonorrhoea, dysentery |
Per os, form not stated |
Taylor 2002 Colombia |
|
Root bark |
Traditional use: cancer, arthritis |
Decoction, per os |
Taylor 2002 Peru |
|
Infusion of the root bark of Uncaria tomentosa |
Traditional use: cancer, arthritis, intestinal disorders |
Infusion, per os |
Taylor 2002 Peru |
|
Bark of Uncaria tomentosa |
Traditional use: for asthma, inflammations of the urinary tract, fevers, abscesses, haemorrhages, impurities of the skin, irregularity of the menstrual cycle, immune disorders, AIDS, cancer, bone pain, gastric ulcers, urinary tract cancer in women, cirrhosis, gastritis, to recover from childbirth, normalize the body and cleanse the system, as a kidney and body cleanser, antacid, cellular reconstituent, cicatrizant |
Per os, form not stated |
Taylor 2002 Peru |
|
Decoction of the bark of Uncaria tomentosa |
Traditional use: malignant tumour, rheumatism, arthritis, diabetes, cirrhosis of the liver |
Two spoonsful of the bark of Uncaria tomentosa are boiled in 1,5 L water for 30 minutes and left to cool. Half a glass of this liquid is taken three times a day before meals |
Roth and Lindorf 2002 |
2.3. Overall conclusions on medicinal use
There are two countries in the European Union where products containing Uncaria tomentosa (Willd.) DC, cortex have been used traditionally for medicinal purposes:
In Spain preparations containing powdered stem bark of Uncaria. tomentosa have been in medicinal use since 1998. In Hungary the powdered stem bark of Uncaria tomentosa and an ethanolic extract have been marketed since 2000 and 2001. Although preparations containing pulvered stem bark of Uncaria tomentosa have been in medicinal use for a period of at least 15 years in the European Union, evidence for the medicinal use for at least 30 years outside of the European Union of the plant part used, the herbal preparation, indication and posology is not available as requested by Directive 2004/24/EC. Consequently a European Union herbal monograph on Uncaria tomentosa (Willd.) DC, cortex cannot be established at present.
3. Non-Clinical Data
3.1. Overview of available pharmacological data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof
3.1.1. Primary pharmacodynamics
Herbal Preparations
Anti-inflammatory properties In vitro
Bark (not specified)
The administration of an aqueous extract of the dried bark of Uncaria tomentosa (UT) (100 pg/ml) attenuated (p<0.05) peroxynitrite-induced (300pM) apoptosis in HT29 (epithelial) and RAW 264.7 cells (macrophage). The extract at concentrations 50-200 pg/ml inhibited the LPS (1 pg/ml) induced iNOS gene expression in HT29 cells and nitrite formation (p<0.05) in both cell-lines at 100 pg/ml concentration. In RAW 264.7 cells, LPS decreased cell viability from 95.9% to 80.1%, UT (100 pg/ml) increased it to 87% (p<0.05). In RAW 264.7 cells the simultaneous administration of UT and LPS caused a significant, 60% inhibition of nitrite formation, p<0.05. UT (100 pg/ml) also inhibited the activation of NF-kB in RAW 264.7 cells in the presence of LPS. The extract was prepared with boiling water (20 g/L) for 30 minutes and then was left overnight in room temperature then it was filtered and diluted to 5 mg/ml (Sandoval-Chachon et al. 1998).
Sandoval et al. (2000) reported that an aqueous extract of the micropulverized bark of Uncaria tomentosa (UT) with or without concentration by freeze-drying have a protective effect against LPS induced TNF-a production in murine macrophages (RAW 264.7 cells). LPS (0.5 pg/ml) increased TNF-a levels from 3 to 97 ng/ml. UT suppressed TNF-a production by approximately 65-85% (p<0.01), but at concentrations considerably lower than its antioxidant activity: freeze-dried EC50=1.2 ng/ml, micropulverized EC50=28 ng/ml. The aqueous decoction of the micropulverized bark was made by boiling water (20 g/L) for 30 minutes, and then filtered (Sandoval et al. 2000).
The anti-inflammatory effects of an aqueous extract of the bark of Uncaria tomentosa (UT) and Uncaria guianensis (UG) were compared. Anti-inflammatory activity was assessed in vitro by inhibition of TNF-a and nitrite production from RAW 264.7 cells, exposed to LPS (50 ng/ml). The total oxindole and pentacyclic alkaloid content of UT was 35 fold > UG. The IC50 value for inhibition of TNF-a production was significantly (p<0.01) higher for UT (14.1 ng/ml) vs. UG (9.5 ng/ml) with maximum inhibitions of 70.6% and 75.5%, respectively. These concentrations were considerably lower than that required for antioxidant activity. The extracts were prepared with boiling water, 50 g/L w/v for 30 minutes, then filtered and freeze-dried. For the experiments they were dissolved in water (20 mg/ml) (Sandoval et al. 2002).
The anti-inflammatory activity of two commercially available Uncaria tomentosa bark extracts, a 80% of ethanolic spray-dried extract (DER 8:1), containing 5.61% of total oxindole alkaloids (TOA) and aqueous freeze-dried Uncaria tomentosa extract, TOA 0.26% were assessed at the concentration range of 50-500 pg/ml by NF-kB EMSA and at 50 pg/ml by COX-1 and -2 assay. Activation of NF-kB was nearly completely reduced by pre-treatment of Jurkat T cells with 500 pg/ml of the hydroalcoholic extract, while the aqueous extract only slightly prevented NF-kB DNA binding at this concentration. Hydroalcoholic extract exhibited an inhibition of COX-1 and -2 of 7.8% and of 21.7%, respectively. In contrast, an inhibitory activity of 32.7% was measured for COX-1 and of 12.2% for COX-2 for the aqueous freeze-dried extract (Aguliar et al. 2002).
Stem bark
Piscoya et al. (2001) reported, that Uncaria tomentosa and guianensis (commercially available purified freeze-dried extracts of stem bark) inhibited TNF-a synthesis/release on a murine macrophage cell line stimulated by LPS. Following low concentrations (1-1000 ng/ml or 50 ng/ml) of pre-treatment with the freeze-dried aqueous extracts of the two species, a significant and dose-dependent reduction in TNF-a levels after LPS stimulation were observed. The inhibition of TNF-a was approximately equivalent for Uncaria tomentosa and Uncaria guaianensis with low IC50 values (10.2, 10.9 ng/ml, respectively) and with a maximum inhibition of 79% and 73%, respectively. However, the extracts had no effect on unstimulated PGE2 production but did significantly reduce PGE2 production stimulated by LPS, suggesting inhibition of cyclooxygenase 2 (COX-2) expression. The dose required (10 pg/ml) was greater than that for suppression of TNF-a production.
In vivo
Bark (not specified)
An aqueous extract of the bark of Uncaria tomentosa (UT) was administered orally in drinking water (5 mg/L) to Sprague-Dawley rats (n=3/group) with indomethacin induced intestinal inflammation. The chronic model of intestinal inflammation was induced by two sc. injections of indomethacin (7.5 mg/kg). Animals were divided into four groups: vehicle control group, injected with indomethacin, injected with indomethacin and supplemented with UT, injected vehicle and supplemented with UT. The extract markedly attenuated indomethacin enteritis as evident by reduced myeloperoxidase activity (p<0.05), morphometric damage and metallothionein expression (69.6 and 216.6 pg/ml with and without UT, p<0.05). The extract was prepared with boiling water (20 g/L) for 30 minutes and then was left overnight in room temperature, filtered and diluted to 5 mg/ml (Sandoval-Chachon et al.
1998).
Cisneros et al. (2005) investigated the effect of an aqueous decoction of the bark of Uncaria tomentosa (UT) on ozone inhalation caused acute pneumonitis, characterized by a high number of infiltrating neutrophils (PMNs) immediately after exposure and increased levels of protein in BALF (bronchoalveolar lavage fluid) in mice. 96 mice were randomly assigned into three groups (n=32), one received water, the other two groups UT extract (DER 1:14) (50% and 100%) diluted with distilled water ad libitum for 8 days. After the treatment they were exposed to 3 ppm O3 for 4 hours and killed 0 or 8 hours after it. When compared to untreated controls, UT-treated mice had significantly (p<0.05) lower levels of protein in BALF, lower degree of epithelial necrosis, higher number of intact epithelial cell nuclei in bronchial wall, and decreased number of PMNs in the bronchiolar lumen. The lung tissue protective effect was dose related. The aqueous decoction was prepared by boiling dry UT bark (20 g/L) in deionized water for three hours, approximately 280 ml of extract were obtained from each 20 g of dry bark, yielding about 14 ml of aqueous extract per gram of dry bark.
The anti-inflammatory activity of two Uncaria tomentosa bark extracts, a 80% of ethanolic spray-dried extract (DER 8:1), containing 5.61% of total oxindole alkaloids (TOA) and aqueous freeze-dried Uncaria tomentosa extract (TOA 0.26%) were assessed and compared in carrageenan-induced paw edema model in BALB/c mice. The extracts dose-dependently and significantly decreased the carrageenan-induced increase in paw volume as compared with control rats. The two extracts were diluted in 1 ml distilled water in concentrations 500, 200, 100 and 50 mg/kg and were administered through a gastric probe during 8 days of pre-treatment. The paw inflammation was measured 4 hours after the carrageenan injection. The negative control group received distilled water, the positive control group indomethacin (7 mg/kg). Hydroalcoholic extract (50 mg/kg) produced an anti-inflammatory effect similar to 7 mg/kg of the non-steroidal drug indomethacin, while the aqueous freeze-dried extract exhibited the same effect at 200 mg/kg. Both extracts used were commercially available products (Aguliar et al. 2002).
The anti-inflammatory effects of oral treatment for 3 days with micropulverized Uncaria tomentosa bark (UT), 5 mg/ml, given in drinking water prior to the oral administration of indomethacin, protected against indomethacin-induced gastritis (20 mg/kg body wt) in Sprague-Dawley rats (number not given). UT elicited a protective effect (p<0.01), the degree of gastric mucosal injury was markedly attenuated and prevented TNF-a mRNA expression and apoptosis (Sandoval et al. 2002).
Root bark
Aquino et al. (1991) reported, that the CHCl3/MeOH (9:1) (50 mg/kg) and the water fractions (84 mg/kg) of a petroleum ether extract of the root bark of Uncaria tomentosa, were the most active using the carrageenan-induced edema model in rat (male Wistar Nossan) paw. The oral pre-treatment with the fractions caused 69.2 and 41.2% inhibition at 3 hours of the inflammatory response, respectively. The anti-inflammatory effects of the MeOH and CHCl3 fractions were not significant. Subjects (n=5/group) received either indomethacin (5 mg/kg), vehicle or fractions at doses equivalent to 2 g of dry bark/kg. One hour after drug administration 1% carrageenan was injected and the paw volumes were measured hourly for 5 hours.
A significant inhibition of stress-induced ulcer formation in rats was shown following pre-treatment with 3 ml of a decoction of Uncaria tomantosa root bark added to drinking water (no further details are discussed). The size and number of large gastric ulcers were significantly inhibited compared to controls (McKenna et al. 2002).
Root
An aqueous extract of the root of Uncaria tomentosa was able to inhibit the edema induced by Bothrops asper snake venom. Six Sprague-Dawley rats were pre-treated with 250 or 500 mg/kg extract i.p., then one hour later 100, 50, 25, 10 and 5 pg/50 pl of B. asper venom was injected in one leg, NaCl to the other. Control groups received dexamethasone and diphenhydramine. The extract of Uncaria tomentosa diminished considerably the edema-forming activity of the venom. The doses of 250 mg/kg and 500 mg/kg showed an anti-inflammatory effect at all times (p<0.05), except for the dose of 250 mg/kg at one hour. Inhibition (paw volume) was observed at 1, 2, 4, 6 and 24 hours after venom injection. The root was extracted with 70°C water (10% w/v) for 30 minutes, then filtered, evaporated and freeze-dried (Badilla et al. 2006).
Unknown plant part
Intestinal morphology of indomethacin-treated rats was fully restored and liver metallothionein expression and inflammatory indices were supressed by Uncaria tomentosa (details regarding plant part and extract missing, conference abstract). In vitro experiments indicated that the antiinflammatory action of Uncaria tomentosa is primarily mediated through the inhibition of inflammatory gene expression involving a suppression of NF-kB. Uncaria tomentosa was only effective when administered prophylactically, consistent with its effects on gene expression (Miller et al. 1999).
Abe et al. (2002) examined the effect of oral administration of Uncaria tomentosa 70% ethanolic extract (paper in Japanese, plant part not known) (0.125, 0.5, 2 g/kg) on carragenan-induced edema in normal and in prednisolone treated mice. The extract was given 1, 23 and 25 hours after the carragenan injection. The extract did not affect inflammatory response, just when it was administered in combination with the extract of Harpagophytum procumbens (0.8 g/kg), it significantly (p<0.05) lowered the thickness of the edema. The Harpagophytum procumbens extract alone did not have any effect on the inflammation either.
Immunmodulatory, immunostimulant properties
In vitro
Bark
The acute effects of Uncaria tomentosa (UT) (70% ethanolic extract of the bark, 2.57% pentacyclic oxindole alkaloids) on granulocyte-macrophage colony forming cells (CFU-GM) were reported. Colonyforming cell (CFC) assays were performed with human hematopoietic stem/precursor cells (hHSPCs) obtained from umbilical cord blood (UCB). An in vitro CFC assay showed an increase in CFU-GM size and mixed colonies (CFU-GEMM) size at the final concentrations of 100 and 200 gg/ml. The spray-dried extract was prepared by ultra-turrax extraction (Farias et al. 2011).
Allen-Hall et al. (2007) showed that treatment of THP-1 monocyte-like cells with a 95% ethanolic extract of the bark of Uncaria tomentosa (6:1) inhibited the MAP-kinase signalling pathway and altered cytokine expression. The treatment with 1 or 10 gl Uncaria tomentosa extracts augmented LPS-dependent expression of IL-ip by 2.4-fold, while inhibiting the LPS-dependent expression of TNF-a by 5.5-fold (p<0.05). It is highly unusual to see the response of these two cytokines to operate in opposite directions. The treatment of THP-1 monocytes with Uncaria tomentosa extracts alone augmented the expression of IL-ip by greater than 20-fold, but did not affect the expression of TNF-a (p<0.05). The treatment of LPS-stimulated THP-1 cells with Uncaria tomentosa extracts blocked ERK1/2 and MEK1/2 phosphorylation in a dose-dependent manner.
Allen-Hall et al. (2010) reported that a 95% ethanolic extract of the bark of Uncaria tomentosa inhibited the LPS-dependent activation of specific NF-kB and AP-1 components. TNF-a and IL-18 are usually regulated similarly and share a number of common promoter elements, including NF-kB and AP-1. Treatment with Uncaria tomentosa inhibited the secretion of TNF-a in LPS-treated THP-1 cells in a dose-dependent manner: 10-320 gg/ml Uncaria tomentosa extract inhibited TNF-a secretion by 3395%. In contrast, treatment with Uncaria tomentosaenhanced LPS-dependent expression of IL-ip: 40 gg/ml enhanced IL-ip by 1.2-fold and 160 gg/ml enhanced IL-ip by 1.4-fold, although 320 gg/ml Uncaria tomentosacompletely blocked LPS-dependent secretion of IL-ip. The ability of Uncaria tomentosa to inhibit TNF-a production was diminished when NF-kB activation was prevented, while IL-ip expression was unchanged. The bark was extracted by exhaustive percolation with 95% ethanol.
Stem bark
Two commercial aqueous extracts of the stem bark of different collections of Uncaria tomentosa were studied on alveolar macrophages. The commercial extracts derived from different areas of Peru, one of the materials (UT1-6.98 mg/g total oxindole alkaloid content) was collected from the Ashaninka region of Peru. The extract was prepared by water extraction of the bark and lyophilisation of the extract. The other water extract (UT2-5.57 mg/g total oxindole alkaloid content) was prepared by water extraction and atomization of material derived from lowland tropical collections between Cusco and Manu National Park. Both of them contained uncarine, speciophylline, mitraphylline, isomitraphylline, pteropodine, and isopteropodine. The extracts were tested at 0.025-0.5 mg/ml. UT2 greatly stimulated IL-1 (10X at max. effect) and IL-6 (7.5X at max. effect) production by rat macrophages in a dose dependent manner in the range of 0.025-0.1 mg/ml compared to control. They were also able to enhance IL-1 (5.2X) and IL-6 (<2X) in LPS-stimulated macrophages compared to control. UT1 had comparable trends in results (not specified) (Lemaire et al. 1999).
Reis et al. (2008) assessed the immunoregulatory activity of a 50% ethanolic extract of the stem bark of Uncaria tomentosa in an in vitro DENV (Dengue Virus-2) infection model. No significant alterations were detected with the treatment of hydro-ethanolic extract in the measured TNF-a, IL-6, IL-10 and IFN-a levels. IL-6, which is strikingly induced after monocyte infection, apparently was not inhibited neither by Uncaria tomentosa or dexamethasone (reference) treatments.
One hundred and seventy-eight plant extracts prepared with ethanol 70% (for 48 hrs. 25°C) from the pharmacopoeia of the Tacana, an ethnic group from Bolivia, were screened for immunmodulatory activity using complement cascade inhibition and ADP-induced platelet aggregation inhibition assays. Six extracts impaired both complement pathways (classical-CPW and alternative-APW), amongst them the stem bark of Uncaria tomentosa (UT). The IC50 values for CPW and APW were 124 and 151 pg/ml respectively. Positive control, heparin had IC50 : 74 and 558 pg/ml. Concentrations were tested from 250 to 3.9 pg/ml. Anti-inflammatory activity did not rely on COX inhibition. UT extract was not an effective inhibitor (at 5 mg/ml) of ADP-induced platelet aggregation, which is linked with the inhibition of the COX pathway (Deharo et al. 2004).
Akesson et al. (2003a) confirmed that a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) inhibits proliferation of normal mouse T and B lymphocytes and that the inhibition is not caused by toxicity or by induction of apoptosis. AE was tested in concentrations from 0.25-1 mg/ml in different assays. AE efficiently inhibited proliferation of primary lymphocytes, stimulated with either T or B cell mitogens (Con A, CD-3 or LPS). The inhibition was more prominent in cultures (mouse spleen cells) stimulated with T cell mitogens as compared with the B cell mitogen LPS, where higher concentrations of AE were required to reach the same level of inhibition. Furthermore, the extract did not interfere with IL-2 production nor IL-2 receptor signalling (mouse CTLL-2 cells). Since there was no discrete cell cycle block in AE -treated cells, the authors proposed that retarded cell cycle progression caused the inhibition of proliferation. Moreover, AE treatment reduced NF-kB activity with almost 50% (LPS stimulated 70Z/3 cells).
Root and stem bark
In a granulocytic test, the average increase in phagocytic activity shown by the stem bark was found to be 10% to 20%, while that of the root bark was on average 30% to 40% (extract type not discussed). The difference in potency was attributed to the low alkaloid content of stem bark and to differences in patterns of the oxindole alkaloids present (McKenna et al. 2002).
Unknown part
Using FACS-based assays, Holderness et al. (2007) screened primary bovine cells for novel y5 T cell agonists. y5 T cells are innate immune cells that participate in host responses against pathogens and cancers. Uncaria tomentosa (commercial product) was extracted in room temperature with water (10 ml/g) then lyophilized to determine the approximate dry weight: 17.6 mg/ml. The extract (44 gg/ml) induced IL-2Ra expression on y5 T cells after 48 hours in culture and induced activation and proliferation of the cells as well, as detected in a 5-day CFSE assay. Activity of the extract was specific to y5 T cells and furthermore, and the activity was not limited to one y5 T cell subset. Positive control agonists were LPS and Con A. Subsequent analysis demonstrated that y5 T cell agonist activity of Uncaria tomentosa extract was due to the condensed tannin fractions of the drug. Polyphenols contributed to 56% of Uncaria tomentosa and 63.7% of the polyphenols were tannins.
The immunmodulatory effect of two commercially available extracts (HE) of the root of Uncaria tomentosa (HCl and 96% ethanolic) were investigated in human peripheral mononuclear cells (PBMC) stimulated with the PHA and Con A in vitro. Compared to unstimulated cells, PHA (phytohaemagglutinin) and Con A (concanavalin A) increased the production of neopterin and the degradation of tryptophan (p<0.01). The extracts inhibited both effects in a dose dependant manner; the lowest effective concentrations were 500-1000 gg/ml (p<0.05). With the highest concentrations complete suppression of mitogen-induced neopterin production and tryptophan degradation was observed, indicating, that extracts interfere with immunopathogenetic pathways, which involve the Th-1 type cytokine IFN-y. The HCl extract contained 0.93% pteropodine, 0.53% speciophylline, 0.34% mitraphylline, 0.25% isopteropodine, 0.16% Uncarine F and 0.05% isomitraphylline. The 96% ethanolic extract contained 0.73% isopteropodine, 0.28% pteropodine, 0.17% isomitraphylline, 0.13% mitraphylline, 0.05% Uncarine F, 0.04% speciophylline, 0.015% rhynchophylline, 0.009% isorhynchophylline, 0.003% corynoxeine and 0.001% isocorynoxeine. A concentration range of 5004000 gg/ml was applied to the cultures from the extracts (Winkler et al. 2004).
In vivo
Bark (not specified)
Bednarek et al. (2002) investigated the influence of the grounded bark of Uncaria tomentosa (commercial product^ on the course of an experimentally induced local pneumonia in calves. The study consisted two groups, Group I (n = 10, 3600 mg/calf/day of Uncaria tomentosa) and Group II (n = 10, placebo), treated for 17 days, orally with the drug in the form of 200 ml decoction. Inflammatory inducer (mineral oil) was used twice on the 4th day. The body temperatures were significantly higher at several time points (P<0.05; P<0.01) in the group of the untreated calves (40.5-41oC), compared with the treated one (39.0-40.5oC). During the treatment, the total number of WBC and the total numbers and percentages of mid-size cells and neutrophils dropped considerably in the group of calves treated with UT, in comparison with the untreated group, but the number of lymphocytes was significantly (p<0.05) higher in the treated animals at the end of the treatment (10.1x109/L), in contrast to those values at the beginning of the treatment (8.6x109/L). In the treated group, the total number of CD2+ cells (T lymphocytes) and the percentage of CD4+ cells (T helper lymphocytes) were significantly higher at the end of the treatment (7.9x109/L, 40.3%, respectively, p<0.05), as compared with respective values initially (5.7x109/L, 29.95%, respectively, p<0.05). None of these changes were observed in the control group of calves. The total number of CD4+ cells on the 18th day of the treatment was conspicuously higher in the treated group (4.9x109/L, 3.2x109/L, respectively, p<0.05) than in the untreated animals. The concentrations of PGE2, PGF2a, and TXB2 were generally lower in the treated animals; at some points of the measurement the differences were statistically significant. In the case of LTB4, no tendency towards lower or higher concentrations was observed.
Nowakowska et al. (2010) evaluated the in vivo influence of Uncaria tomentosa bark aqueous and 96% ethanol extract (DER 1:10) on the metabolic activity of blood granulocytes in mice. Mice were fed for 7 days with both of extracts 200 gg daily, control group was administered vehicle. The metabolic activity of granulocytes was determined by the measurement of their chemiluminescent activity in scintillation counter, after stimulation by Zymosan. Results showed that the water extract highly stimulated the granulocyte chemiluminescence compared to control (25948 Cmp/1000 granulocytes vs. 12506 Cmp/1000 granulocytes, respectively, p<0.001) whereas the ethanol extract didn't reach the level of significance. However the ethanol extract had a tendency to decrease the number of leukocytes compared to control (5830/mm3 vs. 7610/mm3 respectively, p<0.1).
A dried ethanolic extract (200 g drug, 20 hours, 20oC, DER 1:10, ethanol 30%) from the bark of Uncaria tomentosa was evaluated as a potential immunostimulator. BALP/c mice (n=6 in each group) were seven times immunized intragastrically (i.g.) during 14 days with a formalin-inactivated whole Sendai virus (SV) with the dry extract, in two doses (0.56, 5.6 mg). It was found, that the animals inoculated with 5.6 mg extract, induced higher saliva IgA antibodies. Furthermore, the mice immunized e.g. with SV plus 0.56 mg of the extract had significantly higher IgA, IgG and HI (haemagglutination inhibition) antibody responses to SV than did those administered with the SV alone (p<0.05). These results suggest that dry extract from bark of Uncaria tomentosa is useful as a mucosal adjuvant for mice (Bizanov and Tamosiunas, 2005).
Domingues et al. (2011a) investigated the immunmodulatory potential of a 50% ethanolic extract (no further details are discussed) of the bark of Uncaria tomentosa (UT) (total alkaloid content 29.1 mg/ml) on the progression of immuno-mediated diabetes. C57BL/6 male mice were injected with MLDS (40 mg/kg) and treated with UT at 10-400 mg/kg during 21 days by gavage, per os. Control groups received MLDS alone or the respective dilution vehicle. Treating the animals with 50-400 mg/kg of UT caused a significant reduction in the glycemic levels, as well as in the incidence of diabetes. Animals treated with UT at 400 mg/kg presented a higher number of intact islets (p<0.05) and a significant inhibition of destructive insulitis. Furthermore, a significant protection against the loss of insulin-secreting presented p-cells was achieved (p<0.01). The phenotypic analysis indicated that the groups treated with higher doses (100-400 mg/kg) presented increased numbers of CD4+ and CD8+ T-cell values similar to those observed in healthy animals. These same higher doses also increased the number of CD4+ CD25+ Foxp3+ regulatory T-cells. Moreover, the extract modulated the production of Th1 and Th2, with increased levels of IL-4 and IL-5.
The acute effects of Uncaria tomentosa (UT) (70% ethanolic, spray-dried extract of the bark, 2.57% pentacyclic oxindole alkaloids) in the recovery of neutrophils after chemotherapy-induced neutropenia were assessed, by establishing the correlation with filgrastim (rhG-CSF) treatment to evaluate its possible use in clinical oncology. Ifosfamide-treated mice receiving oral doses of 5 and 15 mg of UT and intraperitoneal doses of 3 and 9 gg of filgrastim, respectively, for four days (6 mice/group). The animals were allocated to UT, figrastim and control groups. Bioassays showed that the 5 and 15 mg treatment of UT significantly increased the neutrophil count (4 and 13X higher than control, respectively), and a potency of 85.2% was calculated in relation to filgrastim at the corresponding doses tested. The extract was prepared by ultra-turrax extraction and spray-dried (Farias et al. 2011).
Akesson et al. (2003b) found a dose dependent increase in spleen cell numbers in mice (C57BL/6), supplemented with a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) for 24 days, but the proportion of B, T and NK cells, granulocytes, and memory lymphocytes were normal. The absolute number of splenic T cells (p=0.02), B cells (p=0.03), NK cells (p=0.009) and NKT cells (p=0.02) had significantly increased, the absolute cell number of granulocytes did not increase. However, there were no detectable changes of the lymphoid architecture of the spleen even after long-term treatment (63 days), but spleen cell number was significantly increased as well. When AE treatment was interrupted, the cellularity returned to normal level within four weeks. AE did not have any significant effect on precursor cells or on the accumulation of recent thymic emigrants in the spleen. Thus, accumulation is most likely due to prolonged cell survival, because adaptive transfer experiments demonstrated that AE treatment significantly prolonged lymphocyte survival in peripheral lymphocyte organs, without increasing their proliferation rate. The experimental groups were fed with AE in their drinking water at approxametly daily doses of 125, 250 or 500 mg/kg bodyweight for different periods of time.
Female W/Fu rats (n=8/group) were gavaged daily with a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) of Uncaria tomentosa at the doses of 0, 5, 10,
20, 40 and 80 mg/kg for 8 consecutive weeks. PHA stimulated lymphocyte proliferation was significantly increased in splenocytes of rats treated at the doses of 40 and 80 mg/kg. White blood cells (WBC) from the AE treatment groups of 40 and 80 mg/kg for 8 weeks or 160 mg/kg for 4 weeks were significantly elevated compared with controls (P<0.05) (Sheng et al. 2000a).
The effect of a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) was evaluated in the treatment of doxorubicin (DOX) induced leukopenia in rat model. W/Fu rats (n=11/group) were treated first with DOX 2 mg/kgx3 i.p., then they were daily gavaged with AE (40 and 80 mg/kg) for 16 days, as a positive control, Neupogen, a granulocyte colony stimulator was used. Both AE and Neupogen treatment groups recovered significantly sooner (p<0.05) than DOX group, but in the AE group all fractions of WBC were proportionally increased, while in the Neupogen group mainly neutrophil cells were elevated. DNA repair is possibly involved in these effects (Sheng et al. 2000b).
Unknown part
Eberlin et al. (2005) demonstrated that Uncaria tomentosa extract (UTE) protects mice (BALB/c) from a lethal dose of Listeria monocytogenes when administered prophylactically at 50, 100, 150 and 200 mg/kg for 7 days, with survival rates up to 35%. Uncaria tomentosa extract (UTE, part not specified) was provided as a powder (commercial product), dosed in 1% of total alkaloids. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with L. monocytogenes, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow (p<0.001). Non-infected mice treated with 100 mg/kg UTE also presented higher numbers of CFU-GM in the bone marrow than the controls. Infected and normal mice pre-treated with UTE increased colony-stimulating activity (CSA) in a dose-dependent manner (p<0.01 and p<0.001 for doses 50 and 100 mg/kg respectively). Increases in the levels of IL-1 (p<0.05) and IL-6(p<0.001) were observed in mice infected with L. monocytogenes and treated with 100 mg/kg of UTE. WBC had no significant changes, when infected mice were pre-treated with 100 mg/kg of UTE.
Belteghi and Manzat (2008) carried out an in vivo study, in order to investigate the immunmodulatory virtues of an Uncaria tomentosa-based medicinal product, by administrating the studied product to an experimental lot (n=7) of domestic rabbits (control lot n=7), and monitoring the dynamics of some immune parameters. The product contained 0.19 g Uncaria tomentosa/capsule (no further details are discussed) and the subjects were administered 570 mg UT daily, via drinking water. The study lasted 32 days, on the 4th and 18th day antigenic inoculations with La Sota strain of Newcastle virus were performed to the rabbits of both groups. The haematological results showed that the Uncaria product had a stimulating effect upon the total leukocyte count, but this effect was statistically assured only after the second antigenic inoculation of rabbits (p<0.01). The inhibohemagglutinant titer was, 1.64 fold higher at the final blood sampling, in the experimental lot than in the control lot (p<0.05). The phagocitary index showed a substantial, but statistically insignificant (2.16 fold) increase after the first antigenic inoculation only in the experimental lot.
Fractions and mixtures of isolated constituents
Anti-inflammatory properties
In vitro
Bark
The anti-inflammatory effects of the non-alkaloid HPLC fractions from the bark of Uncaria tomentosa (0.1-100 ng/ml) decreased LPS-induced TNF-a and nitrite production in RAW 264.7 cells (p<0.01) at a concentration range comparable to the parent botanical. The extraction was performed with MeOH:H2O:1.2 HCl (50:50:1), and then the non-alkaloid HPLC fractions were collected (Sandoval et al. 2002).
Immunomodulatory, immunstimulant properties
In vitro
Bark
Reis et al. (2008) assessed the immunoregulatory pentacyclic oxindole alkaloid-enriched (speciophylline, mitraphylline, Uncarine F, pteropodine, isomitraphylline, isopteropodine) or nonalkaloid fractions of the stem bark of Uncaria tomentosa, which were tested in an in vitro DENV (Dengue Virus-2) infection model. These fractions were obtained by sonicating (10 min) the crude EtOH:H2O extract (94.2 g) with HCl 0.1 N (1 l), which was then partitioned with EtOAc. Fractions were tested at 0.1-100 pg/ml. No significant alterations were detected with the non-alkaloidal fraction treatment in the measured TNF-a, IL-6, IL-10 and IFN-a levels. However, the alkaloidal fraction inhibited both TNF-a and IFN-a at concentrations of 100 pg/ml and similar cytokine levels resulted with dexamethasone (reference) treatment (p<0.05). IL-6, which is strikingly induced after monocyte infection, apparently was not inhibited by Uncaria tomentosa or dexamethasone treatments. IL-10 was also hampered significantly by dexamethasone, but there was no significant alteration with the Uncaria tomentosa treatment, although a strong tendency for IL-10 inhibition was observed in cultures treated with the alkaloidal fraction: IL-10 levels after DENV infection were 572± 219 pg/ml, lowered to 244±60 pg/ml after treatment and presented >18% abrogation in all five PBML donors.
Mixture of compounds/part unknown
The immunmodulatory effect of two mixtures of tetracyclic (TOA) and pentacyclic (POA)
oxindole alkaloids of Uncaria tomentosa were investigated in human peripheral mononuclear cells (PBMC) stimulated with the PHA and Con A in vitro. Compared to unstimulated cells, PHA and Con A (concanavalin A) increased the production of neopterin and the degradation of tryptophan (p<0.01). Mixtures of alkaloids of Uncaria tomentosa inhibited both effects in a dose dependant manner, the lowest effective concentrations were 100-175 pg/ml (p<0.01). With the highest concentrations complete suppression of mitogen-induced neopterin production and tryptophan degradation was observed, indicating immunmodulating effect of the alkaloids. POA hydrochlorides mixture contained 1% mitraphylline, 49% pteropodine and 50% isopteropodine. TOA hydrochlorides mixture contained 1% isocorynoxeine, 4% corynoxeine, 39% isorhynchophylline (Winkler et al. 2004).
Wurm et al. (1998) also showed that pentacyclic alkaloids (POA) stimulate endothelial cells in vitro to produce a lymphocyte-proliferation-regulating factor. Supernatants of EA.hy926 endothelial cell cultures incubated with 10 pM POA, significantly (p<0.01-0.001, depending on dilution of supernatants) increased the proliferation of normal resting or weekly activated human B and T lymphocytes. In contrast, proliferation of normal human lymphoblasts and of both the human lymphoblastoid B cell line Raji CCL86 and the human T cell line Jurkat E6.1 was inhibited significantly (p<0.01, 0.001 and 0.005, respectively), while cell viability was not affected. The proliferation of myeloid cell line U-937 was not affected by supernatants of POA stimulated endothelial cell cultures. POA alone did not exert any direct effect on proliferation. Thus the pentacyclic isomers do not affect directly the proliferation but rather induce endothelial cells to release a yet to be identified factor which influences the proliferation of lymphocytes. For generation of supernatants, EA.hy926 cells were incubated with 1 pM POA and TOA. Supernatants of untreated cells served as control. Tetracyclic oxindole alkaloids dose-dependently reduced the activity of pentacyclic oxindole alkaloids on human endothelial cells. POA-preparation contained: 4% speciophylline, 6% Uncarine F, 2% mitraphylline, 3% isomitraphylline, 28% pteropodine and 57% isopteropodine. The TOA preparation contained: 67% rhynchophylline and 33% isorhynchophylline. In the studies of antagonistic effects two separate POA preparations were used: pteropodine group (4% speciophylline, 6% Uncarine F, 30% pteropodine, 60% isopteropodine) and the mitraphylline group (33% mitraphylline, 67% isomitraphylline) (Wurm et al. 1998; Keplinger et al. 1999). Based on this study of Wurm et al. (1998), it has been stated, that the mixture of the two chemotypes of cat's claw are unsuitable for therapeutic use, unless certified to contain less than 0.02% tetracyclic oxindole alkaloids (Laus and Keplinger, 1997; Barnes et al. 2002).On the other hand, one tetracyclic alkaloid of Uncaria tomentosa, isorhynchophylline, was able to induce phagocytosis, while rhychophylline did not affect it (Keplinger et al. 1990). Thus isorhynchophylline may act as an immunostimulant, affecting other pathways than via endothelial cells. Hence, caution is advised, before drawing consequences based on one study, especially, concerning the immune system that has plenty probable targets. Moreover, most of the studies of Uncaria tomentosa were performed with extracts containing both types of alkaloids (Keplinger et al. 1990; Wagner et al. 1985).
A standardized extract (3% total alkaloids, commercial product, no further details) of Uncaria tomentosa (part not specified) was evaluated for ability to activate macrophage and natural killer cells, in vitro by Groom et al. (2007). Macrophage phagocytosis was stimulated up to 4.7-fold, (P<0.01) at concentrations 0.128, 0.385, and 1.28 mg/ml. NK cell synthesis of interferon-Y, macrophage synthesis of IL-12 or NK cell synthesis of granzyme B were not stimulated.
In vitro+in vivo
Domingues et al. (2011b) investigated the effects of a pentacyclic oxindole alkaloid (POA) extract derived from a 50% ethanolic extract of the Uncaria tomentosa bark on lymphocyte phenotype, Th1/Th2 cytokine production, cellular proliferation and cytotoxicity. POA extract was prepared by treatment of the crude 50% ethanolic extract with 0.1 N HCl and then partitioned with EtOAc. The resulting aqueous fraction was treated with NH4OH until a pH of 9-10 was reached, filtered and evaporated. For the in vivo immunotoxicity testing, BALB/c male mice (10/group) were treated once a day with 125, 500 or 1250 mg/kg of POA extract for 28 days. The extract increased the cellularity of splenic white pulp and the thymic medulla and increased the number of T helper lymphocytes and B-lymphocytes. The animals treated with 1250 mg/kg body weight of POA displayed a significant increase in the relative number of lymphocytes (91.4%, p<0.05), which was associated with a decrease in granulocytes (5.5%, p<0.01), compared to control (82% and 16.1% respectively). Also, a large stimulatory effect on lymphocyte viability was observed. However, in vitro mitogen induced (Con A) T lymphocyte proliferation was significantly inhibited at higher concentrations of the POA extract (p<0.05), concentrations tested 10, 50, 100 and 500 pg/ml. Furthermore, an immunological polarization toward a Th2 cytokine profile was observed. POA extract increased the mitogen-induced production of IL-4 (p<0.01) and IL-5 (p<0.001) and caused a strong inhibition of IFN-y (p<0.001) at the highest tested concentration (500 pg/ml). In addition both concentrations of 100 and 500pg/ml inhibited the production of IL-2. Despite the absence of changes in the TNF-a level at 500pg/ml, the lowest tested concentration (100 pg/ml) led to a significant increase (p<0.01).
Isolated constituents
Anti-inflammatory properties In vitro
From the bark of Uncaria tomentosa (200 g extracted with petroleum ether) Wirth and Wagner (1997) isolated Cinchonain 1b which inhibited 5-lipoxygenase (>100% at 42.5 pM/ml).
In vivo
Aquino et al. (1991) reported, that the bioassay-guided fractionation of the petroleum ether extracts of the root bark of Uncaria tomentosa, using the carrageenan-induced edema in rat (male Wistar Nossan) paw, has led to the isolation of a new quinovic acid glycoside, 3-p-0-(p-D-quinovopyranosil)-(27^I)-p-D-glucopyranosyl ester, as one of the active principles. The oral pre-treatment with the compound caused 33% inhibition at 3 hours of the inflammatory response (p<0.05). Subjects (n=5/group) received either indomethacin (5 mg/kg), vehicle or the pure compound at 20 mg/kg. One hour after drug administration 1% carrageenan was injected and the paw volumes were measured hourly for 5 hours.
Mitraphylline a major pentacyclic oxindole alkaloid, present in the bark chloroformic extract of Uncaria tomentosa was tested in vivo against a large range of cytokines that play a crucial role in inflammation. Mice received mitraphylline once a day for 3 days at 30 mg/kg/day by oral route. Then they were subjected to LPS endotoxin (15 mg/kg) and the LPS-induced production of 16 different cytokines was determined by Elisa multiplex. Control group received dexamethasone orally at 2 mg/kg/day. The control group received 0.9% saline solution, while dexamethasone (2 mg/kg/day, oral route) was used as reference. Two hours after the last dose, mice were injected intraperitoneally with saline-diluted LPS, then two hours later sacrificed. Mitraphylline inhibited around 50% of the release of interleukins 1a, 18, 17, and TNF-a. This activity was similar to dexamethasone. It also reduced almost 40% of the production of interleukin 4, while the corticoid did not (Rojas-Duran et al. 2012).
Immunmodulatory, immunostimulant properties In vitro+In vivo
Wagner et al. (1985) reported that six oxindole alkaloids from Uncaria tomentosa (pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, mitraphylline, isomitraphylline) showed a pronounced enhancement effect on phagocytosis. Isopteropodine (10-3-10-5% concentration) had the greatest effect with an elevation of 23.4-55% of the phagocytosis index, in the granulocytic test. Isopteropodine, isorhynchophylline and isomitraphylline were also active with a lesser extent (10.8%-27%), but mitraphylline and rhynchophylline were inactive. However, in vivo carbon clearance test, where an aqueous extract in the form of a water-soluble hydrochloric of the mixed alkaloids of Uncaria tomentosa administered to rats (10 mg/kg, i.p.), have shown that they are not active without the presence of the catechin tannin fraction of the root bark, even though these catechins were shown to be immunologically inactive. In another study speciophylline stimulated granulocyte phagocytosis in vitro by 25% to 35%. Among the tetracyclic oxindoles, dihydrocorynantheine, hirsutine and hirsuteine also stimulated granulocyte phagocytosis by 25% to 35% (McKenna et al. 2002).
Åkesson et al. (2005) reported, that mice exposed to quinic acid (QA), a component of a commercially available filtered aqueous extract (AE), had significantly increased number of spleen cells, thus recapitulating the in vivo biological effect of AE (which was repeated here). Mice were treated with 1, 2 and 4 mg/ml QA for 21 days (n=9-24). Ammonia treated quinic acid (QAA) but not QA, inhibited proliferation of mitogen-stimulated 70Z/3 mouse pre-B lymphocytes. Spleen cells were activated with Con A or LPS in the presence of concentrations of 1 mg/ml AE, QA or 1 and 2 mg/ml QAA. Both QA and AE inhibited NF-kB activity in exposed Jurkat T cells at similar concentrations (0.625-2.5 mg/ml).
Table 4: Overview of the main non-clinical data/conclusions
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Herbal preparations | |||||
|
Anti-inflammatory | |||||
|
Bark |
Aqueous extract of dried bark of U. tomentosa (20 g/L) |
100 qg/ml In the case of iNOS gene expression 50-200 qg/ml |
In vitro HT29 and RAW 264.7 cells |
Sandoval- Chachón 1998 |
Inhibited peroxynitrite-induced apoptosis, LPS induced iNOS gene expression, nitrite formation and cell death and the activation of NF-kB in in the presence of LPS (p<0.05) |
|
Bark |
Aqueous extract of micropulverized bark of Uncaria tomentosa (20 g/L) with or without concentration by freezedrying |
Freeze-dried: 0.001-3 qg/ml Without concentration 0.01-100 qg/ml |
In vitro RAW 264.7 cells |
Sandoval 2000 |
Suppressed LPS induced TNF-a production by 65-85% (p<0.01) freeze-dried EC50=1.2 ng/ml, without freeze-drying EC50=28 ng/ml |
|
Bark |
Aqueous extract of the bark of Uncaria tomentosa (UT) and U. guianensis (UG) (50 g/L) |
Freeze-dried extracts diluted to 20 mg/ml |
In vitro RAW 264.7 cells |
Sandoval 2002 |
The IC50 of TNF-a production was higher for UT (14.1 ng/ml) vs. UG (9.5 ng/ml), p<0.01 |
|
Bark |
Two Uncaria tomentosa bark extracts: 80% ethanolic spray-dried extract (DER 8:1) and aqueous freeze-dried |
5-500 qg/ml |
In vitro NF-kB EMSA (Jurkat T cells) COX1 and 2 assays. |
Aguliar 2002 |
NF-kB activation was nearly completely reduced with 500 qg/ml of the hydroalcoholic extract but aqueous extract only slightly reduced it. COX-1 and 2 inhibition: 7.8% and 21.7% (hydroalcoholic) 32.7% and 12.2% (aqueous freeze-dried) |
|
Stem bark |
Purified freeze-dried extracts of stem bark |
1-1000 ng/ml or 50 ng/ml |
In vitro HT29 and RAW 264.7 cells |
Piscoya 2011 |
Significant and dose-dependent reduction in TNF-a levels after stimulation, equivalent between Uncaria tomentosa and guaianensis IC50 values (10.2, 10.9 ng/ml, respectively) and with a maximum inhibition of 79% and 73%, respectively. The extracts had no effect on unstimulated PGE2 production but did significantly reduce PGE2 production stimulated by LPS. |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Bark |
Aqueous extract of dried bark of U. tomentosa (20 g/L) |
5 mg/l, orally in drinking water |
In vivo Sprague-Dawley rats, with indomethacin induced intestinal inflammation |
Sandoval- Chachon 1998 |
The extract attenuated indomethacin enteritis: it reduced the myeloperoxidase activity, morphometric damage and metallothionein expression (p<0.05) |
|
Bark |
Aqueous extract of the bark of Uncaria tomentosa (20 g\L) DER 1:14 |
50% and 100% UT extract, per os Drinking water ad libitum Pre-treatment |
In vivo Mice (n=32/group) ozone inhalation caused acute pneumonitis |
Cisneros 2005 |
Lung tissue protective effect of pre-treatment: Significantly (p<0.05) lower levels of protein in BALF, lower degree of epithelial necrosis, higher number of intact epithelial cell nuclei in bronchial wall, and decreased number of PMNs in the bronchiolar lumen |
|
Bark |
Two Uncaria tomentosa bark extracts: 80% ethanolic spray-dried extract (DER 8:1) and aqueous freeze-dried Uncaria tomentosa extract |
500, 200, 100 and 50 mg/kg Gastric probe during 8 days Pre-treatment |
In vivo Carrageenan-induced paw edema model in BALB/c mice |
Aguliar 2002 |
The pre-treatment with hydroalcoholic extract (50 mg/kg) produced an anti-inflammatory effect similar to 7 mg/kg of the non-steroidal drug indomethacin, while the aqueous freeze-dried extract exhibited the same effect at 200 mg/kg. |
|
Bark |
Micropulverized bark of U. tomentosa |
5 mg/l, orally in drinking water Pre-treatment |
In vivo Sprague-Dawley rats, with indomethacin induced gastritis |
Sandoval 2002 |
Protective effect (p<0.01), the degree of gastric mucosal injury was markedly attenuated TNF-a mRNA expression and apoptosis was prevented |
|
Root bark |
Fractions from the petroleum ether extract of the root bark of U. tomentosa |
Per os CHCls/MeOH (9:1) (50 mg/kg), Water (84 mg/kg), MeOH and CHCl3 fractions (doses equivalent to 2 g of dry bark/kg) Pre-treatment |
In vivo Carragenan-induced edema in normal and in normal and indomethacin treated Wistar rats (n=5/group) |
Aquino 1991 |
Pre-treatment with the fractions (CHCh/MeOH (9:1) and water) caused 69.2 and 41.2% inhibition at 3 hours of the inflammatory, respectively. |
|
Root bark |
Decoction of Uncaria tomentosa root bark |
Pre-treatment with 3 ml of the added to drinking water |
In vivo Rats |
McKenna 2002 |
The size and number of large gastric ulcers were significantly inhibited compared to controls |
|
Root |
Aqueous (70°C) extract of the root of Uncaria tomentosa (10% w/v), then freeze-dried |
250 or 500 mg/kg extract i.p. Pre-treatment |
In vivo Sprague-Dawley rats (n=6/group) Edema induced by Bothrops asper snake venom |
Badilla 2006 |
The doses of 250 mg/kg and 500 mg/kg showed an anti-inflammatory effect at all times (p<0.05), except for the dose of 250 mg/kg at one hour |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Unknown |
70% ethanolic extract of U. tomentosa |
0.125, 0.5, 2 g/kg Per os Post-treatment |
In vivo Carragenan-induced edema in normal and in prednisolone treated mice (n=5) |
Abe 2002 |
The post-treatment significantly (p<0.05) lowered the thickness of the edema administered together with Harpagophytum procumbens, but not alone |
|
Immunmodulatory | |||||
|
Bark |
Uncaria tomentosa (UT) (70% ethanolic extract of the bark, 2.57% pentacyclic oxindole alkaloids) |
100 and 200 pg/ml |
In vitro Colony-forming cell (CFC) assays performed with hHSPCs |
Farias 2011 |
Increase in CFU-GM size and mixed colonies (CFU-GEMM) size at the final concentrations of 100 and 200 pg extract/ml |
|
Bark |
95% ethanolic extract of the bark of Uncaria tomentosa (exhaustive percolation) |
1 or 10 pl (concentration not given) |
In vitro LPS-treated THP-1 monocyte cells |
Allen-Hall 2007 |
augmented the expression of IL-ip by 20-fold, but did not affect the expression of TNF-a, (p<0.05) |
|
Bark |
95% ethanolic extract of the bark of Uncaria tomentosa (exhaustive percolation) |
10-360 pg/ml |
In vitro LPS-treated THP-1 monocyte cells |
Allen-Hall 2010 |
The treatment: Inhibited the secretion of TNF-a in a dose-dependent manner (33-95%) Enhanced the expression of IL-ip at 40 and 160 pg/ml but blocked at 320 pg/ml. Inhibited the activation of all AP-1 transcription factor subunits but only inhibited some of the NF-kB subunits (p<0.05) |
|
Stem bark |
Two stem bark aqueous extracts of different collections of U. tomentosa: UT1 and UT2 -6.98 and 5.57 mg/g total oxindole alkaloid content respectively |
0.025-0.5 mg/ml |
In vitro Alveolar rat macrophages with or without LPS stimulation |
Lemaire 1999 |
UT2 greatly stimulated IL-1 and IL-6 (10X and 7.5X at max. effect) production in a dose dependent manner and enhanced IL-1 (5.2X) and IL-6 (<2X) in LPS stimulated macrophages. UT 1 had comparable trends in results (not specified) |
|
Stem bark |
50% ethanolic extract of the stem bark of U. tomentosa |
0.1-100 pg/ml |
In vitro DENV (Dengue Virus-2) infection model. |
Reis 2008 |
No significant alterations were detected with the treatment of hydro-ethanolic extract in the measured TNF-a, IL-6, IL-10 and IFN-a levels. |
|
Stem bark |
70% ethanolic extract of the stem bark of Uncaria tomentosa(48 hrs. 25°C) |
250-3.9 pg/ml in complement cascade, 5 mg/ml in ADP-induced platelet aggregation assay |
In vitro Complement cascade inhibition and ADP-induced platelet aggregation inhibition assays. |
Deharo 2004 |
Inhibition of the classical-CPW and alternative-APW complement pathways, IC50: 124 and 151 pg/ml, respectively. ADP-induced platelet aggregation-no inhibition |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Stem bark |
Commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) |
Several concentrations in different assays: 0.125-2 mg/ml |
In vitro Mouse CTLL-2 cells for IL-2 assay, mouse spleen cells, IL-2 ELISA, LPS stimulated 70Z/3 and Jurkat cells for NF-kB |
Åkesson 2003a |
The extract inhibited the proliferation of normal mouse T and B-lymphocytes and the inhibition is not caused by toxicity or by induction of apoptosis. It did not interfere with IL-2 production nor IL-2 receptor signalling, but reduced NF-kB activity with almost 50%. |
|
Stem root bark |
Extract of the stem or root bark of Uncaria tomentosa |
In vitro Granulocytic test |
McKenna 2002 |
Increase in phagocytic activity shown by the root bark was found to be 30% to 40% Increase in phagocytic activity shown by the stalk bark was found to be 10% to 20% | |
|
Unknown |
Aqueous (roomtemp.) extract of Uncaria tomentosa (commercial product) 10 ml/g |
44 pg/ml |
In vitro FACS-based IL-2Ra and CFSE analysis of human and bovine PBMC |
Holderness 2007 |
IL-2Ra activation, proliferation and expression on y5 T cells were induced. The activity was specific to y5 T cells and was not limited to one y5 T cell subset. The activity was due to the condensed tannin fractions of the drug. |
|
Unknown |
HCl and 96% ethanolic Uncaria tomentosa extracts (commercial products) |
Concentration range of 500-4000 pg/ml |
In vitro Human peripheral mononuclear cells (PBMC) stimulated with the PHA and Con A |
Winkler 2004 |
The extracts inhibited the production of neopterin and the degradation of tryptophan in a dose dependant manner; the lowest effective concentrations were 500-1000 pg/ml (p<0.05). At the highest concentrations, complete suppression was observed, indicating immunomodulation effect of the extracts. |
|
Bark |
Decoction of the bark of Uncaria tomentosa |
Group I (n=10, 3600 mg/calf/day) and Group II (n=10, placebo) Per os 3600 mg in 200 ml decoction form, for 17 day |
In vivo Calves (n=10/group) |
Bedranek 2002 |
In the treatment group the peripheral blood neutrophil and MID-cell number and the rectal temperature were significantly lower, the peripheral lymphocyte subsets increased significantly in the total number and % of CD2 + and CD4+ cells and the synthesis and release of pro-inflammatory arachidonate metabolites (eicosanoids) were also inhibited. |
|
Bark |
Water and 96% ethanol extract of Uncaria tomentosa bark (DER 1:10) |
200 pg daily for 7 days Per os |
In vivo BALB/c mice |
Nowakowska 2010 |
Metabolic activity of granulocytes was stimulated by the water extract compared to control (p<0.001). Ethanol extract didn't reach the level of significance. |
|
Bark |
30% ethanolic extract of Uncaria tomentosa bark (Drug solvent ratio 1:10) |
0.56, 5.6 mg of the dry extract seven times Intragasrically |
In vivo BALB/c mice (n=6/group) immunized with a formalin-inactivated whole Sendai virus (SV) with two doses of extract. |
Bizanov 2005 |
Animals inoculated with 5.6 mg of the dry extract induced higher saliva IgA antibodies. Mice immunized e.g. with SV plus 0.56 mg of the extract had significantly higher IgA, IgG and HI (haemagglutination inhibition) antibody responses to SV than did those administered with the SV alone (p<0.05) |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Bark |
50% ethanolic extract of the bark of Uncaria tomentosa (UT) Total alkaloid content 29.1 mg/ml |
10-400 mg/kg during 21 days By gavage, per os |
In vivo immune-mediated diabetes in C57BL/6 male mice |
Domingues 2011a |
Insulinitis protective effect: 50-400 mg/kg of UT caused a significant reduction in the glycemic levels and incidence of diabetes, protection against the loss of p-cells (p<0.01) and higher number of intact islets (p<0.05) Extract modulated the production of Th1 and Th2, with increased levels of IL-4 and IL-5 (p<0.05). |
|
Bark |
Uncaria tomentosa (UT) (70% ethanolic extract of the bark, 2.57% pentacyclic oxindole alkaloids) |
5 and 15 mg of UT extract per os and intraperitoneal doses of 3 and 9 pg of filgrastim, respectively, for 4 days. |
In vivo Ifosfamide-treated mice (n=6/group) |
Farias 2011 |
Treatment significantly increased the neutrophil count (4 and 13X higher than control, respectively), and a potency of 85.2% was calculated in relation to filgrastim at the corresponding doses tested. |
|
Bark |
Commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) |
Approximatly daily doses of 125, 250 or 500 mg/kg bodyweight for different periods of time (63, 24 days), in drinking water |
In vivo C57BL/6 mice (7/group) |
Åkesson 2003b |
A dose dependent increase in spleen cell numbers, but the proportion of B, T and NK cells, granulocytes, and memory lymphocytes were normal. Accumulation is most likely due to prolonged cell survival |
|
Bark |
Commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) |
0, 5, 10, 20, 40 and 80 mg/kg for 8 or 4 consecutive weeks Per os |
In vivo Female W/Fu rats (n=8/group) |
Sheng 2000a |
Lymphocyte proliferation was significantly increased in splenocytes of rats treated at the doses of 40 and 80 mg/kg. White blood cells (WBC) were significantly elevated compared with controls (P<0.05) |
|
Bark |
Commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) |
40 and 80 mg/kg for 16 consecutive days Per os |
In vivo Female W/Fu rats (n=11/group) |
Sheng 2000b |
Both AE and Neupogen (positive control) treatment groups recovered significantly sooner (p<0.05) than DOX group, but in AE all fractions of WBC were proportionally increased, while in Neupogen group mainly neutrophil cells elevated. |
|
Unknown |
Uncaria tomentosa extract (UTE) (not specified) was provided as a powder, dosed in 1% of total alkaloids by Galena Química e Farmaceutica Ltda (Campinas, SP, Brazil). |
50, 100, 150 and 200 mg/kg for 7 days Per os |
In vivo BALB/c mice inoculated i.p. with lethal and sublethal dose of Listeria monocytogenes |
Eberlin 2005 |
Increased survival rates up to 35% Increased numbers of (CFU-GM) in the bone marrow (p<0.001). Increased colony-stimulating activity (CSA) in dose-dependent manner (p<0.01 and p<0.001 for doses 50 and 100 mg/kg respectively). Higher numbers of CFU-GM in non-infected mice, 100 mg/kg UTE WBC had no significant changes Increased levels of IL-1 (p<0.05) and IL-6 (p<0.001) at 100 mg/kg |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Unknown |
Uncaria product (0.19 g Uncaria tomentosa/capsule) |
570 mg/UT/day from capsules for 32 days in drinking water |
In vivo Domestic rabbits, 2 antigenic inoculations with La Sota strain of Newcastle virus (n=7/group) |
Belteghi 2008 |
Uncaria product had a stimulating effect upon the total leukocyte count (p<0.01), inhibo-hemagglutinant antibody titer was 1.64 fold higher than in the control lot (p<0.05). Phagocitary index had a substantial, but statistically not significant (2.16 fold) increases after the first inoculation |
|
Fractions and mixtures of isolated constituents | |||||
|
Anti-inflammatory | |||||
|
Bark |
MeOH:H2O:1.2 HCl (50:50:1) extract of the bark of UT, then nonalkaloid HPLC fractions were collected |
Non-alkaloid HPLC fractions from UT (0.1100 ng/ml) |
In vitro RAW 264.7 cells |
Sandoval 2002 |
Decreased LPS-induced TNF-a and nitrite production (p<0.01) |
|
Immunmodulatory | |||||
|
Bark |
Pentacyclic oxindole alkaloid-enriched (speciophylline, mitraphylline, Uncarine F, pteropodine, isomitraphylline, isopteropodine) or nonalkaloid fractions |
0.1-100 pg/ml |
In vitro DENV (Dengue Virus-2) infection model. |
Reis 2008 |
No significant alterations were detected with the non-alkaloidal fraction treatment in the measured TNF-a, IL-6, IL-10 and IFN-a levels. Alkaloidal fraction inhibited both TNF-a and IFN-a at concentrations of 100 pg/ml and similar cytokine levels resulted with the dexamethasone treatment. Il-6 was not inhibited neither DEX nor the alkaloidal fraction. |
|
Unknown |
Two mixtures of tetracyclic (TOA) and pentacyclic (pOa) oxindole alkaloids of U. tomentosa |
Concentration range of 50-500 pg/ml |
In vitro Human peripheral mononuclear cells (PBMC) stimulated with the PHA and Con A |
Winkler 2004 |
The production of neopterin and the degradation of tryptophan were inhibited in a dose dependant manner, the lowest effective concentrations of 100-175 pg/ml (p<0.01). At the highest concentrations complete suppression was observed, indicating immunmodulating effect of the alkaloids. |
|
Unknown |
Pentacyclic oxindole alkaloids (POA) Tetracyclic oxindole alkaloids (TOA) |
Generation of supernatant: 1pM POA Proliferation assays: supernatants were tested at dilutions from 1:2- |
In vitro EA.hy926 endothelial cells, proliferation assays (B and T lymphocytes, T and B blasts, Raji CCL86 and |
Wurm 1998 |
POA induced EA.hy926 endothelial cells to realese unknown factor(s) into supernatant; which significantly enhanced proliferation of normal human B and T lymphocytes; and inhibited the proliferation of normal human |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
1:32. |
JurkatE6.1) |
lymphoblasts, lymphoblastoid B cell line Raji and T cell line Jurkat (p<0.01, 0.001 and 0.005, respectively) TOA dose-dependently reduced the activity of POA on human endothelial cells | |||
|
Unknown |
Standardized extract (3% total alkaloids) |
0.128, 0.385, and 1.28 mg/ml |
In vitro Il-12, IFN- Y ELISA, Vibrant phagocytosis assay, ELISPOT granzyme B assay |
Groom 2007 |
Macrophage phagocytosis was stimulated up to 4.7-fold, (P<0.01) at all concentrations, NK cell synthesis of interferon-y, macrophage synthesis of interleukin-12 or NK cell synthesis of granzyme B were not stimulated. |
|
Pentacyclic oxindole alkaloid (POA) extract from 50% ethanolic extract of the Uncaria tomentosa bark |
10, 50, 100 and 500 pg/ml for proliferation, 100 and 500 pg/ml for cytokine production |
In vitro Mitogen induced (Con A) T lymphocyte proliferation, T1, 2 cytokine production (IL5, 2, 4, TNF-a, IFN-y) |
Domingues 2011b |
Mitogen induced T lymphocyte proliferation was significantly inhibited at higher concentrations of the extract (p<0.05). Increased mitogen-induced production of IL-4 (p<0.01) and IL-5 (p<0.001), inhibition of IFNY (p<0.001) at the highest tested concentration (500 pg/ml), inhibition of the production of IL-2, No changes in the TNF-a level at 500pg/ml, but significant increase at 100pg/ml (p<0.01) | |
|
Pentacyclic oxindole alkaloid (POA) extract from 50% ethanolic extract of the Uncaria tomentosa bark |
125, 500 or 1250 mg/kg body weight of Uncaria tomentosa extract for 28 days Per os |
In vivo BALB/c male mice (10/group) |
Domingues 2011b |
Increased cellularity of splenic white pulp and the thymic medulla Increased relative number of lymphocytes (91.4%, p<0.05), associated with a decrease in granulocytes (5.5%, p<0.01), compared to control (82% and 16.1% respectively). Stimulatory effect on lymphocyte viability was observed. | |
|
Isolated constituents | |||||
|
Anti-inflammatory | |||||
|
Cinchonain 1b |
42.5 pM/ml |
In vitro |
Wirth 1997 |
inhibited 5-lipoxygenase (>100%) | |
|
Quinovic acid glycoside, 3-(3-O- (p-D- quinovopyranosil)-(27^I)-p-D-glucopyranosyl from the petroleum ether extract of the root bark of U. tomentosa |
Per os 20 mg/kg |
In vivo carragenan-induced edema in normal and in normal and indomethacin treated Wistar rats (n=5/group) |
Aquino 1991 |
33% inhibition at 3 hours of the inflammatory response. | |
|
Herbal preparation tested |
Strength Dosage Route of administration |
Experimental model In vivo/ In vitro |
Reference Year of publication |
Main non-clinical conclusions | |
|
Mitraphylline |
3 days pre-treatment 30 mg/kg/day Per os |
In vivo LPS-induced production of 16 different cytokines was determined in BALB/c mice by Elisa multiplex |
Rojas-Duran 2012 |
Inhibition of approximately 50% of the release of interleukins 1a, 18, 17, and TNF-a. This activity was similar to dexamethasone. It also reduced almost 40% of the production of interleukin 4, while the corticoid did not | |
|
Immunology | |||||
|
pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, mitraphylline, isomitraphylline |
10-3-10-5% concentration |
In vitro Granulocytic test (phagocytosis test) |
Wagner 1985 |
Isopteropodine had the greatest effect with an elevation of 23.4-55% of the phagocytosis index. Isopteropodine, isorhynchophylline and isomitraphylline were also active with a lesser extent (10.8%-27%), but mitraphylline and rhynchophylline were inactive. | |
|
Speciophylline, dihydrocorynantheine, hirsutine and hirsuteine |
In vitro Granulocytic test (phagocytosis test) |
McKenna 2002 |
Speciophylline stimulated granulocyte phagocytosis by 25% to 35%. Dihydrocorynantheine, hirsutine and hirsuteine also stimulated granulocyte phagocytosis by 25% to 35%. | ||
|
Quinic acid (QA) Ammonia treated quinic acid (QAA) |
0.625-2.5 mg/ml |
In vitro Jurkat cells 70Z/3 mouse pre-B lymphocytes |
Åkesson 2005 |
QAA, but not QA, inhibited proliferation of mitogen-stimulated mouse lymphocytes., QAA or QA. Both QA and AE inhibited NF-kB activity. | |
|
pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, mitraphylline, isomitraphylline |
10 mg/kg, i.p. |
In vivo Carbon clearance test Rats |
Wagner 1985 |
They are not active without the presence of the catechin tannin fraction of the root bark, even though these catechins were shown to be immunologically inactive. | |
|
Quinic acid (QA) |
1, 2 and 4 mg/ml in drinking water for 21 days |
In vivo C57BL/6 mice (n=9-24) |
Åkesson 2005 |
Increased number of spleen cells | |
3.1.2. Secondary pharmacodynamics
Antiproliferative properties and mechanisms In vitro
The alkaloid class of Uncaria tomentosa was the most commonly, mainly in vitro tested group across studies and provided limited experimental evidence demonstrating anti-proliferative effects, maybe through pro-apoptotic pathways (Gurrola-Diaz et al. 2011; De Martino et al. 2006). The antiproliferative effects of different extracts (H2O or 25, 50, 96% ethanol or alkaloid enriched) of the bark were tested on several cell-lines (HT-29, SW 707, KB, MCF-7, A-549, OAW-42, HL-60, LLC, B16, Neuro-2a, T24, RT4, CCL-86, TIB-152, K-562, SAOS-2). The inhibitory activities were weak to moderate; the IC50 values of an alkaloid rich fraction and an ethanolic extract of the bark on the KB (human cervical carcinoma) and LLC (LL/2, mouse Lewis lung carcinoma) cell lines were the lowest, 23 and 25 gg/ml, respectively (Pilarski et al. 2010). It was also observed that the inhibition showed a high correlation between the total oxindole alkaloid content and the antiproliferative activity of the preparations. The alkaloid content in preparations increased with the ethanol concentrations reaching the highest value at 96% ethanol.
The hexane (CC-H), ethyl acetate (CC-EA), n-butanol (CC-B) and methanol (CC-M) extracts of a Uncaria tomentosa commercial product (plant part not specified) on human premyelocytic leukaemic HL-60 cell line were compared. The most potent inhibitor of cell viability was CC-H with an IC50 of 13.0 gg/ml, as for CC-B, CC-EA and CC-M IC50 values were 13.5 gg/ml, 18.0 gg/ml 50.3 gg/ml, respectively (Cheng et al. 2007).
Oxindole alkaloids from Uncaria tomentosa, namely isopteropodine, pteropodine, mitraphylline, isorhynchophylline, uncarine F, speciophylline and isomitraphylline were tested on different cell lines (MTC-SK, MHH-ES-1, MT-3, HL-60, SK-N-BE(2), GaMg, U-937, CCRF-CEM, 3T3, HeLa, LSR, C-678, H-460, BT-549, SK-OV-3, SK-MEL, KB). They exhibited weak to moderate activity with IC50 values ranging between 11.8-51 gM, or displayed no activity at all. Mitraphylline was tested in the highest number of cell lines (10); and it had the lowest IC50 values among all the tests performed with different alkaloids on different cells. Mitraphylline had an IC50 value of 11.8, 12.3, and 17.15 gM, against MT-3 (human breast cancer), SK-N-BE(2) (neuroblastoma) and MHH-ES-1 (human Ewing's sarcoma), respectively (Prado et al. 2007; Gimenez et al. 2010).
In vivo
The activity of Uncaria tomentosa preparations with different quantitative and qualitative oxindole alkaloid composition were studied on cancer cells using in vitro and in vivo models by Pilarski et al. (2010). The bark of Uncaria tomentosa was extracted with water or ethanol (50 or 96%) on different temperatures (37°C and boiling) and an alkaloid rich fraction (B/SRT) was prepared as well. Animal studies on mice (21 days, 5 and 0.5 mg daily doses/sample, 6 mice/group) with LLC showed significant inhibition of tumour growth by the aqueous extract (37°C), which exhibited the lowest toxicity in vitro. In contrast the activity of B/96E37 and B/SRT preparations (most effective in vitro) did not reveal any significant antitumour activity. The two control groups were treated with physiological salt solution and DMSO 10%.
The proliferative effect of a 70% ethanolic bark extract of Uncaria tomentosa (UT) (1 hour extraction at 20°C, concentrated, dried, atomized, total alkaloid content was of 5.03%) was demonstrated in the Walker-256 cancer model by Dreifuss et al. (2010). Walker-256 tumour cells were subcutaneously
inoculated in the pelvic limb of male Wistar rats. Daily gavage with UT (10, 50 or 100 mg/kg, Groups UT, n=9) or saline solution (Control, Group C, n=9) was subsequently initiated, until 14 days afterwards. For some parameters, a group of healthy rats (Baseline, Group B, n=5) was added. Compared to control group UT reduced the tumour volume by 46%, 58% and 64% at doses of 10, 50 or 100 mg/kg, respectively. In addition, treatment with UT reduced the activity of AST, but did not reverse the increase of LDH and GGT plasma levels, although all doses effectively reduced urea plasma levels. Treatment also resulted in increased CAT activity in liver, while decreasing it in tumour tissue. SOD activity was reduced in liver as well as in tumour, compared to Group C. The antineoplastic activity may result, partially at least, from the ability of UT to regulate redox and metabolism homeostasis.
The antineoplastic properties of Uncaria tomentosa (UT) 70% ethanolic (BHE) bark extract (1
hour extraction, concentrated, total alkaloid content was of 5.03%) and its two fractions choroformic (CHCl3) and n-butanolic (BuOH) were demonstrated and compared by Walker-256 cancer model. Subsequently to the inoculation, gavage with BHE extract (50 mg/kg) or its fractions (extrapolated doses for both fractions) or vehicle (Control) was performed during 14 days. Baseline values, corresponding to individuals without tumour or treatment with UT, were also included. The number of rats (n) in each of these groups was 4-6. Both the BHE extract and its BuOH fraction (rich in antioxidant substances) successfully reduced tumour weight and volume (tumour mass suppression of 52% and 49%, respectively, p=0.01) and modulated anti-oxidant systems. Inversely, the CHCl3 fraction (rich in pentacyclic oxindole alkaloids) was ineffective. The tumour volume suppression rates of the BHE extract and BuOH fraction groups as compared to the control group were 52% and 58% respectively, while the CHCl3 fraction has similar values as in the control group. Both the BHE extract and its BuOH fraction increased the survival time of the tumour-bearing animals. The BHE extract treated group survived the entire observation period (30 days), but no individual belonging to the control and CHCl3 groups remained alive at the end of the trial (Dreifuss et al. 2013).
DNA repair
In vitro
Bark
Extracts (petroleum ether, chloroform, chloroform:methanol 9:1, methanol, water) and chromatographic fractions (Sephadex LH-20 of chloroform/methanol extract) of Uncaria tomentosa bark showed no mutagenic effect in different strains of Salmonella typhimurium with and without metabolic activation. However, the plant extracts and fractions showed a protective antimutagenic effect (AMES test) in vitro against photomutagenesis in S. typhimurium TA 102. The chloroformic and methanolic extracts were the less (27%) and the most (59%) active extracts (Rizzi et al. 1993).
Skin cultures co-incubated with a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE, 5 mg/ml) reduced skin cell death from UV exposure compared to no treatment (p<0.001), and this protection was accounted for by a concomitant increase in DNA repair measured by TT dimmers DNA lesions. The percent reduction in TT-dimers was found to be statistically significant in the AE group compared with the untreated controls (73% vs. 11%, respectively, p < 0.001) (Mammone et al. 2006).
Stem bark
Antimutagenic activity of Uncaria tomentosa maceration extract (UT mac), Uncaria tomentosa plus Uncaria guianensis maceration extract (UT+UG mac), Uncaria tomentosa reflux extract plus Uncaria guianensis reflux extract (UT+UG ref), oxindole alkaloid purified fraction (OAPF, 62.73% POA) and quinovic acid glycosides purified fraction (QAPF 217 gg/mg) were evaluated by Caon et al. (2014). Maceration and reflux extraction of the stem bark samples were performed with 40% ethanolic solution (DER 1:10). The protective effect of samples at 1000 gg/ml (non-cytotoxic concentration) on UV-induced DNA damage was assessed using the Comet assay with minor modifications. The simultaneous treatment provided greater protective effect on UV-induced DNA damage (reaching protection levels of 75%) than the pre-, or post-treatment, and this effect clearly showed to be dependent on sample concentration (250-1000 gg/ml). Both purified fractions (QAPF and OAPF) showed lower protective effect on UV-induced DNA damage than UT mac (p<0.05) after pre- and simultaneous treatment, and similar protective effect in post-treatment (p>0.05).
In vivo
Bark
Female W/Fu rats (n = 10/group) were gavaged daily with a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) at the doses of 40 and 80 mg/kg for 8 consecutive weeks. Repair of DNA single strand breaks (SSB) and double strand breaks (DSB) 3 hrs after 12 Gy whole body irradiation of rats were significantly improved in AE treated animals (P<0.05) (Sheng et al. 2000a).
Sheng et al. reported (2005) that QA (Quinovic acid) esters showed growth inhibition without cell death in HL-60 and HML cells in vitro, which would be stimulatory to DNA repair. In vivo 50 rats were divided into five groups: doxorubicin (DOX), a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) (80 mg/kg) + DOX, quinic acid (200 mg/kg) + DOX and ammonia-treated quinic acid (QAA) (200 mg/kg) + DOX and saline control. Peripheral blood WBC data indicated, that both QA and QAA could induce recovery from DOX induced leukopenia (7.1 X1012WBC/L) about as effectively as 80 mg/kg AE (8.1, 8.5 and 8.4X1012 WBC/L, respectively, p<0.05). Based on these data it was concluded that a QA analog was at least one class of active ingredients in AE.
Carboxy alkyl esters of Uncaria tomentosa (obtained from a commercially available aqueous extract from the bark of U. tomentosa-AE) were reported to facilitate recovery (4 weeks) of sensorineural functions following exposure to a damaging level of noise. Long-Evans rats were divided into four treatment groups: vehicle-control, noise-only, AE-only and AE+noise. AE treatment facilitated almost complete recovery of outer hair cell function and limited the magnitude of cell loss. The loss of neural sensitivity to pure tone stimuli was inhibited with AE treatment. Therefore, it appears that the multifunctional cytoprotective capacity of AE from Uncaria tomentosa may generalize to otoprotection from acoustic overexposure. Loud-noise exposure simultaneously elicits several injury inducing mechanisms, which indicates that otoprotection would require the targeting of several pathophysiologic mechanisms, such as DNA damage and inflammation (Guthrie et al. 2011).
Single substance
Pteropodine (100-600 mg/kg) was reported to significantly decrease the frequency of sister-chromatid exchanges and micronucleated polychromatic erythrocytes in mice administered with 10 mg/kg of doxorubicin. Furthermore, pteropodine partially corrected bone marrow cytotoxicity induced by doxorubicin, as it showed an improvement in the rate of polychromatic erythrocytes. The antigenotoxic effect of pteropodine was detected with all tested doses. The highest reduction of MNPE (micronucleated polychromatic erythrocytes) was achieved with 600 mg/kg of pteropodine at 24 hrs (89%, p<0.05). Besides, 600 mg/kg of pteropodine increased 25.8% (p<0.05) of the production of lymphocytes over the control value along a 96-hrs assay (Paniagua-Perez et al. 2009).
Antioxidant activity In vitro
There are numerous investigations concerning the antioxidant activity of Uncaria tomentosa, but only four studies were performed in vivo. Amongst the in vitro tests, mainly the aqueous extract of the bark of Uncaria tomentosa was investigated, but ethanolic (50, 70, 96%) extracts of the bark, leaves, aqueous and ethanolic extracts of the bark mixed with leafs and aqueous, dichloromethanic, methanolic extracts of the roots and stem bark were also studied. Different types of assays were carried out in order to measure general free radical, superoxide anion, hydrogen peroxide, hydroxyl radical, hypochlorous acid, lipid peroxidation scavenger activity. Generally, the tested preparations had intermediary antioxidant activity
In a study a correlation between the capacity of DPPH reduction and the proanthocyanidins content was verified (Gongalves et al. 2005). On the other hand, the alkaloid content does not seem to have a role in the antioxidant effect, because in three different assay, Uncaria guianensis was more potent that Uncaria tomentosa (p<0.01), yet the total oxindole and pentacyclic alkaloid content of UT was 35 fold>UG (Sandoval et al. 2002).
In vivo
Bark
The antioxidant effect of 70% ethanolic bark extract of Uncaria tomentosa (UT) was demonstrated in rats with Walker-256 cancer by Dreifuss et al. (2010). The in vivo oxidative stress parameters (Catalase (CAT), SOD and glutathione-S-transferase (GST)) were measured in liver and/or tumour tissues. The presence of W-256 tumour induced significant changes in all of hepatic enzymes. In the control group the mean activity of CAT was reduced by 79%, SOD increased by 252% and GST decreased by 59% when compared to baseline group. The treatment with UT successfully normalised the activities of these enzymes. Regarding to CAT and GST, all tested doses (10, 50 and 100 mg/kg) of UT extract significantly (p<0.05) increased its activities, drawing both enzymes to similar levels of those found in baseline condition. The activity of hepatic SOD was normalized only by the highest dose of UT extract (100 mg/kg). CAT activity for the group treated with 10 mg/kg UT had lower activity in tumour (59.9±5.2 pmol-min-mg-protein-1) than in liver (291±17.8 pmol-min-mg-protein-1), which is quite favourable. Like so, activity of tumour SOD was significantly reduced in all groups treated with UT. In contrast, treatment with UT did not lead to any significant differences in reduced glutathione levels (GSH) and lipid peroxidation (LPO) rates in the tumour tissue.
The antioxidant properties of a 70% ethanolic (BHE) extract of the bark of Uncaria tomentosa (UT) and its two fractions choroformic (CHCl3) and n-butanolic (BuOH) were evaluated and compared in vitro (DPPH) and in vivo in rats (n=4-6/group) with Walker-256 cancer. In the hepatic tissue of the animals of the control group (vehicle), the SOD level was increased (6.36 U SOD/mg of protein), the CAT level was decreased (179.5 mmol/min-mg of protein) when compared to baseline values (1.99 U SOD/mg of protein, 399.8 mmol/min-mg of protein). The CHCl3 fraction generated same values as the control group. Treatment with the BHE extract increased these values (p<0.001 and p<0.05, respectively) to 10.16 U SOD/mg of protein (p<0.001) and the BuOH fraction exhibited a significant increase only in the SOD activity, to 8.8 U SOD/mg of protein (p<0.001). Inversely, in the tumour tissue, SOD activity in the control group was 10.5 U SOD/mg of protein; BHE extract and its BuOH fraction significantly reduced these levels Results in the tumours are in opposition of those found in the liver, but with much lower values of CAT. In the liver samples of the control group 28.22 nmol/mg of protein was the observed level of the LPO. BHE and BuOH group reduced significantly these levels, in an attempt to return this parameter to baseline levels. In the tumour the BHE extract and its BuOH fraction reduced LPO levels in a statistically significant manner, the CHCl3 fraction did not alter this parameterin neither samples (Dreifuss et al. 2013).
The acute effects of Uncaria tomentosa (UT) (70% ethanolic extract of the bark, 2.57% pentacyclic oxindole alkaloids) in the recovery of neutrophils after chemotherapy-induced neutropenia were assessed. Ifosfamide-treated mice received oral doses of 5 and 15 mg of UT and intraperitoneal doses of 3 and 9 pg of filgrastim, respectively, for four days (6 mice/group). There were no differences in levels of non-protein thiols or in the activities of antioxidant enzyme catalases or superoxide dismutase (SOD) among Uncaria tomentosa, filgrastin, and control groups (Farias et al. 2011).
Unknown part
The renoprotective effects of a dry extract of Uncaria tomentosa (UT, part not specified) were demonstrated on ischemic acute kidney injury (AKI) induced by renal clamping in rats (n=35). The groups were: Sham (no ischemia), ischemia (45 mins), UT+ischemia (rats treated with 20 mg UT daily for 5 days prior to the simulation of ischemia), UT+ sham (rats treated with 20 mg UT daily for 5 days). The ischemic animals presented reduction of the renal function (creatinine clearance) when compared to those in the sham group (0.17 ml/min vs. 0.54 ml/min, respectively, p<0.05), confirming the episode of ischemic AKI. The Ischemia+UT group presented attenuation in the reduction of creatinine clearance (0.54 ml/min vs. 0.17 ml/min, p<0.05) in comparison to the group that was not treated. The ischemia group presented an increase in the excretion of urinary peroxides when compared to the sham group (11 nmol/g vs. 3 nmol/g, respectively, p<0.05). In the ischemia+UT group there was a statistically significant decrease in the excretion of urinary peroxides, compared to the ischemia group (3.6 nmol/g vs. ±1.5 nmol/g respectively, p<0.05). The ischemia group presented a statistically significant increase in urinary TBARS when compared to the control group (281 nmol/g vs. 98 nmol/g, respectively, p<0.05). The values of lipid peroxidation (TBARS) were reduced in the group treated with UT in comparison to the ischemia group (151 nmol/g vs. 281 nmol/g, respectively, p<0.05). The pretreatment with UT promoted a functional protection, which may be related to the antioxidant activities of the phytotherapic agent (Vattimo and da Silva, 2011).
Antibacterial and antifungal properties
Although Uncaria tomentosa is not used extensively to treat infections in traditional medicine, recently some in vitro reports evaluating antibacterial and antifungal activities were published. Both extractsof the bark (80% ethanolic, aqueous, methanolic, dichlormethanic) and compounds (isopteropodine, arthocamin A, 5'-hydroxycudraflavone A, dihydrocudraflavone B) were tested, and in the case of some bacterial (B. cereus, B. subtilis, Enterococcus faecalis, Staph. aureus, Staph. epidermidis, E. coli, M. flavus, Strep. Mutans, Klebsiella pneumoniae) and fungal strains (effective against Candida albicans in one out of three study) moderate effects was observed (White et al. 2011; Kloucek et al. 2005; García et al. 2005).
Antiviral effect
The data on the antiviral effects of Uncaria tomentosa is very limited. In two in vitro studies, the hydroalcoholic extracts of the stem bark exhibited antiherpetic activity (Herpes simplex virus type 1, HSV-1), by inhibiting the attachment of HSV-1; and significantly decreased Dengue virus-2-Ag in monocytes as well. Interestingly, the oxindole alkaloid purified fraction and quinovic acid glycosides purified fraction did not present activity against HSV1, yet the alkaloidal fraction was more effective than the extract in the case of DENV infection (Reis et al. 2008; Caon et al. 2014). Moreover_the antiviral activity against Vesicular stomatitis virus was evident for six quinovic acid glycosides, isolated from Uncaria tomentosa (Aquino et al. 1989).
Alzheimer's disease In vitro
Unknown part
A proprietary extract of the root or the inner bark of Uncaria tomentosa (PE) inhibited the formation of both type II diabetes and Alzheimer's disease amyloidosis in vitro, as measured by thioflavin T fluorometry assay. Dose-dependent inhibition of p-amyloid fibril growth and formation was shown when the extract was found also to inhibit p-amyloid-p-amyloid interactions in solid phase binding assay and exhibited a dose-dependent amyloid-dissolving activity against performed Alzheimer's disease amyloid fibrils, with low doses dissolving the fibrils by ~70% in 2 hours of incubation. Similarly, islet amyloid fibrils or islet amyloid polypeptide dissolved by more than 80% in the same time period from exposure to the extract (McKenna et al. 2002). In another study mitraphylline was shown to bind with p-amyloid 1-40 protein (Frqckowiak et al. 2006)
In vivo
Unknown part
It was shown, that a proprietary extract of the root or the inner bark of Uncaria tomentosa (PE) is a potent inhibitor of Ap fibrillogenesis. A modified animal model was used to determine the efficacy of PE on disruption of pre-deposited Ap 1-42 amyloid fibril deposits in brain. Adult Sprague-Dawley rats (n=9/group) were stereotaxically cannulated into the hippocampus and infused for three days with 62.5pM Ap 1-42 (25 pg total), followed by four days of no treatment. Then the animals were infused for seven days with either distilled water or PE at an Ap:PE ratio of 1:5. Animals infused with Ap 1-42 alone followed by distilled water, had Congo red scores of 1.78, whereas animals infused with Ap 1-42 followed later with PE had Congo red scores of 0.64. Therefore, a significant (p<0.01) 64% disruption/dissolution of pre-deposited Ap 1-42 amyloid fibrils was observed following infusion of PE in comparison to controls (Cummings et al. 2000).
An assay guided fractionation and HPLC were used to isolate, characterize and test water-soluble active ingredients within a proprietary extract of the root or the inner bark of Uncaria tomentosa (PE) that possess potent Ap fibrillogenesis inhibitory activity. The mixture of seven major water-soluble ingredients (7C) were purified and tested in various assays to determine their efficacy in comparison to PE and to major alkaloids present in Uncaria tomentosa. 7C was a more potent inhibitor of Ap fibrillogenesis than PE alone. In one study, incubation of PE with Ap 1-42 for 1 day (1:1 weight ratio) caused a 53.2% disruption of Ap fibrils, whereas 7C resulted in a significant 87.3% inhibition. In a rodent model 1-week co-infusion of PE+Ap 1-42 into hippocampus led to a 51.0% inhibition of Ap fibril deposition into brain, whereas 7C+Ap 1-42 resulted in a significant 89.2% inhibition. Amyloid inhibitory effects were not observed using purified alkaloids derived from Cat's claw indicating that 7C likely consists of unique non-alkaloid products (Snow et al. 2000).
A group of major water-soluble components isolated from Uncaria tomentosa (7C), caused a marked reduction of amyloid plaque burden in a transgenic animal model of Alzheimer's disease. Two groups (n=6 for saline-treated; n=5 for 7C treated) of 6-8 month old, plaque-producing transgenic mice were stereotaxically infused for 2 weeks (with osmotic pumps) into cortex with saline or 7C. Quantitative analysis of brain sections revealed that 7C caused a 48.4% reduction in % amyloid burden, a 78.3% reduction in amyloid plaque number, and a 15.3% reduction in plaque diameter (Snow et al. 2001).
In a rat model of Alzheimer's disease p-amyloid deposition, a proprietary extract of the root or the inner bark of Uncaria tomentosa (PE), administered by directing infusion into rat hippocampus caused a significant 74% inhibition of p-amyloid deposition (p<0.01) from a dose of 1 pl, and 87% inhibition from a dose of 10 pl, each applied for seven days. Following the treatment the cellular architecture of hippocampal brain sections showed no obvious adverse effects. According to the author these results indicate a potential use of the extract in the diet as a preventive measure against the deposition of amyloids as part of normal aging, and in Alzheimer's disease. In another study, the in vitro p-amyloid formation-inhibiting, growth-inhibiting, and performed p-amyloid-dissolving activity of cat's claw extract was markedly enhanced by the addition of a standardized Ginkgo biloba extract (McKenna et al. 2002)
Other CNS related activities In vitro
Mainly single compounds were tested in vitro for their CNS related activities (neuroprotection, Parkinson's disease). Neuroprotective activity was shown for isorhynchophylline, isocorynoxeine, hirsuteine and hirsutine against glutamate-induced cell-death (Shimada et al. 1999). Specific water-soluble components derived from Uncaria tomentosa, yielded in a previous study (Snow et al. 2000) inhibited apha-synuclein (using NAC-P) fibrillogenesis (Castillo et al. 2001). Additionally, rhynchophylline and isorhynchophylline were reported to be noncompetitive antagonists of the NMDA receptor, pteropodine and isopteropodine act as positive modulators of muscarinic M1 and 5-HT2 receptors, and corynantheine, dihydrocorynanthe, geissoschizine methyl ether were found to be partial agonists for 5-HT receptors (Kang et al. 2002a, 2002b, Kantani et al. 1985).
Two studies investigated the neuroprotective_antioxidant_effects of two commercially_available_aqueous extracts (AE, NAE). Both extracts had protective effect against 6-OHDA induced cell damage, AE could reduce the aggregation of a-synuclein (Shi et al. 2010, 2013)
In vivo
Unknown part
Bigliani et al. (2013) examined the effect of orally administered Uncaria tomentosa decoction (UTE, part not specified) during 7, 15, 30 and 90 days of treatment on the expression of anxiety, as expressed in the elevated plus maze test in male Albino Swiss mice. UTE revealed an anxiogenic effect in relation to the control group at 15 and 30 days, but it was reversed after 90 days of administration. Thus UTE have a transient anxiogenic effect.
Single substances
Mohamed et al. (2000) reported, that the total alkaloids of Uncaria tomentosa had a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain of mice (n = 18/group); the effect of total alkaloids is partly attributed to the oxindole alkaloids tested. Uncaria tomentosa (plant part not specified, powdered commercial product) was mixed with Ca(OH)2 and steamed for 5 hours, then extracted with hot toluene, concentrated and dissolved with ethyl acetate. Then it was shaken with sulfuric acid (2%), basified with NH4OH and the aqueous layer was extracted with chloroform to give the total alkaloid fraction (698 mg). This extract was used to yield the alkaloids
Uncarine E, Uncarine C, mitraphylline, isorhynchophylline and rhynchophylline. The total alkaloids (1020 mg/kg, i.p.), the single alkaloids (10-40 mg/kg, i.p.) as well as the muscarinic receptor agonist oxotremorine (0.01 mg/kg, i.p.) significantly attenuated the deficit in retention performance induced by the muscarinic receptor antagonist scopolamine. The effective doses of uncarine C and mitraphylline were larger than those of other alkaloid components. Uncarine E (20 mg/kg, i.p.) also blocked the impairment of passive avoidance performance caused by the nicotinic receptor antagonist CPP, but it failed to affect the deficit caused by the benzodiazepine receptor agonist diazepam. Rhinchophylline significantly reduced the mecamylamine-induced deficit in passive avoidance behaviour, but it failed to attenuate the effects of CPP and diazepam. Thus possible, that the glutamatergic systems are implicated in the anti-amnesic effect of Uncarine E.
Rhynchophylline (Rhy) reduced the spontaneous motor activity and enhanced the sedative and hypnotic effects of sodium pentobarbital in mice. 21 mice were divided into three groups: Group A (i.p. saline), Group B (i.p. sodium pentobarbital (SP), 35 mg/kg) and group C (i.p. SP 35 mg/kg and Rhy 10 mg/kg). The righting reflex was normal in group A, while all mice in groups B and C lost their reflex for 13 and 51 minutes, respectively (p<001). Another 28 mice were randomly divided into four groups and injected i.p. SP 20 mg/kg, SP plus Rhy 20 or 40 mg/kg, and only Rhy 40 mg/kg, respectively. In 2 hours the righting reflex was retained in all groups but in group C five out seven mice lost their reflex (p<001). 20 mg/kg i.p. Rhy (n = 10) caused a reduction in the number of motor activity (from 17 to 6 times/min, p<0.01), compared to control (saline, n = 10). Rhy in vivo (20 and 40 mg/kg) also modulated the neuro-transmitter metabolism: increased the 5-HT content in the hypothalamus and cortex, but reduced the DA concentrations in the cortex, amygdala, and spinal cord. Rhy in vitro (3 and 30 pM) promoted the release of endogenous DA from 4 brain regions. The release of 5-HT was increased in 2 brain regions and decreased in hypothalamus slice. However, Rhy inhibited the release of both 5-HT and DA evoked by high potassium (Shi et al. 1993).
A fraction of Uncaria tomentosa (speciophylline, uncarine F, mitraphylline, isomitraphylline, pteropodine, rhynchophylline, isorhynchophylline and isopteropodine, accounting for 95% of the sample) was used to characterize antinociceptive activity in chemical (acetic acid-induced abdominal writhing, formalin and capsaicin tests) and thermal (tail-flick and hot-plate tests) models of nociception in mice. Uncaria tomentosa (UT) fraction given by the i.p. route dose-dependently suppressed the behavioural response to the chemical stimuli (p<0.0001) in the models indicated, and increased latencies in the thermal stimuli models. The antinociception caused by UT fraction in the formalin test was significantly (p<0.0001) attenuated by i.p. treatment of mice with ketanserin (5-HT2 receptor antagonist), but was not affected by naltrexone, atropine), L-arginine, prazosin, yohimbine or reserpine. Together, these results indicate that UT fraction produces dose-related antinociception in several models of chemical and thermal pain through mechanisms that involve an interaction with 5-HT2 receptors (Jurgensen et al. 2005).
Sakakibara et al. showed that one of the alkaloids of Uncaria tomentosa possess sedative effect, tested in male ICR mice, Isorhynchophylline (100 mg/kg, p<0.05) significantly depressed total activity of locomotor activity in mice with and without exication, elicited with methamphetamine, measured by home cage activity apparatus. The investigators interpreted the observation as evidence of a central dopaminergic receptor antagonist activity (Sakakibara et al. 1999).
Oral administration of hirsuteine isolated from Uncaria Uncis cam Ramlus to mice at the doses of 50, 100, and 200 mg/kg inhibited the glutamate-induced convulsion in a dose-dependent manner. The effect of hirsutine, the dihydro derivative of hirsuteine, was less potent than hirsuteine. Isocorynoxeine showed no activity at a 100 mg/kg dose compared with control. Doses used were very high, unobtainable from the oral use of herbal extracts of Uncaria (Mimaki et al. 1997).
Endometriosis, effects on oestrogen, progesterone In vitro
Bark
The aqueous solution of the bark of Uncaria tomentosa (UT) was suggested to interact with distinct binding sites on the oestrogen receptor (ER). A significant reduction of [3H] oestradiol-specific binding with UT (10 and 20 pg) was detected following 1 h of exposure to the drug. When the cytosol was pretreated with UT or tamoxifen (TMX) before addition of [3H] oestradiol, specific binding was reduced by 47.2% and 69.3%, respectively. Increasing concentrations of [3H] oestradiol were incubated with cytosol of hormonedependent tumours in the presence or absence of fixed concentrations (10 and 20 pg) of UT. UT was clearly a noncompetitive inhibitor of [3H] oestradiol binding (Salazar and Jayme 1998).
In vivo
Unknown part
Nogueira Neto et al. (2011a) reported changes in rats (n=29) with experimental endometriosis treated with Uncaria tomentosa extract which were compatible with contraception. UT group received gavage with 32 mg/ml of Uncaria tomentosa aqueous extract (commercial product), 1 ml administered daily and the placebo group received 1 ml of saline 0.9% per day, during for 14 days (both groups); the leuprolide group received leuprolide acetate 1 mg/kg body weight applied single subcutaneous dose. In the 15th day of UT group presented nine samples (90%) with immature ovarian follicles, whereas the placebo group did not present any case and in the leuprolide group there were eight rats (88%) with the same change. The placebo group showed mature corpus luteum in all animals, occurring less frequent in UT (10%) and leuprolide (22%) groups. The uterine epithelium showed weak proliferative in nine (90%) samples of the UT group, in two (20%) animals in the placebo group and seven (77.8%) rats in the leuprolide group. The extract was prepared by grinding 160 tablets of 100 mg in a porcelain mortar dissolved in 500 ml 0.9% NaCl.
Nogueira Neto et al. (2011b) also reported that Uncaria tomentosa extract appears to be effective in endometriosis. Wistar rats (n=24) with experimental endometriosis were divided into two groups. Group UT received Uncaria tomentosa extract orally (32 mg/day), and group C (control group) received a 0.9% sodium chloride solution orally (1 ml/100 g of body weight/day). Both groups were treated with gavage for 14 days. There was a significant increase (p=0.01) between the initial and final average volumes of the autotransplants (endometriosis implant) in the control group, while the treatment with Uncaria tomentosa caused a marked reduction in the growth over time (p=0.009). Histologically, in the experimental group (n = 10) six rats had a well-preserved epithelial layer, three had mildly preserved epithelium, and one had poorly preserved epithelium. The control group (n = 12) presented seven cases (58.3%) of well-preserved epithelial cells and five cases (41.7%) of mildly preserved epithelial cells.
It was reported that in human granulosa cells obtained from patients undergoing in vitro fertilization, Uncaria tomentosa extracts (part not specified) at amounts equivalent to dietary doses, dose-dependently (100 pg/ml to 10 pg/ml) caused statistically significant inhibition of progesterone production. Administered orally to sexually mature female rats for eight weeks, a low dose of cat's claw extract (2 mg/day), equivalent to the manufacturer's suggested daily dosage, produced no significant changes in profiles of electrolytes, kidney, liver or glucose. For six weeks no changes were noticed in circulating hormone levels compared to the untreated controls. By the eighth week however, serum progesterone and oestradiol levels were reduced by 68% and 71%, respectively, in both the high dose group (20 mg/day) and a low dose group (2 mg/day) (McKenna et al. 2002).
Cardiovascular effects
Single substances In vitro
Mainly single substances were tested in vitro for cardiovascular effects. Isorhynchophylline inhibited the automaticity and contractile force of isolated guinea pig atrium, rhynchophylline_caused concentration dependent inhibition of platelet aggregation induced by arachidonic acid, collagen and ADP and hirsutine exhibited calcium channel blocking activity mainly through competitive inhibition of the voltage dependent calcium influx Less potently rhynchophylline and isorhynchophylline were found to inhibit the voltage dependent calcium channels as well (Chen et al. 1992; Yano et al. 1991;. Zhang et al. 1987; Yamahara et al. 1987; Zhu et al. 1995).
In vivo
In several performed in vivo studies rhynchophylline (Rhy) and isorhynchophylline (iRhy) were investigated. Rhy was showed to have a significant inhibition of venous thrombosis in rats, it prevented both ADP and collagen plus adrenaline induced thrombotic death. Rhy also reduced the mean arterial pressure, heart rate, renal blood flow and coronary blood flow in dogs (Chen et al. 1992; Jin et al.
1991; Shi et al. 1992). IRhy was able to reduce the mean arterial flow as well, but not the renal blood flow. It lowered the systolic arterial blood pressure, diastolic arterial blood pressure and heart rate in normo-, and hypertensive rats and dogs (Shi et al. 1989; Shi et al. 1992). In a further study iRhy was inhibited the calcium currents in rats and guinea pigs (Gan et al. 2011)
Other properties
Single substance In vitro
Quinic acid demonstrated protection in Caenorhabidits elegans, improved worm survival under stress Zhang et al. (2012) Ranilla et al. (2010) investigated several Latin American herbs, spices and medicinal plants, and amongst them the decoction of the bark of Uncaria tomentosa with a (46 ± 1 mg/g dw) total phenolic content had the highest a-glucosidase (>80%) and a-amylase (75% at 25 mg of dried sample) inhibition. A significant DPPH radical inhibition (71%) was also found.
No studies are available.
3.1.4. Pharmacodynamic interactions
Aqueous preparations of a commercial product of Uncaria tomentosa (UT) extract was reported to have an effect on the biodistribution of a radiopharmaceutical, the radiobiocomplex sodium pertechnetate (Na99mTcO4) in rats by Moreno et al. (2007). Male Wistar rats were treated with UT (32 mg/ml n=5) or 0.9% NaCl solution (control, n= 5) for 7 days. After this period, Na99mTcO4 (3.7 MBq, 0.3 ml) was injected through the ocular plexus and after 10 mins the rats were killed. There were significant (p<0.05) alterations in Na99mTcO4 uptake between the control and the treatment group in the heart (0.57 vs. 0.39% ATI/organ, p<0.05), in the pancreas (0.07 to 0.19% ATI/g, p<0.05) and in the muscle (0.07 to 0.18% ATI/g p<0.05) after treatment with this extract. Thus caution is advisable in the nuclear medicine examination when the patient is using this herb.
Quilez et al. (2012) investigated changes in the pharmacological effect of diazepam (2 mg/kg) on the CNS when administered together with a commercial product of Uncaria tomentosa (UT)(7.14 mg/kg and 3.54 mg/kg). UT, at both doses, enhanced the action of diazepam on spontaneous motor activity (p<0.001) and, at the lower dose, exploratory ability. UT showed only a slight decrease (19.7%) on muscular relaxation effect of the benzodiazepine.
In the ACCF (American College of Cardiology Foundation) Complementary Medicine Expert Consensus Document (Vogel, 2005) there is one mention about the potential interaction between Uncaria tomentosa and cardiovascular drugs: Increases effects of anticoagulants and antihypertensives; can interfere with protein-based drugs and chemotherapy (no reference).
3.1.5. Conclusions
The pharmacological data is quite diverse on U. tomentosa, concerning the used extracts and biological properties tested. The main concern is, that most of the studies indicate 'bark' for the drug used, without specifying whether it is obtained from the root or the stem. From the 35 studies in the primary pharmacodynamics section 19 studies mentioned just 'bark', 7 studies didn't state the part used and only 5 and 3 studies specified stem bark and root bark, respectively. A number of investigations used commercial products, without adequate information on the contained drug/extract. Thus, it is difficult to draw clear conclusion from the data.
In the in vivo studies, the administered dose ranged between 5 and 2000 mg extract/kg bodyweight, most frequently it ranged from 50-500 mg extract/kg bodyweight.
All of the extracts comprised by the preclinical data were reported to have pleiotropic antiinflammatory or immunmodulatory activity.
Uncaria tomentosa was reported to have moderate antibacterial and antioxidant effect as well. The antioxidant activity most likely contributes to the anti-inflammatory activity. Several studies used the aqueous extracts for investigation, but alkaloid rich fractions are frequently tested as well.
3.2. Overview of available pharmacokinetic data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof
There is one available study about the metabolic fate of an oxindole alkaloid, isorhynchophylline (ISOR), a compound from U. tomentosa. After oral administration of ISOR to rats (37.5 mg/kg) ISOR was identified in plasma, bile, urine and faeces. 11-Hydroxyisorhynchophylline 11-O-p-D-glucuronide (MI1) and 10-hydroxyisorhynchophylline 10-O-p-D-glucuronide (MI2) were found in bile, and free 11-hydroxyisorhynchophylline (MI3) and 10-hydroxyisorhynchophylline (MI4) were found in urine and faeces. Within 24 hrs, 71.6% of ISOR was found in the faeces and 13.8% in the urine. Monitoring by LC-MS showed that 8.5% of ISOR was metabolized to MI3 and MI4 in a ratio of ca. 1:1. Specific inhibition of CYP isoenzymes indicated that CYP2D, CYP1A1/2 and CYP2C participate in ISOR hydroxylation.
Pharmacokinetic interactions
The inhibitory activity of the decoction of the bark of Uncaria tomentosa (conc.: 1.56-100 mg/ml) for cytochrom P450 3A4 was measured in vitro. The IC50 of the decoction was 46.8 mg/ml (Budzinski et al. 2008). Yet, in another study, Uncaria tomentosa tincture was found to be an inhibitor, it gave inhibition readings>100% (saturation of the enzyme) for relative concentrations >3.13% (IC50 :0.79 relative concentration). However, the strength of the inhibition is a questionably significant effect compared to typical CYP 3A4 inhibitors (Budzinski, 2000).
In another study, the inhibitory effects of alcoholic extract of Uncaria tomentosa on CYP2D6, CYP2C9, and CYP2C19 were minor (in order of decreasing potency) (Foster et al. 2003).
3.3. Overview of available toxicological data regarding the herbal substance(s)/herbal preparation(s) and constituents thereof
3.3.1. Single dose toxicity
The oral single dose LD50 could not be calculated because at the maximum concentration of the various Uncaria tomentosa preparations, no lethal effect had been observed. However, it was concluded that the LD50 of a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE) was greater than 8 g/kg since no single death in the treatment groups had been observed at this dose or below it. The LD50 of two other preparations, a bark powder (commercial product) and a water:ethanol extract (4% alkaloids) of Uncaria tomentosa were observed to be greater than 2 and 5 g/kg, respectively. The MTD for AE was also greater than 8 g/kg, while it was greater than 2 g/kg for the bark powder and between 2.5 and 5.0 g/kg for the water:ethanol extract (McKenna et al. 2002).
Keplinger et al. (1999) performed an acute oral toxicity study in mice. Signs of reaction to treatment, observed shortly after dosing, consisted of lethargy and piloerection. Death of two out of ten mice occurred within 4 hrs of treatment. Autopsy revealed haemorrhage of the stomach and intestines, and pallor of the liver and spleen. Recovery of survivors, as judged by external appearance and behaviour, was apparently complete within five days of treatment. This observation was substantiated by normal bodyweight gains, compared with controls and normal autopsy findings. The acute median lethal dose (LD50) to mice of freeze-dried aqueous root extract (containing 35 mg total pentacyclic oxindole alkaloids per g; 6% yield from crude drug) was found to be greater than 16 g/kg bodyweight. Consistent with these results, additional testing with mice using the cat's claw aqueous extract at a dose of 5 g/kg bw and intraperitoneal administration of a dose of 2 g/kg bw reported no apparent toxicity (Valerio and Gonzales, 2005).
A study on cat's claw capsules (U. tomentosa, plant part not specified) were carried out on mice. Acute toxicity study was undertaken by treating mice with a single dose (150 mg/kg body) of cat's claw capsules. Haematological studies revealed a significant reduction in WBC levels (p<0.05) compared to control. Biochemical studies showed significant rise in the levels of AST and ALT. Changes in key hepatic enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatise, enzyme MB of creatinine kinase, glucose, urea and creatinine) and histopatological modifications (heart, liver, kidneys and pancreas) were not observed in mice treated with the drug. Thus it was concluded that Uncaria tomentosa has low toxicity (Ibrahim et al. 2009).
3.3.2. Repeat dose toxicity
Sheng et al. (2000a) did not find acute toxic signs or symptoms in an acute toxicity study, performed on rats in the repeated daily supplement experiments. All groups of the rats gained weight during supplementation while no body weight differences were found among the groups at any time point for a commercially available filtered aqueous extract from the bark of Uncaria tomentosa (AE)
at 40 and 80 mg/kg for 8 weeks and 160 mg/kg for 4 weeks. While no evidence of toxicity was
observed with AE, there was a statistically significant reduction in body weight (P<0.05) and food consumption (P<0.01) in rats receiving the same dose of another water extract (Commercial extract A, water soluble 4:1 Uncaria tomentosa extract, but not purified from high molecular weight toxic components). The histopathological examination revealed no increased pathological changes such as necrosis, fibrosis, increased mitotic activity and proliferation when compared with control rats.
Keplinger et al. (1999) performed a 4-week oral toxicity study in rats. The aqueous acid extract (containing 7.5 mg total oxindole alkaloids per g and 300 mg sodium chloride per g as remnant from neutralization; 10% yield from crude drug) was used in the 4-week study. A daily dose of 1000 mg/kg per day for 28 days caused a slight but statistically significant increase in percentage of lymphocytes and decrease in percentage of neutrophil granulocytes and, in addition, an increase of the relative weight of the kidneys in rats of both sexes. Since the histology of the kidneys was normal, there is no explanation for this finding. There were no differences between the test group and the control group with all other respects. There were no mortalities during the study.
A study on cat's claw capsules (U. tomentosa, drug not specified) were carried out on mice. Subacute and subchronic toxicity studies were undertaken by treating mice with 50 mg/kg body weight administered orally each other day for 7 days for subacute and an oral dose of 10 mg/kg body weight of the drug daily for 90 days for subchronic toxicity studies. Biochemical studies showed significant rise in the levels of AST and ALT in subacute treated mice. Hematological studies on the chronically treated mice revealed no significant difference compared to control, except a mild increase in platelet count. Changes in key hepatic enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatise, enzyme MB of creatinine kinase, glucose, urea and creatinine) and histopatological modifications (heart, liver, kidneys and pancreas) were not observed in mice treated with the drug. Thus it was concluded that Uncaria tomentosa has low toxicity (Ibrahim et al. 2009).
3.3.3. Genotoxicity
Genotoxicity and antigenotoxicity
The aqueous (boiling water) extract of Uncaria tomentosa (drug not specified) was assayed for antigenotoxicity using the Somatic Mutation And Recombination Test (SMART) in Drosophila melanogaster. Hydrogen peroxide was used as an oxidative genotoxicant to test the anti-genotoxic potency. The extract did not show a significant genotoxicity at concentrations tested (0.5-1.9 mg/ml) (Romero-Jimenez et al. 2005).
Two alkaloids, - which can be found in Uncaria tomentosa - uncarine C and uncarine F, were shown to have week but reproducible cytotoxicity to several cell lines and activity in RS322 and RS321 yeast assays. An extract or compound which inhibits these yeast mutants to a greater extent than it inhibits the wild type of strain RS188N is thus expected to contain agents which induce DNA damage, and an extract or compound which shows differential inhibition of the RS321 strain as opposed to the RS322 strain is also presumed to act by inhibition of topoisomerase II. Both uncarine C and F showed weak activity (ICi2: 140 and 120 gg/ml, respectively) against the RS321 and RS322 yeast strains. For comparison: the known active agent, streptonigrin has an ICi2 value of 0.65 gg/ml against the RS321 strain, and 0.4 gg/ml against the RS322 strain while the topoisomerase I inhibitor camptothecin had IC12 values of >20 and 0.6 gg/ml against the same two strains (Lee et al. 1999).
The mutagenic potential of extracts (petroleum ether, chloroform, chloroform:methanol 9:1, methanol, water) and chromatographic fractions (Sephadex LH-20 of chloroform/methanol extract) of Uncaria tomentosa bark was tested at 10, 50, 75, and 100 gg/plate in Salmonella/mammalian microsome TA 98, TA 100, TA 1535, TA 1537 and TA 1538 strains of Salmonella typhimurium, with and without metabolic activation from Aroclor 154-induced rat liver homogenate. Cat's claw did not show evidence of mutagenicity with or without metabolic activation (Rizzi et al. 1993).
3.3.4. Carcinogenicity
3.3.5. Reproductive and developmental toxicity
10 g of the bark of Uncaria tomentosa was extracted with 50 ml of water for 12 hrs in 37°C and its effect were evaluated by application of the chicken embryo model. Among three groups of eggs (n=360), two were injected with different doses of the extract (0.0492 mg/200 pl for group 1 and 0.492 mg/200 pl for group 2). To the third control group 200 pl of physiological salt was applied. Significant differences with ANOVA were observed for MCV (P=0.002), MCHC (P=0.00001) and MCH (P=0.02). Administration disturbed embryogenesis in both cases. In the first group it increased the mean corpuscular volume of erythrocytes and decreased the mean corpuscular haemoglobin concentration. In the second it decreased both mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration (Pilarski et al. 2009).
It was reported that in human granulosa cells, obtained from patients undergoing in vitro fertilization, Uncaria tomentosa extracts (presumably stem bark) at amounts equivalent to dietary doses, dose-dependently (100 pg/ml to 10 pg/ml) caused statistically significant inhibition of progesterone production. Administered orally to sexually mature female rats for eight weeks, a low dose of cat's claw extract (2 mg/day), equivalent to the manufacturer's suggested daily dosage, produced no significant changes in profiles of electrolytes, kidney, liver or glucose. For six weeks no changes were noticed in circulating hormone levels compared to the untreated controls. By the eighth week however, serum progesterone and oestradiol levels were reduced by 68% and 71%, respectively, in both the high dose group (20 mg/day) and a low dose group (2 mg/day). It was concluded that these results indicate, that Uncaria tomentosa has the potential to selectively alter ovarian hormone production and therefore should be used with care. In a patent, mice administered an aqueous extract of the root in their drinking water (6.25 mg/kg and 25 mg/kg, per os) showed no signs of toxicity; however, the female mice, when caged with male mice produced no offspring (McKenna et al. 2002).
3.3.6. Local tolerance
3.3.7. Other special studies
In vitro toxicity studies
An erythrocyte suspension was incubated with four extracts (5-500 pg/ml) of U. tomentosa: ethanol extract of the bark, leaves, aqueous extract of the bark and leaves were incubated with erythrocytes. One gram of the raw material (bark and leaves) was extracted with 10 ml of water or 96% ethanol at 37 °C for 8 hrs, then centrifuged and dried. At these conditions they recovered about 111 mg extract/g of bark and about 158 mg/g of leaves. Extraction with 96% ethanol resulted 123 mg extract/g of bark and 158 mg extract/g of leaves. It was found that no extract of Uncaria tomentosa induced haemolysis. However, a slight, statistically significant decrease in haemoglobin outflow was observed in the erythrocytes incubated with ethanol extracts from the concentration of 100 pg/ml, and the cells incubated with aqueous extracts from the concentration of 250 pg/ml (Bors et al. 2011).
Bors