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Cat's
Claw |
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Cat's Claw (English) Uncaria tomentosa
(Botanical) Rubiaceae (Plant Family)
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Overview |
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Used in the rainforest for over 2,000 years by indigenous tribes, cat's claw
has anti-inflammatory, cytotoxic, and antiviral properties. Traditional
indications include sexually-transmitted diseases, arthritis, gastritis,
contraception (a reported three-year hiatus in fertility), and cancer. Purported
attributes drew attention from the Westernized world: in 1997, it was on the
top-10 list of herb sales in natural food stores in the U.S.
In 1989 the methods for extracting the immune-stimulant oxindole alkaloid
constituents in cat's claw root bark were patented. Primarily the work of
Hildebert Wagner at the Institute for Pharmaceutical Biology, Munich, and Klaus
Keplinger at Innsbruck University, studies revealed that cat's claw was
antiviral in the feline crown virus, the lamb Maed visna virus, human
herpesvirus, and effective against neurobronchitis and allergies. Injections of
the alkaloids raised T-4 lymphocyte counts, and cat's claw preparations
stimulated enhanced phagocytosis, and reduced both the progression of the AIDS
virus and side effects of the therapies used to treat AIDS patients. It also
reduced the side effects of radiation in cancer therapy.
Today, very few studies of cat's claw in humans exist. International research
institutes and manufacturing companies currently conduct studies on the
pharmacokinetics and mechanisms of action for cat's claw and its isolated
constituents. Results of placebo-controlled, phase II trials using cat's claw in
the treatment of patients with HIV and rheumatoid arthritis have not yet been
published. |
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Macro Description |
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Cat's claw is a climbing shrub with woody, thick vines. Growing as high as
100 feet in the Amazon rainforest and tropical countries in South America and
Central America, the vines have curved, claw-like thorns where leaves meet the
stem. Inside the stem is a bitter-tasting, water-like liquid reportedly drunk as
refreshment to relieve fatigue.
Two Uncaria species are called cat's claw, which are differentiated by their
flowers: U. tomentosa has yellow-white flowers; U. guianensis,
reddish-orange flowers. Phytochemically, U. guianensis contains
tetracyclic oxindoles not found in the therapeutically superior U. tomentosa.
The root bark is the source of medicine. Because harvesting the root destroys
the plant, the inner bark of the vine may be used as well. It is unclear whether
this is an equal substitute. |
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Part Used/Pharmaceutical
Designations |
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- Roots
- Bark
- Vine
- Inner bark
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Constituents/Composition |
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- Pentacyclic oxindole alkaloids (alloisopteropodine, alloteropdine,
isomitraphylline, isorhynchophylline, mitraphylline, rhynchophylline)
- Tannins (epicatechin and procyanidins)
- Quinovic acid glycosides
- Polyhydroxylated triterpenes
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Commercial
Preparations |
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Crude bark as tea or in tablets; aqueous-alcohol extracts standardized to
oxindole alkaloids, in liquid form or dried encapsulations |
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Medicinal
Uses/Indications |
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Traditional: anti-inflammatory, antiviral; used for arthritis, dysentery,
gastric ulcer, diabetes, cancer, menstrual disorders, convalescence, general
debility, gonorrhea, cirrhosis
Conditions: acne, asthma, arthritis, bone pain, cancer, depression, fungus,
fistulas, gastritis, gastric ulcer, hemorrhoids, herpes, inflammation of the
urinary tract, immune system disorders, menstrual irregularities, neuralgias,
rheumatism, shingles, wounds
Clinical applications (pursuant to future research): disorders of the
digestive tract; hypertension, and heart disease; HIV, AIDS, and cancers; drug
or radiation side effects; allergy, herpes, shingles, arthritis, tumors, cysts,
and to treat reduced physical and mental stamina |
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Pharmacology |
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Cat's claw has immune-stimulant, anti-inflammatory, and antimutagenic
actions.
Pentacyclic oxindole alkaloids stimulate phagocytosis and activate
T-lymphocytes and macrophages. Quinovic acid glycosides act as an antiviral
against rhinovirus type 1B and vesicular stomatitis virus. The oxindoles
suppress growth in tumor cell lines; five are antileukemic. Root and bark
extracts are antitumor.
In one study, mutagenic metabolites normally formed in the urine of smokers
were absent following dosing with cat's claw.
Anti-inflammatory actions may be due to the quinovic acid glycosides, which
demonstrate 46% to 69% inhibition of inflammation in vivo and in vitro. The
sterols beta-sitosterol, stigmasterol, and campesterol are moderately
anti-inflammatory.
Cat's claw may reduce side effects from chemotherapy, including hair loss,
weight loss, nausea, secondary infections, and skin problems. Cat's claw may
also have cardiovascular effects: Oxindole alkaloids rhynchophylline, hirsutime,
and mitraphylline are hypotensive and vasodilative.
Rhynchophylline inhibits platelet aggregation, prevents blood clots, relaxes
endothelial blood vessels, dilates peripheral blood vessels, lowers heart rate,
and lowers blood cholesterol. |
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Dosage Ranges and Duration of
Administration |
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Traditional use for treating conditions listed above:
- 3 to 25 g dried bark as tea or tablets
- 20 to 30 g finely chopped bark, boiled in a liter of water for 20 to
30 minutes. Take liquid tid.
Conventional use for treating mild stomach pains, sore throats, and colds;
immune function; and minor injuries:
- Tea: 1 g root bark to 250 ml water, boil for 10 to 15 minutes, cool,
and strain. Drink 1 cup, tid.
- Tincture: 1 to 2 ml bid to tid.
- Dry, encapsulated, standardized extract: 20 to 60 mg
daily
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Side
Effects/Toxicology |
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Nontoxic in traditional lore. Loose stools or diarrhea have been noted. The
American Herbal Products Association (AHPA) safety rating: class 4 (indicating
lack of data). Tannin content cautionary. More research could change this safety
rating. |
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Warnings/Contraindications/Precautions |
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At this time, cat's claw should not be used in skin graft or organ transplant
patients. Its use in patients with HIV, AIDS, and tuberculosis is controversial.
Not for children under 3, or during pregnancy or breast-feeding.
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Interactions |
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Cat's claw extract inhibited the cytochrome P450 enzyme system in vitro
(Budzinski et al. 2000). Specific interactions between this herb and
conventional medications metabolized via the P450 system have not been
documented to date. The National Center for Complementary and Alternative
Medicine (NCCAM) is funding research to further evaluate interactions between
botanicals and drugs (Council for Responsible Nutrition 2000).
Indomethacin
In rat studies, cat's claw tea given orally decreased indomethacin-induced
enteritis (Sandoval-Chacon et al. 1998). Cat's claw may protect patients from
gastrointestinal damage associated with nonsteroidal anti-inflammatory
drugs. |
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Regulatory and Compendial
Status |
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U.S. FDA: Dietary supplement.
German Commission E: Not included in phytomedicinal
monographs. |
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References |
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Aquino R, De Simone F, Pizza C, Conti C, Stein ML. Plant metabolites.
Structure and in vitro activity of quinovic acid glycosides from Uncaria
tomentosa and Guettarda platypoda. J Nat Prod.
1989;52:679–685.
Aquino R, De Simone F, Vincieri FF, Pizza C, Gacs-Baitz C. New
polyhydroxylated triterpenes from Uncaria tomentosa. J Nat Prod.
1990;53:559-564.
Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic
Guide to Herbal Medicines. Boston, Mass: Integrative Medicine
Communications; 1998.
Blumenthal M. Herbal update: Una de gato (cat's claw): Rainforest herb gets
scientific and industry attention. Whole Foods Magazine. 1995:62-68,
78.
Blumenthal M, Riggins C. Popular Herbs in the U.S. Market: Therapeutic
Monographs. Austin, Tex: The American Botanical Council; 1997.
Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of
human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and
tinctures. Phytomed. 2000;7(4):273-282.
Council for Responsible Nutrition. NIH Reacts to Herbal Concerns. Released
September 7, 2000. Available at http://www.crnusa.org/shellnr090700.html.
Accessed November 17, 2000.
Davis BW. A "new" world class herb for applied kinesiology practice:
Uncaria tomentosa—a.k.a. Una de Gato (UDG).
Collected Papers of the International College of Applied Kinesiology. 1992.
de Matta SM, Monache FD, Ferrari F, Marini-Bettolo GB. Alkaloids and
procyanidine of an Uncaria sp. from Peru. Farmaco [Sci].
1976;31:527-535.
Keplinger K, et al. Uncaria tomentosa (Willd.)
DC.—ethnomedicinal use and new pharmacological,
toxicological and botanical results. J Ethnopharmacol. 1999;64:23-34.
Lemaire I, et al. Stimulation of interleukin-1 and -6 production in alveolar
macrophages by the neotropical liana, Uncaria tomentosa. J Ethnopharmacol.
1999;64:109-115.
Lininger S, Wright J, Austin S, Brown D, Gaby A. The Natural Pharmacy.
Rocklin, Calif: Prima Health; 1998:246.
McGuffin M, Hobbs C, Upton R, Goldberg A. American Herbal Products
Association's Botanical Safety Handbook. Boca Raton, Fla: CRC Press;
1997.
Ozaki Y. Pharmacological studies of indole alkaloids obtained from domestic
plants, Uncaria rhynchophylla Miq. And Amsonia elliptica Roem. et Schult.
Nippon Yakurigaku Zasshi. 1989;94:17-26.
Sandoval-Chacon M, et al. Anti-inflammatory actions of cat's claw: the role
of NF-kappaB. Aliment Pharmacol Ther. 1998;12:1279-1289.
Senatore A, Cataldo A, Iaccarino FP, Elberti MG. Phytochemical and biological
study of Uncaria tomentosa. Boll Soc Ital Biol Sper. 1989;65:517-520.
Sheng Y, et al. Induction of apoptosis and inhibition of proliferation in
human tumor cells treated with extracts of Uncaria tomentosa. Anticancer Res.
1998;18:3363-3368.
Steinberg PN. Cat's claw: medicinal properties of this Amazon vine.
Nutrition Science News. 1995.
Wurm M, et al. Pentacyclic oxindole alkaloids from Uncaria tomentosa
induce human endothelial cells to release a
lymphocyte-proliferation-regulating factor. Planta Med.
1998;64:701-704.
Yepez AM, de Ugaz OL, Alvarez CM, De Feo V, Aquino R, De Simone F, Pizza C.
Quinovic acid glycosides from Uncaria guianensis. Phytochemistry.
1991;30:1635-1637. |
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Copyright © 2000 Integrative Medicine
Communications This publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
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including any injury and/or damage to any person or property as a matter of
product liability, negligence, or otherwise. No warranty, expressed or implied,
is made in regard to the contents of this material. No claims or endorsements
are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
for changes and new information regarding dosage, precautions, warnings,
interactions, and contraindications before administering any drug, herb, or
supplement discussed herein. | |