(Willd. ex Schult.) DC.
Uncaria tomentosa is a woody vine found in the tropical jungles of South and Central America. In several languages it is known as cat's claw because of its claw-shaped thorns (English cat's claw, although that name is also used for other plants; Spanish uña de gato).
The plant is used in herbalism for a variety of ailments.
Uncaria tomentosa is a liana deriving its name from hook-like thorns that resemble the claws of a cat. U. tomentosa can grow to a length of up to 30 m (100 ft), climbing by means of these thorns. The leaves are elliptic with a smooth edge, and grow in opposing pairs. Cat's claw is indigenous to the Amazon rainforest, with its habitat being restricted primarily to the tropical areas of South and Central America.
There are two species of cat's claw commonly used in North America and Europe, Uncaria tomentosa and Uncaria guianensis, each having different properties and uses. The two are frequently confused but U. tomentosa is the more heavily researched for medicinal use and immune modulation, while U. guianensis may be more useful for osteoarthritis. U. tomentosa is further divided into two chemotypes with different properties and active compounds, a fact ignored by most manufacturers that can have significant implications on both its use as an alternative medicine and in clinical trials to prove or disprove its efficacy. Another species, Uncaria rhynchophylla, has usage in Chinese medicine, and several unrelated species bear the same nickname.
Cat's claw is often promoted for its health benefits and has become a popular herbal supplement. Although there are chemical analysis of the components, in vitro and in vivo in mice studies that support it's benefits, as of 2018 there is no published research on humans that supports major breakthroughs in disease treatments.
Some studies on its effect on rheumatoid arthritis reported modest results, which need confirmation in standardized trials.
The indigenous peoples of South America have used cat's claw for centuries in the belief it is a treatment for various disorders.
Individuals allergic to plants in the family Rubiaceae and different species of Uncaria may be more likely to have allergic reactions to cat's claw. Reactions can include itching, rash and allergic inflammation of the kidneys. In one case study, kidney failure occurred in a patient with Lupus erythematosus. The patient's kidney failure improved after stopping the herbal remedy.
There are other plants which are known as cat's claw (or uña de gato) in Mexico and Latin America; however, they are entirely different plant species, belonging to neither the genus Uncaria, nor to the family Rubiaceae. Some of the Mexican uña de gato species are known to have toxic properties.
- "Uncaria tomentosa". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2008-03-01.
- Gattuso M, di Sapio O, Gattuso S, Pereyra LE (2004). "Morphoanatomical Studies of Uncaria tomentosa and Uncaria guianensis Bark and Leaves". Phytomedicine. 11 (2–3): 213–223. doi:10.1078/0944-7113-00315. PMID 15070175.
- Piscoya J, Rodriguez Z, Bustamante SA, Okuhama NN, Miller MJ, Sandoval M (2001). "Efficacy and Safety of Freeze-Dried Cat's Claw in Osteoarthritis of the Knee: Mechanisms of Action of the Species Uncaria guianensis". Inflammation Research. 50 (9): 442–448. doi:10.1007/PL00000268. PMID 11603848.
- Keplinger K, Laus G, Wurm M, Dierich MP, Teppner H (1999). "Uncaria tomentosa (Willd.) DC. — Ethnomedicinal Use and New Pharmacological, Toxicological and Botanical Results" (PDF). Journal of Ethnopharmacology. 64 (1): 23–34. doi:10.1016/S0378-8741(98)00096-8. PMID 10075119.
- Tyler VE (Sep–Oct 1997). "An herb to forget — Cat's Claw — Uncaria tomentosa". Nutrition Forum. 14 (5).
- Navarro Hoyos M; et al. (2015). "Phenolic Assesment of Uncaria tomentosa L. (Cat's Claw): Leaves, Stem, Bark and Wood Extracts". Molecules. 20 (12): 22703–22717.
- Ernst E (2004). "Complementary and Alternative Therapies for Rheumatoid Arthritis". International Journal of Advances in Rheumatology. 2 (1): 22–25.
- "Cat's Claw". American Cancer Society. 12 September 2011. Retrieved 23 August 2013.
- "Intelihealth article discussing uses and dangers of Cat's Claw". Intelihealth.com. 2005-07-14. Retrieved 2012-09-15.
- Hilepo JN, Bellucci AG, Mossey RT (1977). "Acute Renal Failure Caused by 'Cat's Claw' Herbal Remedy in a Patient with Systemic Lupus Erythematosus" (PDF). Nephron. 77 (3): 361. doi:10.1159/000190304. PMID 9375835.
- M.D. Anderson - Detailed Scientific Review of Cat's Claw
- Dietrich, Fabrícia; Kaiser, Samuel; Rockenbach, Liliana; Figueiro, Fabrício; Scussel Bergamin, Letícia; Monte da Cunha, Fernanda; Bueno Morrone, Fernanda; González Ortega, George; Maria Oliveira Battastini, Ana (May 2014). "Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line". Food and Chemical Toxicology. 67: 222–229. doi:10.1016/j.fct.2014.02.037.
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