Cat’s Claw


Cat’s claw is a vine native to South and Central American tropical rain forests and is so called because thorns on the vine resemble the claws of a cat.


Its Spanish name, uña de gato, may be used to refer to some 20 different plants that have similar sharp curving thorns, but Uncaria tomentosa and Uncaria guianensis are the varieties most recognized for their medicinal properties.

While there are some similarities between these two species, here in the United States, Uncaria tomentosa is the variety of cat’s claw that is used medicinally most often, has been researched the most and is the focus of this document. In general cat’s claw has traditionally been used for inflammatory conditions, gastrointestinal disorders, tumors and as a contraceptive. In Peru it was believed to be sacred to priests in the traditional medicine system of the Asháninka tribe for improving communication between body and spirit.[i]

Although the root of the vine may have higher amounts of many beneficial compounds, it is the bark of the vine that is used in today’s preparations of cat’s claw. Collecting the root endangers the survival of the species and is illegal in Peru. Many compounds in the bark of the cat’s claw plant have been isolated. It was once believed that the alkaloids, such as pentacyclic onxindole alkaloids (POAs) and tetracyclic oxindole acids (TOAs), were the most medicinally active. Many preparations still use POAs as their standardization marker[1]. But other compounds have been isolated, including procyanidins, sterols, catechins and tannins. Recent studies have suggested that the full benefit of cat’s claw comes from a combination of these compounds, not just the alkaloids.

Benefits of Cat’s Claw

Studies on the beneficial effects of cat’s claw have mainly focused on its ability to act as an antioxidant, to modulate inflammation, and to positively affect the immune system.

Antioxidant – Many studies have found the different compounds in cat’s claw to effectively moderate the process of oxidation in the body. Some oxidation is normal and even beneficial, but when too much occurs, the tissues of the body become damaged, leading to undesirable inflammation and alterations in DNA. Antioxidants, like those found in cat’s claw, can help to stop this destructive process and thus protect the tissues of the body.[ii],[iii] Many of the reported benefits of cat’s claw may be attributable to its antioxidants.

Inflammation Modulation – Cat’s claw has been traditionally used for conditions of rheumatism and arthritis. Test tube, animal and human studies have all validated its use for inflammation modulation. In these studies, cat’s claw appears to inhibit excess production of pro-inflammatory compounds and acts as an antioxidant on bodily tissues, which also helps to modulate inflammation.[iv],[v] These protective effects appear to extend to the lining of the digestive tract, which explains its traditional use for gastrointestinal conditions.[vi]

Immune System Support – There are many ways in which cat’s claw may support the immune system. Some studies have suggested that it helps to inhibit viruses and increase white blood cell production. It also may support cell death in cases of uncontrolled cell growth and may even help ease the side effects experienced by patients receiving conventional cancer treatments.[vii],[viii],[ix],[x],[xi]

Using Cat’s Claw

Cat’s claw is found loose for making tea, in a liquid tincture, and in pills. Although tea (or decoction) is the traditional form of use, most clinical research has been done using products that have been standardized to one or more of the alkaloids that naturally occur in cat’s claw. No matter which form you choose, follow the directions given on the label. Cat’s claw is generally recognized as safe although mild intestinal upset is occasionally reported in the beginning of use. As always, caution should be used when starting any new herb, nutrient, or medication, especially if you are already taking other supplements or medications or have a medical condition.

Resources

[1] Because the quality and potency of an herb is dependent on variables in season, soil, weather,  growing location and post-harvest handling, some companies choose to standardize their herbal products in an attempt to deliver a consistent product every time. Standardization in botanical extracts refers to delivering a consistent, measurable amount of a recognized plant constituent, often on believed to be an active ingredient.

[i] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: The American Botanical Council; 2003.

[ii] Shi Z, Lu Z, Zhao Y, et al. Neuroprotective effects of aqueous extracts of Uncaria tomentosa: Insights from 6-OHDA induced cell damage and transgenic Caenorhabditis elegans model. Neurochem Int. 2013;62(7):940-947.

[iii] Bors M, Bukowska B, Pilarski R, et al. Protective activity of the Uncaria tomentosa extracts on human erythrocytes in oxidative stress induced by 2,4-dichlorphenol (2,4-DCP) and catechol. Food Chem Toxicol. 2011;49(9):2202-2211.

[iv] Allen-Hall L, Arnason JT, Cano P, Lafrenie RM. Uncaria tomentosa acts as a potent TNF-alpha inhibitor through NF-kappaB. J Ethnopharmocol. 2010;127(3):685-93.

[v] Rosenbaum CC, O’Mathuna DP, Chavez M, Shields K. Antioxidant and anti-inflammatory dietary supplements for osteoarthritis and rheumatoid arthritis. Altern Ther Health Med. 2010;16(2):32-40.

[vi] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: The American Botanical Council; 2003.

[vii] Dietrich F, Kaiser S, Rockenbach L, et al. Quinovic acid glycosides purified fraction from Uncaria tomentosa induces cell death by apoptosis in the T24 human bladder cancer cell line. Food Chem Toxicol. 2014;67:222-229.

[viii] Dreifuss AA, Bastos-Pereira AL, Fabossi IA, et al. Uncaria tomentosa exerts extensive anti-neoplastic effects against the Walker-256 tumour by modulating oxidative stress and not by alkaloid activity. PLoS One. 2013;8(2):e54618.

[ix] Rinner B, Li ZX, Haas H, Siegl V, Sturm S, Stuppner H, Pfragner R. Antiproliferative and pro-apoptotic effects of Uncaria tomentosa in human medullary throid carcinoma cells. Anticancer Res. 2009;29(11):4519-28.

[x] Farias I, do Carmo AM, Zimmerman ES, et al. Uncaria tomentosa stimulates the proliferation of myeloid progenitor cells.  J Ethnopharmacol. 2011;137(1):856-63.

[xi] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: The American Botanical Council; 2003.