Cat's Claw - Uncaria tomentosa

Detailed Description

A miraculous Amazonian herb.

Botanical Information

Cat's Claw is a woody, climbing or creeping liana (shrub), reaching lengths of up to 30 meters. Its leaves are veined, elliptic to ovoid with smooth margins, measuring 7–9 cm long and 5–9 cm wide. The short petioles (about 1.5 cm) attach opposite pairs of leaves, which have a greenish-yellow upper surface and a pale green, softly hairy underside. The quadrangular stem features large, hooked thorns around its circumference, helping the plant latch onto its support. The inflorescence is about 10 cm long, composed of yellowish-white flowers with petals approximately 5 mm long. The fruit is oval, narrow, around 1 cm in length, containing slender seeds up to 4 mm long.

Origin and Distribution

Cat's Claw originates from the Amazon rainforest, with primary concentrations in the tropical jungles of South and Central America. It prefers humid, poorly drained tropical forests in lowlands or foothills, as well as moist flat or undulating subtropical forests. The plant is found in Belize, Brazil, Peru, Suriname, Honduras, Venezuela, Trinidad, Colombia, Guatemala, Nicaragua, Panama, and Bolivia.

Usage / Dosage

Known as Uña de Gato or Cat's Claw, this Amazonian liana is widely used by indigenous tribes. The medicinal part is the inner bark collected from various sections of the vine. While Cat's Claw has been renowned in traditional medicine for centuries, it entered modern medical research (as Cat's Claw) in the 1980s. Studies have evaluated its active compounds for potential roles in managing lower back pain, inflammatory diseases, cancer, and AIDS.

Cat's Claw extracts have shown significant ability to inhibit the growth of bacterial colonies, including pathogenic human strains (such as E. coli, Salmonella typhimurium). In vitro studies found a reduction in colony growth by up to 68%. At a concentration of 500 mg/ml, extracts also suppressed the growth of fungal biofilms (Candida albicans), supporting a partial antifungal activity.

In one study, 51 volunteers (aged 33–85) received Cat's Claw, experiencing improved quality of life and reduced fatigue, calculated through various questionnaires. Although there were no marked changes in blood markers, after eight months of use, patients with advanced cancer reported increased vitality and a better sense of well-being. Some researchers found Cat's Claw can help prevent tumor spread and shows promise in supporting therapies for certain cancers and cardiovascular diseases. Mailaender et al. documented potent antimutagenic activity, observing a reduction in mutagenic substances in the body soon after administration.

Its active constituents, especially alkaloids and flavanols, have been tested for antioxidant and anti-inflammatory properties. In vitro HPLC tests demonstrated their ability to scavenge free radicals by reducing DPPH, hydroxyl radicals, lipid peroxidation, and modulating TNF-alpha using ELISA. The anti-inflammatory effect was measured by inhibiting TNF-alpha and nitric oxide production. In vivo animal studies showed Cat's Claw could protect the gastric mucosa against indomethacin-induced damage, reduce production of inflammatory mediators, and help prevent apoptosis (programmed cell death), confirming its significant antioxidant and anti-inflammatory effects.

Mitraphylline, a compound in Cat's Claw, reduced TNF-alpha release by 50%, IL-1alpha and IL-beta by 70% in animal models at a dose of 30 mg/kg for three days, showing somewhat less efficacy than dexamethasone. Cat's Claw may thus be a viable option for inflammatory joint diseases. Both ethanol and aqueous extracts increased anti-inflammatory factors in in-vitro chondrocyte cultures and suppressed genomic transcription of pro-inflammatory factors.

Daily Cat's Claw extract for eight weeks decreased pain and stiffness, improved joint function, and reduced the need for pain medication in osteoarthritis. Clinical trials also documented pain relief from physical activity after just one week of treatment, though knee swelling did not significantly decrease in this short term. Studies also suggest benefits for rheumatoid arthritis, with data from moderate-quality sources (though requiring more standardized clinical trials). One study found that using a similar extract for 24 weeks alongside anti-inflammatory medication reduced the number of painful and swollen joints. These findings support the use of Cat's Claw to help maintain healthy joint function.

Conversely, in vitro studies with thyroid cancer cells found that Cat's Claw compounds significantly inhibited cell growth and mitochondrial dehydrogenase activity, indicating an antiproliferative and pro-apoptotic (anti-tumor) effect. There was increased expression of caspase-3 and ADP-ribose polymerase, as well as marked apoptosis from alkaloids like isopteropodine and pteropodine. These promising results highlight Cat's Claw's potential for supporting existing anti-cancer therapies, especially through promoting apoptosis in neuroendocrine tumors.

Further in vivo analyses confirmed that Cat's Claw extract supports dose-dependent increases in several immune system parameters: white blood cell counts, respiratory activity, lysozyme activity, melanomacrophage numbers, villus length in tissues, antibody levels in spleen tissue, and an unexpected increase in growth factors. In a small clinical study of four healthy volunteers taking a 350 mg daily aqueous Cat's Claw extract for six weeks, white blood cell counts rose by about 9%, with similar results in larger follow-up studies. Cumulative findings (including those above) support that Cat's Claw and its compounds strengthen natural immunity by positively influencing various immune system functions.

In a clinical study with women undergoing chemotherapy for breast cancer, Cat's Claw helped reduce decreases in leukocytes and lymphocytes, while neutrophil and monocyte levels rose significantly compared to baseline, regardless of chemotherapy regimens. The probable mechanism is prolonged survival of leukocytes, confirmed by in vivo analysis. Other research found that pentacyclic oxindole alkaloids promoted higher release of endothelial factors supporting lymphocyte production and activation of B and T cells. All studies confirmed that Cat's Claw's bioactive compounds help support the immune system, even in persons with serious illnesses.

Traditional and Folk Medicine

For centuries, Amazonian tribes have used Cat's Claw as a universal remedy for inflammatory diseases. Combined with echinacea, grapefruit, papaya, and others, Cat's Claw is traditionally used to treat papillomavirus-induced warts. Folk medicine recommends Cat's Claw for gastric ulcers, hemorrhoids, inflammatory colitis, intestinal parasites, irritable bowel syndrome, genital herpes (and other viral diseases), measles, chronic fatigue syndrome, arthritis, asthma, and many types of tumors.

Active Compounds

Cat's Claw contains several noteworthy active components, including mitraphylline and isomitraphylline, responsible for its immunostimulant and anti-inflammatory effects. Other active compounds include rhynchophylline and isorhynchophylline (which help prevent platelet aggregation and clot formation), isopteropodine, pteropodine, uncarine alkaloids (such as hirsutine, corynantheine, dihydrocorynantheine), triterpenes (including uncaric, floridic, ursolic acids), triterpenoid quinovic acid, glycosides (tomentosides, pyroquinones, triterpene glycosides), procyanidins (epicatechin, cinchonain, procyanidins A1, B1, B2, B4), plant steroids (beta-sitosterol, stigmasterol, campestanol), and oleanolic acid.

Traditional Dosage

Studies have shown that, for osteoarthritis, a positive effect was seen with 100 mg Cat's Claw extract once daily; for rheumatoid arthritis, 60 mg three times daily; and in more serious cases, an effective dosage was 250–350 mg of aqueous extract or ethanol tincture daily. For use of the inner bark, a decoction is prepared by boiling 5–10 g of bark per 1 liter of water, simmered gently for about 20 minutes. This decoction is typically consumed in amounts of 500–1000 ml per day, either at once or divided as needed.