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Cat's Claw (Uncaria tomentosa)Digestive

Cat's Claw (Uncaria tomentosa)

Overview

Cat's claw is a climbing vine that can grow to 100 feet or more, with stems up to 8 inches in diameter, large glossy leaves, and sharp hooks resembling a cat's claws. Native to tropical rainforests in the central and eastern Andes—especially Peru, Ecuador, and Colombia—it has also been found in Guatemala, Costa Rica, and Panama. Known by the Ashaninka and other indigenous peoples of central Peru for its power in regulating illness, it has been used since ancient times to treat serious conditions ranging from asthma and diabetes to arthritis and cancer. By the early 1990s, over-collection from the wild threatened the species' survival; only sustainably sourced stem bark should be used, rather than root bark.

Traditional uses & properties

Cat's claw is one of the best remedies for normalizing gastrointestinal function, often helpful for ulcers, gastritis, Crohn's disease, and irritable bowel syndrome. Like echinacea, it supports a weakened immune system and reinvigorates the body's efforts to counter infection and inflammation. Its pentacyclic oxindole alkaloids (POAs), triterpenoid glycosides, and tannins including epicatechin and proanthocyanidins provide potent anti-inflammatory, antioxidant, and immunostimulant activity. The POAs stimulate white blood cell production and nonspecific immune resistance, and may inhibit tumor development and growth. Water extracts are strongly anti-inflammatory and may inhibit inflammatory gene expression. Conditions that may benefit include chronic fatigue syndrome, HIV/AIDS, rheumatoid arthritis, ulcerative colitis, asthma, and cancer (particularly breast cancer). It is also useful in countering damaging effects of chemotherapy. The herb has broad-spectrum mild antimicrobial action and antimutagenic properties.

Preparations & dosage

Standard decoction: 6–12 ounces, 3 times daily. Tincture (dried bark 1:5, 60% alcohol): 3–5 ml (0.6–1 tsp.) up to 3 times daily. Capsules or powder: 2,000–7,000 mg, 3 times daily.

Safety & precautions

Avoid during pregnancy and while trying to conceive, as cat's claw has contraceptive activity. Alcoholic extracts may inhibit cytochrome P450 enzyme CYP3A4 in vitro, though clinical relevance is uncertain. The herb may have additive antiplatelet and antihypertensive effects when combined with conventional drugs. One isolated case reported increased levels of atazanavir, ritonavir, and saquinavir in a patient taking cat's claw. Only cat's claw containing POAs should be used medicinally, as tetracyclic oxindole alkaloids (TOAs) may suppress immune function. Some preparations are standardized to contain little or no TOAs. Monitor blood pressure and watch for signs of increased bleeding if using with antiplatelet or antihypertensive medications.

Habitat

Native to tropical rainforests in the central and eastern Andes, especially Peru, Ecuador, and Colombia. Also found in Guatemala, Costa Rica, and Panama. Only stem bark from ecologically sustainable sources should be used.

Traditionally used for

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