(Uncaria tomentosa)

Cat's claw, also known as Una de gato (its Spanish name), is a high-climbing, woody vine that grows profusely in the upper Amazon regions of Peru, Columbia, Ecuador, and other South American countries. At the base of the plant's leaves are two curved thorns that resemble the claws of a cat (hence its name); these allow the vine to climb up trees and other vegetation into the forest canopy. The herb's botanical name, Uncaria, is from the Latin uncus, for "hook."

Two species of cat's claw are harvested for medicinal purposes, Uncaria guianensis, used mainly in Europe, and Uncaria tomentosa, commonly imported into the United States. Among the herbal practitioners of South America, the two species are considered interchangeable.

For hundreds of years, people in the Amazon basin have used cat's claw to treat a broad range of ailments, ranging from cancer, arthritis, and stomach and liver disorders to skin conditions and even contraception. Traditionally, the herb's primary medicinal form has been a decoction, or crude extract, prepared by boiling the inner bark of the stem and parts of the root.

Scientific interest in cat's claw centers on the plant's immune-boosting and anti-inflammatory properties. There is early and speculative evidence that cat's claw may have antiviral and cancer-fighting potential as well.

Health Concern
Osteoarthritis, Rheumatoid arthritis

Active Constituents
According to test tube studies, oxyindole alkaloids in cat’s claw stimulate immune function. Alkaloids and glycosides in cat’s claw have also demonstrated anti-inflammatory and antioxidant activity

Warnings
Cat's claw is very safe and nontoxic. The American Herbal Products Association (AHPA) gives cat's claw a class 4 safety rating which indicates a lack of scientific data to test that the herb is actually safe. In addition, the AHPA does indicate that the tannin content of cat's claw may cause some abdominal pain or gastrointestinal problems including diarrhea. The diarrhea or loose stools tend to be mild and go away with continued use of the herb.

Cat's claw should not be used by individuals with skin grafts or tuberculosis or by those receiving organ transplants. It should not be used by pregnant or breastfeeding women or by children who are under three years of age.