Una de Gato or Cat's Claw is a large woody vine that is indigenous to the Amazon Rainforest and other tropical areas of South and Central America including Peru, Columbia, Ecuador, Guyana, Trinidad, Venezuela, Suriname, Costa Rica, Guatemala, and Panama. It's name is derived from the hook-like thorns that grow along the vine that resemble a claw of a cat. Two closely related species of Uncaria are used almost interchangeably in the rainforests - Uncaria tomentosa and Uncaria guianensis. Both species are large woody vines that can reach over 100 feet high into the canopy with claw-like thorns, however, U. guianensis has thorns which are more curved and reddish-orange flowers, in comparison to U tomentosa's smaller yellowish-white flowers.

Both Uncaria species are used by the indigenous people of the rainforest in very similar ways with a very long history of use. Cat's Claw (U. tomentosa) has been used medicinally by the Aguaruna, Asháninka, Cashibo, Conibo and Shipibo tribes of Peru for at least 2,000 years. The Asháninka Indian tribe in central Peru have been the most closely associated rainforest tribe with Cat's Claw. They have the longest recorded history of use with the plant and are also the largest commercial source of Cat's Claw from Peru today. The Asháninka use Cat's Claw to treat asthma, inflammations of the urinary tract, to recover from childbirth, as a kidney cleanser, to cure deep wounds, for arthritis, rheumatism and bone pain, to control inflammation and gastric ulcers, and for cancer. Indigenous tribes in Piura use Cat's Claw to treat tumors, inflammations, rheumatism and gastric ulcers. Indian tribes in Columbia use the vine to treat gonorrhea and dysentery. Other Peruvian indigenous tribes use Cat's Claw to treat diabetes, urinary tract cancer in women, cirrhosis, gastritis, rheumatism, inflammations and tumors. The Cashibo tribe of eastern Peru believes that Cat's Claw "normalizes the body" and have used it since ancient times to treat fevers, abscesses and to cleanse the system. Other documented indigenous uses in Peru include using this important vine for hemorrhages, impurities of the skin, as a blood cleanser, and for irregularity of the menstrual cycle. Cat's Claw has also been reported to used as a contraceptive by several different tribes of Peru, however, only in excessive amounts. Dr. Fernando Cabieses, a noted authority on Peruvian medicinal plants, explains that the Asháninka boil 11-13 pounds of the root in water until it is reduced to a little more than a cup. This decoction is then taken daily during the period of menstruation for three consecutive months to supposedly cause sterility for three to four years.

With so many documented uses of this important rainforest plant, it is not surprising that it came to the attention of western researchers and scientists. First written about in the mid-1960's by a European teacher, Arturo Brell, and U.S. University professor Eugene Whitworth, the ethnic uses began to be recorded, plant samples taken and initial screening of active constituents performed. Then in the early 1970's came Klaus Keplinger, a journalist and self-taught ethnologist from Innnsbruck, Austria who was responsible for organizing the first definitive studies on Cat's Claw. Keplinger's work in the 1970's and 1980's led to several extracts of cat's claw being sold in Austria and Germany as prescription medicines, four U.S. patents describing the alkaloid extraction methods and the immunostimulating actions of these alkaloids found in Cat's Claw, and fueled worldwide interest in the medicinal properties of this valuable vine of the rainforest. In May of 1994, the World Health Organization sponsored the First International Conference on Cat's Claw in Geneva Switzerland. At the conference, Cat's Claw received official recognition as a medicinal plant and it was pointed out that not since quinine was discovered in the bark of a Peruvian tree in the 17^th century, has any other rainforest plant ever prompted such worldwide attention.

The most attention to date has been on the oxindole alkaloids found in the bark and roots of Cat's Claw which have been documented to stimulate the immune system. Studies indicate at least six of these oxindole alkaloids can increase immune function by up to 50% in relatively small amounts. This has led to its use around the world as an adjunctive treatment for cancer and AIDS as well as other diseases which negatively impact the immunological system. In addition to it's immunostimulating activity for cancer patients, other anti-cancerous properties have been documented on the alkaloids as well as other constituents in Cat's Claw. Five of the oxindole alkaloids have been clinically documented with anti-leukemic properties, and various root and bark extracts have demonstrated anti-tumorous and antimutagenic properties. Reports on observatory trials with cancer patients taking Cat's Claw in conjunction with traditional cancer therapies like chemotherapy and radiation reported fewer side effects to the traditional therapies like hair loss, weight loss, nausea, secondary infections and skin problems.

Another significant area of study on Cat's Claw has focused on its anti-inflammatory properties. While plant sterols like Beta-sitosterol, acids and other antioxidants found in Cat's Claw account for some of these properties, new and novel phytochemicals called quinovic acid glycosides were found in the bark and roots and documented to be the most potent anti-inflammatory constituents found in the plant. These studies indicated that Cat's Claw and some of its constituents could inhibit inflammation from 46% to up 69% in various in vivo and in vitro tests. This validated its long history of indigenous use for arthritis and rheumatism as well as other types of inflammation associated with various stomach disorders and ulcers where it was clinically shown to be effective. This same group of chemicals also demonstrated in vitro antiviral properties in another study.

Cat's Claw also contains the alkaloids, Rhynchophylline, Hirsutine, and Mitraphylline, which have demonstrated hypotensive and vasodilating properties. Rhynchophylline has also shown to inhibit platelet aggregation and thrombosis and may help prevent blood clots in blood vessels, as well as to relax the blood vessels of endothelial cells, dilate peripheral blood vessels, lower the heart rate and lower blood cholesterol.

In herbal medicine today, Cat's Claw is employed around the world for many different conditions. Dr. Schwontkowski reports it being used for the treatment of immune disorders, gastritis, ulcers, cancer, arthritis, rheumatism, irregularities of the female cycle, acne, organic depression, wounds, fungus, fistulas, hemorrhoids, rheumatic disorders, neuralgias, chronic inflammation (vaginal or intestinal), and viral diseases like herpes zoster (shingles). Dr. Brent Davis refers to Cat's Claw as the "opener of the way" because of it ability to cleanse the entire intestinal tract and its effectiveness in treating stomach and bowel disorders such as Crohn's Disease, leaky bowel syndrome, ulcers, gastritis, diverticulitis and other inflammatory conditions of the bowel, stomach and intestines. Dr. Julian Whitaker, M.D. reports using Cat's Claw for its immune stimulating effects, for cancer, in heart problems to help prevent strokes and heart attacks and to reduce blood clots, for diverticulitis and irritable bowel syndrome. Phillip Steinberg, Certified Nutritional Consultant, reports Cat's Claw being beneficial in the treatment of cancer, arthritis, bursitis, rheumatism, genital herpes and herpes zoster, allergies, ulcers, systemic candidiasis, PMS and irregularities of the female cycle, environmental toxin poisoning, numerous bowel and intestinal disorders, organic depression and HIV. Kenneth Jones cites its usefulness in treating diverticulitis, hemorrhoids, peptic ulcers, colitis, gastritis, parasites and leaky bowel syndrome. In Peruvian medicine, Cat's Claw is even being used in veterinary practices today with benefits in dogs and cats with hip dysplasia, arthritis, cancers, Parvo virus, dermatitis and other skin disorders, tumors, FIV, and feline leukemia. In Peruvian herbal medicine, Cat's Claw is used for rheumatism, colic and stomach disorders, prostate inflammation, ulcers, skin disorders, fevers and coughs as well as cancer and AIDS. Toxicity studies were performed in 1997, showing no toxicity for Cat's Claw at any of the dosages measured.

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