scientific name: Uncaria tomentosa other common names: Una de gato, hawk's claw growing areas: Peruvian rain forests of the Amazon basin, as well as Colombia, Ecuador, Guyana, Trinidad, Costa Rica, Guatemala, Panama, and Venezuela physical description: The plant grows as a woody vine and can reach heights of around 100 feet. It earned the common name cat's claw from the claw-shaped thorns that grow from the base of the leaves. Both the bark and the root of the vine are used in the preparation of medicine. The inner bark is preferred as a medicinal source because it regenerates and its harvesting does not harm the vine.
traditional uses: Cat's claw has a history of use going back to the time of the Incas, and it has been continuously used by indigenous peoples of South America for two thousand years. Cat's claw has been used by the Ashaninka Indians of central Peru to treat asthma, urinary tract inflammation, arthritis, and rheumatism. It has also been used by indigenous peoples to treat general inflammations and to treat wounds. In addition, some Indian peoples in Colombia are reported to use it to treat gonorrhea and dysentery.
availability and dosage: It can be found in liquid extract and as bark powder in capsule form. Dosages vary, though'capsules can range from 25 milligrams to 500 milligrams. The raw herb can be found in cut-and-dried form in botanicas.
contraindications: Experts say it is contraindicated for persons undergoing skin grafts and organ transplants, as well as those suffering from coagulation disorders, tuberculosis, and autoimmune diseases.
special precautions: Consult your physician before beginning any use of an ethnobotanical substance for medicinal purposes.
Experts caution that persons taking the herb should watch for signs of bleeding and possible hypotension (low blood pressure).
medical research: Though it has been used medicinally for thousands of years, medical research into cat's claw is relatively new. Interest increased among researchers after 1970, and in 1994 the World Health Organization sponsored a conference in which cat's claw was recognized as a medicinal plant.
Researchers have focused attention on several phyto-chemicals in cat's claw. Among them are okindole alkaloids, found in the bark and roots, which help stimulate the immune system. Researchers have found that other alkaloids present in the plant have diuretic and hypertensive effects and lower the heart rate. Other substances found in cat's claw are believed by researchers to show antiviral and anti-inflammatory properties. Flavo-noids, which are plant substances that give color to flowers and leaves, also protect the human body's cells from damage by oxidation.
The properties of cat's claw are making it useful in the study of possible treatments for AIDS, leukemia, and other forms of cancer. In mid-1999 researchers led by Alan Snow, Ph.D., of the University of Washington in Seattle announced that the National Institutes of Health were funding a study of a substance derived from cat's claw that has been found to inhibit the formation in rats of brain plaque like that associated with Alzheimer's disease. Similar effects were also found when the cat's claw substance, identified as the proprietary product PTI-00703®, was combined with another well-known botanical substance, ginkgo biloba. The results of the clinical trials are expected to be known by early 2001.