Herbs & Supplements

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Uses

Note: In Mexico and the southwestern United States, a plant with the Latin name of Acacia gregii, is known as cat's claw acacia or catclaw acacia. This shrubby tree is not the same as the long South American vine (Uncaria guianensis or Uncaria tomentosa) that produces the cat's claw used in medicine. Acacia gregii may contain a cyanide derivative which is extremely dangerous to take by mouth.

Probably the best-researched use of cat's claw is for the relief of arthritis pain. Results from animal studies and reports of human cases show that taking cat's claw by mouth may have anti-inflammatory effects for individuals with either osteoarthritis (the deterioration of joints due to wear and tear) or rheumatoid arthritis (an autoimmune disease in which the body's immune system attacks cartilage and synovial fluid in joints). Although the reasons are not all known, chemicals in cat's claw are believed to block the production of substances such as prostaglandins and tumor necrosis factor (TNF) alpha, which are involved in inflammation. Cat's claw appears to have little or no effect on swelling associated with arthritis, but some study participants who took it reported less pain during exercise. However, only a few human studies have been conducted and not all the results from those studies have been positive. More research is needed before cat's claw can be recommended for treating arthritis.

Cat's claw is also being studied for a number of other possible uses. Various chemicals that it contains are known to promote the loss of water from the body, relax smooth muscles, and widen small blood vessels in the hands and feet. All these effects may help to lower blood pressure. Cat's claw may have immune-system effects, as well. One theory is that chemicals in it promote the activity of macrophages, which are specialized white blood cells that absorb bacteria and tumor cells and also activate other immune system cells. In animal studies, cat's claw also appeared to promote the production of chemicals that extended the active lives of lymphocytes--white blood cells that fight infection. Lymphocyte production was not increased, however. In other laboratory studies, cat's claw extract stopped the spread of human lymphoma, leukemia, and breast cancer cells. In contrast, results from other laboratory studies may show that cat's claw actually caused certain cancers to spread faster. In one small human study and several animal studies, taking cat's claw may have promoted the repair of DNA damaged by chemotherapy or radiation. All the possible uses of cat's claw need much more research, including well-planned human studies.