Cat's claw effective anti-inflammatory, antioxidant

provided by Albany Medical Center

lbany Medical College researchers have demonstrated in laboratory tests that the ancient herbal medication known as cat's claw has effective anti-inflammatory and antioxidant capabilities. Furthermore, the researchers showed in laboratory animals that the South American plant also prevents the intestinal damage associated with traditional non-steroidal anti-inflammatory agents.

Cat's claw also known as "una de gato" (Uncaria tomentosa) is a climbing vine that grows throughout South America, but is especially abundant in the Peruvian Amazon. It has been used for hundreds, if not thousands, of years as a medicine by the native population of Peru to treat a wide variety of ailments, including arthritis and gastritis, and as an anti-inflammatory agent.

Research on cat's claw conducted by Mark J.S. Miller, Ph.D., professor of pediatrics at Albany Medical College, and Manuel Sandoval, Ph.D., assistant professor of pediatrics, was published in the November issue of the scientific journal Alimentary Pharmacology and Therapeutics (Vol. 12, Issue 12) and released this month. The research was conducted while both researchers were on the faculty of Louisiana State University Medical Center in New Orleans. Drs. Miller and Sandoval came to Albany in July.

The data shows for the first time that the plant protects cells against oxidative stress and provides mechanistic evidence for the widely held belief that cat's claw is an effective anti-inflammatory agent.

"Cat's claw prevents cell death in response to toxic nitrogen oxides, thus making it an effective antioxidant," said Dr. Miller.

Antioxidants have been shown to protect the body against cellular damage caused by free radicals, which are byproducts of oxygen metabolism in the body. Free radicals appear to have a role in the cause of a growing list of diseases such as cancer and cardiovascular disease and even in the aging process itself.

"Nitrogen oxides are produced by the immune system and cause inflammation. These oxides are also components of smog and cigarette smoke and can lead to cancer and other tissue injury," Dr. Miller added.

Dr. Sandoval, who was born and raised in Peru, noted that cat's claw does not affect the levels of nitric oxide (NO), an important component of the immune, neural and cardiovascular systems. In their research, human cells were exposed to peroxynitrite, a powerful oxidant which causes cell death. Those cells which also were exposed to an extract of cat's claw were protected from harm demonstrating the beneficial anti-oxidant properties of the substance.

"Cat's claw directly degrades peroxynitrite and attenuates peroxynitrite-induced cell death," Dr. Sandoval said.

There is mounting evidence that oxidants, nitrogen oxides and free radicals play a role in chronic gut inflammation. As such, it appears that cat's claw which works as an antioxidant could be a beneficial treatment for inflammatory bowel disease, Dr. Miller said.

The second mechanism by which cat's claw may afford benefit is unique among natural products. Cat's claw appears to prevent the activation of NF-KB (Nuclear Factor - KB), a small protein complex that binds to DNA upstream from genes and signals for their replication. Activation of NF-KB is associated with inflammation. By preventing the activation of the transcription factor NF-KB, cat's claw effectively prevents the expression of a wide array of genes that are associated with inflammation.

Additional research presented in the study involved rats with chronic intestinal inflammation, which was induced by injections of the non-steroidal anti-inflammatory drug indomethacin. Rats were separated into four groups, with two groups receiving cat's claw (5 mg/ml) in their drinking water comparable to a "tea" and two groups receiving plain drinking water.

"The rats which received cat's claw showed a near normal intestinal tract whereas the rats which did not receive cat's claw had a pronounced disruption of the mucosal architecture with loss of villi and with pronounced inflammation," said Dr. Miller.

"This is a significant finding," Dr. Miller noted. "This showed that cat's claw prevented the intestinal toxicity of non-steroidal anti-inflammatory agents, which are also used to treat inflammation. Thus cat's claw was not only an effective anti-inflammatory by itself, but it prevented the side-effects of the standard pharmaceutical drugs for these diseases. To date, the pharmaceutical industry has spent about $500 million searching for a medication like this to no avail."

The researchers found that anti-inflammatory actions of the cat's claw were registered at doses that are consistent with the practice of traditional medicine. The rats were treated with a tea made from cat's claw prepared in a manner that was identical to the ethnomedical use of cat's claw in Peru and neighboring regions. The tea is made by boiling air-dried bark of cat's claw in water.

The researchers report that the tea actually "has a palatable taste." Dr. Miller added that he prefers the taste of cat's claw tea to regular tea. Cat's claw is widely available and can be purchased without prescription.

"This study offers definitive evidence that the anecdotal reports of anti- inflammatory properties of cat's claw has a basis in fact and are sufficiently diverse to be considered an important therapeutic entity," the researchers wrote in their study.

During the last 10 years, cat's claw in various forms (extracts, tablets and capsules) has been used in Europe to treat patients suffering from cancer and some viral diseases. It is currently widely available in most western countries in a variety of forms.

Drs. Miller and Sandoval hope to begin clinical trials with cat's claw involving patients with chronic inflammatory diseases, such as arthritis and inflammatory bowel disease, in the spring of 1999.

  Albany Medical Center is the only academic health sciences center in the 25 counties of northeastern New York and western New England. The Medical Center incorporates the 651-bed Albany Medical Center Hospital; the Albany Medical College; the Albany Medical Center Faculty Group Practice; and the Albany Medical Center Foundation, Inc.