 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.  | 
