NASHVILLE, Mar 24, 2009 (UPI via COMTEX) -- A chemical component of licorice
may offer a new way to prevent colorectal cancer without the adverse side
effects of other therapies, U.S. researchers said.
The study, published in the Journal of Clinical Investigation, shows that
inhibiting the enzyme 11beta-hydroxysteroid dehydrogenase type 2 -- either by
treatment with a natural compound found in licorice or by silencing the
11beta-hydroxysteroid dehydrogenase type 2 gene, prevents colorectal cancer
progression in mice predisposed to the disease.
Dr. Raymond Harris, Dr. Ming-Zhi Zhang and colleagues at the Vanderbilt
University Medical Center have been investigating COX-2 regulation in the
kidney. They previously found that inhibiting 11betaHSD2 in the kidney
suppresses COX-2 expression in that organ.
One promising target for chemoprevention is the enzyme cyclooxygenase 2, which
promotes colorectal cancer progression via the action of the enzyme's
inflammatory products -- the prostaglandins.
Inhibiting this enzyme with non-steroidal anti-inflammatory drugs like ibuprofen
or with selective COX-2 inhibitors like Vioxx or Celebrex reduces the number and
size of colon polyps in mice and in patients with an inherited predisposition to
colon cancer.
However, both types of drugs cause serious adverse side effects that limit their
utility for chemoprevention.
Licorice has been used for thousands of years for ailments ranging from coughs
to constipation but even licorice is not without side effects; long-term
consumption can lead to low blood potassium and increases in blood pressure but
they are relatively minor compared to the cardiovascular side effects of COX-2
inhibitors, Harris said.
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Copyright 2009 by United Press International