Chinese Herb May Treat Autoimmune Diseases
Study Shows Herb From Hydrangea
Root Targets Specific Immune Responses
By Daniel J. DeNoon
WebMD Health News
Reviewed by Louise Chang
June 4, 2009 -- A drug derived from an herb used in Chinese medicine for
2,000 years is the first to target specific cells that are overactive in
rheumatoid arthritis, psoriasis, and other autoimmune diseases.
The ancient herb is chang shan, from the root of the blue
evergreen hydrangea. It's been used in Chinese medicine to reduce fever and
fight malaria.
The herb's active compound, febrifugine, is too toxic for use as a modern
drug. In the 1960s, U.S. Army scientists created a febrifugine derivative called
halofuginone as a possible malaria drug, but further study was soon
discontinued.
More recently, halofuginone was found to reduce skin collagen and was tested
as a possible treatment for scleroderma. But until now, nobody knew how the drug
worked.
That may be because the drug's target -- a specific kind
of immune cell
called a Th17 cell -- was identified only in 2006. But now Harvard Medical
School researchers Mark S. Sundrud, PhD, Anjana Rao, PhD, and colleagues show
that halofuginone does indeed inhibit Th17 cells.
That's important, because Th17 cells regulate autoimmune inflammatory
responses. That's the kind of immune response that
goes haywire in a wide range of diseases such as
inflammatory bowel disease,
rheumatoid arthritis, multiple sclerosis,
type 1 diabetes,
eczema, and
psoriasis.
"Halofuginone may herald a revolution in the treatment of certain types of
autoimmune and inflammatory diseases," Rao says in a news release.
Why? Current drugs for autoimmune diseases take a sledgehammer approach. They
smash down many different immune responses, leaving patients vulnerable to
infections and cancers.
A drug that can specifically inhibit one type of immune response would be a
major breakthrough. Halofuginone may turn out to be such a drug.
"This is really the first description of a small molecule
that interferes
with autoimmune pathology but is not a general immune suppressant," Sundrud says
in the news release.
An added bonus: Halofuginone could probably be taken orally, rather than by
injection.
Yet the findings by Sundrud and Rao are based only on mouse studies. They
must be refined and confirmed in humans before any actual drug is developed.
Sundrud and Rao report their findings in the June 5 issue of Science.
SOURCES:
Sundrud, M.S. Science, June 5, 2009; vol 324: pp 1334-1338.
News release, Children's Hospital, Boston.
Jiang, S. Antimicrobial Agents and Chemotherapy, March 2005; vol 49: pp
1169-1176.
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