http://www.reutershealth.com/archive/2002/01/28/eline/links/20020128elin003.html
By Jacqueline Stenson
SAN DIEGO, Jan 28 (Reuters Health)
- Studies have suggested that green tea has anti-inflammatory properties
and new research may help explain why.
Previous animal studies and other
laboratory research have found that chemicals in green tea known as polyphenols
act as anti-inflammatory agents, but the mechanism behind this action was
not well understood.
Now, Ohio researchers have found
that one type of polyphenol known as epigallocatechin-3-gallate, or EGCG,
inhibits the expression of the interleukin-8 gene--a key gene involved
in the inflammatory response.
"We found that this compound reduced
the expression of this gene significantly in a culture cell model," said
study author Dr. Hector Wong of Cincinnati Children's Hospital Medical
Center in Ohio.
"As we increased the dose, the effect
was more profound," he told Reuters Health.
In a laboratory study presented here
Sunday at a meeting of the Society of Critical Care Medicine, the researchers
looked at human lung cells that were cultured in a lab dish and treated
with a protein called tumor necrosis factor, which typically triggers the
expression of IL-8, resulting in the production of the IL-8 protein. In
the body, the IL-8 protein attracts white blood cells to a particular site,
resulting in tissue inflammation, Wong said.
But when the investigators introduced
EGCG in their experiment, they found that it blocked the expression of
IL-8. The higher the dose, the greater the effect.
"This compound can short circuit
this cascade that leads to inflammation," Wong said. It's too soon to advocate
drinking cup after cup of green tea in the hopes of treating inflammation,
but the results are encouraging and deserve further study, Wong noted.
Reports from Asian populations suggest
that green tea consumption may be associated with improvements in various
diseases characterized by inflammation, such as colitis and arthritis,
he noted. Green tea is also thought to play a role in fighting cancer and
heart disease.
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