How green tea may fight inflammation

February 17, 2002

By 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.

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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