Green Tea's Cancer-Fighting Target Found
March 15, 2004 -- A powerful antioxidant found in green tea may
be responsible for the beverage's heralded anticancer benefits.
New research shows that the antioxidant, known as EGCG, binds
to a protein found on tumor cells and dramatically slows their growth.
Researchers say previous studies have shown that green tea
helps protect against a variety of cancers, such as lung, prostate, and breast,
but the mechanisms for these effects are not known.
In the study, published in the April issue of Nature
Structural & Molecular Biology, researchers identified a potential
target for the antitumor action of EGCG on human lung cancer cells that
inhibited cancer cells' growth. By learning more about this target, researcher
may be able to develop new treatments that maximize green tea's cancer-fighting
Explaining Green Tea's Anticancer Benefits
In order to better understand how the antioxidants found in
green tea may protect against cancer, researchers looked at how they affected a
protein found on the surface of cancer cells called laminin receptor.
The study showed that when cancer cells with this protein were
treated with polyphenol EGCG, the growth of the tumor cells was significantly
Researchers say the concentration of the antioxidant required
to produce these anticancer effects was equivalent to those found in the body
after drinking only two to three cups of green tea.
Other components found in green tea, including caffeine, had no
effect on tumor cell growth.
Researchers say the results further the understanding of how
antioxidants interact with cancer cells and may one day lead to more effective
cancer therapies that use green tea as a dietary cancer treatment.