The finding by scientists at the University of Rochester's Environmental Health Science Center appears in the July 21 issue of Chemical Research in Toxicology, published by the American Chemical Society.
Graduate student Christine Palermo and adviser Thomas Gasiewicz, Ph.D., set out to measure the effects of the chemicals found in green tea on a molecule known as the aryl hydrocarbon (AH) receptor, a molecule that frequently plays a role in turning on genes that are oftentimes harmful. Gasiewicz has previously shown how both tobacco smoke and dioxin manipulate the molecule a favorite target of toxic substances to cause havoc within the body.
The team isolated the chemicals that make up green tea and found two that inhibit AH activity. The two substances, epigallocatechingallate (EGCG) and epigallocatechin (EGC), are close molecular cousins to other flavonoids found in broccoli, cabbage, grapes and red wine that are known to help prevent cancer.
While green tea has been much-ballyhooed for its anti-cancer effects as well as other purported abilities such as preventing rheumatoid arthritis and lowering cholesterol, just how the substance works has been a mystery. Scientists do know that green tea contains chemicals that are anti-oxidants and quench harmful molecules. But its effects on the AH receptor have not been thoroughly evaluated until now.
"It's likely that the compounds in green tea act through many different pathways," says Gasiewicz, professor and chair of Environmental Medicine and director of Rochester's Environmental Health Science Center. "Green tea may work differ
Contact: Tom Rickey
University of Rochester Medical Center