An extract in green tea called epigallocatechin gallate (EGCG) has been found to protect against a range of cancers, including lung, prostate and breast cancer but the mechanism behind this has been unclear.
A research team at Kyushu University in Japan report that EGCG inhibits tumour cell growth by binding to a receptor on cells called the 67-kDa laminin receptor. A variety of tumours produce abnormally high levels of 67 LR, and the receptor is thought to be involved in the spread of cancers through the body.
Writing in the online edition of Nature Structural and Molecular Biology (DOI: 10.1038/ nsmb743), the team showed that the growth of human lung cancer cells that have the receptor slows significantly when they are exposed to EGCG at the concentrations reached in the body after drinking just two or three cups of green tea.
A report on the research by Nature notes that other studies have suggested that the 67 LR receptor is involved in the propagation of prion diseases such as vCJD. The Japanese team believe that finding out how EGCG acts on 67 LR might have implications for treating prion diseases, as well as leading to new anti-cancer strategies.
The growing number of studies on green tea have prompted interest from the supplement market, with a number of products in the US now offering 'green tea extract'. DSM has just launched its pure EGCG ingredient in the US, produced at a new plant in Shanghai, China, which has an annual output of 40 tons.