Drinking green tea has a protective effect against some forms of cancer but drinking large amounts can increase the risk of birth defects such as spina bifida – according to previous epidemiological studies.
Today, scientists have reported that a naturally occurring polyphenol (EGCG) isolated from green tea leaves inhibits the growth of cancer cells, in vitro, when present at the low concentrations found in the blood and other tissues of green tea drinkers. EGCG binds to the enzyme DHFR, an established target for anticancer drugs and also implicated in birth defects. EGCG could provide the starting point for a new family of anti-cancer drugs. The research was conducted by a team of scientists at the
Drinking green tea has a protective effect against some forms of cancer but drinking large amounts can increase the risk of birth defects such as spina bifida – according to previous epidemiological studies.
, Spain , in collaboration with the
cancer Norwich, UK .
“This is a very exciting discovery” said Professor Roger Thorneley (leader of the JIC team). “For the first time we have a clear scientific explanation of why EGCG inhibits the growth of cancer cells at concentrations which are found in the blood of people who drink 2 or 3 cups of green tea a day. We have identified the enzyme in tumour cells that EGCG targets and understand how it stops this enzyme from making DNA. This means we may be able to develop new anticancer drugs based on the structure of the EGCG molecule”.
Dr José Neptuno Rodríguez-López (Initiator of the project and leader of the UMU team) takes up the story. “We decided to look at EGCG because we recognised that its structure is very similar to that of the successful anti-cancer drug methotrexate. We discovered that EGCG can kill cancer cells in the same way as methotrexate. However, because EGCG binds to the target enzyme less tightly than methotrexate, it should have decreased side effects on healthy cells. We are now using EGCG as the starting point to design and develop effective new anti-cancer drugs that kill tumour cells but inflict less damage on healthy cells.”