TROY, N.Y. — Green tea can help contribute to a healthy body in a number of ways. Prior studies show a daily cup may improve brain function an even fighting obesity. Now scientists say the traditional Chinese drink could hold the key to beating cancer.
According to researchers at the Rensselaer Polytechnic Institute, green tea may switch on a gene called p53, which blocks the development of tumors. The protein destroys damaged cells or stops them dividing as repairs are carried out. It is mutated or inactivated in most types of cancer. An antioxidant found in green tea, however, improves its efficiency, the study shows.
Study authors say their finding offers hope of a drug that mimics epigallocatechin gallate, or EGCG, the main active compound.
“Both p53 and EGCG molecules are extremely interesting,” says Chunyu Wang, a corresponding author of the study, in a statement. “Mutations in p53 are found in over 50% of human cancer, while EGCG is the major antioxidant in green tea, a popular beverage worldwide. Now we find there is a previously unknown, direct interaction between the two, which points to a new path for developing anti-cancer drugs. Our work helps to explain how EGCG is able to boost p53’s anti-cancer activity, opening the door to developing drugs with EGCG-like compounds.”
How p53 is a cancer kryptonite
Wang considers p53 as “arguably the most important protein in human cancer.” The natural cancer-fighting protein was hailed the “guardian of the genome” after its discovery in 1979. One end, known as the “N-terminal domain,” has a flexible shape, enabling it to serve several functions.
A state of the art scanning technique called nuclear magnetic resonance spectroscopy shows EGCG protects it from degradation. The plant chemical, found in abundance in green tea, is also sold as a herbal supplement. It helps undo constant harm caused by oxygen metabolism. The study, published in Nature Communications, identifies the specific mechanism for the first time.
After production within the body, p53 quickly breaks down when the N-terminal domain comes into contact with a protein called MDM2, keeping quantities low. “Both EGCG and MDM2 bind at the same place on p53, the N-terminal domain, so EGCG competes with MDM2,” says Wang “When EGCG binds with p53, the protein is not being degraded through MDM2, so the level of p53 will increase with the direct interaction with EGCG. That means there is more p53 for anti-cancer function. This is a very important interaction.”
Green tea could unlock new anti-cancer drugs
The study raises hopes of a new generation of anti-cancer drugs that work by boosting p53 activity. It controls the cell cycle. When functioning properly, it activates DNA repair mechanisms and prevents cells with damaged DNA from dividing. If DNA damage is irreparable, p53 induces the cell to destroy itself by undergoing apoptosis, or programmed cell death. When p53 is turned off by mutation or deletion, cells are much more likely to become cancerous, because they will divide uncontrollably even when DNA is damaged.
Since it is commonly switched off in human cancers, reactivating it could potentially provide a powerful way of treating the disease in the future.
The findings also shed fresh light on the benefits of green tea. It has been shown to help prevent a host of diseases including cancer, heart disease and diabetes – and halve the risk of dementia. A study of over 100,000 older Chinese people found those who drank at least three cups of green tea a week were 25 percent less likely to die over the next seven years.
Green tea has been consumed in China for 4,000 years for its beneficial health qualities.
SWNS writer Mark Waghorn contributed to this report.