Green tea
A team of Penn State researchers says that, EGCG (epigallocatechin-3-gallate), an active compound found in green tea can kill oral cancer cells, without affecting the healthy ones.McKay Savage/Flickr

A latest US research reveals that green tea can help fight oral cancer.

A team of Penn State researchers says that EGCG (epigallocatechin-3-gallate), an active compound found in green tea, can kill oral cancer cells without affecting the healthy ones.

The green tea polyphenol facilitated this by targeting mitochondria and reducing the protective ability of the cancer cells.

Mitochondria are the "powerhouses" or parts of the cells that are responsible for converting sugar and oxygen into energy, required for proper functioning of the cells.

"EGCG is doing something to damage the mitochondria and that mitochondrial damage sets up a cycle causing more damage and it spirals out, until the cell undergoes programmed cell death," researcher Joshua Lambert said in a news release. "It looks like EGCG causes the formation of reactive oxygen species in cancer cells, which damages the mitochondria, and the mitochondria responds by making more reactive oxygen species."

"So, it's turning off its mechanism of protection at the same time that EGCG is causing this oxidative stress," Lambert added.

For the study, the researchers exposed cancer cells and normal cells grown on petri dishes to EGCG. They mainly concentrated on the oxidative stress and antioxidant response in these cells. Fluorescent dyes were used to measure mitochondrial function and oxidative stress. Results showed that the EGCG directly affected sirtuin 3, (SIRT3) a protein crucial for the proper functioning of mitochondria and anti-oxidant response.

The researchers expect that the compound may also help fight other types of cancers. "It plays an important role in mitochondrial function and in anti-oxidant response in lots of tissues in the body, so the idea that EGCG might selectively affect the activity of sirtuin 3 in cancer cells -- to turn it off -- and in normal cells -- to turn it on -- is probably applicable in multiple kinds of cancers," Lambert said.

The findings, reported in "Molecular Nutrition and Food Research", are highly promising as oral cancer is one of the leading causes of death in India. According to estimates, every six hours at least one person in the country dies from the disease.

In June last year, Wai-Nang Lee and colleagues from the Los Angeles Biomedical Research Institute found that EGCG inhibited the activity of LDHA, an enzyme that plays a major role in pancreatic cancer.

Additionally, data shows that drinking green tea regularly can help improve mental health, fight diabetes, aid weight loss, treat gum diseases and manage cholesterol. It has also been found effective against cancers of breast, ovary, colon, skin, stomach, lung and bladder.

Green tea, a native to China, is made from a particular species of plant known as Camellia sinensis.