Extracts of tea can inhibit the formation and development of tumors at different organ sites in animal models. These include green tea and tea extracts like polyphenols. There is considerable evidence that tea polyphenols inhibit enzyme activities and signal transduction pathways.
It included especially an active compound epigallocatechin-3-gallate. It results in the suppression of cell proliferation and enhancement of apoptosis. It also works for the inhibition of cell invasion, angiogenesis, and metastasis
The study is long term research as an outcome of prior studies and it appears in Nature.
Tea polyphenols are antioxidants, but they can also generate reactive oxygen species. epigallocatechin-3-gallate can bind directly to several receptors and signaling molecules.
It can also inhibit the functions of key receptors, kinases, proteinases, and other enzymes. It is the major polyphenol from green tea.
What does the research manifest?
The active compound – Epigallocatechin gallate can make the ROS stable. ROS is reactive oxygen species in cancer. Epigallocatechin gallate or EGCG has other anti-cancer roles too. In cancer, the abnormal substances induce suicide signals in normal cells to kill them.
When the normal cells get these signals, they kill and degrade themselves. This is how normal cells start to decrease in number. EGCG can stop these signals and so prevent the cell death in normal cells. EGCG also starves cancerous cells by inhibiting oxygen supply to them. This way, new abnormal cells are not born. It does not affect the abnormal cells.
Why is there a need for more research?
These polyphenolics may also inhibit carcinogenesis. They block the endogenous formation of N-nitroso compounds. Moreover, they also suppress the activation of carcinogens, and trap the genotoxic agents. The effect of tea consumption on cancer is likely to depend on the causative factors of the specific cancer.
Therefore, a protective effect observed on a certain cancer may not be observable with a cancer of a different etiology. Scientists suggest future laboratory and epidemiologic studies to elucidate the relationship between tea consumption and human cancer risk.
Recent studies suggest that many plant-based dietary polyphenolic constituents are effective antioxidants in vitro. These are more effective than vitamins E or C, and thus might contribute significantly to the protective effects in vivo.
It is now possible to establish the antioxidant activities of plant-derived flavonoids in the aqueous and lipophilic phases. Moreover, scientists can assess how activities of individual polyphenols can account for the antioxidant potential of green tea.