Molecular Mechanisms and Biological Implications of Green Tea Polyphenol (-)-Epigallocatechin -3- gallate

Plants constitute a vital part of the biological system in which we exist and are indispensable to humans in every aspect of life. Its major percentage of naturally occurring material used as drugs by people all over the world. The use of plants as food and medicines when man started his life on this planet. Now people started to realize the value of plants as drugs after they felt the serious side effects of modern medicine. The practice of wide usage of plants as medicinal agents is prevalent for centuries in various parts of the world, the most prominent of which are Chinese system of medicine, ayurvedic, siddha and unani system of medicine in India. The realization that there is something interesting in the properties of these medicinal plants dawned with the advent of chemistry in the late 18th century. Chemists gradually started isolating pure substances from various anatomical parts of medicinal plants and concluded that certain active compounds are responsible for the therapeutic actions of the plants. It has been estimated that only 10-15 % of 2,50,000 to 7,50,000 existing species of higher plants have been surveyed for biologically active compounds for the study of its phytochemistry and pharmacology. This review paper deals with the advances in study of green tea, which is the second most consumed beverage in the Worldafter water. Green tea catechins are the flavan-3-ols found in green tea leaves, of the catechins. Out of the various catechins found in green tea, (-)-Epigallocatechin-3-gallate (EGCG) is the most abundant one in green tea leaves. It is the most potent antioxidant polyphenols associated with anti-atherogenic, antitumor and anti-mutagenic activities.