ABSTRACT
Cancer is a serious disease that causes global concern. As one of the most popular beverages in the world, tea has been found to display a great variety of biological activities. Therefore, the possible effect of tea on cancer has drawn much attention in biomedical research. Epidemiological and experimental investigations have provided substantial evidence that tea may exert a blocking effect on carcinogenesis, the process of cancer development, and tea may be useful for the prevention of cancer. In addition to the blocking effect on carcinogenesis, tea and its components have shown antitumor activity, namely, active against existing cancer cells and the growth of tumors. Tea infusion, tea extracts and some tea components are reported to be active against tumors in experimental studies. Among the tea constituents tea polyphenols have been intensively investigated for antitumor activity. Those include (-)- epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epicatechin (EC).
