The physiological role of green tea catechins

Green tea is one of the most popular drinks consumed in the world. Important components contained in green tea and having antioxidant and anticarcinogenic properties are catechins - organic substances belonging to the class of polyphenolic compounds. Green tea contains 4 main catechins: (-)-epicatechin, (-)-epicatechin-3-gallate, (-)-epigallocatechin and (-)-epigallocatechin-3-gallate. This review summarizes the results of key studies, predominantly performed over the last 5 years, which provide evidence that catechins in green tea protect against ultraviolet radiation, can improve the quality of life of patients suffering from cancer, cardiovascular, neurodegenerative, viral, infectious diseases, obesity and a number of other pathologies, as well as serve as a measure for the prevention of these diseases in healthy individuals. The most potent catechin found in green tea has been shown to be (-)-epigallocatechin-3-gallate. The anticarcinogenic effects of (-)-epigallocatechin-3-gallate in the case of prostate cancer, breast cancer, colorectal cancer are presented. The powerful antioxidant activity of catechins can form the basis for the prevention of the development of infectious and viral diseases, as well as improve the quality of life of patients with metabolic syndrome and obesity. Thus, green tea is not only a tonic drink, but also an important tool for the prevention and treatment of human diseases, in the pathogenesis of which free radical oxidation and oxidative stress play an important role. The areas of practical application of green tea catechins can be the treatment of malignant tumors (during a course of chemotherapy or radiation therapy), the treatment of viral, infectious and cardiovascular diseases, skin protection from ultraviolet rays, etc.