EFFECT OF TEA (CAMELLIA-SINENSIS L) ON LIPID-PEROXIDATION IN RAT-LIVER AND KIDNEY - A COMPARISON OF GREEN AND BLACK TEA FEEDING

The antioxidant effects in the liver and kidney obtained from rats fed diets containing 3% green or black tea leaf powder, which were prepar ed from the same lot tea leaves, were studied using the tissue slice-a ntioxidant evaluation method with two lipid peroxidation inducers. Aft er 50 d on the diets, liver slices prepared from green and black tea-s upplemented rats showed significant inhibitory effects against tert-bu tyl hydroperoxide-induced lipid peroxidation. These effects, however, were not proportional to the amounts of (-)-epicatechins and antioxida nt vitamins in the tea leaves. In the kidney, the antioxidant effect w as observed only in the green tea-fed group. A similar antioxidant eff ect on the kidney was observed after oral administration of a major te a polyphenol, (-)-epigallocatechin gallate (50mg/kg body weight for 7 d). Liver slices from black tea-fed rats also inhibited bromotrichloro methane-induced lipid peroxidation. These results demonstrated that di etary green and black tea had antioxidant effects on tissue lipid pero xidation ex vivo.