DNA cleavage reaction and linoleic acid peroxidation induced by tea catechins in the presence of cupric ion

Tea catechins with cupric ion promoted extensive DNA cleavage and fatty acid peroxidation in vitro under aerobic conditions. Neither cupric ions nor polyphenolic compounds including catechins alone induced DNA cleavage. While catalase significantly inhibited the DNA cleavage induced by catechins-Cu2+, superoxide dismutase (SOD) did not, indicating that H2O2 is probably involved in the DNA cleavage. These results suggest that the pro-oxidant property of catechins, which are generally considered to be anti-oxidants and anticarcinogens, is responsible for the O-2 reducing ability of catechins catalyzed by cupric ion. (C) 1997 Elsevier Science B.V.