[Comparative study on the inhibitory effect of green tea, coffee and levamisole on the hepatocarcinogenic action of diethylnitrosamine].

The present study aimed at clarifying whether Chinese green tea, coffee and levamisole (LMS) have similar inhibitory effect on hepatocarcinogenesis induced by diethylnitrosamine (DEN) as they had been proved in our previous aflatoxin B1 (AFB1) experiments. Male Wistar rats were divided into control (A), Green tea (B), coffee (C) and levamisole (D) groups. All rats received the same basic DEN treatment according to the program originally designed by Solt and Farber. During the two weeks before and one week after i.p. injection of DEN, the Groups B, C and D were given 2.5% green tea, 5% coffee and 0.1% LMS diet, respectively. The results demonstrated that coffee, LMS and, in particular, green tea showed inhibitory effect against DEN-induced hepatocarcinogenesis, indicating that green tea can be used as chemopreventive agent for DEN-, as well as for AFB1-induced hepatocarcinogenesis.