[The inhibitory effects of epicatechin complex on diethylnitrosamine induced initiation of hepatocarcinogenesis in rats].

The inhibitory effects of epicatechin complex (ECC) on diethylnitrosamine (DEN) initiation of carcinogenesis and influences of ECC on the phenotypic changes and the levels of oncogene N-ras expression were studied in rats model with multiple small dose DEN induced liver precancerous lesion. Results showed ECC can markedly inhibit DEN induced variant cell foci and nodes, particularly OCT altered and multiple enzyme altered foci and nodes. The dot blot hybridization of the total RNA extracted from liver tissue with 32P-labelled N-ras cDNA probe showed N-ras expression decreased more in ECC treated animals than that in untreated ones. N-ras cDNA-mRNA in situ hybridization in liver sections indicated ECC can markedly inhibit the size of DEN induced variant cell foci and decrease the number of N-ras over expression lesions. Histochemical study showed that the N-ras over expression foci were corresponding to the multiple enzyme and/or OCT altered lesions. The above results showed ECC can apparently inhibit DEN induced initiation of hepatocarcinogenesis in rats.