EFFECTS OF BENZIMIDAZOLE DERIVATIVES ON CYTOCHROME-P450 1A1 EXPRESSION IN A HUMAN HEPATOMA-CELL LINE

1. Induction of endogenous cytochrome P4501A1 (CYP1A1) by benzimidazol e derivatives has been investigated in the human hepatoma cell line He pG2. 2. By Northern and Western blot analysis, omeprazole has been sho wn to be a more potent inducer of CYP1A1 than both lansoprazole and E3 810, whereas pantoprazole did not induce CYP1A1. Similar results were obtained for the CYP1A1 enzyme-specific deethylation of 7-ethoxyresoru fin. 3. The induction of CYP1A1 in the permanent cell line HepG2 corre sponds to results observed in human hepatocytes in primary culture. 4. The results provide experimental evidence that HepG2 cells can be use d as an appropriate tool to examine inducing effects of drugs on the e xpression of CYP1A1.