The role of human cytochrome P4503A4 in biotransformation of tissue-specific derivatives of 7H-dibenzo[c,g]carbazole

► DBC activation via CYP3A4 resulted in micronuclei, DNA adduct formation and mutations in V79MZh3A4 cells. ► The CYP3A4-mediated DiMeDBC activation caused micronuclei followed by apoptosis in V79MZh3A4 cells. ► The genotoxic effects produced by N-MeDBC in V79MZh3A4 cells were negligible. ► The hCYP3A4 may play an important role in DBC and DiMeDBC metabolism. ► The CYP3A4 might only have a marginal function in N-MeDBC metabolism.