Metabolism of the food mutagen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline in human hepatocytes.

2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is a heterocyclic aromatic amine formed during cooking of fish and meat (1). It is mutagenic and carcinogenic in different animal species and is suspected to play a role in the etiology of human cancer (2). Studies performed in animals and with purified human enzymes demonstrated that MeIQx is metabolized by cytochrome P450 (CYP) 1A2 in the liver and CYP1A1 and 1BI in extrahepatic tissues (3). However the metabolic pathways of MeIQx remain incompletely elucidated in humans.