“…In contrast, in humans, at least three CYP450s had been identified as responsible for AFB1 bioactivation to AFBO (CYP1A2, CYP2A6 and CYP3A4) (Omiecinski et al, 1999;Hasler et al, 1999), and there was evidence that the CYP3A4 human enzyme was the most efficient . In view of this lack of information a series of studies were conducted by our group (Diaz et al, 2010a(Diaz et al, , 2010b(Diaz et al, , 2010c in order to investigate which specific avian CYP450 orthologs were responsible for the bioactivation of AFB1 into AFBO. These studies were conducted by using specific human CYP450 inhibitors ( -naphthoflavone for CYP1A1/2, furafylline for CYP1A2, 8-methoxypsoralen for CYP2A6 and troleandomycin for CYP3A4), by correlating AFBO formation with human prototype substrate activity (ethoxyresorufin O-deethylation for CYP1A1/2, methoxyresorufin Odeethylation for CYP1A2, coumarin 7-hydroxylation for CYP2A6 and nifedipine oxidation for CYP3A4) and by investigating the presence of ortholog proteins in avian liver by immunoblot using antibodies specific against human CYP1A1, CYP1A2, CYP2A6 and CYP3A4.…”