α-Naphthoflavone is a naturally occurring compound found in Passiflora. α-Naphthoflavone is an aryl hydrocarbon receptor antagonist and inhibitor of CYP1A1 gene expression. Experiments show inhibitory properties towards cytochrome P450 enzymes, CYP1A1 (P4501A1) and CYP1A2 (P4501A2) (competetive binding) with stimulatory activities towards CYP3A4 (P4503A4) (selective binding). α-Naphthoflavone is an inhibitor of CYP19. α-Naphthoflavone is a naturally occurring compound found in Passiflora. α-Naphthoflavone is an aryl hydrocarbon receptor antagonist and inhibitor of CYP1A1 gene expression. Experiments show inhibitory properties towards cytochrome P450 enzymes, CYP1A1 (P4501A1) and CYP1A2 (P4501A2) (competetive binding) with stimulatory activities towards CYP3A4 (P4503A4) (selective binding). α-Naphthoflavone is an inhibitor of CYP19. An aryl hydrocarbon receptor inhibitor.