Mivotilate is a nontoxic, potent activator of the aryl hydrocarbon receptor (AhR), and acts as a hepatoprotective agent. IC50 & Target: Aryl hydrocarbon receptor^[1] In Vitro: Mivotilate is a nontoxic, potent activator of the aryl hydrocarbon receptor. Mivotilate (YH439) has a novel activation mode that tolerates mutation of histidine 285 to tyrosine^[1]. Mivotilate induces cytochromes P4501A1/2 (CYP1A1/2) through the aryl hydrocarbon (Ah) receptor^[3]. In Vivo: Mivotilate (YH439, 150 mg/kg, p.o.) reduces CYP2E1-mediated NDMA demethylase activity in rats, but shows no obvious effect on NADPH-dependent P450 oxidoreductase activity. Mivotilate (75-300 mg/kg) rapidly decreases immunoreactive CYP2E1 protein. Mivotilate (150 mg/kg, p.o.) inhibits the transcription of CYP2E1 in rats^[2].