Cytochrome P450 (CYP) oxidases are among the main metabolizing enzymes that are responsible for the transformation of xenobiotics, including clinically important drugs. Their activity can be influenced by several compounds leading to decreased efficacy or increased toxicity of co-administered medicines. Flavonoids exert various beneficial effects on human and animal health; therefore they are used as food and feed supplements. However, they are also well-known for their CYP modulating potential. Since the amount of CYP enzymes is highest in the liver, interaction studies are mainly conducted in hepatocytes, however, CYP activity in the gastrointestinal tract is also remarkable. In this study, effects of apigenin (API), quercetin (QUE) and their methylated derivatives trimethylapigenin (TM-API), 3-O-methylquercetin (3M-QUE) and 3',7-di-O-methylquercetin (3'7DM-QUE) on the CYP enzyme activity was examined in IPEC-J2 porcine intestinal epithelial cells. Potential food-drug interactions were studied using flavonoid treatment in combination with inducer and inhibitor compounds. API, TM-API, QUE and 3M-QUE significantly inhibited the CYP3A29 enzyme, while 3'7DM-QUE did not alter its activity. Enzyme inhibition has also been observed in case of some food-drug combinations. Our results support previous findings about CYP modulating effects of flavonoids and highlights the possibility of interactions when flavonoid-containing supplements are consumed during drug treatments.
Keywords: CYP3A29; CYP3A4; IPEC-J2; apigenin; flavonoids; quercetin.