Differential inductive profiles of hepatic cytochrome P450s by the extracts of Sophora flavescens in male and female C57BL/6JNarl mice

Aim of the studySophora flavescens has been used as an antipyretic and analgesic agent. To assess the possible herb–drug interaction, effects of S. flavescens extracts on hepatic cytochrome P450 (P450, CYP) enzymes were studied.Materials and methodsEffects of the extracts prepared by three different pharmaceutical companies on P450 enzymes were investigated in male and female C57BL/6JNarl mice.ResultsIn male mice, extract 1 caused a dose- and time-dependent increase of 7-ethoxyresorufin O-deethylation (EROD) activity. Three-day treatment with 3 g/kg extracts 1–3 elevated EROD, 7-pentoxyresorufin O-dealkylation (PROD), coumarin hydroxylation, and nifedipine oxidation (NFO) activities. In female mice, extracts 1 and 2 increased EROD and PROD activities without affecting coumarin hydroxylation and NFO activities. However, extract 3, which lacked prenylated flavonoids, caused an induction profile in females the same as in males. Treatment with extract 3 fortified with prenylated flavonoids restored the gender difference. An alkaloid, oxymatrine was present in all extracts and increased EROD and PROD activities. At a human equivalent dose (0.18 g/(kg day)), all extracts increased EROD activity.ConclusionsThese results revealed that Cyp1a had a lower induction response threshold. Oxymatrine contributed at least partly to the P450 induction by S. flavescens. At a higher dose, Cyp2a, Cyp2b, and Cyp3a could be induced and the male-specific induction of Cyp2a and Cyp3a was associated with the presence of prenylated flavonoids.

Sophora flavescens extracts 1 and 2 elevated liver microsomal oxidation activities toward coumarin and nifedipine in male, but not in female mice. Extract 3, which lacked prenylated flavonoids, did not show this gender difference. Treatment with extract 3 fortified with prenylated flavonoids rebuilt this difference.Figure optionsDownload as PowerPoint slide