In vitro inhibition of rat CYP1A1 and CYP1A2 by piceatannol, a hydroxylated metabolite of trans-resveratrol.

Piceatannol and its parent compound, trans-resveratrol, decreased the in vitro catalytic activity of rat CYP1A1 and CYP1A2 by mixed inhibition. trans-Resveratrol was not a mechanism-based inactivator of rat CYP1A in vitro and the administration of this compound (50 mg/kg) to rats did not affect hepatic microsomal CYP1A-mediated enzyme activity.

Lack of evidence for induction of CYP2B1, CYP3A23, and CYP1A2 gene expression by Panax ginseng and Panax quinquefolius extracts in adult rats and primary cultures of rat hepatocytes.

Treatment of rats with a single oral dose (10-30 mg/kg) of a crude Panax ginseng extract of unknown ginsenoside content has been reported to modestly increase hepatic microsomal cytochrome P450-mediated aminopyrine N-demethylation activity. In the present study, we compared the effect of P. ginseng and Panax quinquefolius extracts on rat hepatic CYP2B1, CYP3A23, and CYP1A2 gene expression.