[Borneol is an inducer of rat hepatic CYP2D activity in vivo]

Borneol is a traditional Chinese medicine. In the past few years, many studies showed that borneol can improve the bioavailability of other drugs, promoting drugs to cross the blood-brain barrier, so the potential drug interactions between borneol and other medicines have attracted great attention, but the influence of borneol to CYP450 and its isoforms are rarely reported. In this research, male Wistar rats were orally administered by borneol for 7 days, then the mRNA and protein expression and the activities of CYP2D were detected, we also compared the pharmacokinetic parameters of CYP2D's specific substrate between control group and borneol group. The results show that borneol (33, 100 and 300 mg x kg(-1) x d(-1)) have no significant effect on CYP2D, while the activites of CYP2D increased 1.71, 1.97 and 2.89 times comparing to the control group. At the same time, borneol (300 mg x kg(-1) x d(-1)) caused the C(max) decreased 10.6% (P > 0.05), AUC(0-∞) decreased 27.5% (P < 0.01), CL/F increased 41.1% (P < 0.01), V(z)/F increased 23.1% (P > 0.05) of dextromethorphan. Our data provided that borneol speed up dextromethorphan's elimination in vivo. Since the activity of CYP2D can be induced by borneol, the metabolic interactions might happen when borneol and the substrate drug CYP2D are used together.