Effect of pomegranate juice on intestinal transport and pharmacokinetics of nitrendipine in rats.

Pomegranate juice (PJ) is known to be a potent inhibitor of human cytochromes (CYP), particularly CYP2C9 and CYP3A4. The purpose of this study was to investigate the effect of oral PJ on the pharmacokinetics of nitrendipine (10 mg/kg) in rats. The effect of PJ was also investigated on the absorption kinetics of nitrendipine in rats using a single-pass intestinal perfusion model. There was a significant increase in effective permeability, absorption rate constant and fraction of drug absorbed in the pretreated group when compared with the control group, probably due to inhibition of the P-glycoprotein-mediated efflux of the drug by PJ. In comparison with control, PJ treatment significantly increased the area under the concentration-time curve of oral nitrendipine. The peak plasma concentration of nitrendipine was also significantly increased by PJ. However, elimination half-life of nitrendipine was not altered significantly in both PJ co-administered and pretreated groups. These results suggest that PJ inhibits the intestinal metabolism of nitrendipine without inhibiting the hepatic metabolism in rats. Therefore, the concomitant use of PJ, as food supplement, and nitrendipine should be avoided, although further clinical studies need to be undertaken in order to confirm this finding.