Pharmacokinetic drug interactions between apigenin, rutin and paclitaxel mediated by P-glycoprotein in rats.

The aim of present study was to investigate the effects of apigenin and rutin on the pharmacokinetics of paclitaxel after oral administration of paclitaxel with apigenin and rutin to rats. Paclitaxel (40 mg/kg) was administered orally alone and in combination with apigenin and rutin (10, 20, and 40 mg/kg) for 15 consecutive days. In the single-dose pharmacokinetic study (SDS), blood samples were collected on 1st day whereas on 15th day in the multiple-dose pharmacokinetic study (MDS). The plasma concentrations of paclitaxel were increased dose-dependently in the combination of apigenin and rutin compared to that of paclitaxel control in SDS and MDS (p < 0.01). The areas under the plasma concentration-time curve (AUC) and the plasma peak concentrations (C max) of paclitaxel with apigenin and rutin were significantly higher (p < 0.01) than that of the control. The AUCs and C max of paclitaxel were increased with apigenin and rutin in the dose-dependent manner. The half-life (t 1/2) was significantly longer than that of the control. Non-everted sacs were filled with paclitaxel 100 μM in the presence and absence of verapamil (50 μM), apigenin, and rutin (50, 100 μM) and incubated at 37 ºC for 60 min. The absorption of paclitaxel was increased in the presence of apigenin, rutin, and verapamil, a typical P-glycoprotein and Cyp3A4 inhibitor. If these results are confirmed in humans in a clinical setting, the paclitaxel dose should be adjusted when it is given concomitantly with apigenin and rutin.