INFLUENCE OF PIPERINE ON THE PHARMACOKINETICS OF CURCUMIN IN ANIMALS AND HUMAN VOLUNTEERS

The medicinal properties of curcumin obtained from Curcuma longa L. ca nnot be utilised because of poor bioavailability due to its rapid meta bolism in the liver and intestinal wall, In this study, the effect of combining piperine, a known inhibitor of hepatic and intestinal glucur onidation, was evaluated on the bioavailability of curcumin in Fats an d healthy human volunteers. When curcumin was given alone, in the dose 2 g/kg to rats, moderate serum concentrations were achieved over a pe riod of 4 h. Concomitant administration of piperine 20 mg/kg increased the serum concentration of curcumin for a short period of 1-2h post d rug. Time to maximum was significantly increased (P < 0.02) while elim ination half life and clearance significantly decreased (P < 0.02), an d the bioavailability was increased by 154%. On the other hand in huma ns after a dose of 2g curcumin alone, serum levels were either undetec table or very low. Concomitant administration of piperine 20 mg produc ed much higher concentrations from 0.25 to 1 h post drug (P < 0.01 at 0.25 and 0.5 h; P < 0.001 at 1 h), the increase in bioavailability was 2000 %. The study shows that in the dosages used, piperine enhances t he serum concentration, extent of absorption and bioavailability of cu rcumin in both rats and humans with no adverse effects.