The medicinal properties of curcumin and leonurine obtained from Curcuma longa L. and Leonuris sibiricus has demonstrated low efficiency due to their poor bioavailability and its rapid metabolism in the liver and intestinal wall. In this study, the effect of combining piperine, a known inhibitor of hepatic and intestinal glucuronidation, was evaluated on the bioavailability of curcumin and leonurine in rats. When curcumin was given alone, in the dose 200 mg/kg to rats, moderate serum concentrations were achieved over a period of 4 h. Concomitant administration of piperine 10 mg/kg increased the serum concentration of curcumin for a short period of 1-2 h post drug. Time to maximum was significantly increased (P < 0.02) while elimination half life and clearance significantly decreased (P < 0.02). The leonurine serum concentration also showed similar dissipation pattern with solely administration of leonurine alone demonstrated low accumulation as compared to co-administration with piperine. Result obtained also showed that the co-administration of both curcumin and leonurine with piperine enable to increase the bioavailability of curcumin and leonurine for about 261.11% and 154.81% respectively. In conclusion, this study has proven that the co-administration of piperine enhances the serum concentration, extent of absorption and bioavailability of curcumin and leonurine in rats with no adverse effects.
Keywords: Rats, dawley, nutri-pepper, pharmacokinetics study, sprague
