Pavani Uppu and Narsimha Reddy Yellu*
Kaempferol is a natural flavonoid found in many green leafy vegetable plants and it shoes inhibitory action on P-450 (CYP) enzymes. Most of the antidiabetic drugs were metabolized by different CYP enzymes. The present study was conducted in normal and diabetic rats to know the effect of kaempferol on pharmacokinetics and pharmacodynamics of sitagliptin. The rats were administered with different doses of sitagliptin (25mg/kg), kaempferol (30mg/kg) and combination of both. The peak plasma concentration, AUC was increases whereas volume of distribution, clearance was decreases in both normal and diabetic rats. Pharmacodynamics like blood glucose level was decreased during the study period. This is mainly due to inhibition of CYP3A4 enzyme activity by kaempferol and thereby bioavailability of drug in rat serum was increases. Kaempferol significantly decreases the metabolism of sitagliptin and combination of herb-drug has more beneficial effect in diabetic rats. Key words: Kaempferol, CYP enzymes, Sitagliptn, Streptozocin, Pharmacokinetics (pk) and pharmacodynamics (pd).