Effect of Ethanolic Extract of Aerial Parts of Andrographis paniculata on the Pharmacokinetics of Gliclazide in Rats

Abstract

Drug Interaction is the interaction between a drug and another substance that prevents the drug from performing as expected .Complementary and Alternative Medicines(CAM) mostly by herbs is often used concomitantly with conventional medicine and its use may not be disclosed by patient to their physician which may lead to Herb-Drug interactions .The present study aims to find out any possible interaction between the herbal drug i.e., 60% ethanolic extract of aerial parts of Andrographis paniculata on the anti-diabetic drug Gliclazide as these involve metabolic reactions using CYP2C9 and CYP3A4 enzymes .In this study, three groups of Albino wistar rats of either sex were used of which Group –I was used to determine the spiked serum concentration ,group-II treated with oral Gliclazide(2mg/kg) and group-III with ethanolic extract of aerial parts of Andrographis paniculata (2gm/kg) orally for 7 days followed by Gliclazide(2mg/kg) orally on 8th day are used to determine the change in Pharmacokinetic parameters . Blood from different groups were collected from retro-orbital plexus at 1,2,3,4,6,8,12,18,24 hrs after Gliclazide administration and concentration of Gliclazide was determined by using HPLC. There was a significant increase in Cmax,Kel,T1/2 ,AUC and the percentage increase in bioavailability of 63.39% was observed in extract pre-treated group when compared to Gliclazide alone treated group which suggests the decreased metabolism of Gliclazide by Andrographis paniculata involving CYP2C9 and CYP3A4 enzymes .Thus add-on preparations containing Andrographis paniculata may be cautiously used and dose adjustment strategies are to be adopted when administered with Gliclazide to minimize the adverse effects of Gliclazide