Effect of Gymnema sylvestre on the Pharmacokinetic and Pharmacodynamic of Oral Hypoglycemic Drug - Gliclazide in Streptozotocin Induced Diabetic Rats

Abstract

Aims: Effect of the Gymnema sylvestre 100 mg/kg and 500mg/kg) on the pharmacokinetics and pharmacodynamics of (20 mg/kg and 40 mg/kg) Gliclazide. Study Design: Acute and Chronic study Place and Duration of Study: Vaageswari Institute of Pharmaceutical Sciences, Beside LMD Police Station, Ramakrishna Colony, Karimnagar, India, between january 2013 and june 2013. Methodology: Gliclazide was studied in STZ induced six groups of Diabetic rats after single dose administration and multiple dosing for 21 days. Results: Pharmacokinetic studies revealed a decrease in the bioavailability of Gliclazide when given in combination with Gymnema sylvestre. The decrease in bioavailability was contributed by decrease in absorption rate constant and increase in clearance. Where as in the pharmacodynamic study the combination in general showed decrease in serum glucose, urea and cholesterol levels that was contributed by the antidiabetic action of Gymnema sylvestre. But the combination of Gymnema sylvestre and Gliclazide did not decrease the serum glucose, urea and cholesterol levels comparable to Gliclazide when given alone. Histopathological studies revealed that combination of Gymnema sylvestre with Gliclazide increased the volume of islets cells of pancreas. These results indicates Gymnemic acid is a potent hypoglycaemic but it contributes to a decrease in hypoglycemic influence of Gliclazide. Conclusion: The negative influence of Gymnema sylvestre on pharmacokinetics but positive influence on pharmacodynamics of Gliclazide.