Abstract

EFFECT OF GYMNEMA SYLVESTRE ON THE PHARMACOKINETICS AND PHARMACODYNAMICS OF ORAL HYPOGLYCEMIC DRUG – GLIBENCLAMIDE IN STZ INDUCED DIABETIC RATS

Shravan Kumar Dholi, Ramakrishna Raparla , Kannappan

Abstract

Effect of the Gymnema sylvestre (100 mg/kg and 500mg/kg) on the pharmacokinetics and pharmacodynamics of Glibenclamide (0.5 mg/kg and 0.6 mg/kg) was studied in STZ induced six groups of hyperglycemic rats after single dose administration and multiple dosing for 21 days. Pharmacokinetic studies revealed a decrease in the bioavailability of Glibenclamide 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 Glibenclamide did not decrease the serum glucose, urea and cholesterol levels comparable to Glibenclamide when given alone. Histopathological studies revealed that combination of Gymnema sylvestre with Glibenclamide increased the volume of islets cells of pancreas. These results indicates Gymnema sylvestre is a potent hypoglycaemic but it contributes to a decrease in hypoglycemic influence of Glibenclamide. Results have indicated the negative effect of Gymnema sylvestre on pharmacokinetics but positive effect on pharmacodynamics of Glibenclamide.

Keywords: Diabetes, glucose, Gymnema sylvestre, Glibenclamide, pharmacokinetics and pharmacodynamics.