Enhanced Hypoglycaemic Effects of Metformin by Valsartan in a Diabetic Rat Model

Abstract

The objective of this study was to establish the effect of valsartan on the hypoglycaemic effect of metformin. Forty-four 8-week-old Sprague-Dawley rats were fed on a high fat diet or standard diet for six weeks. Diabetes mellitus was induced by administering alloxan monohydrate 120 mg/kg intraperitoneally in rats on high fat diet. Valsartan had no significant effect on blood glucose levels in non-diabetic rats. Treatment of diabetic rats with a combination of metformin and valsartan at 5mg/kg (-10.8±8.5%), 15 mg/kg (-43.0±13.7%), and 30 mg/kg (-28.6±9.1%) for 14 days resulted in significant differences in the change in blood glucose levels compared to treatment with metformin alone (+9.5±9.1%) (F=4.351; d.f.=3;16; p=0.0201). Valsartan enhanced the hypoglycaemic effects of metformin in diabetic rats after two weeks of treatment. However, valsartan did not have significant effect on glucose tolerance in both nondiabetic and diabetic rats.