Antihyperglycaemic Effect of Tetrahydrocurcumin and Pterostilbene: Effect on Key Metabolic Enzymes of Carbohydrate Metabolism in Streptozotocin Induced Diabetes

Abstract

This study is to assess the glucose lowering activity of tetrahydrocurcumin (THC) and pterostilbene (PTS), in diabetes induced rats by streptozotocin (STZ) and nicotinamide. Diabetic rats were treated THC (80 mg/kg body weight) and PTS (40 mg/kg body weight) for 45 days, after which activities of hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, sorbitol dehydrogenase in liver and glycogen content in liver and muscle were assayed. The activities of gluconeogeneic enzymes were significantly increased, whereas the activities of hexokinase, glucose-6-phosphate dehydrogenase and glycogen were significantly decreased in diabetic control rats. Both THC and PTS were able to restore the altered enzyme activities to almost near normal levels. THC was more effective than PTS. Our results indicate that administration of THC and PTS to diabetic animals normalizes blood glucose and causes marked improvement of altered carbohydrate metabolic enzymes during diabetes. The THC administration showed more effective than PTS and metformin.