Effect of an aqueous extract of Phaseolus vulgaris on plasma insulin and hepatic key enzymes of glucose metabolism in experimental diabetes

Oral administration of 200 mg/kg of aqueous extract of Phaseolus vulgaris pods (PPEt) to diabetic animals for 45 days resulted in a significant decrease in blood glucose, glycosylated haemoglobin and significant increase in total haemoglobin and plasma insulin. Similarly oral administration of PPEt to normal animals resulted in a significant hypoglycemic effect. The activities of hepatic hexokinase, glucose 6-phosphatase, fructose-1,6-bisphosphatase and glucose-6-phosphate dehydrogenase, a lipogenic enzyme, were measured in the liver of normal and experimental animals. The activities of the lipogenic enzyme and hexokinase were significantly decreased, whereas the activities of gluconeogenic enzymes were significantly increased in the diabetic liver. Both PPEt and glibenclamide reversed the activities of these enzymes to near normal levels. PPEt was more effective than glibenclamide. The results indicate that the administration of PPEt to diabetic animals normalizes blood glucose and causes a marked improvement of altered carbohydrate metabolic enzymes during diabetes.