Efficacy of asiatic acid, a pentacyclic triterpene on attenuating the key enzymes activities of carbohydrate metabolism in streptozotocin-induced diabetic rats

Abstract

Asiatic acid (AA), a triterpenoid derivative of Centella asiatica, has shown significant biological effects of antioxidant and anti-inflammatory activities. Aim of this investigation was to evaluate the antihyperglycemic effect of AA on the activities of hepatic enzymes of carbohydrate metabolism in streptozotocin (STZ)-induced diabetic rats. To induce diabetes mellitus, rats were injected with streptozotocin intraperitoneally at a single dose of 40mg/kg b.w. Diabetic rats showed significant (p<0.05) increased in plasma glucose, glycosylated hemoglobin and significant (p<0.05) decreased in circulating insulin and hemoglobin. The altered activities of key enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase of carbohydrate metabolism significantly (p<0.05) increased whereas hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase and glycogen content significantly (p<0.05) decreased in the liver of diabetic rats and also increased activities of aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP). Oral administration of AA (5, 10 and 20mg/kg b.w.) and glibenclamide (600μg/kg b.w.) to diabetic rats for 45days prevented the above alteration and reverted to near normalcy. Protection of body weight loss of diabetic rats by AA was also observed. No significant effect was observed in normal rats treated with AA (20mg/kg b.w.). In this search, AA found to be potential bioactive compound to regulate the carbohydrate metabolism by modulating the key regulatory enzymes in diabetic rats. These findings merit further research in this field.