Effect of Rebaudioside A, a diterpenoid on glucose homeostasis in STZ-induced diabetic rats

J Physiol Biochem. 2012 Sep;68(3):421-31. doi: 10.1007/s13105-012-0156-0. Epub 2012 Feb 29.

Abstract

Rebaudioside A (Reb A), a major constituent of Stevia rebaudiana, was recently proposed as an insulinotropic agent. The aim of this investigation was to evaluate the antihyperglycemic effect of Reb A on the activities of hepatic enzymes of carbohydrate metabolism in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in adult male Albino Wistar rats, weighing 180-200 g, by a single intraperitoneal injection at a dose of STZ (40 mg/kg body weight). Diabetic rats showed significant (P<0.05) increase in the levels of plasma glucose and glycosylated hemoglobin and significant (P<0.05) decrease in the levels of plasma insulin and hemoglobin. Activities of gluconeogenic enzymes such as glucose-6-phosphatase and fructose-1,6-bisphosphatase were significantly (P<0.05) increased while hexokinase and glucose-6-phosphate dehydrogenase were significantly (P<0.05) decreased in the liver along with glycogen. Oral treatment with Reb A to diabetic rats significantly (P<0.05) decreased blood glucose and reversed these hepatic carbohydrate metabolizing enzymes in a significant manner. Histopathology changes of pancreas confirmed the protective effects of Reb A in diabetic rats. Thus, the results show that Reb A possesses an antihyperglycemic activity and provide evidence for its traditional usage in the control of diabetes.

MeSH terms

  • Animals
  • Blood Glucose / metabolism*
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / metabolism*
  • Diterpenes, Kaurane / pharmacology*
  • Diterpenes, Kaurane / therapeutic use
  • Glucose-6-Phosphatase / metabolism
  • Glucosephosphate Dehydrogenase / metabolism
  • Glycogen / metabolism
  • Hypoglycemic Agents / pharmacology*
  • Hypoglycemic Agents / therapeutic use
  • Liver / drug effects
  • Liver / enzymology
  • Liver / metabolism
  • Male
  • Rats
  • Rats, Wistar
  • Streptozocin

Substances

  • Blood Glucose
  • Diterpenes, Kaurane
  • Hypoglycemic Agents
  • Streptozocin
  • Glycogen
  • rebaudioside A
  • Glucosephosphate Dehydrogenase
  • Glucose-6-Phosphatase