Antihyperglycemic, Antihyperlipidemic and Antioxidant Activities of Ethanolic Extract of <i>Helleborus niger</i> Linn Roots in Streptozotocin - Nicotinamide Induced Diabetic Rats

Abstract

Helleborus niger L (HN) is widely used in the treatment of diabetes mellitus in the Indian traditional system of medicine. Therefore, the present study was done to evaluate the antihyperglycemic, antihyperlipidemic and antioxidant activities of ethanol extract of HN root (EHN) in streptozotocin (STZ)-nicotinamide (NC) induced diabetic rats. in vitro α-amylase inhibition assay, normoglycemic study and oral glucose tolerance test were carried out in different root extracts of HN. Antihyperglycemic effect was assessed in EHN using diabetic rats, which was identied as the most effective extract by initial screening. EHN (50, 100 and 200 mg/kg) and glibenclamide (5 mg/kg) orally administered daily for 28 days and the animal was observed in next 14 days. Fasting blood glucose (FBG) and body weight was determined weekly basis up to 42 days. On the 42nd day, various biochemical parameters were estimated. The three doses of EHN shows signicantly decrease (p<0.01) in blood glucose levels. The effect was more pronounced in 200mg/kg (71.53%) than 100mg/kg (67.46%) and 50mg/kg (66.63%). In addition, decreased HbA C and improved Hb level were 1 evidenced clearly in diabetic rats. Simultaneously, improvements in serum lipid prole, serum liver prole in diabetic rats were also evidenced clearly. Moreover, body weight and protein levels were increased in diabetic rats. On the other hand antioxidant activity was restored in diabetic rats. Increased glycogen content, glucokinase and decreased glucose-6 phosphatase, fructose 1, 6-biphosphatase effects in liver tissues were observed. EHN preserved islet architecture and prevented hypertrophy of β-cells. The EHN is capable of managing hyperglycemia and complications of diabetes in STZ-NC induced diabetic rats. Hence this plant may be considered as one of the potential sources for the isolation of new oral antihyperglycemic agent(s).