A comparative study of antihyperglycemic effect of Gymnema sylvestre and metformin in streptozotocin induced diabetic rats

Background: Diabetes mellitus (DM) is a metabolic disorder that has the phenotype of hyperglycemia. According to World Health Organization (WHO) there were 65.1 million diabetics in India in 2013, International Diabetes Federation estimates this to increase to 190 million by 2035. Although a number of drugs are available for treatment of DM, their cost and safety profile are major concern. Medicinal plants are used by clinicians for treatment of diabetes. Gymnema sylvestre (GS) extract has been reported to increase insulin levels in diabetic rats. This study was designed to compare the antihyperglycemic effect of Gymnema sylvestre with metformin.Methods: Diabetes was induced in Sprague-Dawley rats using streptozotocin 45mg/kg. Methanolic extract of Gymnema sylvestre 120mg/kg p.o. prepared using Soxhlet apparatus.Results: GS extract reduced blood glucose levels but not statistically significant. GS extract increased HDL and triglycerides, reduced both serum ALT and AST but no statistical significance seen. Metformin significantly increased serum urea, which was not seen in GS extract group. GS extract showed regenerative changes in pancreas, liver and kidney.Conclusions: The study investigation demonstrates that methanolic extract of GS possesses antihyperglycemic and hypolipidaemic activity and so it can be considered as a promising natural remedy in a prediabetic state and in mild hyperlipidaemia to prevent its progression. Increase in β cell regeneration activity could be a probable mechanism of action. However, further long term clinical studies are recommended to define its possible role in diabetes mellitus and hyperlipidaemia. Role of GS as a potential hepatoprotective agent also needs further evaluation