Evaluation of antihyperglycemic and antihyperlipidaemic activity of ethanolic extract of Catharanthus roseus (Linn.) in streptozotocin-induced diabetic rats

In India, native remedies have been used in diabetes treatment. Plants have always been an ideal source of drugs and many of the plants either directly or indirectly are used to formulate the present available drugs. The present investigation was to find out the antihyperglycemic and antihyperlipidaemic effects of ethanolic leaves extracts of Catharanthus roseus in normal and streptozotocin (STZ) induced diabetic rats. Diabetes was induced in adult wistar rats by injecting streptozotocin (STZ, 50 mg/kg) intraperitoneally. The ethanolic extract of C. roseus was orally administered at 100mg/kg/day while glibenclamide was administered at 50mg/kg/day. All animals were treated for 28 days before being sacrificed. The blood glucose levels and serum lipid profile like total cholesterol (TC), triglycerides (TG), phospholipids (PL), low density lipoprotein (LDL), high density lipoprotein (HDL), very low density lipoprotein (VLDL) were determined in all the rats. The ethanolic extract of C. roseus exhibited significant reduction in blood glucose levels, TC, LDL, VLDL and an increase in HDL levels in diabetic rats when compared to the standard drugs. The above results indicate that the plant leaves are capable of ameliorating hyperglycemia in STZ induced diabetic rats. Hence this plant has a potential source for the isolation of new orally active agent for diabetes mellitus. The present investigation established pharmacological evidence to support the traditional claim of this plant being used as an antidiabetic.