Anti-diabetic activity of the chloroform extract of Senecio mikanioides Otto in streptozotocin induced diabetic rats

Objective: In this study, we examined the effect of oral administration of the chloroform extract of Senecio mikanioides Otto for a period of 30 days at doses of 100, 300 or 500 mg/kg body weight/day on streptozotocin induced diabetic rats. Methods: Male Sprague-Dawley rats were divided into five groups and classified into; extract treatment group received 100, 300 or 500 mg/kg body weight per day by oral gavage for 30 days; diabetic group administered intraperitoneally a single dose (75 mg/kg body weight) of streptozotocin (STZ); diabetic rats plus tolbutamide group where diabetic rats received the standard hypoglycemic drug tolbutamide (100 mg/kg body weight per day) by oral gavage for 30 days; diabetic rats plus extract group where diabetic rats received the extract (same doses) by gavage for 30 days; as well as a normal group for comparison. In all of these groups, the levels of glucose and insulin were checked in blood, while the levels of reduced glutathione (GSH), nitric oxide (NO), lipid peroxidation (TBARS) and thioredoxin reductase (TrxR) activity were measured in pancreatic tissues. Results: The results revealed that STZ administration resulted in significant elevation in the level of both TBARS and NO with depletion in the level of GSH as compared with control accompanied with hyperglycemia, hypo-insulinemia and low insulin sensitivity. Moreover, the activity of pancreatic TrxR was lower than the control group. Feeding the diabetic rats for 30 days with the extract normalizes the previous biochemical parameters in dose dependent manner reaching near the tolbutamide treated group at the highest dose. Conclusion: The chloroform extract of Senecio mikanioides Otto exhibited antidiabetic activity and it corrected the insulin level and its sensitivity in experimentally induced diabetic rats in dose dependent manner. The current results clearly indicated the beneficial effects of the chloroform extract of Senecio mikanioides Otto in both controlling hyperglycemia and the protection of the pancreatic islet cells against oxidative stress in the diabetic animals.