The effects of aqueous extract of stevia plant (Stevia rebaudiana) on serum concentration of vaspin and Angiopoietin-like Protein-3 in streptozotocin induced diabetic rats

Considering the importance of the prevalence of diabetes which involves approximately 6% of the world''s adult population، the need for low-calorie natural sweetener is felt more than ever. Recent studies have shown that hormones such as vaspin and Angiopoietin-like Protein3 (ANGPTL3) are associated with diabetes. The purpose of this study is to evaluate the effect of Stevia (Stevia rebaudiana) plant (as a low calorie sugar) on serum concentration of vaspin and ANGPTL3 in diabetic rats. In this case-control study، forty male wistar rats weighing 180-250 g were divided into 5 equal groups: control، diabetic control and doses of 250، 500 and 750 mg/kg/BW/day of Stevia extract treatment. Diabetes was induced by intravenous injection of Streptozotocin (60 mg/kg). After 5 days، the rats with glucose above 300 mg/dl were considered as diabetic. The Stevia treatment groups received 250، 500 and 750 mg of Stevia extract for thirty days. At the end of experiment، blood samples were obtained measurement of vaspin، ANGPTL3، triglycerides، cholesterol، HDL، glucose، insulin and ALP. Histological study of the pancreas and liver biopsy were also performed. The results of the treatment and control groups were analyzed by SPSS software and P<0. 05 was considered statistically significant. The level of alkaline phosphatase، insulin resistance index، glucose and triglyceride were decreased significantly in the groups 250 and 500 compared with the diabetic control group (p≤0. 05). However، insulin levels، HOMA. B، vaspin، ANGPTL3 and weight of the rats in all treatment groups were not significantly different from the control diabetic group. There were no histological changes in pancreatic and liver tissue following Stevia treatment. Administration of Stevia extract via reduction in serum glucose، triglyceride and insulin resistance can be effective in lowering the blood sugar and lipid، also lowering concentrations of serum alkaline phosphatase may have a protective effect on the liver. Howeve it should be considered the appropriate dosage of Stevia etract treatment is very important.