Hypoglycemic and Nephroprotective Effects of Aqueous Extract of Stevia rebaudiana (Sweet Fraction) in Streptozotocin-Induced Diabetic Mice

Background & objectives: Considering the prevalence of diabetes and importance of its prevention, control and treatment, using low-calorie natural sweetener is necessary. Hepatoprotective and antidiabetic properties of the aqueous extract of Stevia rebaudiana were assessed in the present study.

Methods: In this study, 35 mature male mice were divided into 5 groups. Diabetes was induced by administration of 60 mg/kg of streptozotocin intraperitoneally. The negative control group received normal saline and treatment groups received glibenclamide with 0.5 mg/kg and 200 and 400 μg/kg of aqueous extract of S. rebaudiana through gavage for 15 days, respectively. Also, one group was considered as positive control (as non-treated diabetic). On the last day, the blood glucose levels of samples were measured. After periodic acid Schiff (PAS) staining, 5μm of sections were used for stereological analysis.

Results: The blood glucose level was decreased (p<0.05) significantly in aqueous extract-treated groups compared to the untreated diabetic mice. The weight and volume of kidneys, cortex, medulla, proximal and distal tubules, collecting ducts, loop of henle, interstitial tissues, vessels and length of renal tubules decreased significantly (p<0.05) after treatment with aqueous extract of S. rebaudiana (p<0.05). The number and volume of glomeruli restored toward normal levels with high doses of S. rebaudiana.

Conclusion: According to the obtained results, aqueous extract of S. rebaudiana (sweet fraction) can regulate the blood glucose levels and inhibit diabetes-induced renal damages. It seems that S. rebaudiana can be used as an antidiabetic and nephroprotective supplement.