Résumé
In recent years, among antidiabetic medicinal herbs, Stevia received a lot of attention due to its diverse therapeutic applications. Despite extensive reports on the effects of Stevia on the pancreas, its molecular mechanism is not clear yet. In this study, we investigated the protective and preventive effects of oral extracts of Stevia on the pancreas through the stereological methods in streptozocin (STZ) induced diabetic rats. Thus, 66 adult male rats were assigned to six groups (n = 11) viz., healthy control, healthy Stevia (400 mg /kg), diabetic-control, diabetic-metformin (500 mg/kg), diabetic-Stevia and pre-Stevia-diabetic group. Treatment with Stevia significantly reduced fasting blood sugar (FBS) and MDA compared to the diabetic control group (P <0.05). The results indicated that the weight and the volume of the pancreas increased significantly in all our treated groups compared to the diabetic one (P <0.05). The volume density of the pancreatic islands and the number of beta cells increased in healthy and diabetic groups treated with Stevia (P <0.05). However, the pre-treated diabetic rats with Stevia did not show significant preventive effects on the volume and number of beta cells as well as the volume of islets against destructive effects of STZ. More specifically, our results confirmed the protective effects of Stevia through restoring pancreatic cells and repairing the stereological damage induced by STZ.