The possible effects of the aqueous extract of Stevia Rebaudiana on autophagic clearance and sympathetic nerve density in pancreatic β cells of type 2 diabetic rats

Abstract

Background: Diabetes mellitus (DM) is a common metabolic disorder affecting more than 400 million people worldwide. Pancreatic islet cell failure due to partial loss or dysfunction of islet cells is a common feature in type 2 DM. The aim of this study to assess the possible protective role of aqueous extract of stevia on pancreatic β cells of type 2 diabetic rats. Methods: Thirty-two male Sprague Dawley rats were divided into four groups; control, control received stevia, type 2 DM and type 2 DM treated with stevia. For all groups; fasting blood glucose, fasting insulin, pancreatic Malondialdehyde (MDA) and Catalase (CAT) were measured. Western blot analysis for measuring LC3 (microtubule associated protein-1 light chain-3) and LAMP2 (lysosomal associated membrane protein 2) was done. Also, histopathological, histomorphometric studies and tyrosine hydroxylase (TH) and norepinephrine (NE) expression by immunostaing in pancreatic tissues were detected. Results: Type 2 DM resulted in a significant increase in fasting blood glucose, pancreatic MDA, LC3 and LAMP2 expression, TH and NE density with a significant decrease in fasting insulin, pancreatic CAT, pancreatic islet area, the number of islets per unit area and the number of β cell per islet. Also, treatment with stevia extract significantly improved the laboratory and histopathological features of pancreas Conclusion: Stevia extract has protective effects on type 2 DM pancreas by its hypoglycemic and antioxidant actions in addition to its ability to attenuate hyperactive autophagy and sympathetic nerve density.

Keywords

• type 2 Diabetes mellitus
• Stevia Rebaudiana
• Autophagy, antioxidant
• Sympathetic nerve density, pancreatic islets