Silkworm Extract Ameliorates Type 2 Diabetes Mellitus and Protects Pancreatic β-cell Functions in Rats

Abstract

Objective: The aim of the present study was to investigate the hypoglycemic effects of silkworm extract (SE) on experimental type 2 diabetes mellitus (T2DM) rats. Methods: SE was prepared by dissolving freeze-dried silkworm powder in 70% (v/v) aqueous ethanol. T2DM rats were induced by feeding them a high fat diet and an intraperitoneal injection of streptozotocin (STZ). The blood glucose, free fatty acid (FFA), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α) and superoxide dismutase (SOD) levels were detected by enzyme-linked immunosorbent assay (ELISA). The quality of SE was controlled by high performance liquid chromatography (HPLC; Agilent 1260, Agilent, USA). Hematoxylin-eosin (HE) staining was performed for histological evaluation. Antibody expression was assessed via immunohistochemistry (IHC) staining. Results: SE could improve insulin resistance and islet cell function by reducing FFA, MDA and TNF-α levels and increasing SOD level. In addition, pancreatic HE staining analysis revealed that SE has a protective effect on islet β-cells. Conclusions: The present study indicates that SE has hypoglycemic as well as pancreatic protective effects in T2DM model rats.

Keywords

• Silkworm extract
• Hypoglycemic activity
• Type 2 diabetes mellitus (T2DM)
• Insulin resistance
• Pancreatic protection