Effect of total alkaloids of Dendrobium nobile on insulin resistance in diabetic rats with non-alcoholic fatty liver

  Objective: To study the effect of Dendrobium nobile Lindl.alkaloids (DNLA) on insulin resistance in rats with diabetes and non-alcoholic fatty liver (NAFLD).

  Methods: SD rats were fed with high-fat and high-sugar feed for 4 weeks and then intraperitoneally injected with streptozotocin (STZ) 40mg/kg to prepare rat models of diabetes with NAFLD. The modeled rats were randomly divided into model groups, DNLA20mg/ kg group, DNLA40mg/kg group, DNLA80mg/kg group and metformin 100mg/kg group, 10 rats in each group. 10 SD rats were set up simultaneously as a blank control. Blood was taken from the abdominal aorta for 4 weeks after intragastric administration. Fasting blood glucose (FPG) and fasting insulin (FINS) levels, calculation of insulin resistance index (HOMA-IR), HE staining to observe the morphological changes of liver and pancreas, and immunohistochemical detection of insulin in islets.

  Results: FPG, FINS, and HOMA-IR in model rats were significantly increased (P<0.05); compared with the model group, FPG, FINS, and HOMA-IR in the DNLA40mg/kg group and DNLA80mg/kg group were significantly decreased (P<0.05). Fatty degeneration of liver tissue of diabetic rats, pancreatic tissue HE staining showed pancreatic islet atrophy, and the number of cells in the islets decreased; DNLA40mg/kg group and DNLA80mg/kg group compared with the model group, the degree of liver steatosis was reduced, and the number of cells in the islets was higher Many, immunohistochemical detection of insulin expression in the pancreatic islets of diabetic and NAFLD rats was significantly reduced. Compared with the model group, the insulin expression in the pancreatic islets of the DNLA 40 mg/kg group and the DNLA 80 mg/kg group increased to varying degrees.

  Conclusion: DNLA can reduce blood sugar and liver steatosis in rats with diabetes and NAFLD, the mechanism is related to the improvement of insulin resistance.