【Animal experiment】-Effects of total alkaloids of Dendrobium nobile on insulin resistance in rats with diabetes and non-alcoholic fatty liver

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

  Method: Through intraperitoneal injection of streptozotocin (STZ) 40 mg/kg, establish a high-fat high-sugar diet SD rats 4 weeks later, diabetes and NAFLD rat model. The model rats were randomly divided into model groups, DNLA 20 mg/kg group, DNLA 40 mg/kg group, DNLA 80 mg/kg group and metformin. 100 mg/kg group, 10 rats in each group? Set up 10 SD rats at the same time as the blank control group? 4 weeks after intragastric administration, blood was drawn from the abdominal aorta, and calculated by detecting the fasting blood glucose (FPG) and fasting insulin (FINS) levels of rats, insulation resistance index (HOMA-IR), liver and pancreas morphology HE staining Observe the changes, and detect insulin in the islets by immunohistochemistry?

  Result: Model rat FPG? FINS? Compared with the P\u003c0.05 model group, HOMA-IR in the DNLA 40 mg/kg and DNLA 80 mg/kg groups was significantly increased (FPG, FINS and HOMA-IR were significantly reduced (P\u003c0.05). Rat liver tissue has steatosis, pancreatic tissue HE staining shows pancreatic islet atrophy and islet cell reduction under the microscope. Compared with the model group, the DNLA 40 mg/kg group has less fatty liver than the model group. The number of pancreatic islet cells increased; the expression of insulin in the pancreatic islets of diabetic and NAFLD rats was significantly reduced. Is there an increase in insulin expression in the pancreatic islets in the DNLA 40 mg/kg and DNLA 80 mg/kg groups?

  Conclusion: DNLA can reduce blood sugar and liver steatosis in diabetic and NAFLD rats. Is this mechanism related to improving insulin resistance?