【Animal Modeling】-Effect of total alkaloids of Dendrobium officinale on insulin resistance in diabetic rats with non-alcoholic fatty liver disease

  OBJECTIVE: To study the effect of total alkaloids of Dendrobium officinale on insulin resistance in diabetic rats with non-alcoholic fatty liver disease (NAFLD).

  METHODS: SD rats were fed with high-fat and high-sugar diet for 4 weeks and then given intraperitoneal injection of streptozotocin (STZ) 40 mg/kg to establish a rat model of diabetes combined with NAFLD. The model rats were randomly divided into model group and DNLA 20 mg/kg kg group, DNLA40mg/kg group, DNLA80mg/kg group and metformin 100mg/kg group, 10 rats in each group. Simultaneously set up 10 SD rats as blank control. After 4 weeks of intragastric administration, blood was collected from abdominal aorta to detect rats Fasting blood glucose (FPG) and fasting insulin (FINS) levels were measured, and insulin resistance index (HOMA-IR) was calculated. H.E. staining was used to observe the morphological changes of liver and pancreas, and immunohistochemistry was used to detect insulin levels in islets.

  Results: The FPG, FINS and HOMA-IR of the model rats were significantly increased (P<0.05); compared with the model group, the FPG, FINS and HOMA-IR of the DNLA40mg/kg group and the DNLA80mg/kg group were significantly decreased (P<0.05). The liver tissue of diabetic rats suffered from steatosis, and pancreatic islet atrophy was observed under H.E. staining microscope, and the number of cells in the islet was reduced. Compared with the model group, the insulin expression in the islets of the DNLA 40 mg/kg group and the DNLA 80 mg/kg group increased to varying degrees.

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