| Objective: The model of type 2 diabetic rats was prepared and treated with Tangutorum Nitraria Bobr extract to observe the effects of Tangutorum Nitraria Bobr on cognitive function,hippocampal morphology and ultrastructure of neuronal organelles in diabetic rats.Method: The rat model of type 2 diabetes mellitus was established by 12 weeks high-fat diet and one injection of STZ via tail vein.Thirty male SD rats,aged 4 weeks,weighing 80–100 g,were randomly divided into 2 groups: group A: normal control group(NG,n=10)ordinary diet,group B: high-fat diet + STZ group(HFD+STZ,n=20)High-fat diet.At the end of the 12 th week,oral glucose tolerance and insulin tolerance tests were performed in the two groups,and then the type 2 diabetic model was established by injecting streptozotocin 25mg/kg into the tail vein.The random blood glucose level?16.7 mmol/L on the 7th day after streptozotocin injection was taken as the model standard.After the success of the model,the rats were fed for 8 weeks,the rats in group B were randomly divided into model group(DM)and Tangutorum Nitraria Bobr treatment group(DM+NTB),SD rats of the same age served as normal control group.Four weeks after administration,the spatial learning and memory ability of the rats was tested by Morris water maze.The rats were anesthetized by intraperitoneal injection of 10% chloral hydrate,the blood of the abdominal aorta was taken for examination,the brain was immediately decapitated,the hippocampus and cerebral cortex were separated on the ice,and the samples were taken.The morphological changes of the specimens were observed by HE staining and the ultrastructure of meridian organelles in the hippocampus was observed by transmission electron microscope.During the experiment,the body weight and blood glucose of the rats were measured weekly,and the general conditions of the rats(food intake,water intake,hair luster,bedding humidity and mental status)were observed.Results:1.Compared with the normal control group,the body weight of rats fed with high-fat diet increased significantly at the end of 12 weeks(P),and the body weight decreased after streptozotocin intervention(P).There was no difference in food intake,drinking water and urine volume before streptozotocin intervention.After the intervention of streptozotocin,the rats in the normal control group had good mental condition,sensitive response,free movement,bright eyes,flat and shiny hair,dry bedding,and no significant changes in food intake or water intake compared with before.The rats of type 2 diabetes model were dispirited,slow to respond,dull hair,tired and lazy,wet cushion,and significantly increased food intake and drinking water.2.Compared with the normal control group,the glucose tolerance and insulin tolerance test were abnormal in the high-fat diet combined with streptozotocin intervention group.3.In the Morris water maze,the learning and memory ability of type 2 diabetic rats decreased,the escape latency was significantly prolonged,and the number of crossing the target quadrant platform decreased.The intervention of Tangutorum Nitraria Bobr extract can shorten the escape latency and increase the percentage of stay in the target platform quadrant and the number of times crossing the platform of type 2 diabetic rats.4.Through HE staining and transmission electron microscope,it was found that the intervention of Tangutorum Nitraria Bobr extract could improve the abnormal morphology and structure of hippocampus in type 2 diabetic rats.Conclusion:1.The diabetic model of SD rats can be successfully established by 12 weeks of high-fat diet combined with tail vein injection of low-dose streptozotocin,and the spatial learning and memory ability of this model is decreased after 8 weeks of continuous feeding.2.Nitraria tangutorum fruit extract can improve cognitive dysfunction and protect hippocampal neurons in type 2 diabetic rats. |
PDF Full Text Request