The Study Of Shou Er Zhi Capsule To BDNF、 TrkB Gene And Protein Expression In The Rat Hippocampus Of Alzheimer’s Disease

ObjectiveObserved Shou er zhi Capsules’s effect to AD rat model of learning and memory, hippocampus morphology and hippocampus of BDNF, TrkB gene and protein expression. Explore the possible mechanism of hippocampal neuronal damage in AD pathogenesis and Shou er zhi Capsule for its protection.MethodsForty Sprague-dawley (SD) rats were divided into four groups randomly:sham-operation group, model group, Shou er zhi Group (n=10); Inject the aggregation state Aβ25-35in to the position of the surface projection of the SD rat hippocampus CA1region by Stereotaxic instrument to establish the rat model of Alzheimer’s disease; After three days of the modeling, Shou er zhi Group were given Shou er zhi capsules, Donepezil group were given Donepezil, model group and sham-operation group were given an equal volume of Sodium chloride treatment four weeks; Four weeks later, Behavioral changes were inspected to determine the learning and memory of AD rats through the Morris water maze test; HE staining to observe the morphology of hippocampal CA1neurons after the end of the learning and memory test; The levels of expression of BDNF and TrkB in erea CA1of the hippocampus was determined by immunohistochemical staining method; The Real-time Quantitative PCR was used to measure the expression of the levels of BDNF mRNA and TrKB mRNA in the hippocampus and to Observe the effect of Shou er zhi capsule to these indicators.Results1. Learning and memory tests:In the trial of five days of place navigation test, the average escape latency of each group showed a decreasing trend; The average escape latency of model group compared with the sham group was significantly prolonged (P<0.01); The average escape latency of Shou er zhi group and Donepezil group was significantly shorter than in model group (P<0.05or P <0.01), compared wi th sham-group the difference was not significant (P>0.05); The difference of Shou er zhi group and Donepezil group was not significant (P>0.05). In space exploration test, the time and the number of crossing the original platform of the former platform quadrant activities were observed, Compared with sham-group, the time and the number of crossing the original platform of the former platform quadrant activities of model group were significantly reduced (P<0.01); Shou er zhi Group and Donepezil group in the former platform quadrant activity time was significantly prolonged, and through the number of the original platform increased significantly (P<0.01). Compared with the sham group, the difference was not significant (P>0.05); Shou er zhi group and Donepezil group difference was not significant (P>0.05).2. Rat hippocampus in paraffin sections by HE staining:Sham-operation group, hippocampal CA1neurons arranged in neat rows, the structural integrity; Model group hippocampal CA1neurons in irregular arrangement of structural disorder, the cells were significantly reduced; Shou er zhi group and Donepezil group hippocampal CAl cells than the increase in the number of model group, arranged in neat, the structure is relatively complete.3.In paraffin sections of rat hippocampusby immunity tissue staining:Compared with model group, the average optical density of the BDNF and TrKB positive cells in hippocampal CAl region was significantly less than sham-operation group, and most of the cell cytoplasm is lighter, the difference (P<0.01); Shou er zhi group and Donepezil group more visible cytoplasm slightly light brown yellow granular positive cells, the mean optical density of the model group was significantl increased,the difference was significantly (P<0.01), compared with sham group, dyeing to light the average optical density of positive cells was significantly reduced, the difference was significant (P<0.01); Shou er zhi group and Donepezil group no significant differences (P>0.05).4. Rat hippocampus BDNF, TrkB gene determination:In each group of Rats BDNF mRNA and TrKB mRNA expression, model group than sham-group declined (P<0.05); Shou erz hi group and Donepezil group on an upward trend compared with model group (P<0.05), but still lower than the sham-operation group (P<0.05); Shou er zhi group compared with the Donepezil group difference was not obvious (P>0.05).Conclusion1. Injecting Aβ25-35to rats with bilateral hippocampal built AD model is stable and reliable, and good reproducibility.2. Hippocampal neurons loss and structural damage may be the A β25-35resulted in the morphological basis of the AD model rats to study and memory dysfunction. 3. The Shou’erzhi capsules improve the study and memory abil ity of Aβ25-35hippocampal injection AD model rats may be related to Bu shen tian jing, stasis, phlegm resuscitation effect, to some extent by inhibited Aβ25-35deposition in rat brain, reduce toxic injury of hippocampal neurons.4. BDNF, TrKB gene and protein expression lowered in hippocampus may be an important mechanism of Aβ25-35cause AD model rat hippocampus neuronal damage and learning and memory disorders5.BDNF, TrkB gene and protein expression upregulation in hippocampus may be an important mechanism for Shou er zhi Capsule improvement learning and memory ability and neuron protection of Aβ25-35hippocampal injection AD model rats.