Mechanism Of The Protective Effect Of Dihuang Yinzi On Brain Tissue Injury In Experimental Model Rats With Cerebral Ischemia Reperfusion

Research objective:To observe the effect of Dihuang Yinzi on cerebral ischemia reperfusion injury in model rat, to explore the mechanism of Dihuang Yinzi on experimental cerebral ischemia reperfusion animal model of brain tissue injury, to provide the experimental basis for the comprehensive study of Dihuangyinzi against cerebral ischemia injury.Research methods:1.Dihuang Yinzi on rat model of anti free radical oxidation, resistance to apoptosis in experimental studySixty clean SD rats were randomly divided into6groups:sham operation group, model group, nimodipine positive drug group, Dihuang Yinzi high, medium and low dose group.The cerebral ischemia reperfusion was established by ligating bilateral common carotid artery. Sham operation group and model group were lavaged with normal saline, Dihuang Yinzi high, medium and low dose group fed with corresponding drugs,1times a day, used in conjunction7d after molding, nimodipine preoperative30min subcutaneous injection. The activities of SOD、CAT、 GSH-PX and the content of MDA in the serum and brain of rats were observed after cerebral ischemia reperfusion. The expression of Bax、Bcl-2and Caspase-3proteins were detected after cerebral ischemia reperfusion.2. Dihuang Yinzi on promoting angiogenesis in experimental model ratSixty clean SD rats were randomly divided into6groups:sham operation group, model group, nimodipine positive drug group, Dihuang Yinzi high, medium and low dose group.The cerebral ischemia reperfusion was established by ligating bilateral common carotid artery. Model making the second day after administration, sham operation group and model group were lavaged with normal saline, Dihuang Yinzi high, medium and low dose group fed with corresponding drugs, nimodipine group administrated with nimodipine solution,1time a day, for7d. Eighth perfusion fixation from the brain, observe the change of brain hippocampus morphology by HE staining. Microvessel density(MVD) and the expression of VEGF content were detected in rat brain by immunohistochemical method. Research results:1. Dihuang Yinzi on model rat of anti free radical oxidation experiments1.1Results of anti free radical oxidation of rat serum:compared with the model group, positive drug group and decoction of Dihuang Yinzi high, medium and low dose group can significantly increase the activity of SOD, Dihuang Yinzi high, middle dose group can significantly decrease the content of MDA, Dihuang Yinzi high, middle dose group can significantly increase the activity of CAT, no significant differences between the groups on the effect of GSH-Px activity.1.2Results of anti free radical oxidation in rat brain tissue:compared with the model group, positive drug group and Dihuang Yinzi high, middle dose group can significantly increase the activity of SOD, positive drug group and Dihuang Yinzi high, medium and low dose group can significantly decrease the content of MDA, positive drug group and Dihuang Yinzi high, medium and low dose group can significantly increase the activity of CAT, Dihuang Yinzi high dose group can significantly increase the activity of GSH-Px.2. Results of Dihuang Yinzi on resistance to apoptosis in brain tissue of ratExpression of Bax protein in model rat group increased, decreased expression of Bcl-2protein, Caspase-3protein expression increased, with statistical significance compared with the sham operation group, the treatment group can reduce the Bax protein expression, increase Bcl-2protein expression, Caspase-3protein expression was decreased, there was statistical significance compared with the model group.3. Results of Dihuang Yinzi on brain hippocampus morphology changes of model ratResults of HE staining:sham operation group:brain tissue without edema, nerve cells, glial cells and capillary morphology is basically normal. Model group:the formation of typical infarct in hippocampus and surrounding brain tissue. Cerebral infarction area shows a large number of neuronal degeneration, necrosis, reduced cell body deformation, nuclear pyknosis neurons, bite phenomenon, cytoplasm is eosinophilic, known as "red neurons" change; brain edema, blood vessels around the gap increases, the infiltration of inflammatory cells. Dihuang Yinzi groups: Ischemia range than the model group, the pathological changes were slighter than those in model group. Infarction area neuronal degeneration, necrosis were little, there were a few "bite neurons phenomenon"; brain edema, vascular mild congestion, no obvious infiltration of inflammatory cells.4. Results of Dihuang Yinzi on angiogenesis in brain tissue of ratThere was no significant difference of MVD count between the model group and sham operation group, The MVD count of Dihuang Yinzi high, medium and low dose group and positive drug group increased than those of model group, the difference was statistically significant.Content of VEGF in model group was higher than in the sham operation group. Dihuang Yinzi high, medium dose group and positive drug group can increase the content of VEGF expression, the difference was statistically significant compared with the model group.Research conclusion:1. Dihuang Yinzi can significantly inhibit the activity decrease of serum of SOD、CAT and brain tissue of SOD、CAT、GSH-Px and the increase of MDA content of rat model, showed that after cerebral ischemia and reperfusion, free radical in brain tissue is increased, the lipid peroxidation was generated, Dihuang Yinzi can reduce free radical, reduce lipid peroxidation, exhibit good antioxidant effect.2. Dihuang Yinzi can downregulate Bax protein level, upregulation of Bcl-2protein, bax/bcl-2balance regulation in rat brain tissue, downregulation of Caspase-3protein levels, and inhibited apoptosis, and relieve the injury of brain tissue.3. Dihuang Yinzi can significantly improve the pathological changes in rat cerebral infarction model, reduce cerebral edema, reduce the infiltration of inflammatory cells, the function of brain nerve cells in ischemic region recovery has shown good results.4. Dihuang Yinzi can promote the expression of brain tissue of rats with the release of VEGF, promote the brain of rats with cerebral infarction ischemic neovascularization, have the effect of angiogenesis obviously.