Neuroprotective Effect And Mechanism Of CZ-7 On Cerebral Ischemia-reperfusion Injury In Rats

ObjectiveEvaluate the efficacy of CZ-7 injection in the treatment of acute ischemic stroke through behavioral,brain tissue imaging and histological examination,and explore the possible mechanism of its therapeutic effect,providing experimental basis for CZ-7 as a medicine for treating cerebral ischemiatreatment.MethodA Sprague-Dawley(SD)male rat was used as the research object,and a middle cerebral artery occlusion(MCAO)model was established with reference to Longa’ s suture method.The experimental animals were randomly divided into a sham operation group,a model group,an edaravone(Eda,5.57 mg/kg)group,and a CZ-7 group(5 mg/kg).1.To evaluate the effect of CZ-7 on the neural function of cerebral ischemia model rats.The ZeaLonga score,beam balance test,and screen test were performed on the 1st,3rd,7th,and 14th days after modeling to observe the effects of CZ-7 on the motor function and sensory function of rats.2.To detect the changes of CZ-7 on cerebral infarction volume.On the 1st,3rd,7th,and 14th days after ischemia,small animal nuclear magnetic resonance imaging(MRI)scans were performed to detect cerebral infarction volume,paraffin sections were prepared from the materials,and neuronal damage was observed by Nissl staining.3.To explore the effect of CZ-7 on pathological damage mechanism.For rats after MRI imaging scans,brain tissues were isolated and the colorimetric method was used to detect NO content.Western Blot was used to detect inducible nitric oxide synthase(iNOS),poly[ADP-ribose]polymerase 1(Poly(ADP-ribose)polymerase 1,PARP-1)expression.Co-immunoprecipitation(Co-IP)was used to detect neuronal nitric oxide synthasen(nNOS)and post-synaptic Postsynaptic dense region protein-95(PSD-95)interaction.Result:1.Successful establishment of MCAO modelDoppler flowmeter was used to monitor the blood flow value during the model preparation process.After the stable base value was measured through a fixed optical fiber,the MCAO model was prepared,and the blood flow value was reduced to 20-30%of the base value.This proves that rat MCAO modeling was successful.2.Different doses of CZ-7 can significantly change cerebral ischemia-reperfusion injuryCZ-7 injection doses of 5.0,7.5,and 10.0 mg/kg can significantly improve cerebral ischemia-reperfusion injury in rats,and the best effective dose is 5.0 mg/kg.3.CZ-7 can significantly reduce neurological damage in rats with cerebral ischemia reperfusionNeurobehavioral evaluation was performed by ZeaLonga,beam balance test,and screen test.It was found that the neurobehavioral injury caused by MCAO in rats was effectively reduced after CZ-7 administration.For two weeks of continuous administration,the neurobehavioral damage of rats gradually reduced.At the 14th day,the behavioral examination was performed.The nerve function of the administration group was basically restored,especially the screen method was used to evaluate the nerve function.The scores of the Eda group and the CZ-7 group were similar.The sham group scored the same.4.CZ-7 can significantly reduce brain tissue damage in rats with cerebral ischemia reperfusion(1)CZ-7 reduces cerebral infarct area:The results of MRI imaging scans show that the administration of CZ-7 can reduce the infarct area after MCAO in rats.At the same time,CZ-7’ s effect of improving cerebral infarction is better than Eda.After two weeks of continuous administration,the cerebral infarct volume of rats could gradually decrease,but the rats in CZ-7 group had the least damage.(2)CZ-7 reduces neuronal damage:The effect of CZ-7 on neuronal damage was detected by Nissl staining.The results show that CZ-7 can reduce neuronal cell loss and morphological changes,improve the survival rate of neuronal cells,and reduce MCAO.Neuronal damage in the rat cerebral cortex has a significant improvement effect,but the neuron damage in the striatum is not significant.5.CZ-7 can significantly reduce NO content in damaged brain regionsThe detection results of NO content change showed that the NO content of MCAO rats decreased after CZ-7 administration.For two weeks of continuous administration,the NO content of MCAO rats gradually decreased,and the effect of CZ-7 to reduce NO content was better than Eda.6.CZ-7 can significantly reduce NO production in damaged brain regions(1)The iNOS test results showed that:compared with the sham operation group,the iNOS expression in the model group was higher on the third day than on the first day,and then gradually decreased at two time points.The expression of iNOS in the positive drug group gradually decreased from day 1,and the effect of CZ-7 was stronger than that of Eda.(2)The results of Co-IP detection of the combination of nNOS and PSD-95 showed that the expression levels of nNOS and PSD-95 in the total protein were significantly reduced in the model group,and both of them were expressed after CZ-7 treatment Water levels rise.After immunoprecipitation with nNOS and immunoblotting with PSD-95 antibody,the results on days 1 and 3 showed that the expression of PSD-95 bound to nNOS increased in the model group,while PSD-95 bound to nNOS was given after CZ-7 treatment The expression gradually decreased,and the expression level was lower than that of the Eda group.7.CZ-7 reduces nitrification stress injuryThe expression of PARP-1 showed that after continuous administration of CZ-7,the expression of PARP-1 gradually decreased,and the expression of PARP-1 in the CZ-7 group was lower than that in the Eda group.ConclusionCZ-7 can reduce iNOS and reduce the combination of nNOS and PSD-95 to reduce NO concentration in the brain,reduce cerebral ischemia-reperfusion injury,and improve neural function.