Neuroprotective Mechanism Of Butylphthalide Pretreatment In Cerebral Ischemia Reperfusion Injury On Sprague-dawley Rats Through NF-κB Signaling Pathway

Objective：In order to investigate neuroprotective mechanism of Butylphthalide(NBP) pretreatment in cerebral ischemia reperfusion injury on SD rats, the author willapply the method of NBP preconditioning, MCAO/R model of SD rats, TTCstaining, HE staining and immunohistochemical method to observe histopathologicalfrom of rats’brains and to evaluate the expression change of NF-κB/p65and ICAM-1.Method:36healthy adult male SD rats, weight250-280g, were randomly dividedinto3groups: sham-operative group(S group), cerebral ischemia reperfusion group(Mgroup) and NBP preconditioning group(NBP group),12for each group. NBP group wasgiven NBP preconditioning for7days before operation by intraperitoneal injection(200mg/kg/d), while the S group and M group were given the same volume0.9%NaCl.Use the Zea-Longa method to established MCAO/R(ischemia for2hours,reperfusion for24hours) model in NBP and M groups, while S group was exposedcommon carotid artery merely.After completion of MCAO/R models, refer to Zea-Longa5points scale as thestandard to grade neurological scores; use2%chlorination2,3,5-Triphenyl tetrazaliumchloride, TTC, to stain the brain slices to observe the percentage of volume of cerebralinfarction; use Hematoxylin-eosin dyeing (HE dyeing) to observe the changes of brain organization neuron; apply immunohistochemical method to evaluate the expressionchange of NF-κB/p65and ICAM-1by identifying the positive cells.Results:1. The scores of neurologic impairment:After2h ischemia and24h reperfusion,without disturbance of consciousness, rats in S group have no neurologic impairment (0score); compared with S group, M group and NBP group have obvious neurologicimpairment (1-3scores)(P＜0.01); and compared with M group, the impairment of NBPgroup is reduced(P＜0.05).2. The infarction volume:After TTC dyeing, S group is not observed any infarctionarea; compared with S group, M and NBP groups all have focal infarction area(P＜0.01);and compared with M group, the infarction volume of NBP group is smaller(P＜0.05).3. The cell form of brain tissue: All brains of S group have no pathological change,and show normal cerebral organization. The normal cells in M and NBP groupsobviously decrease, and there are a large number of degenerative nerve cells in focalinfarction which have smaller contractive volume, unclear cellular structure, disorderedarrangement, pyknosis and deep stained nuclei, cytoplasm vacuoles and cell-interstitialedema. Compared with M group, the quantities of degenerative and necrotic cells inNBP group are obviously decreased, and the degrees of the cell formation changes andtissues edema are lighter.4. Immunohistochemistry technology results: Compared to S groups, NF-κB/p65and ICAM-1positive cells expression are significantly increased in the other twogroups(P＜0.01); compared with M group, the quantities of NF-κB/p65and ICAM-1positive cells is decreased (P＜0.05).Conclusions:1. The expression of NF-κB/p65and ICAM-1are observed to take part in theprocess of cerebral ischemia reperfusion injury. The activation NF-κB signalingpathway can exacerbate the degree of cerebral ischemia reperfusion injury throughincreasing its downstream factors, such as ICAM-1, which can cause microcirculationdisorder, pro-inflammation respond, cell apoptosis, etc. 2. NBP preconditioning can attenuate cerebral ischemia/reperfusion injury, reducethe neural function defect scales, relieve neuron pathology morphological injurythrough inhibiting the activation NF-κB signaling pathway and reducing the expressionof its downstream factor, ICAM-1.3. NBP can attenuate cerebral ischemic attack, and have neuroprotective effect oncerebral ischemia/reperfusion injury.