The Effects Of Xuelian Injection On TLR4/NF-κB/TNF-α Pathway After Cerebral Ischemia Reperfusion Injury In Mice

Objective: to investigate the effect of Xuelian injection on TLR4/NF-κB/TNF-αsignaling pathway in mice following focal cerebral ischemia reperfusion injury and toexplore the underlying mechanisms. Methods:96Male Kunming mice were randomlydivided into4groups: sham group, control group, Xuelian injection group and Edaravonegroup.Xuelian injection(0.6ml/kg/d) and Edaravone groups(3mg/kg) were intraperitoneal-ly administered the appropriate doses of Xuelian injection or Edaravone each day for7dbefore MCAO.control group were given the same volume of Saline. Neurologicalfunctional deficits and cerebral infarct areas were assessed24h after reperfusion. TLR4positive cells in ischemic area were studied by Immunohistochemical staining. TLR4, P65and P50mRNA expression in ischemic area were detected by RT-PCR. TNF-α level inischemic area was measured with ELISA. Results:(1) Compared with control group, theneurological deficit was significantly improved in both Xuelian injection and Edaravonegroup24h after reperfusion.(P＜0.05).(2)Compared with control group, the infarctvolume was significantly reduced in both Xuelian injection and edaravone group24h afterreperfusion (P＜0.05).(3) Compared with sham group, TLR4positive cells weresignificantly increased in ischemic area of both cortex and hippocampus in the controlgroup24h after reperfusion (P＜0.05). TLR4positive cells were significantly decreased inboth Xuelian injection and edaravone group(P＜0.05). Further we analyze TLR4mRNAexpression in ischemic area by RT-PCR; the analysis consistent with the results fromimmunohistochemistry.(4) Compared with sham group, the mRNA expression of P50andP65subunit of NF-κB were significantly increased in the ischemic area of control group24h after reperfusion detected by RT-PCR(P＜0.05). Compared with control group, P50and P65mRNA level were decreased in Xuelian injection group(P＜0.05), but only P65mRNA level was decreased in Edaravone group(P＜0.05).(4) TNF-α levels were significantly increased at24h after reperfusion in ischemic area of control groupcomparison with sham group measured by ELISA (P＜0.05). Compared with controlgroup, TNF-α levels were significantly reduced in both Xuelian injection and Edaravonegoup (P＜0.05). Conclusion: our data show that TLR4, NF-κB and TNF-α expressionwere increased following focal cerebral ischemia reperfusion injury in mice; pretreatmentwith Xuelian injection improve neurological deficit and reduce infarct volume viadown-regulate the TLR4/NF-κB/TNF-α pathway.