Purpose: To investigate the neuroprotective effect of Shenxiong Drop Pill (SXDP) pretreatment on rats with middle cerebral artery occlusion (MCAO) in rats, and the mechanism involved.Methods: Ninety-nine SD rats were randomly assigned to 4 groups: control group, MCAO group, shamoperated group and SXDP group. The MCAO model was established via thread occlusion. Rats in the SXDP group was administered SXDP 7 days before induction of MCAO. Neurological deficit score (NDS) was determined using Bederson's neurological behavioral scoring method, while cerebral infarction volume was measured using TTC staining. Integrated optical density (IOD) of Nissl Body was evaluated via Nissl staining. Brain water content was measured using dry-wet method. The expression level of AQP4 in brain tissues was determined using immunocytochemistry.Results: The SXDP treatment resulted in significant reduction in NDS, marked improvement in IOD of Nissl Body, and significant reductions in cerebral infarction volume, brain water content, and expression level of AQP4, relative to control (p< 0.05).Conclusion: These results suggest that SXDP pretreatment exerts neuroprotective effect against cerebral ischemia in rats by decreasing in cerebral edema through a mechanism involving downregulation of the expression of AQP4. Keywords: Middle cerebral artery occlusion, Cerebral ischemia, Aquaporins-4, Cerebral edema, Neuroprotection

Purpose: To investigate the effect of Shenxiong Drop Pill (SXDP) on cerebral infarction (CI) in rats, and the involvement of anti-inflammatory response in the process.Methods: Rats were sacrificed at three different time points, viz, 24, 48 and 72 h after establishment of CI model. Neurological deficit score (NDS) was determined using Bederson’s neurological behavioral scoring method, whereas triphenyltetrazolium chloride (TTC) staining was used to show brain injury. The integrated optical density (IOD) of Nissl bodies and caspase-3-positive nerve cells were measured with Nissl staining and SP kit, respectively. The mRNA expression of intercellular adhesion molecule 1(ICAM-1) was determined using reverse transcription-polymerase chain reaction (RT-PCR).Results: SXDP produced neuroprotective effect at high, medium, and low doses. The infarct volumes in the high-, medium- and low-dose SXDP, and cyclophosphamide groups were significantly reduced at each time point. Different doses of SXDP significantly reduced the mRNA expression of ICAM-1 and the IOD of caspase-3.Conclusion: These results indicate that SXDP exerts neuroprotective effects against ischemic injury by negatively regulating ICAM-1/caspase-3 downstream of inflammatory and apoptosis pathways.