Abstract: Objective To observe the effect of kangnao liquid on the expressions of LC3 and Beclin 1 in hippocampus after cerebral ischemia-reperfusion in rats, and to discuss the mechanism. Methods A total of 48 male SD rats were randomly divided into four groups: sham-operation group, model group, kangnao liqiud group [14.30 g/(kg·d)] and edaravone group [10.00 mg/(kg·d)], 12 rats in each group. The rats in kangnao liqiud group and edaravone group were administrated by intragastric administration. The rats in sham-operation group and model group were administrated with equal volume of normal saline. After treating for 7 days, except for the sham-operation group, the middle cerebral artery occlusion (MCAO) model was made by suture method in the other three groups. After 2 h of ischemia, the rats were reperfused for 24 h. Six rats in each group were randomly selected for observing the neurological function. TTC staining was used to observe the morphology of the brain tissue and calculate the percentage of infarction. The morphology of the cerebral cortex and hippocampus was observed by HE staining in the remaining animals, and the expressions of LC3 and Beclin 1 in the hippocampus were detected by immunohistochemical staining. Results Compared with the sham-operation group, model group showed an obvious neurological deficit, and the percentage of cerebral infarction increased significantly. At the same time, nerve cells of cerebral cortex and hippocampus revealed degeneration and necrosis, stroma edema, and the expressions of LC3 and Beclin 1 in hippocampus significantly increased (P＜0.05). Compared with the model group, the neurological deficit symptoms and the percentage of cerebral infarction significantly reduced, changes of neuron morphology were lighter, and the expressions of LC3 and Beclin 1 decreased significantly in kangnao liqiud group and edaravone group (P＜0.05). Conclusion Kangnao liquid shows protective effects on cerebral ischemia-reperfusion, which may be related with the decreased expressions of LC3 and Beclin 1 in hippocampus after cerebral ischemia-reperfusion in rats.

Key words: brain ischemia, reperfusion injury, rats, Sprague-Dawley, kangnao liquid, rats, LC3, Beclin 1