目的 探讨牡荆苷（VT）对急性脑缺血（ACI）再灌注大鼠的神经保护作用及对辅助性T细胞1（Th1）/Th2漂移的影响。方法 制备ACI再灌注大鼠模型，分为模型组，VT低、中、高剂量（0.94、1.88、3.76 mg/kg）组和假手术组，缺血再灌注1 h后，VT各剂量组大鼠ip不同浓度VT，假手术组和模型组大鼠ip等量生理盐水，连续3 d。观察大鼠一般状态，评估给药前后Longa神经功能评分、给药后脑组织神经元细胞形态学变化；对比各组大鼠脑组织DNA单链、双链断裂损伤率；检测大鼠脑组织中Th1、Th2标记物γ干扰素（INF-γ）、白细胞介素-4（IL-4）水平，计算INF-γ/IL-4。结果 ACI再灌注建模成功率为88.89%，建模大鼠均出现精神状态不佳现象，给药后VT各剂量组大鼠状态均有所好转。与模型组比较，VT各剂量组大鼠给药1、3 d后神经功能评分均显著降低（P<0.05），且呈剂量依赖性。HE结果显示，模型组大鼠神经元细胞体积缩小、细胞核固缩，VT各剂量组大鼠给药后神经元细胞损伤均有所减轻，其中高剂量组减轻最为明显。与假手术组比较，模型组大鼠DNA单链、双链断裂损伤率，INF-γ水平及INF-γ/IL-4较显著升高（P<0.05），IL-4水平显著降低（P<0.05）；与模型组比较，VT各剂量组大鼠DNA单链、双链断裂损伤率，INF-γ水平及INF-γ/IL-4均显著降低（P<0.05），IL-4水平显著升高（P<0.05），且呈剂量依赖性。结论 VT对ACI再灌注大鼠神经功能具有保护作用，其中VT 3.76 mg/kg保护作用最佳，可能与调节Th1/Th2细胞平衡向Th2漂移、减轻脑细胞DNA损伤有关。

Objective To investigate the neuroprotective effect of vitexin (VT) on acute cerebral ischemia (ACI) reperfusion rats and its effect on helper T cell 1 (Th1)/Th2 drift. Methods Rat models of ACI reperfusion were established and divided into model group, low, medium and high doses of VT (0.94, 1.88, 3.76 mg/kg) groups and sham operated group. After 1 h of ischemia-reperfusion, rats in different doses of VT were given different concentrations of VT by ip, and rats in sham operated group and model group were given the same amount of saline by ip for three consecutive days. The general state of rats was observed. Longa neurological score before and after administration, and morphological changes of neurons in brain tissue after administration were evaluated and compared. The damage rates of single and double strands breaks of DNA in brain tissue were compared. The levels of Th1 and Th2 markers interferon-γ (INF-γ) and interleukin-4 (IL-4) in brain tissue were measured and the INF-γ/IL-4 was calculated. Results The success rate of ACI reperfusion model was 88.89%. The mental state of rats in the model group was not good, which was improved in the three doses of VT groups after administration. Compared with model group, the neurological function scores of rats in each dose group of VT were significantly decreased 1 d and 3 d after administration (P < 0.05) in a dose-dependent manner. The results of HE showed that the volume of neurons and nucleus of neurons in model group were reduced, and the injury of neurons in VT groups was alleviated after administration, especially in high dose group. Compared with the sham operated group, the damage rates of single and double strand breaks of DNA, INF-γ level and INF-γ/IL-4 in the model group were significantly higher (P < 0.05), while IL-4 level was significantly lower (P < 0.05). Compared with the model group, the rate of DNA single-and double-strand breakage damage, INF-γ level and INF-γ/IL-4 were significantly decreased (P < 0.05) and the level of IL-4 was significantly increased (P < 0.05) in each dose group of VT in a dose-dependent manner. Conclusion VT has protective effect on nerve function in ACI reperfusion rats, and with the best protective effect at dose of 3.76 mg/kg, which may be related to regulating the balance of Th1/Th2 cells to shift to Th2 and alleviating DNA damage in brain cells.