胡黄连苷Ⅱ对大鼠脑缺血损伤后S100β蛋白表达的影响

关键词：胡黄连苷Ⅱ  脑缺血  S100β  大鼠

Keywords:picroside Ⅱ  cerebral ischemia  S100β  rat

摘要：

      摘要 目的：通过正交试验优化胡黄连苷Ⅱ治疗大鼠脑缺血损伤的最佳治疗时间窗和剂量。 方法：应用双侧颈总动脉结扎法建立前脑缺血模型，按照正交试验设计分组，经腹腔注射胡黄连苷Ⅱ干预治疗。应用Holzer胶质细胞染色法观察胶质细胞反应性增生，末端脱氧核苷酰基转移酶介导性dUTP缺口末端标记（TUNEL）法检测细胞凋亡，免疫组化染色和Western blotting检测神经胶质细胞标志蛋白(S100β）表达，逆转录-PCR定量检测脑组织S100β mRNA表达水平。 结果：胡黄连苷Ⅱ可以明显抑制脑缺血损伤后胶质细胞反应性增生、神经细胞凋亡以及S100β表达。其最佳治疗时间窗和剂量，根据TUNEL染色结果分析为脑缺血2.0h腹腔注射5mg/kg体重，根据免疫组化、Western blotting和RT-PCR结果分析为脑缺血1.5h腹腔注射5mg/kg体重。 结论：胡黄连苷Ⅱ可能通过抑制S100β表达减轻缺血性脑损伤。从治疗时间窗最大化和用药剂量最小化的角度综合评价，其最佳治疗时间窗和剂量为脑缺血1.5—2.0h腹腔注射5mg/kg体重。

Abstract:

      Abstract Objective: To optimize the therapeutic dose and time window of picroside Ⅱ in cerebral ischemic injury in rats by orthogonal test. Method: The forebrain ischemia models were established by bilateral common carotid artery occlusion (BCCAO) methods. The successful models were randomly grouped according to orthogonal experimental design and treated by injecting picroside Ⅱ intraperitoneally at different ischemic time with different doses. The reactive glial proliferation was evaluated by Holzer staining and the apoptotic cells counted by TUNEL detection kit. The expressions of neuroglial markers protein S100β were determined by immunohistochemistry assay and Western blotting and the S100β mRNA by RT-PCR. Result: Picroside Ⅱ could significantly suppressed the reactive glial proliferation, the expression of S100β and neuronal apoptosis. The optimized time window and therapeutic dose of picroside Ⅱ in cerebral ischemic injury were ischemia 2.0h with 5mg/kg body weight intraperitoneally according to the apoptotic cells, 1.5h with 5mg/kg body weight intraperitoneally according to the expression of S100β. Conclusion: Picroside Ⅱ might reduce ischemic brain injury by inhibiting the expression of S100β. Combined evaluation from the principle of lowest therapeutic dose with longest time window, the optimized composition of the time window and therapeutic dose of picroside Ⅱ in cerebral ischemic injury were ischemia 1.5—2.0h with 5mg/kg body weight intraperitoneally.