雷公藤甲素对大鼠蛛网膜下腔出血的保护作用

The neuroprotective effect of triptolide on experimental subarachnoid hemorrhage in rats

目的研究雷公藤甲素（TP）对大鼠蛛网膜下腔出血（SAH）后的脑保护作用及其机制。方法48只雄性SD大鼠，在西安交通大学医学部动物实验中心利用颈内动脉穿刺法制作大鼠SAH模型，按随机数字表法将大鼠分为对照组、SAH 3 d组、SAH 3 d＋DMSO组、SAH 3 d＋TP组，每组12只。对SAH大鼠连续给药3 d（SAH 3 d＋TP组腹腔注射TP，剂量0.2 mg/kg，间隔12 h；SAH 3 d＋DMSO组腹腔注射相同剂量DMSO）后，大鼠经心脏灌注取脑，制备脑组织切片。利用HE染色评估大鼠脑皮层的病理改变，利用TUNEL法观察皮层的凋亡情况，利用免疫组化检测小胶质细胞标志物Iba-1的表达变化，利用ELISA检测皮层炎性因子IL-6、IL-1β、TNF-α的水平。各组间比较采用单因素方差分析，组间两两比较采用LSD-t检验进行统计。结果与对照组比较，SAH 3 d组、SAH 3 d＋DMSO组、SAH 3 d＋TP组的皮层均存在细胞水肿、细胞核固缩等病理改变，凋亡细胞数明显增加［（1.50±1.29）个/视野和（39.75±4.11）个/视野、（41.75±6.08）个/视野、18.00±3.92）个/视野］（均P＜0.05），小胶质细胞标志物Iba-1表达增加［（2.20±0.96）个/视野和（20.25±4.57）个/视野、（19.50±4.93）个/视野、（10.00±4.54）个/视野］（均P＜0.05），IL-6、IL-1β、TNF-α等炎性因子的水平升高（均P＜0.05）；与SAH 3 d组比较，SAH 3 d＋DMSO组皮层的病理改变、凋亡细胞数、Iba-1的表达、炎性因子的水平均差异无统计学意义（均P＞0.05），SAH 3 d＋TP组的细胞水肿、核固缩等病理改变明显减轻，凋亡细胞数减少（均P＜0.05），Iba-1的表达减少（P＜0.05），IL-6、IL-1β、TNF-α等炎性因子的水平明显降低（均P＜0.05）。结论TP可以减轻SAH大鼠皮层的病理改变，减少细胞凋亡，抑制小胶质细胞活化，其保护作用可能与降低炎性因子的水平有关。

Objective To investigate the therapeutical effect of triptolide （TP） on subarachnoid hemorrhage （SAH） in rats and its underlying mechanisms. Methods Endovascular perforation technique was used to establish SAH models. TP was used to treat SAH rats by intraperitoneal injection. Rats were randomly divided into control group, SAH 3 d group, SAH 3 d ＋ DMSO group and SAH 3 d ＋ TP group. Pathologic change was observed in rat cortex by HE staining. Cell apoptosis was evaluated by TUNEL assay. Iba-1 considered as microglia marker was assessed by immunohistochemistry. The levels of inflammatory factors including IL-6, IL-1β and TNF-α were detected by ELISA. Results Compared with control group,pathologic changes, such as cell edema, nuclear pyknosis were more obviously; the number of apoptosis cell, the expression of Iba-1 and the level of inflammatory factors including IL-6, IL-1β and TNF-α were all increased in the cortex of SAH 3 d group, SAH 3 d ＋ DMSO group and SAH 3 d ＋ TP group （ P 〈 0.05 ）. There were no significant differences in pathologic changes, the number of apoptosis cells, the expression of Iba-1 and the levels of inflammatory cytokines in the brain cortex between SAH 3 d group and SAH 3 d ＋ DMSO group （P 〉 0. 05）. Compared with SAH 3 d group and SAH 3 d ＋ DMSO group, pathologic changes were alleviated, and the number of apoptosis cells, the expression of Iba-1 and the levels of inflammatory cytokines including IL-6, IL-1β and TNF-α were all decreased in the brain cortex in SAH 3 d ＋ TP group. Conclusion TP could alleviate the pathologic changes, reduce the cell apoptosis and inhibit the microglia activation in rat brain cortex after SAH, and the neuroprotective effect of TP might be associated with the decreased levels of inflammatory cytokines.