中文摘要：

目的探讨雪莲提取物预处理对脑缺血再灌注小鼠脑组织Toll样受体4（Tolllikereceptor4，TLR4）和核因子-κB（nuclearfactor-κB，NF-κB）表达的影响及其可能的神经保护机制。方法72只昆明小鼠随机分为假手术组、生理盐水组、雪莲提取物组以及依达拉奉组，每组18只。雪莲提取物组经腹腔给予雪莲注射液0．8g／kg，依达拉奉组给予依达拉奉3mg／kg，生理盐水组给予同体积生理盐水。连续给药7d后制作大脑中动脉闭塞（middlecerebralarteryocclusion，MCAO）模型，应用2,3，5一氯化三苯基四氮唑染色测定脑梗死体积，应用免疫组织化学染色法检测缺血脑组织TLR4阳性细胞，逆转录聚合酶链反应检测TLR4和NF—κBmRNA表达。结果生理盐水组、雪莲提取物组和依达拉奉组小鼠脑梗死体积分别为（131．55±28．25）mm3、（84．10±13．92）mm3和（65．10±6．78）mm3，存在显著性差异（F=10．158，P=0．012）。雪莲提取物组（P=0．020）和依达拉奉组（P=0．005）梗死体积均显著小于生理盐水组，而雪莲提取物组与依达拉奉组无显著性差异。生理盐水组缺血侧皮质和海马区TLR4阳性细胞数显著多于假手术组（P均〈0．001），雪莲提取物组和依达拉奉组皮质和海马TLR4阳性细胞数均显著少于生理盐水组（P均〈0．05），而雪莲提取物组与依达拉奉组无显著差异。生理盐水组TLR4、p50和p65mRNA表达均较假手术组显著上调（P均为0．000）。雪莲提取物能显著下调缺血再灌注24h时的TLR4、p50和p65mRNA表达（P均为0．000）；依达拉奉能显著下调TLR4和p65mRNA表达（P均为0．000），对p50mRNA表达有下调趋势（P=0．053）；而雪莲提取物组与依达拉奉组之间TLR4和p65mRNA表达均无显著性差异。结论雪莲提取物预处理能显著缩小脑梗死体积，下调TLR4和NF-κB亚基表达，通过抑制缺血后炎症反应发挥神经保护作用。

英文摘要：

Objective To investigate the effects of Saussurea involucrata extract pretreatment on the expression of the Toll-like receptor 4 （TLR4）/nuclear faetor-κB （NF-κB） in focal cerebral ischemia/reperfusion in mice and its possible neuroprotective mechanism. Methods Seventy-two Kunming mice were randomly divided into four goups： sham operation, saline, Saussurea involucrata extract, and edaravone groups （n = 18 in each group）. Saussurea involucrata extract 0.8 g/kg was given intraperitoneally in the Saussurea involuerata extract group; edaravone 3 mg/kg was given in the edaravone group; and the same volume of saline was given in the saline group. A model of middle cerebral artery occlusion （MCAO） was induced after 7 days of continuous injection. Cerebral infarct volume was determined by 2,3,5-triphenyltetrazolium staining, Immunohistochemieal staining was used to detect TLR4-positive cells in ischemic brain tissue. Reverse transcriptase polymerase chain reaction was used to detect the expression of TLR4/NF-KB mRNA. Results The cerebral infarct volume in micein the saline, Saussurea involucrata extract and edaravone groups was 131.55± 28.25 mm3, 84. 10± 13.92mm3 and 65. 10 ± 6. 78 mm3, respectively. There were significant difference （F = 10. 158, P = 0. 012）. The infarct volume in the Sanssurea involuerata extract group （P =0. 020） and edaravone group （P0. 005） was significantly less than that in the saline group, and there was no significantly difference between the 2 groups. The numbers of cortex and TLR4 positive cells in hippocampus area at the ischemic sides in the saline group were significantly more than those in the sham operation group （all P 〈0. 001）. The numbers of positive cells of cortex and TLR4 in the Saussurea involuerata extract group and the edaravone group were significantly decreased compared to the saline group （all P 〈 0. 05）, and there was no significant differences between the Saussurea involucrata extract group and the edaravone group. The expressio