黄芩茎叶总黄酮预处理对脑缺血再灌注大鼠海马Fas, FasL的表达和抗氧化能力的影响

目的:探讨黄芩茎叶总黄酮(scutellaria baicalensis stem-leave total flavonoid,SSTF)预处理对局灶性脑缺血再灌注(I/R)大鼠海马的保护作用及其机制.方法:60只SD大鼠随机分为3组,假手术组、缺血再灌注组和SSTF预处理组.SSTF预处理组术前1周给予SSTF 100 mg·kg-1·d-1,其余两组给等量PBS.各组大鼠分别灌胃给药1周后,采用线栓法制备局灶性脑缺血再灌注模型,缺血2h再灌注24 h后观察海马区病理形态学改变及神经元密度,检测海马Fas,FasL蛋白的表达和海马组织中谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量及乳酸脱氢酶(LDH)活性的改变.结果:SSTF预处理可减轻损伤海马组织的病理学改变,使存活的神经元增加(180±13.2).与I/R组比较,SSTF预处理组海马Fas,FasL阳性细胞明显减少(分别为13.26±3.18,19.08±2.76).SSTF预处理可降低缺血再灌注引起的海马组织MDA含量增加(P＜0.05),提高GSH-Px,LDH酶活性(P＜0.01).结论:SSTF预处理对I/R损伤海马具有保护作用.其作用机制可能与下调Fas,FasL表达和提高I/R大鼠海马组织抗氧化能力有关.

Effect of Scutellaria baicalensis Stem-leave Total Flavonoid on Fas and FasL Expression and Anti-oxidation in Hippocampal Neurons of Rats Induced by Focal Ischemia Reperfusion

Objective: To investigate the protective effects and mechanisms of Scutellaria baicalensis stem-leave total flavonoid (SSTF) preteratment on focal cerebral ischemia reperfusion injury in rat hippocampus. Method: Sixty SD rats were randomly divided into 3 groups as following:sham operation group, ischemia reperfusion group, and SSTF pretreated group. Rats of SSTF were perfused with SSTF, other two groups were given PBS solution instead of SSTF equally in a week before the operation. The model of focal cerebral ischemia reperfusion was reproduced by the suture embolic method after treated with SSTF 1 week. After 2 h of occlusion and 24 h reperfusion, morphological changes of hippocampus neurons were observed. The activity of (glutathione peroxidase,GSH-Px) and (lactate dehydrogenase, LDH), and the content of (malondialdehyde MDA) in hippocampus tissue were measured by colorimetric methods. Fas and FasL expression in the hippocampus were determined by immunohistochemical methods and analyzed by a microimage analysis system. Result: SSTF pretreatment can alleviate the pathological changes in hippocampus area. Compared with I/R group, the positive cell count of Fas and FasL was decreased significantly in SSTF preteratment group. SSTF decreased the content of MDA and increased the activity of GSH-Px and LDH in hippocampus tissue. Conclusion: SSTF pretreatment can ameliorate hippocampus damage induced by focal cerebral ischemia reperfusion in rats, which may be related to down-regulation of Fas and FasL protein expression and increase the anti-oxidant ability of cerebral ischemia reperfusion rats.