杭白菊总黄酮对大鼠缺血/再灌损伤大脑的保护作用

Protective Effects of Total Flavones Extracted from Chrysanthemum Morifolium on Rat Brain Against Cerebral Ischemia-Reperfusion Injury

目的观察杭白菊总黄酮(total flavones extracted from chrysanthemum morifolium,TFCM)对大鼠缺血/再灌损伤大脑的影响,并初步探讨其机制。方法采用大脑中动脉内栓线梗塞法造成大鼠局灶性脑缺血/再灌损伤模型,缺血90min,再灌注22h后,以盐酸2,3,5-三苯基四氮唑染色法测定脑梗死面积,比色法测定脑组织匀浆中超氧化物歧化酶(superoxide dismutase,SOD)活性及丙二醛(malondialdehycle,MDA)含量,采用“10分法”进行神经症状评分。用荧光分光光度计检测氧自由基(reactive oxygen species,ROS)的生成;测定分离脑线粒体540nm处吸光度。结果TFCM(50,100,200mg·kg-1,ip)能明显改善脑缺血/再灌后大鼠神经症状,明显减小梗死面积与全脑面积之比,提高缺血脑组织SOD活性,降低MDA含量,并减少脑组织ROS的生成。TFCM减轻Ca2+诱导的脑线粒体肿胀,此作用可被苍术苷所拮抗。结论TFCM对大鼠缺血/再灌损伤大脑具有显著的保护作用,其作用机制可能与TFCM抗氧化作用进而抑制线粒体肿胀有关。

OBJECTIVE To investigate the effect of total flavones extracted from chrysanthemum morifolium （TFCM） on rat brain against cerebral ischemia/reperfusion injury and to analgze the mechanism. METHODS Adult male Sprague-Dawley rats were sub- jected to middle cerebral artery occlusion for 90 min followed by reperfusion for 22 h. The infarct area of brain was assessed in brain slices stained with 2% solution of 2,3,5-triphenyl tetrazolium chloride. Spectrophotometric assay was used to determine the activity of superoxide dismutase （SOD） and the content of malondialdehyde （MDA） in brain tissue. Neurological deficit was evaluated by using a 10-point neurological function scoring system. Reactive oxygen species （ROS） generation was measured spectrophotofluorometrically. The absorbance of isolated brain mitochondria at 540 nm was measured. RESULTS TFCM （50,100,200 mg·kg^-1, ip） significandy decreased neurological deficit scores and reduced the percentage of infarction in the ipsilateral hemisphere compared with the model group. TFCM significantly increased the SOD activity and decreased the MDA content, and decreased the generation of ROS in the ipsilateral hemisphere. In isolated mitochondria from rat brain pretreated with TFCM, Ca^2＋ -induced mitochondrial swelling was attenuated and this effect was antagonized by atractyloside. CONCLUSION TFCM provides significant protection against cerebral ischemia/reperfusion injury in rats via, at least partly, its antioxidant action and consequently inhibiting the mitochondrial swelling.