灯盏花素对缺血再灌注诱导小鼠学习记忆损伤的保护作用

 目的探讨灯盏花素对脑缺血再灌注诱导小鼠学习记忆损伤的保护机制。方法双侧颈总动脉结扎法建立重复前脑缺血再灌注模型。小鼠随机分为假手术组、模型组、阳性药物对照组(银杏叶提取物,35mg·kg^-1,ip)和灯盏花素治疗组(80,20,5mg·kg^-1,ip)。小鼠适应3d后,灯盏花素治疗组和阳性药物对照组分别腹腔注射灯盏花素和银杏叶提取物,连续给药7d。模型组和对照组在相同时间点注射等量生理盐水。第7天给药30min后,用1.275g·kg^-1乌拉坦腹腔注射麻醉小鼠,重复缺血再灌注手术。术后第2天用开场行为模型检测小鼠在新异环境中的自发行为;第3天用水迷宫检测小鼠学习记忆能力;用紫外分光光度计检测脑组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;同时检测灯盏花素对H₂O₂引起红细胞溶血的影响。结果前脑重复缺血再灌注并没有明显影响小鼠在新异环境中的自发活动和探究行为,但使小鼠的学习记忆能力显著下降,同时伴随脑内SOD活性降低和MDA含量升高。5,20和80mg.kg^-1灯盏花素及银杏提取物能显著提高缺血小鼠学习记忆能力(P<0.05,P<0.01),并提高脑组织SOD活性(P<0.01),使MDA含量明显下降(P<0.05,P<0.01);体外实验表明,0.015g.L^-1以上剂量的灯盏花素能明显降低H₂O₂引起的红细胞溶血率(P<0.05,P<0.01),且呈剂量依赖关系。结论灯盏花素能减轻缺血再灌注引起的脑损伤,改善小鼠学习记忆能力,该作用可能与其提高脑组织抗氧化能力有关。

Protective Effects of Breviscapine on Learning-Memory Dysfunction Induced by Ischemia-Reperfusion in Mice

OBJECTIVE To study the protective effects of breviscapine on learning-memory dysfunction induced by cerebral ischemia-reperfusion in mice.METHODS The mice were divided randomly into sham group,model group,positive control group(extract of leaves of Ginkgo biloba L.,Gb,35 mg·kg^-1)and breviscapine treated group(Bre,80,20,5 mg·kg^-1).After accommodated to new circumstances for 3 d,the mice of positive control and Bre treated groups were treated with Gb of 35 mg·kg^-1 and Bre of 80,20,5 mg·kg^-1(ip)respectively once daily for 7 d,while sham and model groups were injected with 0.9% NaCl(ip).At thirty minutes after drug treatment on day 7,the mice were anesthetized(ethyl carbamate,1.275 g·kg^-1,ip),and ischemia-reperfusion operations were conducted.Repeated cerebral ischemia/reperfusion was induced by fastening bilateral common carotid artery.The next day following surgery,the spontaneous behavior was tested using open field.And learning-memory was measured using Morris water maze on day 3 after surgery.The activity of SOD and the content of MDA were then measured by UV-photospectrometer analysis system.Meanwhile,the inhibiton of breviscapine on oxidative hemolysis induced by H₂O₂ in vitro was detected.RESULTS Ischemia-reperfusion did not affect the spontaneous behavior,but impaired learning-memory,declined the activity of SOD,and increased the level of MDA in mice.It was found that breviscapine(5,20,80 mg·kg^-1)and Gb remarkably improved learning-memory ability(P<0.05,P<0.01),meanwhile promoted the activity of SOD(P<0.01)and decreased the content of MDA(P<0.05,P<0.01)when compared to the ischemic group.The experiment in vitro showed breviscapine(0.015～1.5 g·L^-1)dose-dependently decreased oxidative hemolysis(P<0.05,P<0.01).CONCLUSION Breviscapine shows an improvement effect against the memory impairment in mice induced by ischemia/reperfusion.The improvement of the anti-oxidation activity in brain may be involved in.