小续命汤有效成分组对局灶性脑缺血／再灌注大鼠恢复早期的神经保护作用研究

摘要

目的观察小续命汤有效成分组对局灶性脑缺血／再灌注大鼠恢复早期的神经保护作用。方法选用健康♂ SD大鼠，采用插线法制备大鼠右侧大脑中动脉缺血／再灌注（ MCAO）模型，缺血2 h后实现再灌注。应用Zea-Longa′s级标准评分法评价动物脑缺血程度，将造模成功的大鼠随机分为模型组、小续命汤有效成分低、中、高剂量组和阳性药银杏叶提取物EGb 761组，以假手术大鼠作为对照组，术后1～14 d灌胃给药，每日1次。通过Zea-Longa′s级标准评分、改良神经功能缺损评分（ mNSS ）和转角实验（ CT ）等系列行为学评价手段，评测小续命汤有效成分组对局灶性脑缺血／再灌注大鼠不同恢复时期行为学的变化，每天1次，连续测定14 d；选用TTC染色法观察大鼠脑梗死体积百分比；采用分光光度法检测大鼠脑缺血半暗带和缺血核心区脑组织中脂质过氧化物丙二醛（ MDA）含量和谷胱甘肽过氧化物酶（ GSH-Px）、超氧化物歧化酶（ SOD）、一氧化氮合酶（ NOS）活性的变化。结果随着给药时间延长，与模型组相比，小续命汤有效成分组能够有效降低MCAO大鼠神经功能缺损评分，表现为MCAO大鼠行走趋于正常，平衡木上停留时间增长，感觉功能恢复，转角实验中MCAO大鼠向右转向的比率逐渐接近正常。自给药5d起，与模型组相比，小续命汤有效成分组开始明显改善MCAO大鼠上述神经行为学表现，差异具有显著性（P＜0.05，P＜0.01）。并且小续命汤有效成分组能够明显降低术后5 d和14 d MCAO大鼠脑组织梗死体积百分比（ P＜0.01）。此外，小续命汤有效成分组能够明显减少MCAO大鼠缺血半暗带和核心区脑匀浆的MDA含量和降低NOS活力，提高SOD和GSH-Px活力。结论小续命汤有效成分组对局灶性脑缺血／再灌注大鼠损伤恢复早期即产生神经保护作用，可能与调节脑内氧化－抗氧化平衡有关。%Aim To explore the protective effect of ac-tive components of Xiaoxuming decoction ( XXMD ) on focal cerebral ischemia/reperfusion injury in rats dur-ing early recovery period .Methods The ischemia and reperfusion of middle cerebral artery model rats were established by nylon wire with 2 hours ischemic time on healthy male SD rats .The models of MCAO were eval-uated by Zea-Longa′s standard score .The model rats were randomly divided into sham operation group , the ischemia/reperfusion model group , the active compo-nents group of Xiaoxuming decoction and the positive group (extract of ginkgo biloba leaves EGb 761).Rats were orally administrated with different drugs 24 h after operation for up to 14 days, once a day.The effect of active components of Xiaoxuming decoction on behavior changes of MCAO rats in different recovery period was evaluated by a series of behavioral assessent methods such as modified neurological severity scores and cor-ner test.The infarct volume was observed by TTC stai-ning.Moreover, the contents of MDA and the activities of GSH-Px, SOD and NOS in the penumbra and core tissues of rat brain were detected by spectrophotometric method.Results Compared with the I/R model group, the active components group of XXMD could significantly alleviate the neurological deficit scores with prolonged administration . The motion function tended to be normal , stayed longer on the balance beam, sensory function gradually restored sensitivity , reduced the radio of turning to the right .Among them , compared with model group , the active components of XXMD could effectively improve the neurological dys-function after five days of administration ( P<0.05, P<0.01).Meanwhile, the active components of Xiaox-uming decoction could significantly reduce the infarct volume percentage in the cerebral tissue on post opera-tion day 5 and 14(P<0.01).In addition, the active components of XXMD could reduce the content of MDA and the activity of NOS , increase the activity of SOD and GSH-Px.Conclusion The active components of XXMD can generate neuroprotective effect in early stage of recovery and may play a major role in regula-ting the level of oxidative stress in rat brain .