银杏叶提取物对兔冷冻伤脑水肿的保护作用及其机制(英文)

Mechanism and protective action of Ginlgo biloba extract on cold induced brain edema in rabbits☆

背景:冷冻所致脑水肿,被认为是一种典型的血管源性脑水肿。许多化学递质参与这一过程,其中氧自由基起主导作用,采用银杏叶提取物所具有的氧自由基清除剂作用,可望发挥抗脑水肿及脑保护作用。目的:探讨银杏叶提取物对冷冻所致兔脑水肿的保护作用及其机制。设计:采用完全随机设计,空白对照实验。地点和材料:同济医科大学附属同济医院神经外科,材料由同济医科大学动物中心提供。健康中国家兔30只,体重2.0～2.8kg,雌雄不拘.干预:30只健康中国家兔,单纯随机分为3组:对照组、脑水肿模型组、EGb761处理组,3组家兔分别在术后6,24h断头取脑测定脑组织含水量、脂质过氧化物含量及超氧化物歧化酶活性。主要观察指标:测定脑含水量,脑组织LPO含量及SOD活力的变化。结果:术后6h和24h,脑水肿模型组脑组织LPO含量犤(6.82±1.36)μmol/L,(7.95±2.12)μmol/L犦及脑组织含水量犤(78.56±0.61)%;(79.86±0.54)%犦呈进行性增高,SOD活性则呈进行性下降(P<0.05);EGb761处理组脑组织LPO含量及脑组织含水量增加不显著,且SOD活性回升(P<0.05)。结论:EGb761具有抗脑水肿和保护脑组织的作用。而其减轻脂质过氧化反应,保护脑组织内源性SOD活性,增强脑组织自身清除氧自由基的功能,则可能是其重要的药理作用机制之一。

BACKGROUNDS:Cold induced brain edema has been considered as a typical vasogenic cerebral edema.Many chemical transmitters,predominantly oxygen free radicals,have been involved in this pathological process. Whether extract of Ginkgo biloba(EGb761),as an oxygen free radical scavenger,could be potentially used as an agent against brain edema needs further study. OBJECTIVE:To explore the effect of EGb761 in preventing cold induced brain edema and the action mechanism. DESIGN:Controlled,completely randomized trial design. SETTING AND MATERIALS:The experiment was performed in the Department of Neurosurgery,Tongji Hospital, Tongji Medical University.Thirty normal rabbits of either sex,weighing 2.0-2.8 kg,were used. INTERVENTION:The rabbits were randomized into control group,brain edema model group and EGb761 treatment group,sacrificed 6 and 24 h after operation respectively to determine the brain water content,cerebral lipid peroxidative product(LPO) concentration and superoxde dismutase(SOD) activity. MAIN OUTCOME MEASURES:The contents of brain water and LPO in brain tissue and SOD activity. RESULTS:At 6 and 24 h after the operation,LPO concentration [(6.82±1.36) μmol/L and(7.95±2.12)μmol/L]and brain water content[(78.56±0.61) %and(79.86±0.54) %] showed gradual increase in the model group,with declined SOD activity(P< 0.05).In EGb761 treatment group,LPO concentration and brain water content increased only mildly,but the activity of SOD increased from( P< 0.05). CONCLUSIONS: EGb761 plays a role in fighting brain edema and protecting brain tissue,possibly through alleviating lipid eroxydation, protecting endogenous SOD activity and enhancing oxygen free radical eliminating function of the brain.