黄芪提取物对大鼠全脑缺血再灌注和小鼠缺氧性损伤的保护作用

Protective effects of extract of astragalus on injuries of global cerebral ischemia and reperfusion in rats and anoxia in mice

目的 研究黄芪提取物 (EA)对大鼠全脑缺血再灌注和小鼠缺氧性损伤的保护作用。方法 采用小鼠常压耐缺氧实验和小鼠断头实验 ,观察EA对小鼠耐缺氧能力的影响 ;采用大鼠四动脉结扎模型 ,观察EA对缺血再灌注大鼠脑水肿 ,脑组织中超氧化物歧化酶 (SOD)活性、丙二醛(MDA)含量 ,血浆和海马内皮素 (ET)及病理性改变的影响。结果 EA能延长常压耐缺氧实验小鼠的存活时间及快速断头后小鼠的张口喘气时间 ;EA能减轻缺血再灌注大鼠脑组织的水肿程度 ,提高SOD活性、降低MDA含量 ,降低血浆和海马ET的含量 ,减轻病理性损伤。结论 EA对脑缺血再灌注和缺氧性损伤有明显的保护作用 ,减轻全脑缺血模型大鼠的脑水肿和病理性损伤 ,其作用机制可能与EA抗氧化。

AIM Protective effects of extract of astragalus on injuries of global cerebral ischemia/reperfusion in rats and anoxia in mice. METHODS Acute anoxia in mice were produced by hypoxia under normal pressure and decapitation. In these two models the survival time and persistent time of gasping were observed. The global ischemia and reperfusion in rats was made by four-vessel occlusion (4-VO). After 20 min ischemia and 24 h reperfusion, the brain index and water content in brain was detected. MDA content and SOD activity of brain homogenate were tested. Endothelin concentration was determined both in plasma and hippocampus. The pathological changes of cortex tissue were observed by light microscope. RESULTS EA(50,100 mg·kg -1) significantly prolonged the survival time and persistent time of gasping in mice subjected to acute anoxia. EA(20,40,80 mg·kg -1) markedly reduced brain edema induced by global ischemia and reperfusion. EA(40,80 mg·kg -1) decreased MDA content and increased SOD activity in brain homogenate, and also inhibited ET concentration both in plasma and hippocampus. The pathological changes of cortex tissue were less serious in rats treated with EA. CONCLUSION EA has protective effects on cerebral ischemia and anoxia injuries that may relate to anti-oxidation and inhibition of ET production.