黄芪多糖对缺血性脑损伤大鼠的神经保护作用及其机制研究

Study on neuroprotective effects of astragalan in rats with ischemic brain injury and its mechanisms

目的:探究缺血性脑损伤后,黄芪多糖(AG)对海马CA1区神经元重塑中粘附分子(NCAM)以及c-fos表达的影响。方法:取Wistar雄性大鼠100只,随机分成假手术组(SOG)、模型组(MG-1d,3d,7d),低剂量黄芪多糖治疗组(L-AGTG-1d,3d,7d),高剂量黄芪多糖治疗组(H-AGTG-1d,3d,7d),每组10只。所有MG和AGTG组颈部切开阻断右侧大脑中动脉,造成缺血性脑损伤后,AGTG组腹腔注射AG(5 mg/kg和15 mg/kg)。于1 d,3 d和7 d分别脑血流再灌注,随即评分神经功能缺损情况后取材,测算神经元凋亡数,免疫组织化学法和RT-PCR法半定量分析检测海马CA1区神经元NCAM和c-fos的表达。结果:L-AGTG和H-AGTG的神经功能缺损评分和海马神经元凋亡数显著低于MG(P<0.05或P<0.01),海马CA1区NCAM和c-fos的表达显著高于MG(P<0.05或P<0.01)。结论:黄芪多糖改善缺血性脑损伤大鼠的神经功能,可能与促进海马NCAM和c-fos表达,而阻止或逆转海马神经元凋亡有关。

Objective： To study the effects of astragalan （AG） on the expression of the neural cell adhesion molecule（NCAM） and c-fos of hippocampus CA1 region after the ischemic brain injury in rats. Methods： One hundred male Wistar rats （ 180- 220 g） were divided into ten groups randomly, they were sham operated group（ SOG, n= 10）, three model group（ MG-1 d, 3d, 7d, n= 10）, as well as three low and high dose astragalan treannent groups （L/H-AGTG-ld, 3d, 7d, n = 10）, respectively. And then, middle cerebral artery of MG and AGTG were intercepted by operation inducing brain injured. Their cerebral blood vessel were reperfused on 1,2, 3 d, respectively, after the L/H- AGTG were treated with the AG（5 ing/kg and 15 mg/kg, ip）. After neurologic impairment（NIP） was scored, animals were decapitated to take out hippocampus for counting apoptosis , determining the expression of the NCAM and c-fos by immunohistochemistory method and RTPCR semiquantitative analysis, respectively. Results： The NIP scores and apoptotic cell of the L-AGTG and H-AGTG were significantly lower than MG （ P 〈 0.05 or P 〈 0.01 ）. The expression of NCAM and c-fos were significantly higher than the MG（ P 〈 0.05 or P 〈 0.01 ）. Conclusion： Astragalan could improve significantly neural function of ischemia brain injury in rats, the mechanism concerned probably with blocking or reversing apoptosis of hippocampus by promoting the expression of the NCAM and c-fos of hippocampus CA1 region.