黄芪提取物对Aβ_(25-35)诱导的海马神经细胞Bcl-2和Bax表达的影响

Effect of extract of Astragalus on the protein expression of Bcl-2 and Bax in hippocampal nerve cells induced by Aβ_(25-35)

目的探讨黄芪提取物(EA)对Aβ_(25-35)所致海马神经元损伤的保护作用及其作用机制。方法分离孕18 d的胎鼠的海马神经细胞进行体外培养,实验分为3组:对照组、模型组和黄芪组。对照组:只加入无B27神经生长因子的神经基础培养基(NB)原液培养24 h;模型组:加入无B27神经生长因子的NB原液,再加入终浓度为10μmol/L Aβ_(25-35)培养24 h;黄芪组:加入无B27神经生长因子的NB原液,先加入终浓度为黄芪提取物20 mg/L培养4 h,再加入终浓度为10μmol/L Aβ_(25-35)培养20 h。在倒置显微镜下观察各组海马神经细胞形态学变化;采用乳酸脱氢酶(LDH)法和3-(4,5-甲基噻唑-2)-2,5-苯基的氮唑溴盐(MTT)法检测细胞活性;Western blot检测各组海马神经细胞Bcl-2和Bax蛋白的表达情况。结果模型组的海马神经细胞活性明显下降,细胞出现凋亡的典型的形态学特征,Bcl-2蛋白的表达水平下降而Bax蛋白的表达水平升高,与对照组比较,差异有统计学意义(P<0.05)。黄芪组海马神经细胞活性提高、凋亡的细胞数减少,Bcl-2蛋白的表达水平升高而Bax蛋白的表达水平下降,与模型组比较,差异有统计学意义(P<0.05)。结论黄芪提取物对Aβ_(25-35)所诱导的海马神经元损伤具有一定的保护作用,可能与其降低海马神经细胞Bcl-2蛋白的表达水平升高Bax蛋白的表达水平有关。

[Objective]To investigate the protective effect and its mechanism of extract of Astragalus（EA）hippocampal neuron damage induced by Aβ25-35.[Methods]Hippocampal nerve cells of 18 days fetal rats were separated in vitro,and were divided into3 groups： control group,model group and EA group. Control group was treated with NB culture medium without B27 for 24 hours.Model group was treated with NB culture medium without B27 and 10 μmol/L Aβ25-35（final concentration）for 24 hours. EA group was also given NB culture medium without B27,and treated with 20 mg/L EA（final concentration）for 4 hours,finally treated with10μmol/L Aβ25-35 for 20 hours. The morphological changes of hippocampus nerve cells in each group were observed under inverted microscope. The cell vitality was determined by LDH method and MTT method. The protein expression levels of Bcl-2 and Bax in the hippocampus nerve cells were determined by Western blot test. [Results]Hippocampal nerve cell activity of model group was obviously decreased,the typical morphological features of apoptosis were found,the protein expression level of Bcl-2 decreased and that of Bax increased,and the differences were statistically significant as compared with control group（P〈0.05）. Hippocampal nerve cell activity of EA group increased,the number of apoptosis cells decreased,the protein expression level of Bcl-2 increased and that of Bax decreased,and the differences were statistically significant as compared with model group（P〈0.05）.[Conclusion]The extract of Astragalus has certain protective effect on hippocampal neuron damage induced by A β25-35,its mechanism may related to reduce the protein expression level of Bax in hippocampus and increase the protein expression level of Bcl-2.