远志皂苷元对H2O2诱导的大鼠海马神经元损伤的影响及其机制

摘要

AIM : To ohserve the effect of senegenin ( Sen ) on hippocampal neuron injuries induced by H2O2.METHODS : Hippocampal neurons were isolated from neonatal SD rats.The primarily cultured neurons were divided into control group, H2O2 group, Sen group and Sen + H2O2 group.The cell viability, the content of malondialdehyde( MDA )and the activity of superoxide dismutase( SOD ) in the neurons were detected after treated with Sen.The morphological changes of nucleus of the neurons were observed hy Hoechst 33258 staining.The mRNA expression of bcl -2 and bax was quantified by real - time PCR.The protein levels of Bcl -2 and bax were measured by Western blotting.The activity of caspase - 3 was also assayed.RESULTS : Compared with H2O2 group, the levels of antioxidative enzyme were increased in Sen + H2O2 group ( P ＜0.05 ).In addition, mRNA expression of bcl - 2 increased and that of bax decreased ( P ＜ 0.05 ) in Sen + H2O2 group.Moreover, Sen increased the protein level of Bcl - 2, and reduced the protein level of Bax and the activity of caspase - 3 in the neurons exposed to H2O2( P ＜0.05 ).CONCLUSION: The protective effect of Sen on hippocampal neurons with H2O2 - induced injury may be involved in the mechanisms of neuronal antioxidative response, the regulation of Bcl - 2 family and suppression of caspase - 3 activity.%目的:观察远志皂苷元(senegenin,Sen)对过氧化氢(H2O2)诱导的SD大鼠海马神经元损伤的影响并探讨其作用机制.方法:SD大鼠海马神经元培养至第6 d,随机分为正常组、H2O2组、Sen+ H2O2 组和Sen组,药物干预后检测细胞存活率、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,并用 Hoechst 33258染色观察细胞核形态变化,荧光定量PCR(real-time PCR)检测神经元凋亡相关基因bcl-2和bax的表达,进一步采用Western blotting观察Bcl-2和Bax蛋白表达,酶荧光活性检测试剂盒测定caspase-3的活性改变.结果:与正常组相比,H2O2组细胞存活率降低.与H2O2组相比,20 μmol/L Sen+ H2O2 组细胞存活率升高,SOD活性升高,MDA含量下降,并且远志皂苷元能够上调bcl-2 mRNA表达、下调bax mRNA表达,降低caspase-3活性,Western blotting结果进一步表明Bcl-2蛋白表达升高,Bax蛋白表达下降,各指标均有显著差异(P<0.05).结论:远志皂苷元对H2O2处理的海马神经元有一定保护作用,其机制可能与远志皂苷元增强海马神经元抗氧化能力、调节细胞凋亡相关蛋白从而抑制凋亡有关.