远志皂苷元对H_2O_2诱导的大鼠海马神经元损伤的影响及其机制

Effect of senegenin on H_2O_2-induced damage in hippocampal neurons of SD rats

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West-ern 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,20μmol/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。

AIM：To observe 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 by 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（P0.05）.In addition,mRNA expression of bcl-2 increased and that of bax decreased（P0.05） 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（P0.05）.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.