刺五加皂甙对谷氨酸毒性神经元凋亡的保护作用

目的观察神经元在谷氨酸毒性损伤时一氧化氮(NO)的动态变化及其与凋亡的关系,探讨刺五加皂甙(ASS)的有效保护浓度。方法采用谷氨酸(Glu)诱导的皮质神经元凋亡模型。随机分成Glu组、正常对照组及ASS3组;用流式细胞仪检测神经元凋亡率,用硝酸还原酶法测定细胞培养上清液中NO的含量,用MTT法测定神经元存活率并在电镜下观察细胞形态学变化。结果(1)Glu呈剂量和时间依赖性增加神经元培养液中NO含量,ASS能不同程度地减少NO含量;(2)与Glu共培养的神经元,其存活率呈剂量和时间依赖性下降,ASS能增加神经元存活率;(3)经Glu处理的神经元发生凋亡,细胞超微结构呈现凋亡样改变,其凋亡率与正常对照组比较有显著性差异(P<0.01)。ASS能减少Glu毒性神经元凋亡。结论NO介导了Glu毒性神经元凋亡,ASS可能通过抑制NO的释放及其神经毒性作用,拮抗Glu引起的神经元凋亡。

Effects of acanthopanax senticousus saponins against glutamate-induced neuronal apoptosis

Objective To explore the effects of acanthopanax senticousus saponins(ASS) on the dynamic changes of nitric oxide(NO) during cortex neuronal apoptosis induced by glutamate.Methods The model of apoptosis induced by glutamate was established on cultured cortical neurons.The neurons were divided randomly into control group,Glu group and ASS group.The rate of neuronal apoptosis was measured by flow cytometer,NO contents were determined by nitrate reductive assay and neuron survival was measured by MTT assay.The changes of morphology were observed by electron microscopy.Results (1)Compared with the control group,glutamate could make the release of NO increasing in cultured cortical neurons dose-and time-dependently,ASS could inhibit the glutamate effect.(2)Compared with the control group,glutamate could make the cortical neuron survival decreasing dose-and time-dependently,ASS could make neuron survival increasing.(3)Compared with the control group,glutamate could induce cultured cortical neuron apoptosis and increase the rate of neuron apoptosis(P<0.01).The most striking ultrastrctural changes of apoptosis were observed by electron microscopy in Glu group neurons.ASS could decrease cultured cortical neuron apoptosis induced by glutamate.Conclusions The apoptosis of cortical neurons induced by glutamate was mediated by NO.ASS could ameliorate neuronal apoptosis induced by glutamate via inhibiting the release of NO and protecting neurons against NO neurotoxicity.