人参多糖通过抑制ROS水平和凋亡保护H2O2诱导的心肌细胞氧化应激损伤

为探讨人参多糖缓解心肌氧化损伤的功效，利用过氧化氢(H2O2)诱导的H9c2大鼠心肌细胞建立体外心肌氧化损伤模型，利用四甲基偶氮唑蓝(MTT)检测细胞存活率，试剂盒检测乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)和丙二醛(MDA)，流式细胞术检测活性氧(ROS)和细胞凋亡，Western Blot法检测细胞凋亡相关蛋白.结果表明：与对照组(Con)比较，H2O2能够使细胞存活率显著下降(P<0.001)；与H2O2诱导组(模型组，Mod)比较，6.25 μg/mL人参多糖预防治疗24 h将细胞存活率由(57.47±5.08)%提高到(85.65±4.28)%(P<0.001)，说明人参多糖能够对抗H2O2诱导的细胞毒性作用.流式细胞术DCFH-DA染色结果显示：与Con组比较，H2O2显著升高细胞ROS水平；而人参多糖预防治疗24 h后细胞ROS水平降低，提示人参多糖能够抑制H2O2诱导的H9c2细胞活性氧水平升高，并通过降低MDA含量及提高SOD活性缓解氧化应激损伤.同时，人参多糖可通过增加H2O2诱导损伤引起的Bcl-2/Bax比值，降低凋亡相关蛋白表达来缓解氧化应激导致的细胞凋亡.总之，人参多糖通过抑制ROS水平和细胞凋亡保护心肌细胞氧化应激损伤，为阐述人参保护心脏功效机制及产品研发提供了实验依据.

Protective effect of ginseng polysaccharides on oxidative stress injury in cardiomyocytes by reducing ROS level and apoptosis

The aim of this study was to investigate protective effect of ginseng polysaccharides (GPS) on oxidative damage induced by hydrogen peroxide (H2O2) in rat cardiomyocytes H9c2. MTT assay was used to evaluate cell viability. The biochemical parameters of oxidative damage， lactate dehydrogenase (LDH)， superoxide dismutase (SOD) and malonaldehyde (MDA) were measured by testing kits. The percentage of apoptosis and reactive oxygen species (ROS) production in the cells were determined by flow cytometry. And apoptosis-related protein was detected by Western blot. The results showed that GPS (6.25 μg/mL) significantly enhanced cell viability from (57.47±5.08) % to (85.65±4.28) % (P<0.001)， which indicated that GPS protected H9c2 cells from H2O2-induced cytotoxicity. The results from DCFH-DA staining showed that ROS production was decreased by GPS through decreasing the content of MDA and increasing the activity of SOD. Moreover， GPS inhibited H2O2-induced apoptosis through increasing the ratio of Bcl-2/Bax and reducing the level of apoptosis-related protein. We concluded that GPS protected cardiacmyocytes from oxidative stress injury though reducing ROS production and apoptosis， which provided theories foundation for molecular mechanism of GPS and the development of ginseng-related products for the protection of heart injury.