二苯乙烯苷通过抑制NF-κB的激活减轻MPP＋诱导的PC12细胞凋亡

目的：探讨2,3,5,4＇-四羟基二苯乙烯-2-o-β-D-葡萄糖苷（2,3,5,4＇-tetrahydroxystibene-2-o-β-D-glucoside,TSG）对1-甲基-4-苯基吡啶离子（1-methy-4-phenylpyridinium,MPP＋）诱导PC12细胞凋亡的影响及其可能机制。方法：四甲基偶氮唑蓝（MTT）比色试验检测PC12细胞活性;Hoechst33258染色法测定细胞凋亡;Westernblotting检测NF-κB（P65）和IκBα蛋白的表达。结果：MPP＋（300μmol/L）作用于PC12细胞24h后,与正常对照组比较,细胞存活率降低（53.3±3.4%）（P〈0.01）;细胞染色质固缩,细胞核呈致密浓染。TSG（1,5,10μmol/L）预处理24h后,细胞存活率增加（60.8±1.9%）,（70.1±1.8%）（P〈0.01）,（81.2±1.9%）（P〈0.01）;细胞核凝聚明显减少,且具有量一效关系。另外,MPP＋可使PC12细胞核中NF-κB（P65）蛋白表达升高,细胞浆中IκBα蛋白表达降低;与MPP＋处理组细胞相比,TSG预处理后,PC12细胞核中高表达的NF-κB（P65）蛋白水平明显降低,细胞浆中低表达的IκBα蛋白水平升高。结论：TSG对MPP＋诱导的PC12细胞凋亡具有浓度依赖性的抑制作用,其作用机制可能与抑制NF-κB的激活有关。

Effect of 2,3,5,4＇-tetrahydroxystibene-2-o-β-D-glucoside in mitigation of MPP＋-induced Apoptosis of PC12 Cells

Objective：To explore the protective effect of TSG on MPP＋ induced PC12 cells apoptosis.Methods：The PC12 cells viability was measured by 3-4,5-dimethylthiazol-2-y1]-2,5-diphenyhetrazolium bromide（MTT）.The morphological change of PC12 cells was observed by Hoechst 333258 staining.The expression level of NF-κB（P65） and IκBα protein was detected by Western blotting.Results：Compared with the control group,the ratio of cell survival decreased（53.3±3.4%）（P0.01）;cyto-chromatin concentration;nu-cleus showing strong staining after MPP＋ treatment with PC12 cells for 24h.The ratio of cell survival increased（60.8±1.9%）,（70.1±1.8%）（P0.01）,（81.2±1.9%）（P0.01）after TSG（1,5,10μmol/L） pretreatment with PC12 cells for 24h;cyto-chromatin concentration re-duced and show the relation between quantity and result.Moreover,MPP＋ is able to increase the expression level of NF-κB（P65）protein in the nucleus,decrease the expression level of IκBα protein in the cytoplasm of PC12 cells.The high expression level of NF-κB（P65）protein in the nucleus is decreased and the low expression level of IκBα protein in the cytoplasm of PC12 cells is increased after TSG pretreatment with PC12 cells,compared with MPP＋ treatment group.Conclusion：TSG plays a possible neuroprotective role in MPP＋-in-duced apoptosis of PC12 cells by a concentration-dependent manner,and the mechanism of the effects of TSG may be involved in inhi-biting NF-κB activation.