枸杞多糖对电离辐射所致小鼠骨髓单核细胞凋亡的抑制作用

Inhibition effects of lycium barbarum polysaccharide on apoptosis of murine bone marrow mononuclear cells induced by ionizing radiation

[目的]探究枸杞多糖对X射线所致的小鼠骨髓单核细胞(BMNCs)凋亡的作用机制。[方法]体外培养BMNCs,建立放射损伤细胞模型。X射线照射后枸杞多糖组立即给予100、200、400、800μg/mL枸杞多糖,辐射对照组和正常组给予等量不含枸杞多糖的RPMI1640培养液,分别于照射后24、48、72、96 h采用MTT法检测细胞活力,用流式细胞术(FCM)检测细胞凋亡率,用JC-1荧光探针法检测细胞线粒体膜电位,用分光光度法检测细胞中半胱氨酸蛋白酶(Caspase)-3活性,用蛋白免疫印迹法检测B淋巴细胞瘤(Bcl)-2和细胞色素C的表达。[结果]照射后24 h,与辐射对照组相比:枸杞多糖各组和正常组细胞活力均升高(P <0.01);枸杞多糖各组和正常组细胞凋亡率分别降低5.95%、5.84%、5.33%、3.96%、5.48%(P <0.01);200、400、800μg/mL枸杞多糖组和正常组线粒体膜电位下降的细胞数占总细胞数的比例明显减少(P <0.01)(分别减少5.79%、10.16%和11.21%、19.01%);枸杞多糖各组和正常组Caspase-3活性下降(P <0.05);400、800μg/mL枸杞多糖组和正常组Bcl-2的表达明显升高(P <0.05),细胞色素C的表达量明显下降(P <0.05)。[结论]枸杞多糖对X射线所致的小鼠骨髓单核细胞的凋亡有抑制作用,可能是通过作用于Caspase-3,细胞色素C和Bcl-2所在的线粒体途径来实现。

[ Objective ] To investigate the mechanism of action of lycium barbarum polysaccharides （LBP） in X ray radiation induced apoptosis of bone marrow mononuclear cells （BMNCs）. [ Methods] BMNCs were cultured in vitro to establish a radiation injury, cell model. LBP groups received 100, 200, 400, and 800 pg/mL LBP immediately after X ray irradiation, while the control grmip and normal group were treated with equivalent LBP- free RPMI1640 medium. The cell viability was detected by MTT assay at 24, 48, 72, 96 h after irradiation. The apoptosis rate was examined by flow cytometry （FCM）. The mitochondrial membrane potential was detected by JC-I fluorescent probe assay. The activity of Caspase-3 was measured by spectrophotometry. The expressions of Bcl-2 and cytochrome C were detected by Western blot. [ Results ] At 24h after irradiation, the cell viabilities in the LBP groups and the normal group were all increased compared with the control group （P〈0.01）. The apoptotic rates of the LBP groups and the normal group were decreased by 5.95%, 5.84%, 5.33%, 3.96%, and 5.48% respectively compared with the control group （P〈 0.01）. Compal-d with the control group, the proportion of cells with decreased mitochondrial membrane potential to total in the 200, 400, 800μg/mL LBP groups and the normal group were obviously decreased （P〈0.01） （reduced by 5.79%, 10.16%,11.21%, and 19.01%, respectively）. The Caspase-3 activities in the LBP groups and the normal group were significantly lower than those in the control group （P〈0.05）. Compared with the control group. the expressions of Bcl-2 in the 400 and 800 lag/mL LBP groups and the normal group were significantly increased （P〈 0.05）, and lhe cy/ochrome C expressions were significantly decreased （P〈 0.05）. [ Conclusion ] LBP can inhibit the apoptosis of BMNCs induced by X ray radiation, which may be achieved through influencing mitochondrial pathways of Caspase-3, Cytochrome C, and Bel-2.