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 μg/mL LBP immediately after X ray irradiation, while the control group and normal group were treated with equivalent LBPfree 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-1 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 24 h 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). Compared with the control group, the proportion of cells with decreased mitochondrial membrane potential to total in the 200, 400, 800 μg/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 μg/mL LBP groups and the normal group were significantly increased (P < 0.05), and the cytochrome 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 Bcl-2.
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