Effect of oxidative stress on the activity of human osteoblastic MG63 cells

To investigate the morphology and proliferation viability in oxidative stress induced damage in human MG63 cells.

The MG63 cells were treated with superoxide anion (O2^.-) produced by different con-centrations of xanthine/xanthine oxidase enzymatic reactions to establish the model of oxidative stress in MG63 cells, using the xanthine oxidase inhibitor oxypurinol to observe the reverse effect of oxypurinol on xanthine/xanthine oxidase induced damage in human MG63 cells. Using the flow cytometry, the production of intracellular reactive oxygen species (ROS) induced by xanthine/xanthine oxidase induced cellular oxidative stress damage was evaluated by the oxidation-sensitive fluorescent probe, the 2'7'-dichlorofluorescin diacetate. Cellular viability and morphology was evaluated by the MTT assay and the phase contrast microscope.

Xanthine/xanthine oxidase induced intracellular ROS production in a dose- and time- dependent manner (P < 0.05). The cellular viability was reduced and cellular morphology was damaged, too (P < 0.05). Xanthine/xanthine oxidase induced the damage of the cellular morphology. At the same processing time, the higher the xanthine/xanthine oxidase concentration, the higher intracellular ROS fluorescence intensity value, and the lower OD value, the difference was statistically significant (P < 0.05). The intracellular mean ROS fluorescence intensity in xanthine/xanthine oxidase + oxypurinol combined treatment group was significantly lower compared with the same concentration of xanthine/xanthine oxidase (P < 0.05). At the same concentration of xanthine/xanthine oxidase, with the extension of treatment time, the intracellular mean ROS fluorescence intensity gradually increased, the OD value decreased, compared with the control group, the intracellular mean ROS fluorescence intensity of 120 min increased to 345% of the control, was the highest among the xanthine/xanthine oxidase groups. The OD value of 24 h was the 22.9% of the control group, was the lowest among the xanthine/xanthine oxidase groups, cell proliferation activity decreased more obvious.

Xanthine/xanthine oxidase could induce oxidative stress damaged the cellular morphology and reduced the cellular viability in MG63 cell lines. The oxypurinol (the inhibitor of xanthine oxidas) could reverse the oxidative stress injury induced by xanthine/xanthine oxidase in human osteoblastic cells.