Objective To assess the effects of silica nanoparticles on oxidative damage and apoptosis in human lung adenocarcinoma A549 cells.
Methods A549 cells were treated with silica nanoparticles at mass concentrations of 25, 50, 100, and 200 mg/L, respectively, for 24 and 48 h, and the control group was exposed to the culture media without silica nanoparticles. The morphologies of A549 cells after 24 and 48 h exposure were observed by fluorescence microscope. Cell viability was measured by cell counting kit (CCK-8), cell inhibition rate and 50% inhibitory concentration (IC50) were calculated, and the curve of percentage of cell inhibition was also drawn. Malondialdehyde (MDA), superoxide dismutase (SOD), and lactate dehydrogenase (LDH) were detected by commercial kits. Flow cytometry was used to detect reactive oxidative species (ROS) and apoptosis rate.
Results After being exposed to silica nanoparticles for 24 and 48 h, the A549 cells showed various morphological changes, including cell vacuolar degeneration and cell shrinkage. The cell inhibition rates were both increased after 24 and 48 h treatment compared with the control group (P < 0.05). Moreover, the IC50 of the 24h exposure group was 125.8mg/L and that of the 48 h exposure group was 50.83 mg/L. The levels of MDA, LDH, ROS, and the apoptosis rates were higher in the groups exposed to higher doses of silica nanoparticles (P < 0.05) and the SOD levels showed in an inverse manner (P < 0.05).
Conclusion Silica nanoparticles could change cell morphology, aggregate oxidative stress, increase ROS, and even lead to cell apoptosis and death in A549 cells.
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