Olfactory Ensheathing Cell-Conditioned Medium Protects Astrocytes Exposed to Hydrogen Peroxide Stress

The purpose of this study was to observe the effects of olfactory ensheathing cell conditioned medium (OECCM) on damaged astrocytes after exposure to H₂O₂ in vitro. OECCM was used to treat astrocytes after injury, which was induced by exposure to 500 μmol/L H₂O₂ for 20 min. The cell morphology was then observed under a light microscope, cell viability assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell ultrastructure observed with transmission electron microscopy (TEM), and apoptosis assessed by Annexin V staining followed by cytometry and Western blot. H₂O₂ induced severe damage to astrocytes as evidenced by decreased cell number, pathological changes in cell morphology, and significantly elevated cell apoptosis. Cells incubated with OECCM displayed significantly improved cell viability and decreased cell apoptotic rate. Under TEM, H₂O₂-treated cells showed partially broken plasma membranes, swollen rough endoplasmic reticula, visible vacuoles, and swollen or deformed mitochondria with ruptured cristae. Incubation with OECCM significantly ameliorated these pathological changes in astrocytes. These results suggest that OECCM may protect astrocytes from oxidative damage by promoting cell survival while reducing apoptosis of the damaged cells.