Hydrogen peroxide induces apoptosis of BJAB cells due to formation of hydroxyl radicals via intracellular iron-mediated fenton chemistry in glucose oxidase-mediated oxidative stress

The aim of this study was to determine if hydrogen peroxide (H₂O₂) generated by glucose oxidase (GO) induces apoptosis or necrosis of BJAB cells and which radical is the direct mediator of cell death. We found that GO produced H₂O₂ continuously in low concentrations, similar to in vivo conditions, and decreased proliferation and cell viability in a dose-dependent manner. The GO-mediated cytotoxicity resulted from apoptosis, and was confirmed by monitoring the cells after H33342/ Annexin V/propidium iodide staining. Decreases of mitochondrial membrane potential and intracellular glutathione level were found to be critical events in the H₂O₂,-mediated apoptosis. Additional experiments revealed that H₂O₂ exerted its apoptotic action through the formation of hydroxyl radicals via the Fenton rather than the Haber-Weiss reaction. Moreover, intracellular redox-active iron, but not copper, participated in the H₂O₂-mediated apoptosis.