Oxidative DNA damage and necrotic cell death in differentiated SH-SY5Y cells induced by continuous extremely low-frequency magnetic field exposure

Extremely low-frequency (ELF) magnetic fields generated by power-line sources are ubiquitous, yet their long-term effects on neuronal cells remain unclear. We investigated whether continuous exposure (72 – 96 h) to a 60 Hz ELF magnetic field induces oxidative DNA damage and alters cell death pathways in differentiated SH-SY5Y human neuroblastoma cells. Neuron-like cells generated by retinoic acid and brain-derived neurotrophic factor were exposed to 1–3 mT ELF magnetic fields for 96 h, with sham-exposed cells as controls. Chromosomal integrity (Hoechst 33258 staining), apoptosis/necrosis (Annexin V–FITC/propidium iodide flow cytometry), oxidative DNA damage (apurinic/apyrimidinic site analysis), and redox balance (total oxidant and total antioxidant status) were assessed. ELF magnetic field exposure caused intensity dependent nuclear abnormalities, increased oxidative DNA lesions, early oxidative imbalance, and a predominance of necrotic over apoptotic cell death. These findings indicate that continuous low-intensity ELF magnetic field exposure disrupts redox homeostasis and compromises genomic stability in differentiated neuronal cells.