Mild Oxidative Stress on the PC12 Cell Line: A Simple Model of Chronic Neural Tissue Oxidative Damage

Abstract

　Here we constructed a mild oxidative system using the PC 12 cell line for ex vivo screening of antioxidants that are effective in reducing chronic oxidative damage in neural tissues. Nerve growth factor-induced differentiated PC 12 cells were exposed to various concentrations of hydrogen peroxide (H₂O₂) for six days. For three days after treatment initiation, the survival rate of cells exposed to less than 50 μM H₂O₂ was similar to that of untreated cells, whereas H₂O₂ concentrations higher than 50 μM exhibited a significant lethal effect. However, six days after treatment initiation, the survival rate of cells exposed to 50 μM H₂O₂ decreased significantly. This condition may thus mimic natural chronic oxidative damage of neural tissues. A well-known antioxidant, _N-acetyl-_L-cysteine, was added either before, during, or after H₂O₂ exposure to rescue cells from oxidative damage. _N-acetyl-_L-cysteine addition before and during oxidant treatment significantly rescued cells from damage, while addition after H₂O₂ treatment exhibited only a weak rescue effect. This simple method may be applied to screen for natural and artificial antioxidants with further modifications.