Objectives: To determine if changes in cellular glutathione are associated with para-aminophenol-induced neurotoxicity.
Methods: Two neuroblastoma cell lines, mouse Neuro2a and human SH-SY5Y, were selected as models for this study. Cells were treated with para-aminophenol at 1–500µM or with plain culture medium as a control for 6, 24, or 48 hours (n=6). Cell viability was quantified by a standard MTS colorimetric assay. As a marker of redox status, total cellular glutathione was determined in Neuro2a cells treated with 0, 10, or 25µM para-aminophenol for 6 or 24 hours using an established glutathione reductase-Ellman’s reagent enzymatic recycling method (n=6). Data were analyzed by one-way ANOVA tests followed by Dunnett’s tests.
Results: In both cell lines, concentrations of para-aminophenol from 10–500µM caused significant decreases in cell viability compared to the control group at all three time points. Glutathione levels were significantly reduced after 6 hours of treatment at 25µM (p=0.008), whereas levels were significantly increased in the 10 and 25µM groups at 24 hours (p=0.007 and 0.000009, respectively) compared to controls.
Conclusions: Para-aminophenol showed similar levels of cytotoxicity in the human and murine neuroblastoma cell lines tested. Alterations in cellular glutathione suggest induction of oxidative stress may be involved in para-aminophenol neurotoxicity. Future experiments will focus on testing involvement of endocannabinoid receptors in the observed stress responses. Supported by Congressional funds conferred to the Naval Medical Research Unit-San Antonio.
Keywords: Cell biology, Cell culture, Neuroscience, ROS and Toxicology