In Vitro Analysis of the Potential Role of NOX-1 in Monosodium Glutamate-Induced Oxidative Stress and Cytotoxicity in HT-22 Hippocampal Neuronal Cells

Abstract

Monosodium glutamate (MSG) is extensively used as a flavor enhancer in the food industry and is consumed in considerable amounts through daily diet. In this study, the potential toxic effects of MSG on hippocampal neuronal cells, which are particularly rich in glutamate receptors, were examined in the HT-22 mouse hippocampal neuronal cell line within a toxicity model framework, focusing on cytotoxicity and oxidative stress. For this purpose, HT-22 cells were cultured under appropriate cell culture conditions and treated with MSG at concentrations of 1, 5, 20, and 100 µM for 24 hours. Cell viability was assessed by XTT assay, and total antioxidant status (TAS) and total oxidant status (TOS) were measured using the Rel Assay commercial kit to determine the oxidative stress status. NADPH oxidase-1 (NOX-1) expression was determined by immunofluorescence to evaluate the potential effects of MSG on NOX-mediated oxidative mechanisms. Data were analyzed using one-way ANOVA followed by post hoc test; p<0.05 was accepted as the threshold for statistical significance. Analysis of the findings revealed that cell viability, TAS/TOS levels, and NOX-1 expression showed no statistically significant change at any of the applied MSG concentrations compared to the control group. While these results indicate that MSG does not elicit a measurable cytotoxic or oxidative stress response in HT-22 cells under the tested concentration range and exposure duration, further studies under different experimental conditions are warranted.