Concomitant intake of high levels of monosodium glutamate and taurine induces adverse effects in the rat brain.

A common food additive, monosodium glutamate (MSG), is a source of glutamate, the primary excitatory neurotransmitter in the central nervous system, and has been associated with neuronal damage at high levels. Taurine (TAU), a naturally occurring amino acid, is widely used in energy drinks alongside caffeine and sugar. Given the widespread consumption of these products, this study investigated the potential adverse effects of high levels of MSG, TAU, and their combination on systemic and brain oxidative stress/antioxidant balance, as well as cortical histology. Young male Wistar rats (10 weeks old) were randomly assigned to four groups: MSG (1 g/kg/day), TAU (300 mg/kg/day), MSG+TAU (1 g/kg/day + 300 mg/kg/day), and control (CON) group (saline), all administered via oral gavage for 21 days. While serum trace element levels (Cu, Zn, Se) remained unaffected, total oxidant status was significantly higher in the MSG and MSG+TAU groups compared to the TAU and control groups. Oxidative stress markers (8-OHdG and 4-HNE) were elevated in the serum, cortex, and hippocampus of all experimental groups, accompanied by increased total oxidant status and decreased total antioxidant status in these samples. Histological analysis revealed neuronal disorganization and pericapillary edema in the cerebral cortex. These findings indicate that excessive exposure to these compounds may disrupt redox balance and brain tissue integrity to varying degrees, with combined exposure producing more pronounced deleterious effects. Overall, these results suggest that frequent consumption of foods and beverages containing MSG and taurine, particularly at high levels, may pose significant health risks to young individuals.