Effect of Monosodium Glutamate on Behavioral Phenotypes, Biomarkers of Oxidative Stress in Brain Tissues and Liver Enzymes in Mice
World Journal of Neuroscience
The effects of oral administration of low doses of monosodium glutamate (MSG) on behavioral phenotypes, biomarkers of oxidative stress in the brain and liver enzymes in mice were evaluated in this study. Mice were treated orally with MSG (100, 250 and 500 mg/kg) daily for 21 days before testing for behavioral phenotypes; memory, anxiety, spontaneous motor activity (SMA) and depression. Thereafter, the brain levels of malondialdehyde (MDA) and glutathione (GSH) as well as the activities of liver
... activities of liver enzymes, aminotransferase (AST) and alanine aminotransferase (ALT) were determined spectrophotometrically. MSG did not produce significant (P > 0.05) impairment of memory in the Y-maze test. It also failed to modify the behaviors of mice in the elevated plus maze and light/dark transition tests of animal models of anxiety. MSG had no significant effect on SMA but produced depressive-like symptoms in the forced swim test at a dose of 500 mg/kg. Moreover, it increased the levels of MDA and decreased GSH concentrations in brain tissues of mice. The activity of AST and ALT were elevated in the blood of MSG-treated mice suggesting liver injury. Taken together, these findings suggested that MSG induced oxidative stress in the brain and impaired liver functions but did not produce any behavioral abnormalities in mice at lower doses.