TITLE:
Effect of Monosodium Glutamate on Behavioral Phenotypes, Biomarkers of Oxidative Stress in Brain Tissues and Liver Enzymes in Mice
AUTHORS:
Solomon Umukoro, Gabriel Oluwafemi Oluwole, Henry Egbewunmi Olamijowon, Adrian Itiviere Omogbiya, Anthony Taghogho Eduviere
KEYWORDS:
Monosodium Glutamate, Depression, Oxidative stress, Liver Enzymes
JOURNAL NAME:
World Journal of Neuroscience,
Vol.5 No.5,
November
6,
2015
ABSTRACT: 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 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.