Some Biochemical Changes in Brain and Blood of Experimental Rats Resulting From Monosodium Glutamate (MSG) Administration

Objective: Monosodium glutamate (MSG) is one of the commonest food additives in
the world and it is a commonly used flavor enhancer. In recent years MSG
consumption has increased as flavoring in cooking. Interestingly, little is known
about its effects on oxidative stress and some metabolic changes. Aim of the study:
The aim of this study was to elucidate the effect of oral ingestion of MSG on some
biochemical changes in the brain and blood of experimental rats to demonstrate the
adverse effects of that widely used flavor enhancer. Materials and methods: This
study was carried out on 50 white albino rats which were divided into two equal
groups; control group and MSG treated group. All groups were subjected to
estimation of serum lipid profile, free fatty acids (FFs) and malondialdehyde (MDA)
levels. Also brain tissue levels of L-glutamate, gamma amino butyric acid (GABA)
and MDA were measured for all groups. Results: The present study showed that oral
feeding of MSG significantly increased final body weight, visceral fat weight,
impaired glucose tolerance and a state of dyslipidemia with an increased serum free
fatty acid level. Significant increase of both serum and brain MDA tissue levels were
also documented. MSG-treated group also showed significant increase of brain L.
glutamate and significant decrease of brain gamma amino butyric acid (GABA) levels
as compared to the control. Conclusion: On the basis of these results it could be
concluded that MSG may be an inductive factor of several biochemical and metabolic
alterations taking place in healthy subjects, which clearly must contribute to the
development of obesity, decreased glucose tolerance and some excitotoxic effects.
Recommendations: The present findings are alarming, and throw doubts upon the
unscrupulousness of current use of the flavoring agent MSG in fast processed and
canned foods. Much work is still to be performed to determine other adverse effects
on other organs.