Related Experiment Video
Updated: Jul 5, 2025
Using Enzyme-based Biosensors to Measure Tonic and Phasic Glutamate in Alzheimer's Mouse Models
Published on: May 3, 2017
Monosodium Glutamate Even at Low Dose May Affect Oxidative Stress, Inflammation and Neurodegeneration in Rats
Rashmi Kesherwani1, Sukanya Bhoumik1, Raushan Kumar1
1Department of Biochemistry, University of Allahabad, Allahabad, 211002 India.
Abstract:
Monosodium glutamate (MSG) is a widely used flavour enhancer. A daily intake of MSG at high dosage (2000-4000 mg/kg body weight) is reported to be toxic to humans and experimental animals. The present study aims to investigate the toxic effect of oral administration of MSG at low concentrations (30 and 100 mg/kg body weight) by evaluating biochemical parameters of oxidative stress and inflammation in blood; expression of neuroinflammatory gene and histopathological changes in brain on male Wistar rats. The administration of MSG significantly increases serum level of fasting glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein and decrease level of high-density lipoprotein. Significant low level of FRAP, GSH, SOD, CAT and higher level of MDA, PCO, AOPP, PMRS, NO, CRP, IL-6, TNF-α confirms substantial oxidative stress followed by inflammation after 100 mg MSG treatment. RT-PCR figure shows significant expression of neuroinflammatory gene IL-6 and TNF-α and histopathological examination revealed severe neurodegeneration in hippocampus (CA1 and CA3) and cerebral cortex region of brain at 100 mg MSG treatment. Our result provides evidence that MSG administration at 30 mg does not impose toxicity, however at 100 mg/kg body weight, which is considered a low dose, there is significant toxic effects and may be detrimental to health.
Insights
Even low doses of monosodium glutamate (MSG) can be toxic. A daily intake of 100 mg/kg body weight caused significant oxidative stress, inflammation, and neurodegeneration in rats, suggesting potential health risks.
Area of Science:
- Biochemistry
- Toxicology
- Neuroscience
Background:
- Monosodium glutamate (MSG) is a common food additive.
- High MSG intake (2000-4000 mg/kg) is known to be toxic.
- The effects of low-dose MSG exposure require further investigation.
Purpose of the Study:
- To evaluate the toxic effects of low-dose oral MSG (30 and 100 mg/kg) in male Wistar rats.
- To assess biochemical markers of oxidative stress and inflammation.
- To examine neuroinflammatory gene expression and brain histopathology.
Main Methods:
- Oral administration of MSG at 30 and 100 mg/kg body weight.
- Biochemical analysis of blood parameters (glucose, lipids, oxidative stress markers).
- Gene expression analysis (RT-PCR) for neuroinflammatory markers (IL-6, TNF-α) and histopathological examination of brain tissue.
Main Results:
- MSG at 100 mg/kg significantly altered lipid profiles and increased oxidative stress markers (MDA, PCO, AOPP) while decreasing antioxidants (GSH, SOD, CAT).
- Elevated inflammatory markers (CRP, IL-6, TNF-α) and nitric oxide (NO) were observed.
- Significant upregulation of IL-6 and TNF-α genes and severe neurodegeneration in the hippocampus and cerebral cortex were noted.
- MSG at 30 mg/kg showed no significant toxicity.
Conclusions:
- Oral MSG administration at 100 mg/kg induces significant oxidative stress, inflammation, and neurodegeneration in rats.
- Low-dose MSG (100 mg/kg) can be detrimental to health.
- MSG at 30 mg/kg did not exhibit toxicity in this study.
