This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Farombi, E O Articles by Onyema, O O Search for Related Content PubMed PubMed Citation Articles by Farombi, E O Articles by Onyema, O O Social Bookmarking                   What's this?

Monosodium glutamate-induced oxidative damage and genotoxicity in the rat: modulatory role of vitamin C, vitamin E and quercetin

Department of Biochemistry, Drug Metabolism and Toxicology Research Laboratories, College of Medicine, University of Ibadan, Nigeria; olatunde_farombi{at}yahoo.com

O O Onyema

Department of Biochemistry, Drug Metabolism and Toxicology Research Laboratories, College of Medicine, University of Ibadan, Nigeria

Monosodium glutamate (MSG) continues to function as a flavor enhancer in West African and Asian diets. The present study examines the modulatory effects of dietary antioxidant vitamin C (VIT C), vitamin E (VIT E) and quercetin on MSG-induced oxidative damage in the liver, kidney and brain of rats. In addition, the effect of these antioxidants on the possible genotoxicity of MSG was investigated in a rat bone marrow micronuclei model.

MSG administered intraperitoneally at a dose of 4 mg/g body wt markedly increase malondialdehyde (MDA) formation in the liver, the kidney and brain of rats. Simultaneous administration of VIT C, VIT E and quercetin to MSG-treated rats significantly reduced this increase in MDA induced by MSG. VIT E reduced lipid peroxidation most in the liver followed by VIT C and then quercetin, while VIT C and quercetin showed a greater ability to protect the brain from membrane damage than VIT E.

The decreased glutathione (GSH) level elicited by MSG in the three organs corresponded with marked increase in the activity of glutathione-S-transferase (GST). While MSG increased (P B / 0.001) the activities of superoxide dismutase and catalase in the liver, it decreased significantly the activities of these enzymes in the kidney and the brain. The three antioxidants were effective at ameliorating the effects of MSG on GSH levels and the enzymes in the three organs examined. While MSG increased the activity of glucose-6-phosphatase in the liver and kidneys of rats (P B / 0.001), the activity of the enzyme was abysmally low in the brain. There were marked increases in the activities of alanine aminotransferase, aspartate aminotransferase and g-glutamyl transferase in rats treated with MSG. The antioxidants tested protected against MSG-induced liver toxicity significantly.

MSG at a dose of 4 mg/g significantly (P B / 0.01) induced the formation of micronucleated polychromatic erythrocytes (MNPCEs). Co-treatment of rats with VIT C and quercetin inhibited the induction of MNPCEs by MSG (P B / 0.001). VIT E failed to protect against MSG-induced genotoxicity.

The results indicate that dietary antioxidants have protective potential against oxidative stress induced by MSG and, in addition, suggest that active oxygen species may play an important role in its genotoxicity.

Key Words: antioxidants • dietary vitamins • genotoxicity • micronucleus • monosodium glutamate • oxidative stress

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				J. Rubio, W. Qiong, X. Liu, Z. Jiang, H. Dang, S.-L. Chen, and G. F. Gonzales Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice Evid. Based Complement. Altern. Med., October 9, 2008; (2008) nen063v1. [Abstract] [Full Text] [PDF]