Molecular study to the effect of monosodium glutamate on rat gingiva

Abstract

Background Monosodium glutamate (MSG) is a flavor enhancer widely used throughout the world. It is the salt of glutamic acid, one of the naturally occurring amino acids. It is produced commercially and has classified as generally recognized as safe. Nevertheless, it has been alleged to cause many ills. Objective The present work aimed to evaluate the genotoxic effects of MSG on the rat gingiva. Materials and methods Thirty adult Wistar rats weighting 150–250 g at the age of 6–8 weeks were used in this study. They were partitioned evenly into three groups, each group of 10 rats. Group 1 was the first group that was maintained as control group. Group 2 was the first experimental group while group 3 was the second experimental group. Rats in groups 2 and 3 were administered MSG at two different doses, 15 and 30 mg/kg body weight respectively for 6 weeks. Each gingival tissue sample was divided evenly to be processed and prepared for routine histological examination and molecular study. Results Using hematoxylin and eosin stain, gingival sections presented variable structural changes in both experimental groups including hyperchromatism, pleomorphism of basal cell layer and cytoplasmic basophilia. Group 2 showed areas of epithelial atrophy while group 3 presented acanthosis and hyperkeratosis. Analysis of DNA extracted from gingival tissue samples using five different primers showed marked decrease in the DNA quality. The genotoxic effect of MSG was more declared in group 3 that exhibited the least numbers of bands created with the tested five primers. Conclusion It can be concluded that MSG is genotoxic agent to gingival tissue that has deleterious effects on DNA. These effects were clearly detected in the molecular study and supported by the routine histological findings of the current work.