Monosodium Glutamate is Associated With Testicular Histomorphometric Alterations, Inflammation and Apoptosis in Male Wistar Rats: An Experimental Animal Study

Abstract

Background

Monosodium glutamate (MSG) is a widely used food additive, yet concerns persist regarding its potential reproductive toxicity. Previous studies have associated MSG exposure with oxidative stress, inflammation and apoptosis, which may contribute to testicular damage and impaired spermatogenesis. However, its dose-dependent effects on histological, biochemical and inflammatory parameters of the testes remain underexplored.

Objective

This study investigates the dose-dependent effects of chronic MSG exposure on testicular structure, histomorphometric alterations, inflammatory markers (tumour necrosis factor-alpha [TNF-α]) and apoptotic activity (Caspase-3) in male Wistar rats.

Methods

Thirty male Wistar rats were assigned to five groups (n = 6). Group A (control) received distilled water, while Groups B, C, D and E received MSG at 30 mg/kg, 100 mg/kg, 300 mg/kg and 1000 mg/kg, respectively, for 60 days. Histological assessment, testicular protein concentration, TNF-α and Caspase-3 expression were analysed.

Results

Histological analysis revealed progressive seminiferous tubule disorganisation, germinal epithelium atrophy and expanded interstitial spaces in higher MSG doses. Combined H&E and reticulin staining enabled detection of cellular changes and reticular fibre alterations not fully apparent with routine histology alone. Luminal and tubular diameters, cross-sectional area and germinal epithelium height were significantly reduced (p < 0.05). TNF-α levels increased dose-dependently, indicating inflammation, while Caspase-3 expression was significantly elevated (p < 0.05), suggesting increased apoptosis.

Conclusion

Chronic MSG exposure is associated with dose-dependent testicular damage, characterised by histological degeneration, inflammation and apoptosis. These changes suggest potential impairment of spermatogenic function. Public awareness and further research on protective strategies against MSG-induced testicular toxicity are recommended.