Monosodium Glutamate-induced Testicular Toxicity and the Possible Therapeutic Role of Stem Cells versus Zinc Oxide Nanoparticles in Adult Albino Rats: Histological, Immunohistochemical and Biochemical Study

Introduction: Monosodium glutamate (MSG), the most common food additive that has been used as a flavor enhancer, can result in testicular damage. Such damage can be alleviated by bone marrow-derived mesenchymal stem cells (BM-MSCs) and zinc oxide nanoparticles (ZnONPs).Aim of the study: to elucidate the histo-pathological, immune-histochemical and biochemical changes in MSG-induced testicular injury and assess the possible therapeutic action of stem cells versus zinc oxide nanoparticles.Subjects and Methods: Fifty rats were divided into five groups: control, sham control, MSG-treated, stem cell-treated and ZnONPs-treated groups. Light microscopic, immune-histochemical; caspase 3 and proliferating cell nuclear antigen (PCNA), testosterone levels, malondialdehyde (MDA)/glutathione (GSH), B-cell lymphoma (Bcl-2) / BCL2-Associated X Protein (BAX) and histomorphometric analysis were performed.Results: MSG-treated groups revealed degenerated seminiferous tubules, widen interstitial spaces with fluid exudates along with significantly increased BAX level, caspase 3 expression and raised MDA mean values. Concurrently, MSG has a significant decline in GSH, Bcl-2, PCNA and spermatogenic cells count as related to the control groups. MSCs and ZnONPs-treated groups demonstrated relief of the pathological changes. Conclusions: The injurious changes induced by MSG on the testis were noticeably ameliorated when treated with either stem cells or ZnONPs. Stem cells displayed better effects