The potential cytoprotective effect of Vitamin C and Vitamin E on monosodium glutamate-induced testicular toxicity in rats

ABSTRACT Background Monosodium glutamate (MSG) has been recognized as flavor enhancer that adversely affects male reproductive systems. Objective The study was conducted to explore the conceivable protective effects of vitamin C and/or vitamin E on testicular toxicity induced by MSG in rats. Materials and Methods Thirty male Wistar albino rats were divided (six per group) into: control, MSG, MSG + Vitamin C, MSG + Vitamin E and MSG + Vitamin C + Vitamin E groups. The duration of the study was three weeks. Assessment of serum testosterone, leuteinizing hormone (LH), malondialdehyde (MDA), glutathione peroxidase (GPX), interleukin-10 (IL-10) ,and tumor necrosis factor (TNF-α) were done. Histopathological examination of the testes of the rats was performed using histological, histochemical (Periodic Acid Schiff reaction (PAS)), and immunohistochemical (Proliferating cell nuclear antigen (PCNA), androgen receptors (ARs), Caspase-3) techniques. Results MSG-group was associated with significant decrease in serum testosterone, LH, GPX, and IL-10 (P < 0.05) and significant increase in serum MDA and TNF-α (P < 0.05) when compared with control group. MSG-group revealed many histopathological changes in the testis including degeneration of the germinal epithelium, absence of sperms in the lumina of tubules, widened vacuolated interstitium, marked deposition of the collagen fibers, very strong PAS reaction and marked immunohistochemical changes. Administration of vitamin C or vitamin E significantly reduced these changes; however, the combination of vitamin C and vitamin E provided more potent protection against the toxic effect of MSG than using each vitamin alone. Also, there was insignificant difference (P > 0.05) between MSG +Vitamin C and MSG +Vitamin E groups. Conclusion Vitamin C and Vitamin E act synergistically in reducing MSG-induced testicular toxicity via antioxidant, anti-inflammatory and antiapoptotic effects of both vitamins.