Multifaceted impacts of monosodium glutamate on testicular morphology: insights into pyroptosis and therapeutic potential of resveratrol.

Abstract

Background: Monosodium glutamate is a food additive and flavour enhancer in processed foods and soups that is considered to affect testicular histology. The aim of this research was to investigate the impact of monosodium glutamate (MSG) on testicular structure in rats and explore the potentially protective effects of resveratrol.

Materials and methods: Four experimental groups involved in our study contained 10 rats in each. The first group was a control group; in the second group (the resveratrol group) control rats received 20 mg/kg of resveratrol via oral gavage; in the third group (the MSG group) rats received monosodium glutamate (MSG) at a dose of 60 mg/kg body weight daily, via a gastric tube. The fourth group we called the MSG + resveratrol group. Serum levels of testosterone, FSH, and LH were measured. Testicular specimens were prepared for measurement of oxidative stress markers, and gene expression of NLRP3, caspase-3, and GSK-3b. Moreover, paraffin blocks contained testicular tissue used for histological and immunohistochemical examination. Additionally, seminal smears from epididymis were examined.

Results: MSG administration adversely affected testosterone production, hormonal levels, and sperm parameters, Histological examination revealed marked testicular degeneration, and oxidative stress assessments indicated an elevated level of MDA, a lipid peroxidation marker, and decreases in SOD and CAT, two antioxidant enzymes. Moreover, MSG induced apoptotic and pyroptotic markers and its gene expressions. Importantly, the administration of resveratrol reversedthese detrimental effects of MSG, demonstrating its corrective influence on hypothalamic-pituitary-gonadal axis disruption, the improvement of sperm parameters, the attenuation of oxidative stress, and anti-apoptotic activity and anti-pyroptotic effects. The expression of Ki-67 as a cell proliferation marker further supported the positive response to spermatogenesis dysfunction upon resveratrol treatment.

Conclusions: This article sheds light on the protective effect of resveratrol against MSG-induced testicular damage, with an exploration of its mechanistic role.