EJMS

Abstract

Introduction: ZnO NPs has the third highest global production volume, where it is widely used in a variety of industries and medical application. As such, there is an increased risk of exposure to potential hazardous effects of ZnO NPs. Aim of the study: to investigate the possible histological changes in the seminiferous tubules following a prolonged administration of ZnO NPs and the potential protective role of quercetin. Material and methods: 24 adult male albino rats, with an average weight of 150-200 gm, were equally divided among 3 groups as follows: Group I (A & B) (control gp), group II (the treated group) and group III (the protected group) that received ZnO NPs in a dose of 300 mg/ kg body weight / day, simulataneuosly with quercetin in a dose of 200 mg/kg body weight /day orally for 28 days. Testes were dissected and specimens were processed for light and electron microscopic examinations. ZnO NPs were characterized using transmission electron microscope, Nano Zeta sizer particle analyzer and X-ray diffraction. A morphometric study was also performed to compare between heights of the seminiferous epithelium of the different groups. Results: Histologically, seminiferous tubules of the control groups revealed normal histological structure. Light microscopic examination of group II, revealed several changes in the seminiferous tubules such as distortion, basal laminae disruption, and focal widening of the interstitium. Some tubules appeared with sloughed spermatogenic cells in their lumina or hypoplastic germinal epithelium. Many spermatogenic cells were seen with evident cytoplasmic vacuoles or widening of the intercellular spaces. Sertoli cells were infrequently encountered in most of the tubules. Ultra structure results confirmed the light microscopic findings. Sertoli cells appeared with increased lysosomes and multiple myelin figures. Dark, eccentric or karyolytic nuclei of some spermatogenic cells were seen as well. Ultrastructural changes were also encountered in different cut sections of the spermatozoa. Group III results showed variable degrees of preservation of the histological structure of the tubules and germinal epithelium. Conclusion: ZnO NPs can cause testicular toxicity, that can be prevented to a great extent by quercetin. Key words: ZnO Nps, seminiferous tubules, quercetin.