RESUMO
BACKGROUND: This research delves into the reproductive toxicology of zinc oxide nanoparticles (ZnO-NPs) in male Sprague Dawley rats. It specifically examines the repercussions of Zn accumulation in the testes, alterations in testosterone levels, and histopathological changes in the gonadal tissues. AIMS: The primary objective of this study is to elucidate the extent of reproductive toxicity induced by ZnO-NPs in male Sprague Dawley rats. The investigation aims to contribute to a deeper understanding of the potential endocrine and reproductive disruptions caused by ZnO-NPs exposure. METHODS: Characterization techniques including SEM-EDX and XRD affirmed the characteristic nature of ZnO-NPs. Twenty-five healthy post weaning rats (200-250 g) were intraperitoneally exposed to different concentrations of ZnO-NPs @ 10 or 20 or 30 mg/kg BW for 28 days on alternate days. RESULTS: Results showed significant dose dependent decline in the body weight and testicular somatic index of rats. It also showed significant dose dependent accumulation of Zn in testis with increasing dose of ZnO-NPs. Conversely, serum testosterone level and sperm count were reduced with increasing dose of ZnO-NPs. Histological results showed dose dependent abnormalities i.e., vacuolization, edema, hemorrhage, destruction of seminiferous tubules, loss of germ cells and necrosis in rat testis. CONCLUSION: The findings of this study clearly indicate that high doses of zinc oxide nanoparticles (ZnO-NPs) can adversely affect the structural integrity and functional efficacy of the male reproductive system. Given these results, it becomes crucial to implement stringent precautionary measures in the utilization of ZnO-NPs, particularly in cosmetics and other relevant sectors. Such measures are imperative to mitigate the toxicological impact of ZnO-NPs on the male reproductive system and potentially on other related physiological functions. This study underscores the need for regulatory vigilance and safety assessments in the application of nanotechnology to safeguard human health.