Abstract
OBJECTIVE: To evaluate the effects of zinc oxide nanoparticles on mouse spermatogenesis. METHODS: Thirty two adult male NMRI mice were used. Experimental Groups (ZNP-1-ZNP-3) received one of the following treatments daily for 35 days: 5, 50 and 300 mg/kg zinc oxide nanoparticles respectively. Control group received only distilled water. Epididymal sperm parameters, testicular histopathology, morphometric analysis and spermatogenesis assessments were performed for evaluation of the zinc oxide nanoparticles effects on testis. RESULTS: Epididymal sperm parameters including sperm number, motility and percentage of abnormality were significantly changed in 50 and 300 mg/kg zinc oxide nanoparticles treated mice (p < 0.01). Histopathological criteria such as epithelial vacuolization, sloughing of germ and detachment were significantly increased in 50 and 300 mg/kg zinc oxide nanoparticles treated mice (p < 0.001). 300 mg/kg zinc oxide nanoparticles induced formation of multinucleated giant cells in the germinal epithelium. 50 and 300 mg/kg zinc oxide nanoparticles also caused a significant decrease in seminiferous tubule diameter, seminiferous epithelium height and maturation arrest (p < 0.001). CONCLUSION: Zinc oxide nanoparticles act as testicular toxicant and further studies are needed to establish its mechanism of action upon spermatogenesis.