Repeated exposure to iron oxide nanoparticles causes testicular toxicity in mice.

The aim of this study was to determine whether repeated exposure to iron oxide nanoparticles (Fe2 O3 -NPs) could be toxic to mice testis. Fe2 O3 -NPs (25 and 50 mg/kg) were intraperitoneally administered into mice once a week for 4 weeks. Our study showed that Fe2 O3 -NPs have the ability to cross the blood-testis barrier to get into the testis. The findings showed that exposure resulted in the accumulation of Fe2 O3 -NPs which was evidenced from the iron content and accumulation in the testis. Furthermore, 25 and 50 mg/kg Fe2 O3 -NPs administration increased the reactive oxygen species, lipid peroxidation, protein carbonyl content, glutathione peroxidase activity, and nitric oxide levels with a concomitant decrease in the levels of antioxidants-superoxide dismutase, catalase, glutathione, and vitamin C. Increased expression of Bax, cleaved-caspase-3, and cleaved-PARP confirms apoptosis. Serum testosterone levels increased with increased concentration of Fe2 O3 -NPs exposure. In addition, the histopathological lesions like vacuolization, detachment, and sloughing of germ cells were also observed in response to Fe2 O3 -NPs treatment. The data from our study entailed that testicular toxicity caused by Fe2 O3 -NPs exposure may be associated with Fe2 O3 -NPs accumulation leading to oxidative stress and apoptosis. Therefore, precautions should be taken in the safe use of Fe2 O3 -NPs to avoid complications in the fertility of males. Further research will unravel the possible molecular mechanisms on testicular toxicity of Fe2 O3 -NPs.