Toxicity Investigation of Nano-SiO2 on Male Reproductive System in Pubertal Mice

Abstract BackgroundPuberty is a crucial stage to gain reproductive capacity, but it is also a period vulnerable to exogenous materials. While exposure to nanoparticles (NPs) has been linked to toxic responses in reproductive system in previous findings, little is known about the age-dependent effect of NPs, let alone the underlying mechanism. In the present study, we assessed male fertility parameters and explored its mechanism following intraperitoneal exposure to Nano-Silicon dioxide (Nano-SiO2) in mice during puberty.Methods40 mice aged 5 weeks were divided into 2 groups after 1 week acclimation and then exposed to 40mg/kg Nano-SiO2 dissolved in saline or vehicle controls by intraperitoneal injection every day over a period of 7-day, respectively. Changes in the structure and function of male reproductive organs were detected after exposure.ResultsNano-SiO2 exposed through intraperitoneal injection could cause damage to the testicular and epididymal histological architecture and reduce the level of sex hormone (testosterone), leading to a decrease in sperm quality and quantity. Furthermore, Nano-SiO2 could induce oxidative stress and inflammation in male reproductive tissues, indicated by reduced activity of antioxidants (superoxide dismutase, SOD) and increased level of the lipid peroxidation marker (malondialdehyde, MDA), which leads to the activation of cell apoptosis.ConclusionExposure to Nano-SiO2 in pubertal mice could cause toxicity on male reproductive system via inducing oxidative stress and activating TNF-α mediated apoptotic pathway.