Study of different doses of zinc oxide nanoparticles by intraperitoneal and gavage methods on testicular tissue in Wistar rats: An experimental study.

Background: Zinc oxide nanoparticles (ZnO-NPS) are widely used inhuman life; however, they do have side effects on human health.

Objective: This study aimed to evaluatethedifferent doses of ZnO-NPS on testicular tissue.

Materials and methods: 35 male Wistar rats(10-12 wk, 220 $\pm$ 20gr) were divided into 7 groups of 5, including the control group (gavaged distilled water daily), sham group (received intraperitoneal doses of distilled water twice a week). The group receivedintraperitoneal ZnO-NPS (25, 50, and 100 mg/kg body weight, twice a week), and gavage (150 and 200 mg/kg body weight daily). All stages of the test were performed in 4 wk then serum testosterone and tissue malondialdehyde, and ferric reducing antioxidant power levels were measured, also testes histopathological evaluation was performed.

Results: Our results showed that a reduced cell population of spermatozoa was observed in the group that received 25 mg/kg ZnO-NPS, while a reduced cell population of spermatozoa, edema, hyperemia, and vacuolar degeneration were observed in the group that received 50 and 100 mg/kg ZnO-NPS. The maximum amount of lesions were observed in the dose of 200 mg/kg. The highest amount of ferric reducing antioxidant power and testosterone levels were observed in the control group. Also, a 100 mg/kg intraperitoneal dose of ZnO-NPS and 150 mg/kg oral dose of ZnO-NPS were suitable doses to create a model of male genital lesions.

Conclusion: Nanoparticles are harmful factors for the reproductive system and consequently affect infertility, which requires the toxicity of the concentration of these nanoparticles to be evaluated and controlled.