Background and purpose: Cyclophosphamide (Cyclo) is a common chemotherapy medicine that reduces male fertility. Various antioxidant agents have been used to reduce the side effects of chemotherapy medicines. Zinc oxide nano particles (nZno) have been introduced as a potent antioxidant. This study aimed at investigating the protective effects of nZno on testis tissue structure in Cyclo treated mice.

Materials and methods: We conducted an experimental study in which 15 adult male mice were divided into three groups (n=5 per group) and treated for 4 weeks as: 1) control: normal saline (0.1 cc daily), 2) treatment I: Cyclo (15 mg/kg, once a week) and 3) treatment II: Cylo (15 mg/kg kg, once a week) + nZno (5mg/kg, daily) intraperitoneally. Twenty four hr after the last administration of drugs, the animals were euthanized and right testes were isolated and fixed. Five-micrometer testicular tissue sections were prepared according to routine histotechnique process and were studied by light microscope.

Results: Compared with the control group, cyclophosphamide reduced the diameter and septal epithelium thickness of the seminiferous tubuli, primary spermatocyte, spermatid, and spermatozoid (P≤0.05) while co administration of nZno with cyclophosphamide prevented these changes (P≤0.05). nZno also prevented the luminal extension and epithelial disorganization of seminiferous tubuli induced by cyclophosphamide.

Conclusion: nZno could prevent testicular tissue changes and reduction of spermatogenic cell counts induced by cyclophosphamide.