The protective effects of melatonin on testis, sperm parameters quality, and in-vitro fertilization in mice following treatment with aflatoxin B1: An experimental study.

Abstract

Background: Aflatoxin B1 (AFB1) contamination of foods and animal feeds is a public health issue. Exposure to AFB1 induces oxidative stress and can cause male reproductive toxicity. Melatonin (MLT) is a neuro-hormone produced by the pineal gland and the testis and is known as a potent antioxidant.

Objective: This study aims to determine the protective effect of MLT on testicular tissue alterations, sperm parameter indexes, and in vitro fertility assays in mice treated with AFB1.

Materials and methods: In this experimental study, 28 adult male NMRI mice (8-10 wk old, 25-27 gr) were divided randomly into 4 groups: control, MLT (20 mg/kg/day, intraperitoneally), AFB1 (50 $\mu$ g/kg/day, intraperitoneally) and MLT+AFB1. After 35 consecutive days, testis histological changes, sperm quality parameters, the rate of sperm with DNA damage, and in vitro fertilization outcomes up to the blastocyst stage were surveyed and compared between groups.

Results: Our results showed that AFB1 administration induced histological alterations in the testis and significantly decreased all the sperm parameters and in vitro fertility (fertilization and blastocyst formation rates) compared to control. Additionally, the percentages of immature sperms and sperms with DNA damage significantly (p $<$ 0.001) increased in the AFB1-treated group. MLT treatment in the MLT+AFB1group significantly increased testis quality and sperm parameters and improved in vitro fertilizaton rate and in vitro embryonic development.

Conclusion: These findings demonstrated that MLT can compensate for the adverse effects of AFB1 on the quality of testicular tissue, sperm parameters, sperm DNA, and in vitro fertilization outcomes.