Mycotoxins as potential cause of human infertility - a review of evidence from animal and cellular models

Mycotoxins are secondary toxic metabolites produced by Aspergillus, Penicillium, and Fusarium species of fungi, when they infect and proliferate on various agricultural commodities either in the field and/or during storage. The well-known detrimental health effects of mycotoxins in humans include liver cancer, Balkan endemic nephropathy, child growth impairment, immune suppression, neural tube defects and death in acute exposure. However, growing evidence also suggests that mycotoxins may negatively influence human fertility. Studies using animal and cell models indicate that zearalenone, deoxynivalenol, ochratoxin A and aflatoxin B1 can adversely affect fertility, mainly through damage to sex organs, gametes and disruption of steroidogenesis. For instance, animal models have indicated that exposure to the aforementioned mycotoxins can promote adverse effects on spermatozoa, sertoli and Leydig cell function, oocyte maturation, and uterine and ovarian development and function, both in vivo and ex vivo. They may also induce oxidative stress resulting in sperm DNA damage and subsequently, reduced fertilisation rates and lower embryo quality. Furthermore, mycotoxins may act as endocrine disrupters, altering the steroid hormone homeostasis, consequently leading to subfertility or infertility. In humans, zearalenone has been linked to precocious puberty in girls, correlating with extremely high serum oestrogen levels whereas aflatoxin B1 has been linked to poor sperm quality in infertile males. Considering that multiple exposures to these mycotoxins have been reported in humans and that there is a homology in organ systems between animals and humans, these findings may have clinical relevance in human infertility. This review critically examines mycotoxins as potential cause of human infertility using available data from animal and cellular models.