Zearalenone (ZEA) is a mycotoxin produced mainly by fungi in foods and feeds. It is frequently involved in reproductive disorders of farm animals and occasionally in hyperoestrogenic syndromes in humans. ZEA and its metabolites possess oestrogenic activity in cattle, pigs and sheep. However, oral or interperitoneal administration of ZEA is relatively low acute toxic in mice, rat and pig. ZEA transformed into two metabolites α-zearalenol (α-ZEA) and β-zearalenol (β-ZEA) in animals which are subsequently conjugated with glucuronic acid. Moreover, ZEA has also been shown to be hepatotoxic, haematotoxic, immunotoxic and genotoxic. α-Zearalenol is a major hepatic metabolite in rats of zearalenone which impacts mammalian reproduction and development [1].

In vitro: The binding characteristic of α-ZEA was less potent with estrogen receptors than the parent compound [2]. α-zearalenol showed pronounced effects on uterotropic activity [3]. α-ZEA inhibited normal sperm motility, but stimulated hyperactive motility in the remaining motile cells and simultaneously induced the acrosome reaction [4].

References:
[1].  Zinedine A, Soriano J M, Molto J C, et al. Review on the toxicity, occurrence, metabolism, detoxification, regulations and intake of zearalenone: an oestrogenic mycotoxin[J]. Food and chemical toxicology, 2007, 45(1): 1-18.
[2].  Kiang D T, Kennedy B J, Pathre S V, et al. Binding characteristics of zearalenone analogs to estrogen receptors[J]. Cancer research, 1978, 38(11 Part 1): 3611-3615.
[3].  Mirocha C J, Pathre S V, Behrens J, et al. Uterotropic activity of cis and trans isomers of zearalenone and zearalenol[J]. Applied and environmental microbiology, 1978, 35(5): 986-987.
[4].  Filannino A, Stout T A E, Gadella B M, et al. Dose-response effects of estrogenic mycotoxins (zearalenone, alpha-and beta-zearalenol) on motility, hyperactivation and the acrosome reaction of stallion sperm[J]. Reproductive Biology and Endocrinology, 2011, 9(1): 134.