Nonsteroidal mycotoxin alternariol is a full androgen agonist in the yeast reporter androgen bioassay

- Recent studies have shown that alternariol (AOH) may act as a potential endocrine disruptor.
- The estrogenic and (anti) androgenic activity of AOH was tested in vitro with the use of yeast-based reporter gene bioassays.
- AOH acted as a weak, partial estrogen receptor agonist.
- AOH showed full androgenic response in the yeast androgen bioassay.
- AOH at concentrations higher than 5 μM enhanced the activity of testosterone.

Alternariol (AOH) is a toxic metabolite of phytopathogenic fungi of the Alternaria spp. and important contaminant of agricultural commodities.According to the recent studies, AOH has a potential to modulate the endocrine system of humans and animals. In the view of these reports, our study addressed the effects of AOH on human estrogen receptor (hERα) and androgen receptor (hAR) signaling with the use of the yeast estrogen and androgen reporter bioassays.Our results show that, apart from a weak estrogenic response, AOH induces full androgenic response of the bioassay with the EC50 of 269.4 μM. The androgenic potency of AOH relative to testosterone (T) is 0.046%. Moreover, in the presence of T, AOH at 5 μM acts as a weak antiandrogen, whereas at higher concentrations AOH sum up with the androgenic activity of T in a dose-dependent manner, suggesting additive effect.To our knowledge it is the first report of the androgenic potency of natural, nonsteroidal substance and may have the impact on the direction of the further studies. Further research is warranted to clarify the role of AOH in disruption of AR signaling in humans and animals.

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