The impact of zearalenone (ZEN) on female reproduction remains an issue, since its effects may differ among exposed cell types. Besides the use of decontaminants in animal diet, other approaches should be considered to minimise ZEN effects after exposure. Since the first organ in contact with ZEN is the gastrointestinal tract, we hypothesise that products of microbiota metabolism may play a role in ZEN detoxification. We aimed to evaluate the effect of 1 µmol/L ZEN and 1 µmol/L equol (a microbial metabolite), alone or in combination, on the survival and morphology of in vitro cultured ovarian preantral follicles. Ovaries from 12 sheep were collected at a local abattoir and fragmented, and the ovarian pieces were submitted to in vitro culture for three days in the presence or absence of the test compounds. The follicular morphology was impaired by ZEN, but equol could alleviate the observed degeneration rates. While ZEN decreased cell proliferation in primary and secondary follicles, as well as induced DNA double-strand breaks in primordial follicles, all these observations disappeared when equol was added to a culture medium containing ZEN. In the present culture conditions, equol was able to counteract the negative effects of ZEN on ovarian preantral follicles.
Keywords: xenoestrogens; mycotoxin; ovary; sheep; in vitro culture
Key Contribution: This study evaluates the ability of a microbiota metabolite (equol) to minimise the negative effects of zearalenone (ZEN) on the initial development of ovine preantral follicles. The improved follicular survival when equol is added to a culture medium containing ZEN suggests that this phytoestrogen plays a role in counteracting the toxicity of ZEN. Although equol should not be claimed as a mycotoxin detoxifier; microbiota modulation to increase the synthesis of this phytoestrogen might alleviate the impact of ZEN on early staged female gametes.
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