P234 - ECE_3795 - Impact of in utero exposure to sesamol on folliculogenesis

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Abstract The growing popularity of vegetarian and vegan diets has significantly increased our exposure to phytoestrogens, which are potential endocrine disruptors. Sesamol, obtained by roasting sesame seeds, is classified as a phytoestrogen. As hormonal variations play a decisive role in the formation and differentiation of the reproductive system, pregnancy represents a period of increased sensitivity to endocrine disruptors. Through its ability to cross the placental barrier and interact with estrogen receptors, sesamol could impact the development of the reproductive system of babies exposed in utero. The aim of this study is to investigate the consequences of prenatal exposure to sesamol on folliculogenesis and blood hormone levels in F1 offspring. Pregnant rats were orally exposed to different doses of sesamol (30 or 100 mg/kg/day) from the 14th to the 19th day of gestation. Histological analysis of the ovaries was performed in newborn (aged 4 days) or adult (aged 120 days) animals from the F1 offspring. In newborn rats, in utero exposure to sesamol does not affect the relative proportion of pre-antral follicles. However, morphometric analysis of the ovaries revealed an increase in apoptosis of oocytes present in primordial follicles, resulting in a rise in the number of atretic follicles. The proliferation rate of follicular and thecal cells was also assessed by anti-BrdU immunohistochemistry. Our results show that sesamol has no impact on the proliferation rate of these cells at this stage of life. In adulthood, the proportion of the different types of follicles is not affected by the treatment. By contrast, sesamol induces a significant increase in the number of S-phase cells in the granulosa of antral follicles. An increased frequency of polyovular follicles is also observed in treated animals. The alteration of the zona pellucida and the corona radiata in these abnormal follicles could impact the process of gamete recognition and fertilisation. ELISA tests carried out on blood serum samples showed that exposure to sesamol has no significant impact on testosterone and oestrogen levels. By contrast, a significant increase in AMH concentration was observed in animals exposed to a dose of 100 mg/kg/day. In conclusion, prenatal exposure to sesamol induces morphological alterations in the ovaries, such as an increase in oocyte apoptosis within primordial follicles and a resurgence of polyovular follicles. The increased synthesis of AMH associated with these morphological alterations could have an impact on fertility.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.