Endocrine Abstracts

Introduction: Parabens, esters of para-hydroxybenzoic acid, are widely used as an antimicrobial agent in the cosmetic products and pharmaceutical industries. Recently, it has been reported that parabens including methyl-, ethyl-, propyl-, butyl-, isopropyl-, and isobutylparaben act as xenoestrogens, a class of endocrine disruptors. In this study, we hypothesized that parabens may disrupt ovarian follicle maturation in female rats during the neonatal period.

Methods: Fifty-five female neonatal rats were divided into eleven groups, and were given daily subcutaneous injection, with methyl-, propyl- and butylparaben (62.5, 250, or 1000 mg/kg/day) at neonatal 1–7 days. The total mRNA and protein were extracted from the ovaries excised at the postnatal day 8 of female rats, and the levels of AMH mRNA and protein were analyzed by real-time PCR and Western blot analysis. The ovaries were also fixed and stained with H&E for histological analysis.

Results: The regulation of AMH gene expression was modulated by propyl-, butyl-parabens and methyl-paraben. The mRNA and protein levels of AMH significantly were increased by treatment of butylparaben while they were decreased by methyl-paraben. The number of follicles was counted and classified into primordial, primary, or secondary stages after serial sections of the ovary. The histological results showed that total number of follicles and primordial follicles was increased by butylparaben compared to a negative control.

Conclusion: Butylparaben may have an estrogenic effect to disrupt ovarian follicle development in the neonatal female rat.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.