Propylparaben inhibits mouse cultured antral follicle growth, alters steroidogenesis, and upregulates levels of cell-cycle and apoptosis regulators

Propylparaben is prevalently used in cosmetics, pharmaceuticals, and foods; yet, its direct effects on the mammalian ovary are unknown. We investigated the direct effects of propylparaben on the growth and steroidogenic function of mouse antral follicles. Antral follicles were isolated from the ovaries of Swiss mice (age: 32-42 days) and cultured in media with dimethylsulfoxide vehicle control or propylparaben (0.01-100 μg/mL) for 24-72 h. Follicle diameter was measured every 24 h to assess growth. Follicles and media were collected at 24 and 72 h for gene expression and hormone measurements. Propylparaben (100 μg/mL) significantly inhibited follicle growth (48-72 h). Further, propylparaben exposure increased expression of cell cycle regulators (CDK4, Cdkn1a), an apoptotic factor (Bax), and a key steroidogenic regulator (Star). In media, propylparaben decreased accumulation of dehydroepiandrosterone-sulfate, but increased testosterone and 17β-estradiol. Overall, our findings suggest that propylparaben disrupts antral follicle growth and steroidogenic function by altering the cell-cycle, Apoptosis, and steroidogenesis pathways.