Propylparaben negatively impacts IN VITRO preimplantation mouse embryo development

Parabens are chemicals widely used in personal care products and food as antimicrobial preservatives. They exhibit potential estrogenic activity by binding to estrogen receptors 1 and 2, classifying them as endocrine-disrupting chemicals. Given the substantial daily exposure of women to parabens, it is crucial to investigate their effects on the female reproductive system. Previous studies in mouse models have shown that paraben exposure impacts ovarian development, resulting in an increase in cystic follicles and a decrease in corpora lutea. However, the effects of parabens on embryo development have not been extensively studied. This study aimed to determine the impact of propylparaben exposure on preimplantation embryo development in vitro. We tested the effects of 0 (0.075 % DMSO), 0.5 μg/mL, 5.0 μg/mL, 10 μg/mL, and 15 μg/mL propylparaben on rate of development of mouse zygotes to hatched blastocyst stage, quantified the number of inner cell mass (ICM) and trophectoderm (TE) cells in hatched blastocysts, and the distribution of cytoskeletal F-actin. The percentage of hatched blastocysts was significantly decreased at 0.5 μg/mL and 10 μg/mL compared to controls. Propylparaben treatment did not alter TE cell numbers. However, treatment with 0.5 or 15 μg/mL significantly decreased the number of ICM cells compared to controls. Additionally, the intensity of phalloidin fluorescence staining for F-actin was significantly reduced at 10 μg/mL and 15 μg/mL propylparaben. In summary, our findings show that propylparaben exposure disrupts ICM formation, impacts the cytoskeletal filamentous actin (F-actin) network, and alters the rate of hatched blastocyst development in preimplantation mouse embryos.