Propylparaben induces apoptotic cell death in human placental BeWo cells via cell cycle arrest and enhanced caspase-3 activity

Backgrounds Propylparaben is one of the most commonly used preservatives in pharmaceuticals, food items, and personal care products. However, growing evidence demonstrates that propylparaben has a harmful effect on various human tissues. In this study, we investigated the cytotoxic effects of propylparaben on the human placental cell line, BeWo. Objective We investigated whether propylparaben caused placental cell death using relevant cytotoxic endpoints, including cell viability, proliferation, cell cycle, and apoptosis, in BeWo cells. However, instead of using conventional methods of protein analysis from pooled samples, we precisely quantified protein expression at the single cell level by flow cytometric analysis. Results Propylparaben significantly reduced cell viability in a dose-dependent manner. It induced cell cycle arrest at the sub-G1 phase by reducing the expression levels of cyclin D1, whereas the cell population at the G0/G1 and S-phases was decreased. Furthermore, propylparaben induced apoptosis by enhancing the activity of caspase-3. Conclusion Collectively, our results suggest that propylparaben causes cytotoxic effects in human placental BeWo cells by inducing cell cycle arrest and apoptosis.