Effect of the endocrine disruptor Bisphenol A in in vitro models of human placenta

Endocrine disrupter chemicals (EDCs) are environmental pollutants of agricultural or industrial origin which may influence human reproductive health. Bisphenol A (BPA) is widely used as a monomer in polycarbonate plastics and epoxy resins of dental sealants and in other types of plastics. This compound has estrogenic activity and human placenta is a target organ because it expresses Estrogen receptors α and β. In this study we investigated the effect of BPA on in vitro models of human placenta. We firstly, used the trophoblast cell lines BeWo to evaluate the median lethal concentration (LC50) assayed by alamar Blue test and the effective lethal concentration (EC50) by hormone β-hCG assay. Secondly, the model of primary cultures of villous explants from human placenta was used to evaluate the effect of non-toxic chemical concentrations on β-hCG secretion. Data on BeWo cells showed BPA toxicity at concentrations higher than 5x10-5M (LC50=1.32x10-4M and EC50=2.61x10-5M, for cell viability and hormone secretion, respectively). Although non-toxic BPA concentrations at 10-9M significantly induced the β-hCG secretion by primary chorionic villous explants. The findings suggest that low but environmentally relevant levels of BPA produce functional effects on human placenta when no evidence of toxicity is present.