Estrogenic potency of food-packaging-associated plasticizers and antioxidants as detected in ERα and ERβ reporter gene cell lines

This study presents the estrogenic potency of 21 food-packaging-associated compounds determined for the first time, using two transfected U2-OS (human osteoblasts devoid of endogenous estrogen receptors) estrogen receptor (ER) alpha and beta cell lines. Six plasticizers and three antioxidants were slightly estrogenic in the ER alpha cells. The model compounds bisphenol A and nonylphenol, one plasticizer [tris(2-ethylhexyl) trimellitate (TEHTM)], and two antioxidants (propyl gallate and butylated hydroxyanisole) were estrogenic in both ER alpha and ER beta cells. Compared to estradiol (E-2), these compounds appeared to be relatively more estrogenic in the ER beta cells than in the ER alpha cells. Three sorbitol-based plasticizers activated neither ER alpha nor ER beta and may be good replacements of existing plasticizers. All responses were additive with the response of E-2. This indicates that they may contribute to the total effects of the pool of estrogenic compounds humans are exposed to. The estrogenic potencies of these compounds, together with the suggested beneficial effect of ER beta-mediated responses and adverse ER alpha-mediated effects, support the importance of detecting characteristics for ER alpha and ER beta response separately in independent models, as done in the present study.