Estrogenic potency of food-packaging-associated plasticizers and antioxidants as detected in ERa and ERb 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 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 and ER cells. Compared to estradiol (E2), these compounds appeared to be relatively more estrogenic in the ER cells than in the ER cells. Three sorbitol-based plasticizers activated neither ER nor ER and may be good replacements of existing plasticizers. All responses were additive with the response of E2. 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-mediated responses and adverse ER-mediated effects, support the importance of detecting characteristics for ER and ER response separately in independent models, as done in the present study