Estrogenic Activity of Persistent Organic Pollutants and Parabens Based on the Stably Transfected Human Estrogen Receptor-α Transcriptional Activation Assay (OECD TG 455)

Screening of estrogenic activity on dichloro diphenyl trichloroethane (DDT), dichloro diphenyl dichloro ethylene (DDE), dieldrin, heptachlor, aldrin, chlordane, lindane, polybrominated diphenyl ethers (PBDE) and parabens was compared using Organization for Economic Cooperation and Development (OECD) test guideline 455 (TG455). The estrogenic activity of DDT was 58,000-fold ($PC_{50}$, $1.67{\times}10^{-6}$ M) less than $17{\beta}$-estradiol($E_2$) ($PC_{50}$, $2.88{\times}10^{-11}$ M) but DDE, dieldrin, heptachlor, aldrin, chlordane, lindane and PBDE did not show any estrogenic activity in this assay system. In the case of paraben compounds, the rank of relative transcriptional activation (logRTA) was butyl paraben -1.63752 ($PC_{50}$, $1.25{\times}10^{-7}$ M) > isobutyl paraben -2.34008 ($PC_{50}$, $6.3{\times}10^{-7}$ M) > ethyl paraben -2.64016 ($PC_{50}$, $1.26{\times}10^{-6}$ M) > isopropyl paraben -2.73993 ($PC_{50}$, $1.58{\times}10^{-6}$ M) > propyl paraben -2.84164 ($PC_{50}$, $2.0{\times}10^{-6}$ M). Our data suggest that OECD test guideline TG455 may be useful as a screening tool for potential endocrine disruptors.