In vitro profiling of endocrine disrupting potency of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) and related hydroxylated analogs (HO-PBDEs)

The potential of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) and its related hydroxylated analogs (2′-HO-BDE28, 6-HO-BDE47, 4′-HO-BDE17, and 4′-HO-BDE49) to modulate estrogen/thyroid/androgen receptor-(ER, TR, AR), mediated responses were investigated by use of reporter gene assays. Exposure to 1 or 10 μM, 4′-HO-BDE17 significantly up-regulated expression of Luc, whereas other four chemicals did not induce Luc expression under control of the ER. Anti-estrogenic potency was observed for 4′-HO-BDE17 (IC50 = 1.14 μM) > 6-HO-BDE47 (IC50 = 2.65 μM) > 2′-HO-BDE28 (IC50 = 9.49 μM) > BDE47 (IC50 = 21.11 μM). No anti-estrogenic effect of 4′-HO-BDE49 was observed. Both 4′-HO-BDE17, 4′-HO-BDE49 resulted in greater responses of Luc expression induced by T3. BDE47, 2′-HO-BDE28, 6-HO-BDE47 did not show any effect on the expression of Luc induced by 5 nM T3. 6-HO-BDE47 (IC50 = 0.34 μM) > 4′-HO-BDE17 (IC50 = 1.41 μM) > BDE47 (IC50 = 3.83 μM) > 2′-HO-BDE28 (IC50 = 29.22 μM) exhibited anti-androgenic potency, while 4′-HO-BDE49 did not show androgenic transcriptional activity.