Fig. 1.

Transcriptional and ligand-binding assays of 37 flavonoid compounds. (A) T47D-KBLuc transcriptional assays showing ERE-luciferase reporter activity of 13 out of 37 flavonoid compounds from four different subclasses, revealed 13 phytoestrogenic compounds able to transcriptionally activate ER in a dose-dependent manner. The red line represents a 2-fold cutoff for positive hits. RLU, relative luciferase unit, normalized to β-gal control. Data are shown as mean ± S.D. (B) Relative ligand-binding affinity of 12 compounds to ERα or ERβ.