Effect of 7-O-β-D-Glucopyranosylchrysin and its Aglycone Chrysin Isolated from Podocytisus caramanicus on Estrogen Receptor α Transcriptional Activity

A screening of Greek Fabaceae extracts identified the methanolic extract of Podocytisus caramanicus Boiss. & Heldr. as having proliferative activity on human breast cancer cells (MCF-7). Using transient transfection experiments, we have first used three compounds described for their estrogen-like properties, E-2, genistein (Gen) and biochanin A (Bch), as controls to evaluate our cellular model. Secondly, we have demonstrated that the 7-O-beta-D-glucopyranosylchrysin (Glc-chr), the most abundant flavone of the extract, and its aglycone chrysin were able to increase estrogen receptor a transcriptional activity in MCF-7 cells. We have also shown that the estrogenic activity of Glc-chr could be completely suppressed by the pure estrogen antagonist ICI 182,780 suggesting that the effect of Glc-chr is mediated by ER alpha.