Baicalein and genistein display differential actions on estrogen receptor (ER) transactivation and apoptosis in MCF-7 cells.

Genistein is a soy isoflavone that has attracted much attention for its chemopreventive properties. Baicalein is a flavone found in Scutellaria species, and its structure is analogous to that of genistein. We examined the two flavones' antiestrogenicity by using a transient transfection model. Our results indicated that baicalein could suppress 17beta-estradiol-induced transactivation in cells expressing estrogen receptor alpha, whereas no antagonistic activity was seen in genistein. Cell death assay and flow cytometry analysis demonstrated that baicalein was a stronger apoptosis inducing agent than genistein. Considering all the criteria tested, baicalein could be a better chemopreventive agent than genistein.