Estrogenic and Anticarcinogenic Properties of Kurarinone, a Lavandulyl Flavanone from the Roots of Sophora flavescens

Kurarinone, a lavandulyl flavanone, was isolated from a polyphenolic extract of the roots of Sophora flavescens using fractionation guided by estrogenic activity, which was determined by recombinant yeast and Ishikawa Var-I bioassays. Kurarinone showed weak estrogenic activity both in the yeast screen and in the Ishikawa Var-I assay with EC50 values of 4.6 and 1.66 μM, respectively. Furthermore, kurarinone was found to have potent cytotoxic activity (IC50 value = 22.2 μM) against human MCF-7/6 breast cancer cells in the sulforhodamine-B assay.