Liquiritigenin is a plant-derived highly selective estrogen receptor β agonist

After the Women's Health Initiative found that the risks of hormone therapy outweighed the benefits, a need for alternative drugs to treat menopausal symptoms has emerged. We explored the possibility that botanical agents used in Traditional Chinese Medicine for menopausal symptoms contain ER beta-selective estrogens. We previously reported that an extract containing 22 herbs, MF101 has ER beta-selective properties. In this study we isolated liquiritigenin, the most active estrogenic compound from the root of Glycyrrhizae uralensis Fisch, which is one of the plants found in MF101. Liquiritigenin activated multiple ER regulatory elements and native target genes with ER beta but not ER alpha. The ER beta-selectivity of liquiritigenin was due to the selective recruitment of the coactivator steroid receptor coactivator-2 to target genes. In a mouse xenograph model, liquiritigenin did not stimulate uterine size or tumorigenesis of MCF-7 breast cancer cells. Our results demonstrate that some plants contain highly selective estrogens for ER beta. (C) 2007 Elsevier Ireland Ltd. All rights reserved.