Phytoestrogens from Genista halacsyi (Leguminosae)

The genus Genista is remarkably rich in isoflavones, which consider to be the most well studied phytoestrogens. In continuation of our research for new phytoestrogens, the aerial parts of Genista halacsyi Heldr., an endemic plant of Greece, was studied. Firstly, by classical separation methods several isoflavones were isolated namely: genistein, daidzein, biochanin, 8Meo-formononetin, isoprunetin, 3'OH-isoprunetin, genistin, 8C-glucopyranosylgenistein, 8C-glucopyranosylorobol and 8C-glucopyranosyl-4'glucopyranosylgenistein. In continuation, high-speed counter-current chromatography (HSCCC), a chromatographic technique that eliminates irreversible absorption of the sample onto solid support with an excellent sample recovery was used to isolate larger amounts. The estrogenic activity of all isolated compounds was tested using estrogen receptor-positive MCF7 and estrogen receptor-negative MDA-MB-231 cell lines. Their affinity for binding to estrogen receptors α (ERα) and β (ERβ), was also tested. In addition, we assessed their ability to promote the proliferation of estrogen receptor positive MCF7 breast carcinoma cells and the induction of Alkaline phosphatase activity in Ishikawa endometrial carcinoma cells, as well as, their ability to regulate the transcription of ERE-dependent reporter genes. We concluded that the tested compounds exhibit substantial estrogenic activity at concentrations of 1–10µM.