Estrogenic activities of ten medicinal herbs from the Middle East

Traditional medicinal plants have long been recognized as remedies and important sources of treatment for developing countries. In the present study, we report on a detailed study to quantify the presence of five known phytoestrogens in 10 widely used herbs used in the Middle East. Surprisingly some of these plants were almost devoid of tested phytoestrogens, whereas others were very rich in known phytoestrogens. For example, Hibiscus sabdariffa was found to be the richest in quercetin and daidzein, whereas Cyperus conglomeratus had the highest concentrations of kaempferol and genistein. On the other hand, Salvadora persica was almost devoid of the screened phytoestrogens. Ethanolic extracts were further tested for their proliferative activities in cell-culture using estrogen-responsive breast cancer cell lines (MCF-7) and were found to fall into three distinct groups based on their estrogenic activities. The most potent herbal extract (O. vulgare) was further fractionated and the fractions were analyzed again for phytoestrogenic content (using high-performance liquid chromatography) and proliferative activity. Our results indicate that the proliferative activities of some of the extracts and fractions are not completely attributable to the phytoestrogens screened, thus it is likely that some of these plants may have other (perhaps yet unknown) phytoestrogens.