Plant derived ligands of nuclear receptors and their biological effects

Extracts from plants contain a multitude of biologically active compounds which have been ascribed various beneficial effects on health. Although these factors act through different mechanisms, their interactions with nuclear receptors have attracted a great deal of interest. In particular those compounds which bind to estrogen receptors, the so called phytoestrogens, are the subject of much discussion in terms of their potential beneficial or possibly harmful effects on human health. An example of suggested uses of phytoestrogens, often in the form of fermented or non-fermented „health food“, is against postmenopausal symptoms, as an alternative to substitution with synthetic estrogens. Another hotly debated issue is the use of soy in baby food. Quite clearly, babies on this diet are exposed to substantial quantities of estrogen receptor activating compounds and one might ask what consequences this might have on the development of these individuals. Estrogens act through two receptor isoforms, estrogen receptor α and estrogen receptor β, with often opposite effects. Interestingly, phytoestrogens in general seem to bind better to estrogen receptor β, a relatively recently discovered receptor whose important physiological functions are becoming better and better known. Further studies on the health implications of consumption of phytoestrogen containing food are well motivated.