Endocrine modulation and the fragile balance of homeostasis--an overview

Endocrine modulation by natural and synthetic chemicals and the eventually resulting beneficial or adverse effects for human and animal health are controversially debated not only among scientists but particularly in the public. Most information is available on so-called environmental estrogens, however the amount of information on substances interfering with other hormonal axes steadily increases, particularly on those exhibiting (anti)androgenic activities. The aim of this paper is to summarize existing data and to give an overview on the potential pathways leading to interferences of environmental hormones with homeostasis and eventually resulting health effects. Experimental evidence suggests the hypothesis that fetal and neonatal organisms may be at risk if exposed to environmental estrogens. In contrary, it appears as if phytoestrogens, particularly those with selective estrogen receptor modulator- (SERM-)like activities have the potential to be useful in medical application, both as dietary means and as pharmaceuticals. Lacking valid information about the detailed analysis of the molecular mode of action for environmental estrogens, the possibility for an ultimate classification of environmental estrogens in "dangerous endocrine disruptors" and phytoestrogens in "useful pharmaceuticals" cannot be supported conclusively. Nevertheless both activities are likely.