Cerebral concentration and toxicity of endocrine disrupting chemicals: The implication of blood-brain interfaces

Endocrine disrupting chemicals (EDCs) act on peripheral endocrine organs or interfere with general endocrine pathways. Several EDCs alter the central regulation of neuroendocrine pathways, and affect neurological functions, and as such can be classified as neurotoxic molecules. Environmental pollutants classified as EDCs and affecting the central nervous system include perfluoroalcanes, parabens, phthalates, organotins, bisphenols, benzophenones, polychlorinated biphenyls, and dioxins. In this review we provide a brief description of these families of EDCs. We report and compare the EDC concentrations measured in the brain of humans and wild animals naturally exposed to these molecules, as well as in the brain of laboratory animals experimentally exposed to EDCs. The importance of using sophisticated analytical tools to detect EDCs in the brain is pointed out. The ability of blood-brain interfaces to reduce the brain exposition to EDCs in adult and during development is discussed in relation with the specific morphological, transport and metabolic properties of these cellular layers. Finally, we review the evidence that the neuroprotective functions of blood-brain interfaces can be altered by EDCs, a process that may participate to the central toxic action of these molecules. Overall this analysis points to the implication of blood-brain interfaces in setting the extent of central EDCs toxicity, although most evidence is indirect. Therefore, more specific blood-brain interface-oriented studies are called for in this field of EDC neurotoxicology.