In a press release published on September 3, 2015 the Institut national de la santé et de la recherche médicale (Inserm) informs about a new study on ‘cocktail effects’ of endocrine disrupting chemicals (EDCs). The study was published in the peer-reviewed journal Nature Communications. Researchers Vanessa Delfosse and colleagues, based at Inserm, the University of Montpellier and further research institutes in France, demonstrated in vitro that the pharmaceutical estrogen 17α-ethinylestradiol (EE2, CAS 57-63-6) and the persistent organochlorine pesticide trans-nonachlor (TNC, CAS 39765-80-5) cooperatively bind to a nuclear receptor (NR) and synergistically activate it. By substituting natural ligands, EDCs can deregulate NR signaling and cause reproductive, proliferative and metabolic disorders. The researchers found that the binary mixture of EE2 and TNC “induces a substantial biological response at doses at which each chemical individually is inactive.” They suggest that the binding of ‘supramolecular ligands’, such as the mixture of EE2 and TNC, with NRs contributes to the synergistic toxic effect of chemical mixtures. The researchers conclude that their findings may have broad implications for the fields of endocrine disruption, toxicology and chemical risk assessment.

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Inserm (September 3, 2015). “Light shed on the underside of the ‘cocktail effect’ of endocrine disruptors.


Delfosse, V. et al. (2015). “Synergistic activation of human pregnane X receptor by binary cocktails of pharmaceutical and environmental compounds.Nature Communications 6:8089.