Pyrethroid and their metabolite, 3-phenoxybenzoic acid showed similar (anti)estrogenic activity in human and rat estrogen receptor alpha-mediated reporter gene assays

Pyrethroids are commonly used as pesticides which are suspected as endocrine disruptors in many studies; however, still we do not know their effects on different species. To compare their effects on human estrogen receptor (hER alpha) and rat estrogen receptor (rER alpha), we developed a hER alpha and rER alpha mediated luciferase reporter assay to investigate the (anti)estrogenic activities of three frequently used pyrethroids (fenvalerate, cypermethrin, permethrin) and their metabolite 3-phenoxybenzoic acid (3-PBA). All three pyrethroids significantly induced expression of the luciferase, while none of them were antagonistic to 1 nM E-2 mediated induction. Interestingly, 3-PBA, showed antagonist activity by decreasing the effect of 1 nM E-2 to 55.12% in hER alpha assay and to 45.12% in rER alpha assay. Our results firstly demonstrated that pyrethroids and 3-PBA showed similar response in the hER alpha and rER alpha mediated reporter gene assay, which indicated that data derived from reporter gene assay or other receptor mediated assay systems with rat ER system might be used to predict to estrogenic or anti-estrogenic effects to human systems. (C) 2013 Elsevier B.V. All rights reserved.