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Agonist/antagonist activity of three pesticides on the estrogen r | 51960
Journal of Clinical Toxicology

Journal of Clinical Toxicology
Open Access

ISSN: 2161-0495

+44 1478 350008

Agonist/antagonist activity of three pesticides on the estrogen receptor alpha in a recombinant yeast assay


3rd International Summit on Toxicology & Applied Pharmacology

October 20-22, 2014 DoubleTree by Hilton Hotel Chicago-North Shore, USA

Margherita Lavorgna, Marina Isidori, Emma Criscuolo, Chiara Russo and Alfredo Parrella

Posters: J Clin Toxicol

Abstract :

T he focus of scientific concern about pesticides is still high due to their continuous use. Pesticides have been found in all compartments from soil to atmosphere, ground and surface waters as well as in human tissues. Despite their environmental low concentrations, they can induce chronic toxic effects on whole aquatic organisms, acting as pseudo-persistent pollutants, given continuous introduction into the environment. Another effect of pesticides might be that, once absorbed,they interfere with the normal functions of the endocrine system by mimicking or antagonizing the action of natural hormone17β-estradiol (E2). The aim of the present study was to assess the potential endocrine activity of three pesticides: cyfluthrin, a pyrethroid derivative insecticide, iprodione, an imidazole fungicide and endosulfan, an organochloride insecticide. In addition, the combined effect of the single compounds with E2 and tamoxifen, an anti-estrogen was investigated. The estrogenic activity was investigated in vitro by a recombinant yeast system (YES assay) carried out on Saccharomyces cerevisiae-RMY326 which expresses the human estrogen receptorα (hERα). It includes expression plasmids carrying the reporter gene lac-Z,encoding the β-galactosidase, used to measure the receptor activity. The β-galactosidase activity was determined by adding the colorimetric substrate, 2-nitrophenyl-β-galactoside; the absorbance of the samples was measured at 420 nm. The results showed that cyfluthrin, iprodione and endosulfanbind to the hERα of yeast cells with a relatively low affinity when compared to estradiol, used as the positive control. Endosulfan was the most potent with EC50 values equal to 1.1∙10-8 M (1000 times less than 17β-estradiol). The results obtained co-incubating different concentrations of single pesticide with increasing concentrations of tamoxifen (1.0∙10-7 to 1.0∙10-4 M) indicated a non-competitive antagonism of all chemicals while when combined with E2 (1.0∙10-11 to 1.0∙10-7 M), cyfluthrin was anti-estrogenic, iprodione and endosulfan anti-estrogenic at lower concentrations and agonist at higher concentrations. No evidence of synergism was observed when the single compounds were tested in combination with tamoxifen or E2. These findings confirm the estrogen mimetic activity of some pesticides and show that in vitro estrogenic assays such as YES test could be a useful tool to give an overall knowledge of the estrogenic potency of xenobiotics

Biography :

Margherita Lavorgna has completed her PhD in 2006 from Second University of Naples (Italy). Since 12/2010, she is researcher of General and Applied Hygiene. Her research activity is addressed to toxic, genotoxic and endocrine interference activity of environmental xenobiotics as well as microbiology of waters and food. She has published 26papers on peer reviewed national and international journals

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