Effect-directed analysis of endocrine-disrupting compounds in multi-contaminated sediment: identification of novel ligands of estrogen and pregnane X receptors.
Effect-directed analysis (EDA)-based strategies have been increasingly used in order to identify the causative link between adverse (eco-)toxic effects and chemical contaminants. In this study, we report the development and use of an EDA approach to identify endocrine-disrupting chemicals (EDCs) in a multi-contaminated river sediment. The battery of in vitro reporter cell-based bioassays, measuring estrogenic, (anti)androgenic, dioxin-like, and pregnane X receptor (PXR)-like activities, revealed multi-contamination profiles. To isolate active compounds of a wide polarity range, we established a multi-step fractionation procedure combining: (1) a primary fractionation step using normal phase-based solid-phase extraction (SPE), validated with a mixture of 12 non-polar to polar standard EDCs; (2) a secondary fractionation using reversed-phase-based high-performance liquid chromatography (RP-HPLC) calibrated with 33 standard EDCs; and (3) a purification step using a recombinant estrogen receptor (ER) affinity column. In vitro SPE and HPLC profiles revealed that ER and PXR activities were mainly due to polar to mid-polar compounds, while dioxin-like and anti-androgenic activities were in the less polar fractions. The overall procedure allowed final isolation and identification of new environmental PXR (e.g., di-iso-octylphthalate) and ER (e.g., 2,4-di-tert-butylphenol and 2,6-di-tert-butyl-α-methoxy-p-cresol) ligands by using gas chromatography coupled with mass spectrometry with full-scan mode acquisition in mid-polar fractions. In vitro biological activity of these chemicals was further confirmed using commercial standards, with di-iso-octylphthalate identified for the first time as a potent hPXR environmental agonist.
Unité Écotoxicologie In Vitro et In Vivo, INERIS, Parc ALATA, Verneuil-en-Halatte, France.
Nicolas
N
Creusot
Hélène
H
Budzinski
Patrick
P
Balaguer
Saïd
S
Kinani
Jean-Marc
JM
Porcher
Selim
S
Aït-Aïssa
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D052244:Endocrine Disruptors / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D000077297:Pregnane X Receptor; D011960:Receptors, Estrogen / Q000819:agonists / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000819:agonists / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D052616:Solid Phase Extraction / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D052244:Endocrine Disruptors; D008024:Ligands; D000077297:Pregnane X Receptor; D011960:Receptors, Estrogen; D011987:Receptors, Steroid; D014874:Water Pollutants, Chemical