Masking effect of anti-androgens on androgenic activity in European river sediment unveiled by effect-directed analysis.
This study shows that the androgen receptor agonistic potency is clearly concealed by the effects of androgen receptor antagonists in a total sediment extract, demonstrating that toxicity screening of total extracts is not enough to evaluate the full in vitro endocrine disrupting potential of a complex chemical mixture, as encountered in the environment. The anti-androgenic compounds were masking the activity of androgenic compounds in the extract with relatively high anti-androgenic potency, equivalent to 200 nmol flutamide equivalents/g dry weight. A two-step serial liquid chromatography fractionation of the extract successfully separated anti-androgenic compounds from androgenic compounds, resulting in a total androgenic potency of 3,820 pmol dihydrotestosterone equivalents/g dry weight. The fractionation simplified the chemical identification analysis of the original complex sample matrix. Seventeen chemical structures were tentatively identified. Polyaromatic hydrocarbons, a technical mixture of nonylphenol and dibutyl phthalate were identified to contribute to the anti-androgenic potency observed in the river sediment sample. With the GC/MS screening method applied here, no compounds with AR agonistic disrupting potencies could be identified. Seventy-one unidentified peaks, which represent potentially new endocrine disrupters, have been added to a database for future investigation.
Institute for Environmental Studies (IVM), Faculty of Earth and Life Sciences, VU University, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands.
Jana M
JM
Weiss
Timo
T
Hamers
Kevin V
KV
Thomas
Sander
S
van der Linden
Pim E G
PE
Leonards
Marja H
MH
Lamoree
D000726:Androgen Antagonists / Q000032:analysis* / Q000494:pharmacology; D000728:Androgens / Q000378:metabolism*; D001530:Belgium; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D015394:Molecular Structure; D045483:Rivers / Q000737:chemistry*
D000726:Androgen Antagonists; D000728:Androgens