Endocrine disrupting, mutagenic, and teratogenic effects of upper Danube River sediments using effect‐directed analysis

Abstract

Effect-directed analysis (EDA) can be useful in identifying and evaluating potential toxic chemicals in matrixes. Previous investigations of extracts of sediments from the upper Danube River in Germany revealed acute nonspecific and mechanism-specific toxicity as determined by several bioassays. In the present study, EDA was used to further characterize these sediments and identify groups of potentially toxic chemicals. Four extracts of sediments were subjected to a novel fractionation scheme coupled with identification of chemicals to characterize their ability to disrupt steroidogenesis or cause mutagenic and/or teratogenic effects. All four whole extracts of sediment caused significant alteration of steroidogenesis and were mutagenic as well as teratogenic. The whole extracts of sediments were separated into 18 fractions and these fractions were then subjected to the same bioassays as the whole extracts. Fractions 7 to 15 of all four extracts were consistently more potent in both the Ames fluctuation and H295R assays. Much of this toxicity could be attributed to polycyclic aromatic hydrocarbons, sterols, and in fraction 7-naphthoic acids. Because the fraction containing polychlorinated biphenyls, polychlorodibenzodioxin/furan, dichlorodiphenyltrichloroethane, and several organophosphates did not cause any observable effects on hormone production or a mutagenic response, or were not detected in any of the samples, these compounds could be eliminated as causative agents for the observed effects. These results demonstrate the value of using EDA, which uses multiple bioassays and new fractionation techniques to assess toxicity. Furthermore, to our knowledge this is the first study using the recently developed H295R assay within EDA strategies.

The value of zebrafish as an integrative model in effect-directed analysis - a review

“…For that, there was exposure of the zebrafish to compounds known to cause specific effects such as anti-convulsant activity [39], glucose uptake [45], pro-angiogenesis [36,37], antiangiogenesis [19,44], or estrogenic effects [52,56]. Regarding negative control conditions, most of the studies reported the testing of solvent controls in the same concentration as for the respective sample testing [19,32,34,35,[38][39][40]43,44,47,[49][50][51]53,55]. Some studies have additionally evaluated a medium only condition in addition to the solvent control [36,37,42,54,56,57].…”

“…When the application of multiple biossays aimed to evaluate distinct bioactivities, the tests were mostly performed in parallel. For instance, bioassay batteries evaluated the occurrence of different toxicity mechanisms [50,51] or effects on different trophic levels in the two TIE studies [32,33]. When instead the aim of multiple methods was to analyse different aspects of the same bioactivity or toxicity mechanism, there was the prevalence of tiered approach biotesting [19,39,45].…”

“…Other studies applied methods with additional experimental models, mostly cell-based (e.g. [19,45,51]) but also bacteria [46,50] and rodent [39] assays. When the application of multiple biossays aimed to evaluate distinct bioactivities, the tests were mostly performed in parallel.…”

“…dimethyl sulfoxide (DMSO), in concentrations ranging from 0.01% [35], 0.1% [31,45], 0.2% [26], 0.5% [46,47], 1% [33,[48][49][50] up to 2% [51]. In addition, ethanol was also used as a carrier by a few studies, in concentrations of 0.001% for experiments with larvae [40,41] or 0.435% for experiments with zebrafish adults [42].…”

“…Natural product studies aimed to identify bioactive compounds for pharmacological applications, investigating mostly plant extracts [19,[34][35][36][37][38][39][40][41][42][43][44][45] but also extracts of bacteria [46], cyanobacteria and algae [47], seaweed [48] and marine organisms [49]. Environmental toxicology studies aimed to identify the toxic compounds in various environmental samples, including marine and fluvial sediments [50][51][52], soil [53], cyanobacteria and algae [54,55], industrial effluent [33], rubber tyre leachates [32], oil sand process waters [56,57] and river pore water [58]. Finally, fish skin extracts were investigated in a behavioural sciences study [59].…”