Identifying reference chemicals for thyroid bioactivity screening

Wegner, Susanna; Browne, Patience; Dix, David J.

doi:10.1016/j.reprotox.2016.08.016

Cited by 25 publications

(14 citation statements)

References 70 publications

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“…Unlike for estrogenic activity, the results for thyroid disruption were unexpected based on previous studies, where effluents have not shown high potential for thyroid disruption (Jugan et al, 2009;Escher et al, 2013). However, these studies were based on in vitro studies, which may be less responsive compared to the Xenopus embryonic thyroid assay because thyroid hormone disruptors act via non-receptor based mechanisms of action (Wegner et al, 2016).…”

Section: Wastewater Toxicitymentioning

confidence: 95%

Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review

Välitalo

Kruglova

Mikola

et al. 2017

International Journal of Hygiene and Environmental Health

209

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Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics. Regardless of the growing concerns related to antibiotics in the environment, there are still evident knowledge gaps related to antibiotics, as there is only limited or no ecotoxicological data on many potentially harmful antibiotics.

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Section: Wastewater Toxicitymentioning

confidence: 95%

Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review

Välitalo

Kruglova

Mikola

et al. 2017

International Journal of Hygiene and Environmental Health

209

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“…As previously stated, more than a 100 of the 287 pesticides examined by European Food Safety Authority (EFSA) had features indicative of thyroid disruption ( 155 ). In the recent review of chemicals that could be used as reference for thyroid disruption screening, Wegner and colleagues identified a number of phytopharmaceuticals or biocides with TH-disrupting activity ( 244 ). To cite a few, their list contained different classes of fungicides and organophosphates, along with a number of juvenile hormone analogues.…”

Section: Pesticidesmentioning

confidence: 99%

“…Finally, a pyridine-based juvenile hormone analogue pesticide, Pyriproxyfen, has been suggested as a TH-active substance ( 244 ). This and other findings led us and colleagues to suspect it could be implicated in the increased incidence of Zika-induced microcephaly in north eastern Brazil ( 266 ), especially given its use at high levels in drinking water during the outbreak ( 266 ).…”

Section: Pesticidesmentioning

confidence: 99%

Thyroid-disrupting chemicals and brain development: an update

Mughal

Fini

Demeneix

2018

Endocrine Connections

131

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This review covers recent findings on the main categories of thyroid hormone–disrupting chemicals and their effects on brain development. We draw mostly on epidemiological and experimental data published in the last decade. For each chemical class considered, we deal with not only the thyroid hormone–disrupting effects but also briefly mention the main mechanisms by which the same chemicals could modify estrogen and/or androgen signalling, thereby exacerbating adverse effects on endocrine-dependent developmental programmes. Further, we emphasize recent data showing how maternal thyroid hormone signalling during early pregnancy affects not only offspring IQ, but also neurodevelopmental disease risk. These recent findings add to established knowledge on the crucial importance of iodine and thyroid hormone for optimal brain development. We propose that prenatal exposure to mixtures of thyroid hormone–disrupting chemicals provides a plausible biological mechanism contributing to current increases in the incidence of neurodevelopmental disease and IQ loss.

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“…However, it should be noted, that severity grading in thyroid histopathology is based on an idealized model which used the powerful inhibitor of TH synthesis propylthiouracil (PTU) (Brucker-Davis, 1998; , and may therefore overlook the effects of other THADCs with more subtle effects. By combining curated data from scientific literature and results from validated assays in the US EPA Endocrine Disruptor Screening Program, i.e., the female and male rat pubertal assays and the Amphibian Metamorphosis Assay (AMA), Wegner et al (2016) proposed an additional 28 reference THADCs with various MoA which could serve to further characterize the response of different assays and endpoints.…”

Section: The Challenge Of Assessing Th (Dys)functionmentioning

confidence: 99%