Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.watres.2021.117415
Licence creative commons licence
Title (Primary) Toxic effects of substituted p-benzoquinones and hydroquinones in in vitro bioassays are altered by reactions with the cell assay medium
Author Tentscher, P.R.; Escher, B.I.; Schlichting, R.; König, M.; Bramaz, N.; Schirmer, K.; von Gunten, U.
Source Titel Water Research
Year 2021
Department ZELLTOX
Volume 202
Page From art. 117415
Language englisch
Topic T9 Healthy Planet
Supplements https://ars.els-cdn.com/content/image/1-s2.0-S0043135421006138-mmc1.docx
Keywords oxidative stress; genotoxicity; carcinogenicity; electrophiles; oxidation; quinones
Abstract Substituted para-benzoquinones and hydroquinones are ubiquitous transformation products that arise during oxidative water treatment of phenolic precursors, for example through ozonation or chlorination. The benzoquinone structural motive is associated with mutagenicity and carcinogenicity, and also with induction of the oxidative stress response through the Nrf2 pathway. For either endpoint, toxicological data for differently substituted compounds are scarce. In this study, an oxidative stress response, as indicated by the AREc32 in vitro bioassay, was induced by differently substituted para-benzoquinones, but also by the corresponding hydroquinones. Bioassays that indicate defense against genotoxicity (p53RE-bla) and DNA repair activity (UmuC) were not activated by these compounds. Stability tests conducted under incubation conditions, but in the absence of cell lines, showed that tested para-benzoquinones reacted rapidly with constituents of the incubation medium. Compounds were abated already in phosphate buffer, but even faster in biological media, with reactions attributed to amino- and thiol-groups of peptides, proteins, and free amino acids. The products of these reactions were often the corresponding substituted hydroquinones. Conversely, differently substituted hydroquinones were quantitatively oxidized to p-benzoquinones over the course of the incubation. The observed induction of the oxidative stress response was attributed to hydroquinones that are presumably oxidized to benzoquinones inside the cells. Despite the instability of the test compounds in the incubation medium, the AREc32 in vitro bioassay could be used as an unspecific sum parameter to detect para-benzoquinones and hydroquinones in oxidatively treated waters.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=24888
Tentscher, P.R., Escher, B.I., Schlichting, R., König, M., Bramaz, N., Schirmer, K., von Gunten, U. (2021):
Toxic effects of substituted p-benzoquinones and hydroquinones in in vitro bioassays are altered by reactions with the cell assay medium
Water Res. 202 , art. 117415 10.1016/j.watres.2021.117415