Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.scitotenv.2020.143030
Document accepted manuscript
Title (Primary) Bioanalytical equivalents and relative potencies for predicting the biological effects of mixtures
Author Zhou, S.; Peng, S.; Brack, W.; Doering, J.A.; Seiler, T.-B.; Hollert, H.
Source Titel Science of the Total Environment
Year 2021
Department WANA
Volume 763
Page From art. 143030
Language englisch
Topic T9 Healthy Planet
Keywords 2,3,7,8-TCDD: 2,3,7,8-tetrachlorodibenzo-p-dioxin; EXR: 7-ethoxyresorufin; AhR: aryl hydrocarbon receptor; BEQ: bioanalytical equivalent; Bio-BEQ: bioassay-detected BEQ; Chem-BEQ: chemically analyzed BEQ; CA model: concentration addition model; CALUX: Chemically Activated Luciferase gene eXpression; EROD: 7-ethoxyresorufin-o-deethylase; IA model: independent action model; REP: relative potency; NF-κB: Nuclear Factor Kappa B; MoA: modes of action; PAH: polycyclic aromatic hydrocarbon; TEF: toxicity equivalency factor
Abstract Bioanalytical equivalents (BEQs) of mixtures and environmental samples are widely used to reflect the potential threat of pollutants in the environment and can be obtained by bioassays or using chemical analysis combined with relative potencies (REPs). In this study, the relationships between bioassay-detected BEQs (Bio-BEQs) and chemically analyzed BEQs (Chem-BEQs) were studied. BEQs and REPs are correlated with effect level and the concentration-response curves of the reference standard and sample. Thus, effect level (e.g., EC10, EC25 and EC50) should be addressed for the BEQ values obtained from bioassays or chemical analyses. The previous prerequisites for REPs application (i.e., curves that are parallel and have the same maximum response) are redundant, and the use of REPs for the calculation of BEQs or in risk assessment should instead be based on the same effect level. For a complex mixture with many components, all active components can be regarded as dilutions of a standard compound for inducing a specific effect. Relative toxicity estimates based on EC50 ignore the contribution of weak-active components with maximum response below EC50 of the reference standard, especially in complex mixtures or environmental samples. REPs based on an effect level EC10 that can be clearly discriminated from background response are recommended for BEQ calculation. As an example, the aryl hydrocarbon receptor (AhR)-mediated activity of US EPA priority polycyclic aromatic hydrocarbons (PAHs) in RTL-W1 cells was used to assess the reliability of REPs for mixture toxicity prediction based on the effect level EC10.
Persistent UFZ Identifier
Zhou, S., Peng, S., Brack, W., Doering, J.A., Seiler, T.-B., Hollert, H. (2021):
Bioanalytical equivalents and relative potencies for predicting the biological effects of mixtures
Sci. Total Environ. 763 , art. 143030 10.1016/j.scitotenv.2020.143030