Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Sep;37(9):2273-2280.
doi: 10.1002/etc.4178. Epub 2018 Jul 11.

The advantages of linear concentration-response curves for in vitro bioassays with environmental samples

Beate I Escher  1   2 , Peta A Neale  3 , Daniel L Villeneuve  4
Affiliations

The advantages of linear concentration-response curves for in vitro bioassays with environmental samples

Beate I Escher et al. Environ Toxicol Chem. 2018 Sep.

Abstract

In vitro assays and high-throughput screening (HTS) tools are increasingly being employed as replacements for animal testing, but most concentration-response curves are still evaluated with models developed for animal testing. We argue that application of in vitro assays, particularly reporter gene assays, to environmental samples can benefit from a different approach to concentration-response modeling. First, cytotoxicity often occurs at higher concentrations, especially for weakly acting compounds and in complex environmental mixtures with many components. In these cases, specific effects can be masked by cytotoxicity. Second, for many HTS assays, low effect levels can be precisely quantified because of the low variability of controls in cell-based assays and the opportunity to run many concentrations and replicates when using high-density well-plate formats (e.g., 384 or more wells per plate). Hence, we recommend focusing concentration-response modeling on the lower portion of the concentration-response curve, which is approximately linear. Effect concentrations derived from low-effect level linear concentration-response models facilitate simple derivation of relative effect potencies and the correct application of mixture toxicity models in the calculation of bioanalytical equivalent concentrations. Environ Toxicol Chem 2018;37:2273-2280. © 2018 SETAC.

Keywords: Bioanalytical equivalent concentration; Dose-response modeling; Environmental toxicology; In vitro toxicology.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Relationship between sigmoidal log-CRCs and linear CRCs
Figure 2.
Figure 2.
Examples for the proposed linear CRC evaluation. A. Wastewater treatment plant effluent enriched with SPE, run in the AhR CALUX assay for activation of the arylhydrocarbon receptor (data from Nivala 2018). B. Drinking water enriched with SPE, run in the AREc32 assay for oxidative stress response (data from Hebert 2018). C. 579 chemicals spiked to a pristine creek water sample, run in the ER-GeneBLAzer assay for estrogenicity (Neale 2018). The empty symbols are cell viability data and the filled symbols activity data with different symbols from different independent experiments and the same symbols in activity and cytotoxicity from a matching experiment.
Figure 3.
Figure 3.
If the slopes of the log-CRCs are not the same for reference compound and chemical i, then the REPi are dependent on the effect level (A). For log-CRC with the same slope (B) and linear-CRCs (C), the REPi are independent of the effect level.
Figure 4.
Figure 4.
Recommended processing of CRC data of environmental samples. A. Measured effect yields often U-shaped CRCs due to cytotoxicity overlaying activation. B. All concentrations above the IC10 for cytotoxicity should be removed for analysis of effect. C. The linear-CRC model should be only applied to data <30% effect (linear range, see Figure 1).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Baston DS, Denison MS. 2011. Considerations for potency equivalent calculations in the Ah receptor-based CALUX bioassay: Normalization of superinduction results for improved sample potency estimation. Talanta 83:1415–1421. - PMC - PubMed
    1. Brand W, De Jongh CM, van Linden SC, Mennes W, Puijker LM, van Leeuwen C, van Wezel A, Schriks M, Heringa M. 2013. Trigger values for investigation of hormonal activity in drinking water and its sources using CALUX bioassays. Environ Internat 55:109–118. - PubMed
    1. Brennan JC, He G, Tsutsumi T, Zhao J, Wirth E, Fulton MH, Denison MS. 2015. Development of Species-Specific Ah Receptor-Responsive Third Generation CALUX Cell Lines with Enhanced Responsiveness and Improved Detection Limits. Environ Sci Technol 49:11903–11912. - PMC - PubMed
    1. Brinkmann M, Hecker M, Giesy JP, Jones PD, Ratte HT, Hollert H, Preuss TG. 2018. Generalized concentration addition accurately predicts estrogenic potentials of mixtures and environmental samples containing partial agonists. Toxicol in Vitro 46:294–303. - PubMed
    1. Buchinger S, Grill P, Morosow V, Ben-Yoav H, Shacham-Diamand Y, Biran A, Pedahzur R, Belkin S, Reifferscheid G. 2010. Evaluation of chrono-amperometric signal detection for the analysis of genotoxicity by a whole cell biosensor. Anal Chim Act 659:122–128. - PubMed

Publication types

Substances

LinkOut - more resources

  NODES
INTERN 1
twitter 2