In vitro or not in vitro: a short journey through a long history

Abstract

The aim of ecotoxicology is to study toxic effects on constituents of ecosystems, with the protection goal being populations and communities rather than individual organisms. In this ecosystem perspective, the use of in vitro methodologies measuring cellular and subcellular endpoints at a first glance appears to be odd. Nevertheless, more recently in vitro approaches gained momentum in ecotoxicology. In this article, we will discuss important application domains of in vitro methods in ecotoxicology. One area is the use of in vitro assays to replace, reduce, and refine (3R) in vivo tests. Research in this field has focused mainly on the use of in vitro cytotoxicity assays with fish cells as non-animal alternative to the in vivo lethality test with fish and on in vitro biotransformation assays as part of an alternative testing strategy for bioaccumulation testing with fish. Lessons learned from this research include the importance of a critical evaluation of the sensitivity, specificity and exposure conditions of in vitro assays, as well as the availability of appropriate in vitro-in vivo extrapolation models. In addition to this classical 3R application, other application domains of in vitro assays in ecotoxicology include the screening and prioritization of chemical hazards, the categorization of chemicals according to their modes of action and the provision of mechanistic information for the pathway-based prediction of adverse outcomes. The applications discussed in this essay may highlight the potential of in vitro technologies to enhance the environmental hazard assessment of single chemicals and complex mixtures at a reduced need of animal testing.

Celebrating 20 years of SETAC German Language Branch (GLB)

“…The articles [i.e., (critical) reviews as well as discussion and research papers] provide a broad basis for such dialogue and Box 1 gives an overview of the articles in this special issue. For instance, the need for holistic and solution-oriented monitoring of the chemical status of European water bodies [7] and urgent preventive measures with respect to marine litter plastics and microplastics [8], current developments in the evaluation of nanoparticles [9], soil ecotoxicology [10], in vitro methods [11], and sustainable plant protection [12] are discussed.…”

“…10 Institute of Aquatic Ecology, University of Duisburg-Essen, Essen, Germany. 11 Institute for Environmental Research, RWTH Aachen University, Aachen, Germany.…”

<i>In vitro</i> metabolism of pesticides and industrial chemicals in fish

“…Under these circumstances, many regulations encourage the development and use of alternative methods based on the 3R (replace, reduce and refine) principle. 8,9) One approach in fish metabolism is to reduce the number of fish and the testing concentration in the existing test methods, 10) but it is still cumbersome to estimate the metabolic rate constant (k M ) 11) and identify relevant metabolites to be further assessed. Another is an in silico approach, such as QSAR and toxicokinetics based on the mode of action, which successfully estimated the uptake and elimination rates of a chemical at a satisfactory level by using its log K ow and molecular descriptors.…”

“…Another is an in silico approach, such as QSAR and toxicokinetics based on the mode of action, which successfully estimated the uptake and elimination rates of a chemical at a satisfactory level by using its log K ow and molecular descriptors. 8,9) However, the application of this method to the estimation of k M , which is the single most influential factor in toxicokinetics, 12,13) is insufficient, 14) and no concrete information on metabolites is available. As an alternative experimental approach, in vitro methods using subcellular fractions or hepatocytes have been conveniently utilized to obtain the depletion rate constant of a chemical in fish.…”

A general strategy to control antibody specificity against targets showing molecular and biological similarity: Salmonella case study

“…In the diagnostic field, it means the realisation of receptors able to bind analytes that are important for the monitoring of human and animal health 2 , food safety 3 , 4 , and environmental pollution 5 – 7 .…”