Abstract
Liver toxicity is a leading systemic toxicity of drugs and chemicals demanding more human-relevant, high throughput, cost effective in vitro solutions. In addition to contributing to animal welfare, in vitro techniques facilitate exploring and understanding the molecular mechanisms underlying toxicity. New ‘omics technologies can provide comprehensive information on the toxicological mode of action of compounds, as well as quantitative information about the multi-parametric metabolic response of cellular systems in normal and patho-physiological conditions. Here, we combined mass-spectroscopy metabolomics with an in vitro liver toxicity model. Metabolite profiles of HepG2 cells treated with 35 test substances resulted in 1114 cell supernatants and 3556 intracellular samples analyzed by metabolomics. Control samples showed relative standard deviations of about 10–15%, while the technical replicates were at 5–10%. Importantly, this procedure revealed concentration–response effects and patterns of metabolome changes that are consistent for different liver toxicity mechanisms (liver enzyme induction/inhibition, liver toxicity and peroxisome proliferation). Our findings provide evidence that identifying organ toxicity can be achieved in a robust, reliable, human-relevant system, representing a non-animal alternative for systemic toxicology.
Highlights
Toxicology is undergoing a paradigm shift, from predominantly observational science, to predominantly predictive science focusing on target-specific, mechanism-based, biological observations, contingent upon in vitro data and in silico predictions, often referred to as toxicology for the twenty-first century (Hartung 2009)
When applying metabolomics to fresh liver microtissues, the amount of biological material obtained in each microtissue was not sufficient to reliably measure metabolites, i.e., many of the metabolites were below the limit of detection/quantitation
HepG2 cells are easier to handle than primary human hepatocytes and are superior regarding reproducibility
Summary
Toxicology is undergoing a paradigm shift, from predominantly observational science (based on animal testing), to predominantly predictive science focusing on target-specific, mechanism-based, biological observations, contingent upon in vitro data and in silico predictions, often referred to as toxicology for the twenty-first century (Hartung 2009). The development and application of modern tools can provide deeper insights into the molecular mechanisms underlying toxicity in a high throughput manner (Attene-Ramos et al 2015; Liu et al 2015). Such developments are being driven by the need to improve the safety evaluation of chemicals in a more efficient, human-relevant context (Judson et al 2014) to meet changing regulations and promote the use of nonanimal models to predict toxicity (Ramirez et al 2013b). Those used to fulfil regulatory requirements rely on apical endpoints, such as signs of clinical toxicity, hematology, urinalysis as well as clinical and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
