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Sample Preparation of Caenorhabditis elegans for GC-MS-Based Metabolomics in Toxicity Assessment.

The nematode Caenorhabditis elegans, widely recognized as a model organism due to its ease of breeding and well-characterized genomes, boasts complete digestive, reproductive, and endocrine systems, as well as conserved signaling pathways shared with mammals. It has become an invaluable resource for metabolomics research, particularly in examining responses to chemical or environmental factors and toxicity assessments. In this article, we provide detailed, step-by-step protocols for cultivating C. elegans and conducting metabolomics analyses, specifically focusing on sample preparation for GC-MS analysis in response to toxic compound treatments. We highlight the critical choice of extraction solvent, introducing two representative systems for extracting metabolites from C. elegans.

Animals

Unveiling phthalate esters biodegradation from microbial community to Pseudarthrobacter scleromae HL-1: Kinetics, genomic insights, pathways, toxicity assessment and environmental remediation.

Phthalate esters (PAEs) are ubiquitous synthetic plasticizer pollutants posing severe ecological and human health risks. This study compared microbial community structures and dibutyl phthalate (DBP) degradation kinetics of two consortia: 7-day enriched MC1 (50 mg/L DBP) and 6-cycle acclimated MC7 (50-1000 mg/L DBP), demonstrating directional DBP stress selection generated a low-diversity, highly specialized degradative community with a 25.4 mg/L/h maximum degradation rate (Vmax), 1.68-fold higher than MC1. Four dominant DBP-degrading strains were isolated from MC7; Pseudarthrobacter scleromae HL-1 showed the highest efficiency with 17.1 mg/L/h Vmax and complete 500 mg/L DBP removal within 72 h, broad substrate spectrum, and strong adaptability after optimization. Whole-genome sequencing and GC-MS/MS elucidated a dual-parallel DBP mineralization pathway, first reported in Pseudarthrobacter, integrating ester hydrolysis and side-chain β-oxidation. ECOSAR and Chlorella vulgaris bioassays confirmed progressive toxicity attenuation, with > 99% relative toxicity reduction after 72 h and no toxic intermediate accumulation. Natural lake water trials with trace background PAEs showed HL-1 successfully colonized aquatic environments, reshaped indigenous communities into synergistic degradative consortia, and achieved 99.2% DBP removal in 84 h. This work provides comprehensive insights into PAE biodegradation mechanisms from community to single strain and highlights HL-1 as a promising candidate for remediating PAE-polluted aquatic ecosystems.

Genomic analysis

[Toxicity by relay. I. General principles of a new method for the assessment of Toxicity of addivitives to animal feeds].

Chemical substances added for various purposes to the feeds of farm-reared animals may enter the body of these animals. This may lead to the persistence, in food offered for human consumption, of residues which may be potentially toxic under conditions of repeated absorption over the greater part of the life span. The evaluation of the safety of these residues for man poses complex problems. Their ideal solution demands very often a number of careful experiments. The methodology called "toxicity by relay" consists essentially of the submission of the animal feed itself, which is likely to contain a mosaic of residues, to long-term testing in laboratory animals. Provided a satisfactory safety factor can be applied, this methodology can contribute information permittinga conclusion regarding the acceptablity, even provisionally, of the feed additive for the use which is envisaged. In addition this methodology enables the provision of results constituting a criterion for the rejection of the additive under test. For these reasons it appears to us an appropriate procedure, taking its place among the tests to be undertaken for the toxicological evaluation of additves to the feeds of farm-reared animals.

Animal Feed

[Methods of assessing the toxic properties of polymeric filling materials (author's transl)].

This paper discusses the results of experiments conducted with a view to determining the hidden effects of epoxy composites, which cannot generally be ascertained through the use of various toxicological, biochemical, immunological, allergic, morphological, and cytological methods of examination. To discover possible hidden effects of epoxy filling materials experimental use was made of the following methods: hunger diet, ethylalcohol supply, and composite extract supply. Shifts in functions of the organism were evaluated by the following criteria: weight dynamics of animals, histamine content of the blood, and eosinopenic reaction of the blood. The data obtained by the authors shows that it is possible for functional straining to be used as a method of discovering possible hidden harmful effects of dental polymers.

Alcohol Drinking

Adequacies and inadequacies in assessing murine toxicity data with antineoplastic agents.

Previous retrospective analyses have suggested a very positive correlation in toxic doses of antineoplastic agents between mice and humans. Additional toxicological information has now been accumulated and reveals a noticeable variability in the existing data base. Nevertheless, it is likely that mouse toxicological studies will become a principal determinant for estimating initial doses to be used in humans. Recognition of the factors responsible for differences in determinations of toxic dose levels in mice will enhance the proper utilization of this approach.

Animals

ToxAssay: a hierarchical model-driven tool for advanced toxicogenomics biomarker discovery.

MOTIVATION: Understanding the genetic basis of drug-induced toxicity is crucial for drug development. In-silico analysis of toxicogenomics datasets facilitates early detection of toxicity biomarkers. However, existing tools struggle with the complex interdependencies among hierarchically structured variables, leading to inaccurate biomarker identification. To address this limitation, we developed a Hierarchical Linear Model (HLM) and implemented it in the R package ToxAssay, offering extensive functionality for comprehensive toxicity assessment. RESULTS: ToxAssay outperforms existing methods by improving biomarker detection and computational efficiency. Applied to glutathione depletion-induced toxicity, it prioritized 71 key genes and identified 26 core genes with high discriminative accuracy (AUC = 0.97) and strong cross-correlation (Pearson's r = 0.88) with external datasets. Additionally, our advance outcome pathway (AOP) analysis algorithm uncovered disease outcomes linked to glutathione depletion. These findings provide precise insights into the molecular mechanisms driving drug-induced toxicity. AVAILABILITY AND IMPLEMENTATION: ToxAssay is available as an open-source R package at https://github.com/Fun-Gene/toxassay.

Biomarkers

Exploring the Translation of Organ-on-a-Chip Technology for Human-Relevant Diagnostic Biomarkers.

Microphysiological systems (MPSs) are gaining traction as a viable alternative model for toxicity studies. Further characterization is necessary to explore the full translational potential of MPSs to human physiology, along with the utility of these platforms to serve as a diagnostic tool. Multiomics analyses have emerged as a key means for identifying host biomarkers associated with chemical and drug exposure. Correlations between published human omics and MPS technology omics data will inform the potential of organ chips to accurately represent human responses and provide an alternative approach for improved biomarker discovery for toxicity assessment and exposure identification. To interrogate these potential overlaps, TissUse Chip3 multiorgan chips (MOCs) seeded with kidney organoids, liver organoids, and respiratory tract tissue were exposed to low, therapeutic, and toxic doses of acetaminophen (n = 4 for each condition) for 24 h and subjected to proteomic and metabolomic analysis. The data from our organ chips are largely consistent with biomarkers and dysregulations identified in published human omics data, in vitro and in vivo data, to include the identification of several known acetaminophen metabolites and biotransformation products. These data suggest that organ chips may be a suitable surrogate for human biomarker identification and drug or hazardous chemical exposure diagnosis.

Humans

ToxiVerse: chemical bioprofiling, toxicity data sharing and customizable predictive modeling.

MOTIVATION: Chemical toxicity assessment is critical for drug development and environmental safety. Computational models have emerged as a promising alternative to animal testing and now play a significant role in efficiently evaluating new chemicals. To address the urgent need for user-friendly machine learning tools in computational toxicology, we developed ToxiVerse, a public web-based platform. RESULTS: ToxiVerse provides automatic chemical bioprofiling, curated toxicity datasets, and a predictive modeling interface designed for researchers who lack programming expertise. The platform comprises three integrated modules: (i) Bioprofiler, which provides chemical descriptors by combining chemical-bioactivity data from PubChem assays with a machine learning-based data gap-filling procedure; (ii) Database, which hosts ∼50 000 curated chemicals covering diverse toxicity endpoints; and (iii) Cheminformatics, which enables dataset upload, chemical curation, and automatic generation of quantitative structure-activity relationship models for toxicity prediction. AVAILABILITY: The tool is accessible at www.toxiverse.com, and source code is available at https://github.com/zhu-research-group/toxiverse.

Quantitative Structure-Activity Relationship

Bridging Organ-on-a-Chip and Omics: A Multi-Dimensional Frontier in Biomedical Research.

Organ-on-a-Chip (OOC) technology offers a powerful platform for replicating human tissue-specific microenvironments, thereby narrowing the translational gap between conventional biomedical models and actual human physiology. Concurrently, omics technologies deliver comprehensive molecular-level insights into biological systems. This review highlights the transformative potential of integrating OOC platforms with high-throughput omics methodologies. We systematically examine the classification, structural configurations, and engineering principles underlying OOC systems, alongside the defining attributes of key omics domains-genomics, transcriptomics, proteomics, and metabolomics. The convergence of dynamic OOC models with advanced omics technologies enables high-resolution, multi-dimensional analyses across numerous biomedical applications, including drug metabolism, disease mechanisms, environmental toxicity assessments, and host-microbiome interactions. This interdisciplinary integration is driving a paradigm shift in precision and translational medicine. However, several challenges remain to be addressed, such as the development of whole-organ mimetics, adaptation of sample collection techniques, and real-time artificial intelligence-based integration of biosensor data with multi-omics datasets. Addressing these hurdles will be vital for unlocking the full potential of this technological synergy in biomedical science.

Multiomics

Integrated functional, metabolomic, and biotransformation profiling of mycotoxin hepatotoxicity in 2D and 3D human hepatic models.

Mycotoxins pose a major risk to food safety and human health, yet their hepatotoxic mechanisms remain incompletely characterized due to limitations in conventional in vitro models. In this study, we systematically compared mycotoxin-induced hepatotoxicity and metabolomic profiling across two human hepatic models cultured under 2D monolayer and 3D spheroid conditions. The various mycotoxins (Aflatoxin B1, Citrinin, Deoxynivalenol, Ochratoxin A, Patulin, and Zearalenone) exhibit distinct metabolic signatures, thereby serving as an appropriate panel for comprehensively evaluating diverse hepatotoxic mechanisms. Mycotoxin exposure induced concentration-dependent hepatotoxicity accompanied by functional impairment and structural disruption in hepatic models. Metabolomic profiling revealed distinctive regulatory patterns between 2D and 3D hepatic models, with 3D spheroids showing consistent down-regulation across multiple intracellular metabolic pathways and altered extracellular metabolite release, whereas 2D monolayers predominantly exhibited global metabolic activation. In silico-assisted MS/MS analysis further demonstrated that Phase I biotransformation was largely conserved across models, whereas Phase II conjugation reactions were more frequently detected and exhibited greater model specificity in 3D spheroids. Overall, these findings indicate that 3D hepatic spheroids capture more integrated and coordinated hepatotoxic and metabolic responses to mycotoxins compared with 2D monolayer systems. These distinctive regulatory dynamics support their value as a physiologically relevant platform for toxicity assessment and mechanistic investigation.

3D hepatic spheroids

Behavioral assessment of visual toxicity.

A wide variety of behavioral methods has been employed with animals to assess visual changes induced by drugs or toxicants. The methods range from simple to complex, from broad screening devices to narrowly focused techniques. Their relative advantages for the environmental toxicologist are discussed. Manipulation of stimulus values is an essential ingredient in the identification of specific sensory functions. The percentage of correct choices from a discrete-trial, multiple-choice discrimination procedure is to be preferred to measures of response rate, speed or reaction time when experiments require answers about specific visual functions.

Animals

Integrating structure and experimental data annotations with computational modeling framework for predicting micro-nanoplastics toxicities.

The wide use of plastic materials leads to increased emissions of micro-nanoplastics (MNPs) into the environment, raising significant concerns about their impact on human health. Traditional experimental approaches for assessing MNPs toxicity are costly, time-consuming, and there are no experimental protocols that are universally acceptable. Computational modeling using machine learning (ML) approaches provides an efficient alternative to MNP toxicity assessment. However, most modeling studies of MNPs are limited due to the lack of high-quality data and there are few previous modeling studies considering complex structures of MNPs for model training. To address this challenge, we constructed three MNP datasets with popular toxicity endpoints from various resources and used nanostructure annotation techniques to create virtual MNPs (vMNPs) for all MNP structures. The MNP structures were digitalized from annotated vMNPs, and geometrical descriptors were calculated using the Delaunay Tessellation approach. Moreover, important experimental information, such as concentrations and cell lines, were transformed into extra training variables. Partial least squares regression (PLSR) models were built using both experimental and geometrical descriptors and validated through a leave-one-out cross validation procedure. The resulting models showed reasonable performance in predicting toxicity potentials of MNPs for the three endpoints in the present datasets. Moreover, an additional library of vMNPs with their predicted properties and bioactivities was constructed, directing further research of new MNPs. This study provides three novel ML models for MNPs by integrating geometrical and experimental descriptors, which have the potential to assess new MNPs for their toxicity. The modeling strategy developed in this study can be easily expanded to model other MNP toxicity endpoints and create promising new models for MNP toxicity assessments.

Data annotation

Tissue distribution as a factor in species susceptibility to toxicity and hazard assessment. Example: methylmercury.

Data on the tissue distribution and pharmacokinetics of methylmercury(MeHg) in cats and humans were utilized as an example of how such data can assist in extrapolating toxicity data between animal species. These data demonstrate that the whole-body half-time for clearance of MeHg was the same for cats (76.2 +/- 1.6 days) and humans (78 +/- 5 days) and that the concentration of MeHg in the brain at comparable signs of toxicity were the same (10 ppm) in the two species. However, the blood:brain ratio of MeHg concentration was 10 times as high in cats (1:1) as humans (1:10). From these data it was hypothesised that the no-effect level of methylmercury intake in cats should be 10 times that for humans. This hypothesis was verified from data o MeHg toxicity in cats and humans which demonstrated that ataxia developed in cats at a minimum dose of 46 microgram MeHg/kg body wt/day with blood MeHg levels of 6 to 8 ppm; humans developed ataxia with blood MeHg levels of 0.6 to 0.8 ppm and an estimated intake of 4 microgram MeHg/kg body wt/day.

Animals

An in vivo model for assessing effects of drugs and toxicants on immunocompetence.

An in vivo assessment of the capacity of exposed animals to respond to antigenic challenge is recommended as the first screening phase for detecting potential immunotoxicants, with subsequent in vitro functional tests utilized to pinpoint the site of induced cellular alteration. Risk assessment of a candidate toxicant is based on a comparison of immune profiles of exposed animals with those of animals treated with prototype immunotoxicants. Extrapolation to man is facilitated by the use of licensed vaccines for antigenic challenge and the selection of clinically useful pharmaceutical drugs as prototype immunotoxicants. Three chemically induced alterations in immune responses are presented: 1) Immunosuppression characterized by impaired capacity to produce IgG and IgM classes of antibody on stimulation, 2) chronic high levels of IgE antibody in response to commonly encountered antigens, 3) modification of the capacity to mount an inflammatory response to antigenic material.

Animals

Hazards from chemicals: scientific questions and conflicts of interest.

All substances are toxic when the dose is large enough. In order to regulate the use of chemicals, we need to measure the level at which toxic effects are found. Epidemiological evidence suggests that present levels of chemical use do not lead to widespread harmful contamination of the human environment. For chemicals, most of the problems of toxicity are found in the workplace, while the population at large gets most of its toxic effects from voluntary exposure to substances such as tobacco smoke and ethanol. The prevention and control of toxic effects depends on a series of steps. This begins with measurement of toxicity in model systems, such as laboratory animals, and the estimation of the likely exposure of workers or consumers. Reliable extrapolation of information gathered from animals to the diverse and biochemically differing human population depends on understanding mechanisms of toxic effects. The toxic effect and mechanisms of action of substances such as carbon tetrachloride or paracetamol have been extensively investigated, and our ability to predict toxicity or develop antidotes to poisoning has had some success, but epidemiology is still an essential part of assessment of toxic effects of new chemicals. The example of phenobarbitone shows how animal experiments may well lead to conclusions which do not apply to man. After measurement of toxicity and assessment of likely hazards in use comes the final evaluation of the use of a chemical. This depends not only on its toxicity, but also on its usefulness. The direct effects on health may be small in comparison with the indirect advantageous effects which a useful substance such as vinyl chloride may bring. The assessment of risks and benefits of new chemicals can be partly removed from a political style of discourse, but the evaluation of the relative weight to be attached to these risks and benefits is inescapably political. The scientific contribution must be to allow the debate to take place in the light of maximum clarity of information about the consequences of use of chemicals.

Acetaminophen