Experimental Toxicology Research Articles

Predictive, integrative, and regulatory aspects of AI-driven computational toxicology – Highlights of the German Pharm-Tox Summit (GPTS) 2024

The 9th German Pharm-Tox Summit (GPTS) and the 90th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT) took place in Munich from March 13–15, 2024. The event brought together over 700 participants from around the world to discuss cutting-edge developments in the fields of pharmacology and toxicology as well as scientific innovations and novel insights. A key focus of the conference was on the rapidly increasing role of computational toxicology, artificial intelligence (AI), and machine learning (ML) into the field, marking a shift away from traditional methods and allowing the reduction of animal testing as primary tool for toxicological risk assessment. Tools such as Toxometris.ai showcased the potential of AI-based risk assessments for predicting carcinogenicity, offering more ethical and efficient alternatives. Additionally, computer-driven models like computer-aided pattern analysis (C@PA) for drug toxicity prediction were presented, emphasizing the growing role of chem- and bioinformatic applications in computational sciences. Throughout the summit, there was a strong focus on the need for regulatory innovation to support the adoption of these advanced technologies and ensure the safety and sustainability of chemical substances and drugs.

Breast Cancer-Related Chemical Exposures in Firefighters.

To fill a research gap on firefighter exposures and breast cancer risk, and guide exposure reduction, we aimed to identify firefighter occupational exposures linked to breast cancer. We conducted a systematic search and review to identify firefighter chemical exposures and then identified the subset that was associated with breast cancer. To do this, we compared the firefighter exposures with chemicals that have been shown to increase breast cancer risk in epidemiological studies or increase mammary gland tumors in experimental toxicology studies. For each exposure, we assigned a strength of evidence for the association with firefighter occupation and for the association with breast cancer risk. We identified twelve chemicals or chemical groups that were both linked to breast cancer and were firefighter occupational exposures, including polycyclic aromatic hydrocarbons, volatile aromatics, per- and polyfluoroalkyl substances, persistent organohalogens, and halogenated organophosphate flame retardants. Many of these were found at elevated levels in firefighting environments and were statistically significantly higher in firefighters after firefighting or when compared to the general population. Common exposure sources included combustion byproducts, diesel fuel and exhaust, firefighting foams, and flame retardants. Our findings highlight breast-cancer-related chemical exposures in the firefighting profession to guide equitable worker's compensation policies and exposure reduction.

MTS, WST-8, and ATP viability assays in 2D and 3D cultures: Comparison of methodologically different assays in primary human chondrocytes.

Tissue engineering enables the production of three-dimensional microtissues which mimic naturally occurring conditions in special tissues. These 3D culture systems are particularly suitable for application in regenerative medicine or experimental pharmacology and toxicology. Therefore, it is important to analyse the cells in their 3D microenvironment with regard to viability and differentiation. Tetrazolium assays (WST-8 and MTS) are still the methods of choice for estimating the number of living, metabolically active cells, with WST-8 being cell-impermeable compared to MTS. In contrast to these methods, the ATP assay is an endpoint method based on the luciferase-induced reaction of ATP with luciferin after cell lysis. We compared three methodologically different proliferation/toxicity assays (MTS, WST-8, ATP) in monolayer (2D) and 3D culture systems to improve the technically challenging determination of the number of viable cells. Chondrocytes were isolated from human articular cartilage. Three different test systems (MTS, WST-8, ATP) were applied to monolayer cells (2D, varying cell numbers) and spheroids (3D, different sizes) in 96-well plates. The intracellular ATP concentration was determined by luciferase-induced reaction of ATP with luciferin using a luminometer. Formazan formation was measured spectrophotometrically after different incubation periods. Evaluation was performed by phase contrast microscopy (toxicity), correlation of cell count and ATP concentration or absorption signal (Gompertz function) and propidium iodide (PI) staining to proof the cell lysis of all cells in spheroids. In 2D culture, all three assays showed a good correlation between the number of seeded cells and the ATP concentration or absorption data, whereas the MTS-assay showed the lowest specificity. In 3D culture, the spheroid sizes were directly related to the number of cells seeded. The absorption data of the WST-8 and MTS assay correlated only for certain spheroid size ranges, whereas the MTS-assay showed again the lowest specificity. Only the measured intracellular ATP content showed a linear correlation with all spheroid sizes ranging from 100-1000 μm. The WST-8 assay revealed the second-best sensitivity which allows the measurement of spheroids larger than 240 μm. Phase contrast observation of monolayer cells showed toxic effects of MTS after 6 h incubation and no signs of toxicity of WST-8. Staining with propidium iodide showed complete lysis of all cells in a spheroid in the ATP assay. Among tetrazolium-based assays, WST-8 is preferable to MTS because of its non-toxicity and better sensitivity. When determining the number of viable cells in the 2D system, caution is advised when using the ATP assay because of its two-phase slope of the correlation graph concerning cell number and intracellular ATP. In 3D systems of human chondrocytes, the ATP-assay is superior to the other two test systems, as the correlation graph between cell number and intracellular ATP is biphasic. Since differentiation processes or other metabolic events can influence the results of proliferation and toxicity assays (determination of viable cells), this should be taken into account when using these test systems.

Widely targeted quantitative lipidomics reveal lipid remodeling in adipose tissue after long term of the combined exposure to bisphenol A and fructose.

Adipose tissue is the main organ that stores lipids and it plays important roles in metabolic balance in the body. We recently reported in Human and Experimental Toxicology that the combined exposure to BPA and fructose may interfere with energy metabolism of adipose tissue. However, it is still unclear whether the combined exposure to BPA and fructose has the possibility to induce lipid remodeling in adipose tissue. In the present study, we performed a widely targeted quantitative lipidomic analysis of the adipose tissue of rats after 6 months of BPA and fructose combined exposure. We totally determined 734 lipid molecules in the adipose tissue of rats. Principal component analysis (PCA) showed the group of the combined exposure to higher-dose (25μg/kg every other day) BPA and fructose can be distinguished from the groups of control, higher-dose BPA exposure and fructose exposure clearly. Partial least squares-discriminant analysis (PLS-DA) and univariate statistical analysis displayed lipids of PC(18:0_ 20:3), TG(8:0_14:0_16:0), TG(12:0_14:0_16:1), TG(10:0_16:0_16:1), TG(12:0_ 14:0_18:1), TG(14:0_ 16:0_16:1), TG(14:0_14:1_16:1), TG(8:0_ 16:1_16:2), TG(14:1_16:1_ 16:1), TG(16:1_18:1_18:1), TG(16:0_16:1_20:4) and TG(15:0_18:1_ 24:1) may contributed the most to the discrimination. These findings indicated that combined exposure to BPA and fructose has the potential to cause lipid remodeling in adipose tissue.

The suitability of a polydimethylsiloxane-based (PDMS) microfluidic two compartment system for the toxicokinetic analysis of organophosphorus compounds

Organ-on-a-chip platforms are an emerging technology in experimental and regulatory toxicology (species-specific differences, ethical considerations). They address gaps between in vivo and in vitro models. However, there are still certain limitations considering material, setup and applicability. The current study examined the suitability of a commercially available polydimethylsiloxane-based (PDMS) organ-chip for the toxicokinetic characterization of the highly toxic nerve agent VX and the organophosphate pesticide parathion. The respective concentrations of 1000 µmol/L and 100 µmol/L VX and parathion were chosen deliberately high in order to study concentrations even if high compound absorption by PDMS might occur. Neuronal and liver spheroids, totaling 2 × 106 cells were used to study concentration changes of VX and parathion. In addition, VX enantiomers were quantified. The current study suggests a significant absorption of VX, respectively parathion by PDMS. This might require future investigation of alternative materials or coatings to limit absorption for organophosphorus compounds in toxicokinetic studies.

How do German pharmacologists publish in the non-peer-reviewed science magazine Biospektrum?

Publications in peer-reviewed journals are the most important currency in science. But what about publications in non-peer-reviewed magazines? The objective of this study was to analyze the publications of scientists, with a focus on pharmacologists, in the non-peer-reviewed German science magazine Biospektrum from 1999 to 2021. Biospektrum is edited by five scientific societies in Germany including the Society for Experimental and Clinical Society Pharmacology and Toxicology (DGPT) and provides opportunities to researchers to showcase their research to a broad audience. We analyzed 3197 authors of 1326 articles. Compared to the fields of biochemistry, microbiology, and genetics, pharmacology was largely underrepresented. Just three institutions in Germany contributed most papers to Biospektrum. Researchers with a doctoral degree were the largest author group, followed by researchers with a habilitation degree. Among all major fields, women were underrepresented as authors, particularly as senior authors. The Covid pandemic leads to a drop of publications of female first authors but not last authors. Compared to publications in the peer-reviewed journal Naunyn–Schmiedeberg’s Archives of Pharmacology (Zehetbauer et al., Naunyn-Schmiedebergs Arch Pharmacol 395:39–50 (2022)), female pharmacologists were underrepresented in the Biospektrum. Thus, German pharmacologists as a group do not value investing in “social impact” gained by publications in Biospektrum, and this attitude is even more prominent among female pharmacologists. Investing less in “social impact” by female pharmacologists may result in reduced visibility on the academic job market and may contribute to reduced opportunities to achieve high academic positions.

Influence of high-bromine poultry products on clinical-biochemical blood parameters of white rats

Bromine content in fodder and water for laying chickens in Ukraine gradually increasing, thereby accumulating in the poultry production (eggs and meat): according to the data, intake of bromine with chicken eggs in 2020 has almost doubled, compared with 2016. Taking into account the ability of bromine to accumulate and the scales of consumption of poultry products, it is relevant to study the effects of high bromine concentration on the level of thyroid hormones and clinical-biochemical parameters of blood of white rats. At the laboratory of Toxicological Monitoring of the National Scientific Center the Institute of Experimental and Clinical Veterinary Medicine and the Department of Experimental Pharmacology and Toxicology of the State Institution V.Y. Danylevskyi Institute of Problems of Endocrine Pathology of the National Academy of Medical Sciences of Ukraine, we carried out studies on white outbred male rats (n = 144). The diet of experimental groups was supplemented with eggs and meat containing high bromine concentration. We determined increase in the coefficients of liver weight and decrease in the coefficients of lung weight in the experimental rats. Moreover, we determined changes in the biochemical blood profile, in particular: after egg consumption, there occurred 20.0–22.0% decrease in the enzymatic activity of alanine aminotransferase, 23.0–48.4% in the activity of aspartate aminotransferase, and on average 21.3% decrease in alkaline phosphatase, compared with the control; after meat consumption, the level of total proteins decreased by 8.6%, glucose by 12.2–14.5%, also there were 13.8–18.5% decrease in the activity of alanine aminotransferase and 12.1–83.0% increase in the activity of aspartate aminotransferase on the 28th day, and 23.2–35.3% decrease in the activity of alkaline phosphatase. After the intake of both poultry products, the blood serum of animals was observed to have decrease in the level of overall thyroxine and overall triiodothyronine (1.3 times on average, depending on the period of study). The results of the studies can help in prediction and timely alleviation of the negative impact of poultry products with high bromine content on the human organism.

Preclinical species gene expression database: Development and meta-analysis.

The evaluation of toxicity in preclinical species is important for identifying potential safety liabilities of experimental medicines. Toxicology studies provide translational insight into potential adverse clinical findings, but data interpretation may be limited due to our understanding of cross-species biological differences. With the recent technological advances in sequencing and analyzing omics data, gene expression data can be used to predict cross species biological differences and improve experimental design and toxicology data interpretation. However, interpreting the translational significance of toxicogenomics analyses can pose a challenge due to the lack of comprehensive preclinical gene expression datasets. In this work, we performed RNA-sequencing across four preclinical species/strains widely used for safety assessment (CD1 mouse, Sprague Dawley rat, Beagle dog, and Cynomolgus monkey) in ∼50 relevant tissues/organs to establish a comprehensive preclinical gene expression body atlas for both males and females. In addition, we performed a meta-analysis across the large dataset to highlight species and tissue differences that may be relevant for drug safety analyses. Further, we made these databases available to the scientific community. This multi-species, tissue-, and sex-specific transcriptomic database should serve as a valuable resource to enable informed safety decision-making not only during drug development, but also in a variety of disciplines that use these preclinical species.

Modeling issues in experimental toxicology and medicine. Zero-order biomodels

Introduction. The creation of adequate models for studying the processes of human interaction with the environment is a key problem of modern experimental biology and medicine. This is due to the fact that both the results of the conducted studies and the recommendations developed on their basis depend on the choice of the biological object and the characteristics of the factor directly affecting it. It should be noted that errors related to both the discrepancy between the developed experimental pathology and the simulated conditions for humans, and the choice of a method for assessing the safety of xenobiotics are critical and can lead to serious consequences. The study aims to determine the existing trends in biomodeling and extrapolation of the results currently being implemented in experimental toxicology and medicine based on the analysis of literature data. Materials and methods. We have used forty five domestic and foreign scientific publications as materials. The research method was the analysis and generalization of the materials presented in scientific publications. Results. The scientists considered such components of extrapolation modeling as the creation of an adequate model, compliance with the principles of proper laboratory, as well as extrapolation of the obtained data to humans. We have given the definition of an experimental model of the disease as a condition developing in a laboratory animal under the influence of an etiological factor, which most fully reflects the main manifestations of the disease that arose on the basis of a common human and used biomodel of pathogenesis. We introduced the term "zero-order biomodels" and defined it as an object used for biomodeling and also presented a classification of zero-order biomodels. Conclusion. Currently, issues related to their standardization are of increasing importance in conducting biomedical research, which is reflected in the appearance of a large number of regulatory documents regulating not only the procedure for conducting them, but also the requirements for biological models used for these studies. However, despite the existing trends, the key point in conducting all studies was and still is the issues related to the extrapolation of the data obtained to humans. The conducted analysis suggests that new biological models (of the zero-order) are being actively introduced into the practice of biomedical research according to their characteristics fully corresponding to the prototype - human biological material obtained from various sources. A distinctive feature of these models is the absence of the need to extrapolate the results obtained to humans. The analysis shows that at present there are all prerequisites for conducting preclinical studies using almost the entire spectrum of biological models of the zero-order specified in this publication within the existing legal framework.

Experimental and Computational Nanotoxicology-Complementary Approaches for Nanomaterial Hazard Assessment.

The growing development and applications of nanomaterials lead to an increasing release of these materials in the environment. The adverse effects they may elicit on ecosystems or human health are not always fully characterized. Such potential toxicity must be carefully assessed with the underlying mechanisms elucidated. To that purpose, different approaches can be used. First, experimental toxicology consisting of conducting in vitro or in vivo experiments (including clinical studies) can be used to evaluate the nanomaterial hazard. It can rely on variable models (more or less complex), allowing the investigation of different biological endpoints. The respective advantages and limitations of in vitro and in vivo models are discussed as well as some issues associated with experimental nanotoxicology. Perspectives of future developments in the field are also proposed. Second, computational nanotoxicology, i.e., in silico approaches, can be used to predict nanomaterial toxicity. In this context, we describe the general principles, advantages, and limitations especially of quantitative structure–activity relationship (QSAR) models and grouping/read-across approaches. The aim of this review is to provide an overview of these different approaches based on examples and highlight their complementarity.

Abstracts of the 88th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT).

Abstracts of the 88th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT).

DYNAMICS, INFORMATIVITY AND PREDICTIVE VALUE OF BODY TEMPERATURE AT SULFUR MUSTARD INTOXICATION IN RATS

Introduction. In experimental toxicology, the selection of criteria characterizing the toxicological process play an important role in evaluating the effectiveness of the means of prevention and treatment of intoxication. Aim of the study: study of the dynamics, informativity and prognostic significance of rectal temperature at sulfur mustard intoxication in rats. Results of the study. The results showed that intramuscular injection of sulfuric mustard in rats in the range of doses from minimally lethal to absolutely lethal is accompanied by a dose-dependent decrease in rectal temperature at 3-days of intoxication. In the studied sample, the dividing capacity (AUC) of the rectal temperature index at the intoxication peak (3-d day) for mortality was 0,94 (95 % CI 0,8–0,91), which corresponds to excellent predictive ability. The sensitivity and specificity parameters for rectal temperature were 0,86 (95 % CI 0,8–0,91) and 0,90 (95 % CI 0,83–0,95), respectively. Conclusions. Rectal temperature values reflect the dynamics and severity of sulfur mustard intoxication in rats. This criterion has a high informative and predictive value in relation to the death and can be reasonably included in the program of evaluation of the effectiveness of the developed means of prevention and treatment of sulfur mustard.

Simultaneous Alcohol and Marijuana Use Among Young Adults: A Scoping Review of Prevalence, Patterns, Psychosocial Correlates, and Consequences.

BACKGROUNDAlcohol and marijuana are commonly used by young adults, and use of both substances, particularly at the same time, is prevalent among this population. Understanding the prevalence, patterns, correlates, and consequences of simultaneous alcohol and marijuana (SAM) use is important to inform interventions. However, this literature is complicated by myriad terms used to describe SAM use, including use with overlapping effects and same-day co-use.OBJECTIVESThis scoping review identifies and describes the peer-reviewed literature focused on SAM use by young adults and distinguishes simultaneous use from same-day co-use of alcohol and marijuana. This review also provides a narrative summary of the prevalence of SAM use, patterns of SAM and other substance use, psychosocial correlates, and consequences of SAM use.ELIGIBILITY CRITERIAThis review is limited to papers written in English and published in peer-reviewed journals between January 2000 and August 2021. It includes papers assessing simultaneous use or same-day co-use of alcohol and marijuana among young adults ages 18 to 30. Review papers, qualitative interviews, experimental lab studies, policy work, toxicology or medical reports, and papers focused on neurological outcomes are excluded.SOURCES OF EVIDENCEPubMed, PsycINFO, and Web of Science databases were searched. Databases were selected and the search strategy developed in consultation with an information specialist.CHARTING METHODSA data charting form was utilized to specify which information would be extracted from included papers. Eight categories of data were extracted: (1) research questions and hypotheses; (2) sample characteristics; (3) study procedures; (4) definition of SAM use; (5) prevalence of SAM use; (6) patterns of SAM and other substance use; (7) psychosocial correlates of SAM use; and (8) consequences of SAM use.RESULTSA total of 1,282 papers were identified through initial search terms. Through double-blind title/abstract screening and full-text review, the review was narrowed to 74 papers that met review inclusion criteria. Review of these papers demonstrated that SAM use was prevalent among young adults, particularly among those who reported heavier quantities and more frequent use of alcohol and marijuana. Enhancement-related motives for use were consistently positively associated with SAM use. SAM use was associated with greater perceived positive and negative consequences of alcohol and/or marijuana use. Inconsistencies in prevalence, patterns, correlates, and consequences were found between studies, which may be due to large variations in measurement of SAM use, populations studied, methodological design (e.g., cross-sectional vs. intensive longitudinal), and the covariates included in models.CONCLUSIONSThe literature on simultaneous use and same-day co-use of alcohol and marijuana has expanded rapidly. Of the 74 included papers (61 on SAM use; 13 on same-day co-use), 60 papers (47 on SAM use; 13 on same-day co-use) were published within the last 5 years. Future research focusing on the ways in which SAM use confers acute risk, above and beyond the risks associated with separate consumption of alcohol and marijuana, is needed for understanding potential targets for intervention.

A word of caution regarding Ceftriaxone.

Ceftriaxone is a well-known antibiotic belonging to the third generation of cephalosporins. This broad-spectrum drug is highly effective against gram negative and gram-positive bacterial infections and is frequently used to treat severe bacterial infections in pediatrics, including disseminated gonococcal infections, sepsis and meningitis. However, concerns have been raised regarding the drug’s safety as it is prone to various side effects like bilirubin encephalopathy, cholestasis, pseudolithiasis and rarely hepatitis and pancreatitis.1 A prospective study in 154 children published in Human and Experimental Toxicology in 2016 further validate this point.2 According to this study, out of 84, 20.9% children treated with ceftriaxone had abnormal biliary sonographic findings and 15.1% had biliary lithiasis whereas cefotaxime was found to be comparatively safer. Worrying facts related to Ceftriaxone should definitely be taken into consideration as ceftriaxone is a standard treatment for several bacterial infections in children and is being prescribed at a regular basis in many countries. In fact, a clinical study performed in a secondary care hospital of Karachi, Pakistan, declared it the most frequently prescribed antibiotic.3 Physicians should prescribe ceftriaxone with caution. Ceftriaxone should be avoided in neonates especially those with hyperbilirubinemia. Caution must be advised for the use of intravenous ceftriaxone with intravenous calcium containing solutions as their concomitant use can lead to life threatening adverse reactions.4 Patient should seek medical help if they experience diarrhea, jaundice, confusion, headache, heart palpitations etc. Similar drugs with a safer adverse effect profile should be considered as a future alternative. Continuous..

Use of (Q)SAR genotoxicity predictions and fuzzy multicriteria decision-making for priority ranking of ethoxyquin transformation products

Ethoxyquin (EQ; 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) has been used as an antioxidant in feed for pets and food-producing animals, including farmed fish such as Atlantic salmon. In Europe, the authorization for use of EQ as a feed additive was suspended, due to knowledge gaps concerning the presence and toxicity of EQ transformation products (TPs). Recent analytical studies focusing on the detection of EQ TPs in farmed Atlantic salmon feed and fillets reported the detection of a total of 27 EQ TPs, comprising both known and previously not described EQ TPs. We devised and applied an in silico workflow to rank these EQ TPs according to their genotoxic potential and their occurrence data in Atlantic salmon feed and fillet. Ames genotoxicity predictions were obtained applying a suite of five (quantitative) structure–activity relationship ((Q)SAR) tools, namely VEGA, TEST, LAZAR, Derek Nexus and Sarah Nexus. (Q)SAR Ames genotoxicity predictions were aggregated using fuzzy analytic hierarchy process (fAHP) multicriteria decision-making (MCDM). A priority ranking of EQ TPs was performed based on combining both fAHP ranked (Q)SAR predictions and analytical occurrence data. The applied workflow prioritized four newly identified EQ TPs for further investigation of genotoxicity. The fAHP-based prioritization strategy described here, can easily be applied to other toxicity endpoints and groups of chemicals for priority ranking of compounds of most concern for subsequent experimental and mechanistic toxicology analyses.

JEG-3 placental cells in toxicology studies: a promising tool to reveal pregnancy disorders.

Placental alterations are responsible for adverse pregnancy outcomes like preeclampsia and intrauterine growth restriction. And yet, placenta toxicology has not become a fully-fledged toxicology field. Because placenta is very often seen only as a barrier between the mother and the fetus, there is a lack and therefore a need for an experimental human model with technical recommendations to study placenta toxicology. In vitro approaches are recommended in experimental toxicology as they focus on a specific biological process and yield high-throughput screening methods. In the present study, we first established incubation conditions to preserve signatures of the human JEG-3 cell line identity while enabling toxicity detection. JEG-3 cells prepared in our incubation conditions were renamed JEG-Tox cells. As placental alterations are mainly triggered by uncontrolled apoptosis, we second used known apoptotic agents pregnant women are exposed to, to check that JEG-Tox cells can trigger apoptosis. Ethanol, bisphenol F, quinalphos, 4,4’-DDT, benzalkonium chloride, phenoxyethanol, propylparaben, and perfluorooctanic acid all induced chromatin condensation in JEG-Tox cells. Our incubation conditions allow JEG-Tox cells to keep placental cell identity and to respond to toxic chemicals. JEG-Tox cells are a pertinent model for placenta toxicology and could be used to better understand pregnancy alterations.

Personalized toxicology: phenomenology, relevance, development prospects

Personalized toxicology is a research area that studies the individual toxicity of hazardous chemical compounds by experimental and clinical toxicology based on new molecular medicine approaches, including genetics and epigenomics, for prevention, diagnosis, and treatment of chemically induced diseases.
 Goal of Research.To study individual genetically and epigenetically induced mechanisms of bodys response to exposure to chemical substances, and their effect on preclinical and reversible changes, development of intoxications, and long-term effects, as well as assessment of the individual health risk of exposure to a chemical factor.

Induction and repression effects on CYP and transporter protein abundance by azole mixture uptake in rat liver.

Detection of mixture effects is a major challenge in current experimental and regulatory toxicology. Robust markers are needed that are easy to quantify and responsive to chemical stressors in a broad dose range. Several hepatic enzymes and proteins related to drug metabolism like cytochrome-P-450 (CYP) enzymes and transporters have been shown to be responsive to pesticide active substances in a broad dose range and are therefore good candidates to be used as markers for mixture toxicity. Even though they can be well quantified at the mRNA level, quantification on the protein level is challenging because most of these proteins are membrane bound. Here we report the development of mass spectrometry-based assays using triple-x-proteomics (TXP) antibodies in combination with targeted selected ion monitoring (tSIM) to quantify changes of protein levels due to exposure to mixtures of pesticide active substances. Our results indicate that changes on the protein level of CYP1A1, ABCB2, ABCC3 are in line with observations on the mRNA and enzyme activity level and are indicative of mixture effects. Therefore, the tests are promising to reveal effects by chemical mixture effects in toxicological studies in rats.

Acute chloroquine poisoning: A comprehensive experimental toxicology assessment of the role of diazepam

Background and PurposeResurgence in the use of chloroquine as a potential treatment for COVID‐19 has seen recent cases of fatal toxicity due to unintentional overdoses. Protocols for the management of poisoning recommend diazepam, although there are uncertainties in its pharmacology and efficacy in this context. The aim was to assess the effects of diazepam in experimental models of chloroquine cardiotoxicity.Experimental ApproachIn vitro experiments involved cardiac tissues isolated from rats and incubated with chloroquine alone or in combination with diazepam. In vivo models of toxicity involved chloroquine administered intravenously to pentobarbitone‐anaesthetised rats and rabbits. Randomised, controlled treatment studies in rats assessed diazepam, clonazepam and Ro5‐4864 administered: (i) prior, (ii) during and (iii) after chloroquine and the effects of diazepam: (iv) at high dose, (v) in urethane‐anaesthetised rats and (vi) co‐administered with adrenaline.Key ResultsChloroquine decreased the developed tension of left atria, prolonged the effective refractory period of atria, ventricular tissue and right papillary muscles, and caused dose‐dependent impairment of haemodynamic and electrocardiographic parameters. Cardiac arrhythmias indicated impairment of atrioventricular conduction. Studies (i), (ii) and (v) showed no differences between treatments and control. Diazepam increased heart rate in study (iv) and as with clonazepam also prolonged the QTc interval in study (iii). Combined administration of diazepam and adrenaline in study (vi) improved cardiac contractility but caused hypokalaemia.Conclusion and ImplicationsNeither diazepam nor other ligands for benzodiazepine binding sites protect against or attenuate chloroquine cardiotoxicity. However, diazepam may augment the effects of positive inotropes in reducing chloroquine cardiotoxicity.Linked ArticlesThis article is part of a themed issue on The Pharmacology of COVID‐19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc

Handheld Sensor for Point-of-Care Methanol Detection in Breath and Liquor

Handheld Sensor for Point-of-Care Methanol Detection in Breath and Liquor