Toxicological Relevance Research Articles

Analytical methodologies for the determination of sterigmatocystin in food and current concentration levels

Sterigmatocystin (STE) is a possible human carcinogenic compound (2B) according to the International Agency for Research on Cancer classification. Structurally, STE is a precursor to aflatoxins, sharing a similar polyketide-derived biosynthetic pathway, which underscores its toxicological relevance. It has been reported to occur in a variety of foodstuffs including cereals and cereal-based products, spices, cheese, and nuts, among others. STE poses a substantial challenge to food safety and addressing this issue requires a comprehensive strategy encompassing prevention, monitoring, and regulation to protect both human and animal health from its harmful effects. The present paper presents the analytical methodologies for the determination of STE in foodstuffs and the reported levels of STE in food, based on a review of scientific publications from 2021 to 2024. Significative progress has been made in the development of analytical methodologies for STE determination in food; however, further advancements in analytical techniques, standardized protocols, and monitoring are essential to improve risk assessment and guide effective mitigation strategies.

Soft plastic fishing lures as a potential source of chemical pollution - Chemical analyses, toxicological relevance, and anglers’ perspectives

Soft plastic lures (SPLs) are commonly used artificial lures in recreational angling. Anglers regularly lose SPLs while fishing and there is little knowledge about the environmental impacts of lost SPLs. As with other plastic items, SPLs contain phthalates and other persistent additives that may leach into water. In this study, 16 randomly chosen SPLs of common models were analyzed for the leaching of persistent, water-soluble plastic additives, including phthalates. The estrogenicity of sample extracts from a subsample of 10 SPLs was assessed using luciferase reporter gene bioassays. Over a period of 61 days, 10 of the 16 SPLs leached the targeted phthalates dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP) and di-n-butyl phthalate (DnBP) at median detectable concentrations ranging from 10 ng/g sample BBP to a median of 1001 ng/g DMP as well as 45 persistent, mobile, and toxic (PMT) plastic additives. DEP was detected most frequently in 8 SPLs, followed by BBP (2 SPLs), DMP (2 SPLs) and DnBP (1 SPL). The extract from one SPL with comparatively low phthalate and PMT plastic additive levels was active in the bioassay, indicating high endocrine-disruptive potential, presumably due to unknown additives that were not among the target substances of the methodology used in this study. The study was supplemented by a mail survey among anglers, in which attitudes of anglers towards SPLs were investigated. The survey indicated that SPL loss is a common event during angling. Most participants were concerned about potential ecological impacts of SPLs, wanted the ingredients of SPLs to be labelled and supported legal restrictions concerning toxic ingredients of SPLs. The study shows that SPLs are a potential source of environmental pollution, may pose human health risks and need further investigation, considering the frequent use of SPLs in recreational angling.

Toxicologic analysis of 35 drugs in post mortem human blood samples with focus on antihypertensive and antiarrhythmic drugs

Antiarrhythmic and antihypertensive drugs are frequently encountered in post mortem analysis, and the question may arise as to whether they were administered in therapeutic doses, and if they were taken in accidental, intentional, or suicidal overdose scenarios. Therefore, a novel analytical method was developed and validated for the quantification of 35 drugs with toxicological relevance, including antihypertensive and antiarrhythmic drugs (ajmaline, amlodipine, amiodarone, atenolol, bisoprolol, carvedilol, clonidine, desethylamiodarone, diltiazem, donepezil, doxazosin, dronedarone, esmolol, flecainide, lercanidipine, lidocaine, metoprolol, nebivolol, nimodipine, pindolol, prajmaline, propafenone, propranolol, sotalol, urapidil, and verapamil), as well as other medications commonly found in combination (sildenafil, tadalafil, atorvastatin, clopidogrel, dapoxetine, memantine, pentoxifylline, rivastigmine, and ivabradine). The method enables simultaneous identification and quantification in blood samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS).Validation exhibited excellent linearity across the concentration range for all analytes. Precision and accuracy were within acceptable limits, with bias and relative standard deviation (RSD) values consistently below 9 % and 10 %, respectively. Selectivity and specificity assessments confirmed the absence of any interference from contaminants or co-extracted drugs. The method demonstrated very high sensitivity, with limits of detection (LOD) as low as 0.01 ng/ml and limits of quantification (LOQ) as low as 0.04 ng/ml. Extraction recovery exceeded 57.5 % for all analytes except atenolol, and matrix effects were <17 % for all analytes except pindolol. Processed sample stability evaluations revealed consistent results with acceptable deviations for all analytes. In addition, the method was specifically tested for the use in post mortem analysis. The applicability of our method was demonstrated by the analysis of two authentic human autopsy blood samples.

A sensitive method for the determination of per- and polyfluoroalkyl substances in food and food contact material using high-performance liquid chromatography coupled with tandem mass spectrometry

Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges.

Occurrence and toxicological relevance of pesticides and trace metals in agricultural soils, sediments, and water of the Sogamoso River basin, Colombia

Historical pesticide use in agriculture and trace metal accumulation have long term impact on soil, sediment, and water quality. This research quantifies legacy and current-use pesticides and trace metals, assessing their occurrence and toxicological implications on a watershed scale in the Sogamoso River basin, tributary of the Magdalena River in Colombia. Organochlorine pesticides (22), organophosphates (7), and azole fungicides (5), as well as trace metals cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) were analyzed in croplands and along the river. Toxic units (TU) and hazard quotients (HQ) were calculated to assess the mixture toxicity. Organochlorines were detected in 84% of soils, 100% of sediments, and 80% of water samples. Organophosphates were found in 100% of soil and sediment samples, as well as in 70% of water samples. Azole fungicides were present in 79% of soils, 60% of sediments, and in 10% of water samples. Total pesticide concentrations ranged from 214.2 to 8497.7 μg/kg in soils, 569.6–12768.2 μg/kg in sediments, and 0.2–4.1 μg/L in water. In addition, the use of partition coefficient (Kd) and organic carbon fraction (foc) allowed the distribution analysis for most of the pesticides in sediments, suspended particulate matter (SPM), and water systems, but not for soils. Concentrations of trace metals Cu, Zn, Pb, and Zn exceeded international quality guidelines for agricultural soils in 16% of the samples. Furthermore, Cu and Zn concentrations exceeded sediment quality guidelines in 50 and 90% of the samples, respectively. These findings demonstrate the broad distribution of complex mixtures of trace metals, legacy organochlorines, and current-use pesticides across the basin, indicating that conventional agriculture is a significant source of diffuse pollution. Sustainable agricultural practices are needed to mitigate adverse impacts on ecosystems and human health.

Solvent-free parallel artificial liquid membrane extraction for drugs of abuse in plasma samples using LC-MS/MS

BackgroundParallel artificial liquid membrane extraction (PALME) is a 96-well plate setup variant of liquid-phase microextraction. Basic or acidic analytes are extracted in neutral form from the sample, through a supported liquid membrane (SLM), and into aqueous acceptor. PALME is already considered a green extraction technique, but in the current conceptual work, we sought to make it even greener by replacing the use of organic solvents with essential oils (EO). PALME was combined with LC-MS/MS for analysis of plasma samples and multiple drugs of abuse with toxicological relevance (amphetamines, phenethylamines, synthetic cathinones, designer benzodiazepines, ayahuasca alkaloids, lysergic acid diethylamide, and ketamine). ResultsFourteen EO were compared to organic solvents frequently used in PALME. The EO termed smart & sassy yielded the best analyte recovery for all drugs studied and was thus selected as SLM. Then, factorial screening and Box-Behnken were employed to optimize the technique. The extraction time, concentration of base, sample volume, and percentage of trioctylamine significantly impacted analyte recovery. The optimum values were defined as 120 min, 10 mmol/L of NaOH, 150 μL, and 0%, respectively. Once optimized, validation parameters were 1–100 ng mL-1 as linear range, accuracy ±16.4%, precision >83%, 1 ng mL-1 as limit of quantitation, 0.1–0.75 ng mL-1 as limit of detection, matrix effect <20%, and recovery 20–106%. Additionally, EO purchased from different production batches were tested and achieved acceptable reproducibility. Data were in compliance with requirements set by internationally accepted validation guidelines and the applicability of the technique was proven using authentic samples. SignificanceIn this study, the use of an EO provided a solvent-free sample preparation technique suited to extract different classes of drugs of abuse from plasma samples, dismissing the use of hazardous organic solvents. The method also provided excellent sample clean-up, thus being a simple and efficient tool for toxicological applications that is in agreement with the principles of sustainable chemistry.

Enzymatic synthesis of the modified mycotoxins 3-lactyl- and 3-propionyl-deoxynivalenol

The use of lactic acid bacteria as a low-cost sustainable management tool to prevent further build-up of Fusarium mycotoxins during grain storage is increasingly propagated. It has been reported that even deoxynivalenol contamination already formed in the field can be reduced by such treatment in unknown ways. An enigmatic deoxynivalenol derivative, 3-lactyl-deoxynivalenol, has been reported already in 1982 as the toxic principle of Fusarium-infected barley from China, but very little is known about this metabolite. Here, we show that the enzymatic machinery of Fusarium graminearum is sufficient for its biosynthesis. Similarly, when challenged with propionic acid, F. graminearum can form a novel modified mycotoxin, 3-propionyl-deoxynivalenol. Lactic acid and propionic acid are first converted into lactyl-CoA and propionyl-CoA, respectively. These acyl-CoA derivatives can subsequently be used by the 3-O-acyltransferase encoded by TRI101. We expressed the respective genes in E. coli and utilized the affinity-purified proteins for enzymatic synthesis of the reference substances 3-lactyl- and 3-propionyl-deoxynivalenol. The structures of the purified compounds were confirmed by nuclear magnetic resonance spectroscopy. Preliminary toxicological assessment using in vitro translation assays indicated residual toxicity, most likely due to reactivation of deoxynivalenol by de-acylation. In conclusion, this study reports a method to synthesize 3-lactyl- and 3-propionyl-deoxynivalenol reference substances, which will be highly useful to determine occurrences of these acylated deoxynivalenol-derivatives in cereal samples and to perform more detailed studies to evaluate their toxicological relevance.

Cellular effects of microplastics are influenced by their dimension: Mechanistic relationships and integrated criteria for particles definition.

The definition of microplastics (MPs) is nowadays too generic from a biological perspective, since different characteristics of these particles might influence their effects. To provide experimental evidence that size is an important factor to be considered, Mediterranean mussels Mytilus galloprovincialis were exposed to five size classes of polyethylene fragments (PE-MPs, 20–50 μm, 50–100 μm, 100–250 μm, 250–500 μm, 500–1000 μm). After 10 days of exposure, MPs ingestion and mechanistic relationships between particles size and cellular effects were analysed through a wide panel of biological alterations, including immune system responses, cholinergic function, antioxidant system, lipid metabolism and peroxidation. Results were further elaborated through a Weight of Evidence approach, summarizing the overall biological significance of obtained results in a hazard index based on the number and magnitude of variations and their toxicological relevance. PE-MPs 500–1000 μm were identified as the less biologically reactive size class due to the limited ingestion of particles coupled with the lack of biological effects, followed by PE-MPs 250–500 μm, which slightly altered the cholinergic function and lysosomal membranes. Conversely, PE-MPs smaller than 250 μm provoked a more consistent onset of biological alterations in terms of immune system composition and functioning, redox homeostasis, and lipid metabolism. The overall findings of this study highlight the importance of considering the size of particles for monitoring and risk assessment of MPs, introducing a more integrated evaluation of plastic pollution that, beside particles concentration, should adequately weigh those characteristics triggering the onset of biological effects.

Acute and subchronic oral toxicity study of Camelina sativa oil in Wistar rats

ObjectiveThe aim of these studies was to ascertain if Camelina sativa oil is harmful in both the acute and subchronic states. MethodsWistar rats of both sexes were used in an acute toxicity test, and the fatal dosage (LD50) of oral Camelina sativa oil was greater than 27.6 g/kg bw. Rats were gavaged with Camelina sativa oil at dosages of 0.00, 0.92, 1.84, and 3.68 g/kg bw per day for 90 days. In addition, satellite groups were established in the control and high-dose groups for a 28-day recovery period. The following factors were assessed: mortality, clinical anomalies, body weight, food intake, hematological, serum biochemistry, urine, gross necropsy, and histology. ResultsThere were no observable toxicity-related changes in any of the three dosage groups. There is no toxicological relevance to the change in the high-dose hematological indicator PLT at the conclusion of the recovery period because it was within the usual range for this strain in our laboratory. The test material did not result in any pathological alterations, according to a pathological examination. ConclusionSince the results of the current study, the no-observed-adverse-effect-level (NOAEL) for Camelina sativa oil in rats has been determined to be greater than 3.68 g/kg bw.

Genotoxicity Evaluation of Titanium Dioxide Nanoparticles In Vivo and In Vitro: A Meta-Analysis.

Recent studies have raised concerns about genotoxic effects associated with titanium dioxide nanoparticles (TiO2 NPs), which are commonly used. This meta-analysis aims to investigate the potential genotoxicity of TiO2 NPs and explore influencing factors. This study systematically searched Chinese and English literature. The literature underwent quality evaluation, including reliability evaluation using the toxicological data reliability assessment method and relevance evaluation using routine evaluation forms. Meta-analysis and subgroup analyses were performed using R software, with the standardized mean difference (SMD) as the combined effect value. A total of 26 studies met the inclusion criteria and passed the quality assessment. Meta-analysis results indicated that the SMD for each genotoxic endpoint was greater than 0. This finding implies a significant association between TiO2 NP treatment and DNA damage and chromosome damage both in vivo and in vitro and gene mutation in vitro. Subgroup analysis revealed that short-term exposure to TiO2 NPs increased DNA damage. Rats and cancer cells exhibited heightened susceptibility to DNA damage triggered by TiO2 NPs (p < 0.05). TiO2 NPs could induce genotoxicity, including DNA damage, chromosomal damage, and in vitro gene mutations. The mechanism of DNA damage response plays a key role in the genotoxicity induced by TiO2 NPs.

N-Acetylcysteine Displaces Glutathionyl-Moieties from Hg2+ and MeHg+ to Form More Hydrophobic Complexes at Near-Physiological Conditions.

The anthropogenic release of Hg is associated with an increased human exposure risk. Since Hg2+ and MeHg+ have a high affinity for thiols, their interaction with L-glutathione (GSH) within mammalian cells is fundamentally involved in their toxicological chemistry and excretion. To gain insight into the interaction of these mercurials with multiple small molecular weight thiols, we have investigated their competitive interactions with GSH and N-acetylcysteine (NAC) at near-physiological conditions, using a liquid chromatographic approach. This approach involved the injection of each mercurial onto a reversed-phase (RP)-HPLC column (37 °C) using a PBS buffer mobile phase containing 5.0 mM GSH to simulate cytosolic conditions with Hg being detected in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). When the 5.0 mM GSH mobile phase was amended with up to 10 mM NAC, gradually increasing retention times of both mercurials were observed. To explain this behavior, the experiment with 5.0 mM NAC and 5.0 mM GSH was replicated using 50 mM Tris buffer (pH 7.4), and the Hg-containing fractions were analyzed by electrospray ionization mass spectrometry. The results revealed the presence of Hg(GS)(NAC) and Hg(NAC)2 for Hg2+ and MeHg(GS) and MeHg(NAC) for MeHg+, which suggests that the coordination/displacement of GS-moieties from each mercurial by the more hydrophobic NAC can explain their retention behavior. Since the biotransformations of both mercurials were observed at near-physiological conditions, they are of toxicological relevance as they provide a biomolecular explanation for some results that were obtained when animals were administered with each mercurial and NAC.

Minimal Eliciting Allergic Contact Dermatitis Concentrations in Normal versus Damaged Skin: Clinical and Toxicologic Relevance

Minimal Eliciting Allergic Contact Dermatitis Concentrations in Normal versus Damaged Skin: Clinical and Toxicologic Relevance

Difficulties in translating in vitro hazards of local acute irritants to relevant human risk: Learnings from Captan and Folpet

In order to assess the regulatory value of New Approach Methodologies (NAMs), authors should provide their opinion on the physiological and exposure relevance of observed in vitro effects for correlation with predicted in vivo effects. Further, peer-reviewers should be encouraged to request such information during review. This is critical to scientifically transition to animal-free, reliable, robust and -- most importantly -- relevant regulatory toxicology and risk assessment approaches. Recently published studies using NAMs for the fungicides Captan and Folpet illustrate the difficulties and limitations of applying NAMs to adequately assess the toxicological relevance of these substances.

Environmental Concentrations of the Type 2 Diabetes Medication Metformin and Its Transformation Product Guanylurea in Surface Water and Sediment in Ontario and Quebec, Canada.

Metformin, used to treat Type 2 diabetes, is the active ingredient of one of the most prescribed drugs in the world, with over 120 million yearly prescriptions globally. In wastewater-treatment plants (WWTPs), metformin can undergo microbial transformation to form the product guanylurea, which could have toxicological relevance in the environment. Surface water samples from 2018 to 2020 and sediment samples from 2020 were collected from six mixed-use watersheds in Quebec and Ontario, Canada, and analyzed to determine the metformin and guanylurea concentrations at each site. Metformin and guanylurea were present above their limits of quantification in 51.0% and 50.7% of all water samples and in 64% and 21% of all sediment samples, respectively. In surface water, guanylurea was often present at higher concentrations than metformin, while the inverse was true in sediment, with metformin frequently detected at higher concentrations than guanylurea. In addition, at all sites influenced solely by agriculture, concentrations of metformin and guanylurea were <1 µg/L in surface water, suggesting that agriculture is not a significant source of these compounds in the investigated watersheds. These data suggest that WWTPs and potentially septic system leaks are the most likely sources of the compounds in the environment. Guanylurea was detected at many of these sites above environmental concentrations of concern, where critical processes in fish may be affected. Due to the scarcity of available ecotoxicological data and the prominence of guanylurea across all sample sites, there is a need to perform more toxicological investigations of this transformation product and revisit regulations. The present study will help provide toxicologists with environmentally relevant concentration ranges in Canada. Environ Toxicol Chem 2023;42:1709-1720. © 2023 His Majesty the King in Right of Canada and The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

Changes in hydrocarbons and elemental distribution in peloids during maturation processes (Sečovlje Salina Nature Park Slovenia)

In Sečovlje Salina Nature Park, the therapeutic mud matured in the natural sedimentary environmental site. This work aimed to determine the influence of the peloid maturation process on the hydrocarbon and elemental distributions, as well as changes in morphology. For this purpose, the sample before and after maturation was examined using various methods.n-Alkanes were the most abundant among saturated hydrocarbons in both immature and mature peloid samples. The results showed that the maturation mainly influenced the change in distribution and concentration (from 378 to 1958 ppm) of n-alkanes. The organic matter (OM) of the immature peloid sample was characterized by a slight prevalence of long-chain and odd carbon-numbered n-alkanes, maximizing at n-C27. However, mature peloid's OM showed a similar share of short-, mid- and long-chain n-alkanes with a slight dominance of short-chain members, maximizing at n-C16. The origin of short-chain and even carbon-numbered n-alkanes was attributed to microbial precursors (e.g., Leptolyngbyaceae).Hopanes were considerably more dominant compared to steranes in both peloids. The hopane series of immature peloid was characterized by the dominance of 22,29,30-trinor-hop-5(6)-ene (C27 hopene), as well as the presence of C30-hop-22(29)-ene (diploptene), which are widespread in cyanobacterial species. The aromatic fraction of immature peloid pointed to the predominance of polycyclic aromatic hydrocarbons (PAHs). As peloid aging progressed, the sample was richer in methyl-branched alkanes, carboxylic acids, their methyl esters, and thermodynamically more stable hopanes and steranes.The presence of elements with toxicological relevance during maturation was reduced below the limits prescribed in most of the directives for cosmetic products. It specifically refers to: As, Ni and Se. A higher concentration of total sulfur in the mature peloid can be related to gypsum precipitation in the summer and/or more intensive microbial activity.

Impaired physiological responses and neurotoxicity induced by a chlorpyrifos-based formulation in Caenorhabditis elegans are not solely dependent on the active ingredient

The current massive and indiscriminate agrochemicals usage, which is inexorably linked to the toxic consequences to the environment and people, represents a great concern. Our work aimed to compare the toxicity induced by chlorpyrifos in its pure form (CPF) with that of a commercial formulation containing allegedly inert ingredients (CBCF) using Caenorhabditis elegans as in vivo model. After a 48 h exposure period, CBCF was 14 times more lethal than CPF; Hatching, brood size, body length and motor-related behavioral parameters were decreased, but these effects were significantly higher in CBCF-exposed worms. Additionally, CBCF induced significant morphological changes in cholinergic neurons, which are associated with the motor-related behavioral parameters. Finally, by analyzing the CBCF, we detected the presence of potentially-toxic metals that were not specified in the label. The presented results highlight the toxicological relevance of components present in the commercial formulations of pesticides, which have been claimed as inert compounds.

Polycyclic aromatic hydrocarbons (PAHs) in Egyptian red sea sediments: Seasonal distribution, source Identification, and toxicological risk assessment

This study investigated the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in sediments from the shoreline of the Red Sea. 16 PAH concentrations ranged from 1.43 to 4990.69 µg/g dry weight to 1.64 to 6397.69 µg/g dry weight during spring and autumn, respectively. Most sites with the highest PAH concentrations were (4–6 rings) compounds. The sources of PAHs were analyzed using principal component analysis (PCA) and diagnostic ratios between combinations of PAHs. The results indicated that the pyrogenic source was the primary source of PAHs. The results showed that surface sediment from all sample sites presents low to sporadic toxicity concerns to marine organisms. Total carcinogenicity and mutagenicity of eight priority PAHs ranged from 0.03 to 863.96 and 0.09 to 1197.85 µg/g dry weight, respectively (TEQBaP and MEQBaP). BaP accounted for most of the influence among the eight carcinogenic PAHs and could be employed as a particular PAH toxicity indicator. Using the toxic equivalent quotient (TEQcarc) and incremental lifetime cancer risk (ILCR) to estimate human health risk, it has been determined that sediment contaminated with PAHs in some study area stations may possess the capacity to cause cancer, particularly in children. The ecological risk posed by PAHs was evaluated using a risk quotient (RQ). The RQPAHs estimated for the samples revealed that the study region was at a high-risk level. Anthropogenic hydrocarbon inputs that were more pronounced in locations connected to maritime activity are described in this study. Further monitoring studiesencompassing different environmental matrices about PAHs pollution and their toxicological relevance should be conducted.

Overview of systematic toxicological analysis strategies and their coverage of substances in forensic toxicology.

Systematic toxicological analysis (STA) is the process of using an adequate analytical methodology to detect and identify as many potentially toxicologically relevant compounds as possible in biological samples. STA is an important part of everyday routine work within forensic toxicology, and several methods for STA have frequently been published and reviewed independently. However, the many drugs and other substances involved, as well as the constant emergence of new ones, may pose a major challenge in STA, which often demands a strategy involving multiple analytical methods in parallel. Such strategies have been published and evaluated less frequently despite their relevance in forensic toxicology. This mini-review briefly summarizes commonly applied methods for STA in forensic toxicology, including gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-MS (LC-MS) methods, and highlights some of their potential pitfalls. Second, it provides an overview of previously reported strategies to conduct STA, including a presentation of the STA strategy applied in the authors' laboratory. This involves broad drug screening by LC-high-resolution MS, supported by targeted screening and quantification using LC-tandem MS, headspace (HS)-GC-MS, HS-GC-flame ionization detector and other complementary methods. The STA strategy aims to cover as many potentially relevant drugs as possible and seeks to reduce potential pitfalls arising in forensic casework. The review underlines that not every substance can be identified in all circumstances even with a comprehensive STA strategy.

Quinolizidine alkaloids in lupine flour and lupine products from the German retail market and risk assessment of the results regarding human health

This study describes the analysis of five quinolizidine alkaloids (QA), i.e. 13-OH-lupanine, lupanine, lupinine, angustifoline and sparteine in 30 samples of lupine flours, lupine seeds and derived products collected 2019–2021 on the German retail market. QA occur as secondary metabolites in plants of lupine species. Certain QA are of toxicological relevance. The analytical determination performed by LC-MS/MS revealed some samples with high QA concentrations (up to 21,000 mg/kg), particularly in bitter lupine seeds. As those concentrations would result in substantial exceedances of the maximum tolerable intake values proposed by health authorities, they must be considered as a health concern.

Functional interactions between potassium-chloride cotransporter (KCC) and inward rectifier potassium (Kir) channels in the insect central nervous system

The K+/Cl− cotransporter (KCC) is the primary mechanism by which mature neurons maintain low intracellular chloride (Cl−) concentration and has been shown to be functionally coupled to the GABA-gated chloride channels (GGCC) in Drosophila central neurons. Further, pharmacological inhibition of KCC has been shown to lead to acute toxicity of mosquitoes that highlights the toxicological relevance of insect KCC. Yet, gaps in knowledge remain regarding physiological drivers of KCC function and interactions of ion flux mechanisms upstream of GGCC in insects. Considering this, we employed electrophysiological and fluorescent microscopy techniques to further characterize KCC in the insect nervous system. Fluorescent microscopy indicated insect KCC2 is expressed in rdl neurons, which is the neuron type responsible for GABA-mediated neurotransmission, and are coexpressed with inward rectifier potassium (Kir) 2 channels. Coexpression of Kir2 and KCC2 suggested the possibility of functional coupling between these two K+ flux pathways. Indeed, extracellular recordings of Drosophila CNS showed pre-block of Kir channels prior to block of KCC led to a significant (P < 0.001) increase in CNS firing rates over baseline that when taken together, supports functional coupling of Kir to KCC function. Additionally, we documented a synergistic increase to toxicity of VU0463271, an established KCC inhibitor, above the expected additive toxicity after co-treatment with the Kir inhibitor, VU041. These data expand current knowledge regarding the physiological roles of KCC and Kir channels in the insect nervous system by defining additional pathways that facilitate inhibitory neurotransmission through GGCC.