Frontiers in toxicology最新文献

Introduction: Essential oils (EO), rich in bioactive metabolites with biocidal activity, present great potential for agricultural applications as new biopesticides. However, their high volatility and sensitivity to environmental conditions limits their application. To address these limitations, nanotechnology-based formulations have been developed, incorporating EO into natural clays such as montmorillonite (MMT). Due to its colloidal properties, high adsorption capacity, and modifiable surface, MMT serves as an effective carrier for stabilizing EO while controlling their release. Besides aiming to enhance EO efficacy, these MMT-based formulations also aim to minimize EO toxicity to non-target organisms.

Materials and methods: In this study, the toxicity of Satureja montana EO (SM EO), of its dispersant agent Tween 20^®, of the MMT nanoclay and of the nanoclay-EO formulation was evaluated using aquatic (Aliivibrio fischeri, Raphidocelis subcapitata, Lemna minor and Daphnia magna), and terrestrial (Folsomia candida and soil microbiota) non-target model organisms, following standard protocols.

Results: Among the tested species, R. subcapitata and D. magna, exhibited the highest sensitivity, with D. magna showing an EC₅₀ of 0.011 mg mL^-1 and a complete growth inhibition being observed for R. subcapitata at concentrations ≥0.021 mg mL^-1, for the nanoclay-EO formulation. F. candida reproduction was also significantly reduced for all tested concentrations of the nanoclay-EO formulation. In contrast, it was observed a stimulatory effect on soil microbial activity particularly for dehydrogenase and acid phosphatase enzymes.

Discussion: These findings suggest that the nanoclay-EO formulation did not reduce the toxicity of SM EO, and in some cases, may even raise ecotoxicological concerns, particularly for aquatic and soil invertebrates. This study highlights the importance of detailed ecotoxicological evaluations of biopesticide formulations based on plant-based and materials as essential oils, and other natural materials, as they cannot be assumed as safe compounds. To the best of our knowledge ecotoxicological data is limited for most of the EO including some that already in the market. Based on these results, the concentrations to be tested for efficacy against target organism (safe to non-target organism) should be lower than 0.007 mg mL^-1.

New approach methodologies (NAMs) aim for animal-free chemical risk assessments. However, many in vitro NAM models still depend heavily on Matrigel and collagen despite the ethical, reproducibility, and biomedical concerns regarding the use of animal-derived materials. As awareness regarding this problem grows, several animal-free extracellular matrix hydrogel alternatives have emerged in the market. However, NAM studies with alternative hydrogels are rather scarce. The present study provides a concise review of commercially available animal-free hydrogels as well as an experimental screening approach to identify biocompatible candidates for HepaRG cell culturing under static and dynamic conditions in a 96-well plate and an OrganoPlate 3-lane device (Mimetas B.V.), respectively. The hydrogels evaluated herein include PeptiMatrix Core and PuraMatrix as synthetic peptides, VitroGel Organoid-3 as a synthetic polysaccharide, GrowDex as a wood-derived polysaccharide, and a Matrigel-collagen mix as the animal-derived reference. The health and functionality of the HepaRG cells were assessed via viability, lactate dehydrogenase leakage, albumin and bile acid secretion, CYP3A4 enzyme activity, and gene expression analyses. All animal-free hydrogels tested herein supported HepaRG cell proliferation in both culture conditions, although the cells had inadequate structure support and exhibited lower hepatic synthetic capacity in the OrganoPlate microphysiological system device. Notably, the cells grown in PeptiMatrix 7.5 showed promising metabolic competence under perfusion, making it a potential candidate for xenobiotic metabolism studies after further optimisation. These findings serve as a starting point to encourage scientists to take steps towards more animal-free cell culturing.

Botanicals (e.g., extracts derived from plants, algae, or fungi) are increasingly utilized by consumers with the hope of enhancing their health, managing symptoms, or preventing ailments; however, these products have often had limited pre-market toxicity testing. Traditional toxicity testing (e.g., rodent testing) is complicated by the nature of botanicals as complex mixtures and the potential for lot-to-lot variability in chemical constituents. Cardiotoxicity is a key area of concern, as adverse effects on the cardiovascular system can have severe consequences, and although not commonly reported, there have been reports of adverse cardiac events. New approach methodologies (NAMs) offer human-relevant, efficient, innovative, and cost-effective solutions for evaluating the cardiotoxicity of botanicals. The Botanical Safety Consortium (BSC) was established to focus on identifying suitable NAMs to screen for potential toxicities associated with these widely used products. This manuscript outlines the BSC Cardiotoxicity Working Group's approach for evaluating NAMs for assessing the potential cardiotoxicity of botanicals. These NAMs leverage in vitro models, such as human-induced pluripotent stem cell-derived cardiomyocytes, and techniques like microelectrode arrays, voltage and calcium optical mapping, contractile force measurement, and mitochondrial function assays to evaluate botanical-induced effects on the cardiovascular system. Using well-characterized botanical extracts as case studies, the BSC aims to refine a toolkit for high-throughput and human-relevant cardiotoxicity screening. This foundational work supports the broader goal of improving botanical safety assessment practices and advancing the application of NAMs in regulatory toxicology.

Hericium erinaceus (Lion's mane) and Trametes versicolor (Turkey Tail) mushrooms have an extensive history of use in traditional medicine and as food. Oftentimes, they are available as extract preparations produced from selected life stages such as fruiting body or mycelium. Their composition may vary based on where they are grown and the conditions of post-harvest preparation. Despite their widespread traditional use and popularity, comprehensive toxicological assessments, particularly of whole mushroom powders, remain limited. This study was conducted to evaluate whether the commercially available Organic Lion's Mane M2-102-10 powder (H. erinaceus mycelial biomass and fruiting body cultured on oats) and Organic Turkey Tail M2-101-03 powder (Trametes versicolor mycelial biomass and primordia cultured on oats) cause acute toxicity, subchronic toxicity, and genotoxicity in rats. The tests were carried out in accordance with OECD guidelines. The results demonstrated that both Organic Lion's Mane M2-102-10 powder and Organic Turkey Tail M2-101-03 powder did not induce acute toxicity, showed no evidence of subchronic oral toxicity in rats at doses up to 2000 mg/kg body weight/day, and exhibited no genotoxicity in either in vitro or in vivo assays.

Introduction: Plant cell culture (PCC) technology is currently being developed to produce plant foods partially decoupled from traditional agriculture practices. By now, the safety of the ingredients produced by PCC technology for food or nutritional purposes has to be tested.

Materials and methods: In this study, the oral safety and toxicity of two novel PCCs, scurvy grass (SG) (Cochlearia danica) and rowan (RW) (Sorbus aucuparia), and to characterize the macro- and micronutrient quality, including proteomic profiles, to identify potential allergens.

Results: Nutritional composition analysis showed that both SG and RW PCCs profiles are comparable to other berry cell lines with a good amount of protein, dietary fibre and vitamins. Potential allergens were identified via proteomics based on structural similarity. The acute and subacute toxicity profiles of the PCC samples were evaluated based on OECD guidelines. For both PCCs, no deaths, behavioral changes, nor metabolic effects were observed at 2000 mg/kg. In the 28-day repeated oral exposure subacute toxicity study, no mortality or significant adverse clinical, hematological, or metabolic effects were observed for either SG or RW.

Discussion: These findings indicate that the no-observed-adverse-effect level (NOAEL) for both PCCs exceeds 2000 mg/kg. Overall, our findings indicate that the consumption of these PCCs could be considered safe and non-toxic, although further assessments on potential allergens and phytohormone accumulation are necessary to fully ensure consumer safety. This study highlights the oral safety of PCCs for consideration as a novel food ingredient and serve as a basis for evaluating toxicological impacts of PCCs.

Introduction: Microcystins (MCs) are alarming aquatic contaminants having extensive health implications in fish. Despite growing concern, comprehensive studies on long term effects of MCs remain unexplored in Labeo rohita (rohu). This study aims to bridge the gap by investigating the pathophysiological effects of long-term sublethal exposure to microcystin-LR (MC-LR), the most toxic congener.

Methods: Healthy rohu juveniles (mean weight 25 ± 2.1 g), sourced from institute farm were acclimatized for 2 weeks. The sublethal experimental study consisted of two treatments (control group: T0 and one-tenth 96 h-LD₅₀ dose group: T1) in three replications (10 fish per tank). The toxic effects were examined after 90 days by analysing histomorphology, ultrastructure, oxidative stress level, serum biochemistry, and the gene expression levels of antioxidant enzyme [superoxide dismutase (SOD) and catalase], immune-related (lysozyme, and immunoglobulin M), pro-inflammatory cytokine (interleukin-1β), apoptosis (caspase 9) and detoxification enzyme [phase I: CYP1A and CYP3A; phase II: glutathione-S-transferase (GST)] genes following standard analytical methods. Statistical analysis was performed using SPSS v. 22.0, IBM software. Parameters were analysed using an unpaired t-test. The results were expressed as mean ± standard error (SE).

Results: MC-LR induced significant histological and ultrastructural alterations including vacuolation, hepatocyte degeneration, disintegration of heterochromatin, loss of nucleolus and mitochondrial swelling. It significantly (p-value <0.05) altered the immune and serum biochemical indices. Interestingly, the modulation in the expression of SOD, catalase, GST, CYP1A and CYP3A genes in different organs indicated their involvement in the antioxidant and detoxification process. A significant upregulation of GST expression in all organs signifies its potential as a prominent biomarker other than phase I enzymes.

Discussion: Based on these findings, it is deduced that even sublethal levels of MC-LR can disrupt intrinsic antioxidant defences, immune responses, and detoxification mechanisms in rohu, potentially compromising fish health in natural ecosystems. This is the first report to detail long-term impacts in rohu, elucidating the mechanism of damage induced by MC-LR and also providing valuable insights for environmental monitoring and toxin management.

Introduction: Shark and ray species are particularly vulnerable to pollutant bioaccumulation, including metals and metalloids, due to their k-strategist characteristics and mid-high trophic level. The angular angelshark (Squatina guggenheim) is a benthic and highly endangered species distributed from southeastern Brazil to southern Argentina. Despite being threatened with extinction and banned from marketing and consumption in Brazil, it is still widely consumed in several states. However, studies addressing metal and metalloid contamination in the meat of this species have not yet been conducted in Brazil.

Objectives: This study aimed to determine metal and metalloid contamination levels in S. guggenheim and to assess human health risks associated with its consumption by infants, children, teenagers, and adults, considering consumption frequencies ranging from one to five times per week.

Results: etal and metalloid concentrations in muscle tissue were generally lower than those reported for other benthic Squatinidae species, except for Pb and Rb. Several elements were reported for the first time in this species, providing baseline data. Although a favorable Se:Hg balance suggested a potential protective effect, multiple toxic and potentially toxic elements were detected, posing significant human health risks, particularly for infants and children. Arsenic concentrations exceeded Brazilian safety limits, while Ti and Rb were present at relatively high levels, despite the absence of established regulatory thresholds. Estimated intake values and non-carcinogenic risk indices (THQ and HI) surpassed safety limits for As (notably the inorganic As 10% fraction), Cu, MeHg, and Se in different scenarios, with As exceeding the acceptable threshold by up to 415 times, even under low-frequency consumption. Carcinogenic risk (CR) estimates indicated concerning levels for As and Pb across age groups.

Conclusions: The results highlight significant human health risks associated with the consumption of S. guggenheim, particularly for vulnerable populations such as infants and children. These findings highlight the urgent need for continuous monitoring of benthic elasmobranchs and reinforce caution regarding their consumption.

Agrichemicals such as herbicides, fungicides, insecticides, and biocides are widely used in agriculture, yet some are associated with adverse effects in humans and the environment. While many of these chemicals have been extensively studied in vitro and are included in the EPA's ToxCast program, comprehensive in vivo comparisons using RNA sequencing across structurally diverse agrichemicals, in a single screening platform, are lacking. In this study, we examined structurally diverse agrichemicals found in the U.S. Environmental Protection Agency's (EPA) Toxcast Phase I and II library by statically exposing early life stage zebrafish at 6 h post fertilization (hpf) until 120 hpf at concentrations ranging from 0.25 to 100 µM. Morphological outcomes were assessed at 120 hpf across 10 endpoints, including yolk sac edema, craniofacial malformations, and axis abnormalities. Chemicals that produced robust concentration-response relationships were selected for transcriptomic profiling. For transcriptomic analysis, zebrafish were statically exposed to each chemical and sampled at 48 hpf, prior to the onset of morphological effects observed at 120 hpf. Differential expression analysis identified between 0 and 4,538 differentially expressed genes (DEGs) per chemical, with no clear correlation to morphological severity. Both DEG and co-expression network analyses revealed chemical-specific expression patterns that converged on shared biological pathways, including neurodevelopment and cytoskeletal organization. Key regulatory genes such as mylpfa and krt4 were identified within co-expression modules, suggesting their potential role in conserved toxicity mechanisms. Semantic similarity analysis of enriched gene ontology (GO) terms, when compared to existing datasets, highlighted gaps in the annotation of neurodevelopmental processes, indicating that some in vivo effects may not be fully captured by current curated resources. The results provide new insights into the modes of action of diverse agrichemicals and establish a framework for understanding how agrichemical structure relates to biological function in a vertebrate model.

Introduction: The frequency of cyanobacterial blooms seems to have increased globally in recent decades due to human induced eutrophication and climate change. Cyanobacterial blooms can produce several groups of toxins, among which microcystin-LR (MC-LR) is one of the most abundant. Effects of MC-LR on avian microbiome have not been studied and studies in laboratory murines have been limited to metabarcoding of prokaryotes.

Methods: Using RNA shotgun sequencing, we compared the richness and composition of metabolically active prokaryotes, expressed virulence factors, antimicrobial resistance genes, metabolic pathways, Gene Ontology terms, enzymes, and proteins in mallards (Anas platyrhynchos) that were orally exposed to a sublethal dose of MC-LR for one week and unexposed birds.

Results: Richness and composition of all compared features did not differ between exposed and control birds and none were differentially expressed between exposure groups. However, richness and/or composition of all features except virulence factors and Carbohydrate Active enzymes had multiple-fold greater dispersion in exposed birds than in controls. This effect was especially pronounced in expressed metabolic (MetaCyc) pathways.

Discussion: Our results suggest that MC-LR exposure had a stochastic (rather than deterministic) effect on cecal microbiota, especially its function. Observed disturbance of the microbiota homeostasis is consistent with the Anna Karenina Principle. This principle has been documented in a wide range of eukaryotes using primarily microbial community metabarcoding. Although stochastic disturbance of microbiota function has been hypothesized, our study seems to be the first to demonstrate this in an experimental study.

Introduction: Iron oxide nanoparticle formulations are widely used in clinical applications and have recently been explored for hyperthermia therapy, cancer imaging and treatment. Here, we report the effects of intravenously injected pegylated or poly acrylic acid decorated iron oxide nanoparticles coated with hydroxyethyl starch (HES) on host immune system and organs. These particles were compared with sucrose coated iron oxide nanoparticle (Venofer^®) and the coating compound HES-both FDA approved agents-alongside non-iron oxide polystyrene nanoparticles coated with HES (micromer^®).

Methods: Toxicity analysis was performed in healthy female normal FVB/NJ mice 60 days after nanoparticle injection, with complete blood analysis conducted at multiple time-points. In a separate cohort, nanoparticle biodistribution 24 h post-intravenous injection was evaluated using a HER2 overexpressing breast cancer mouse model.

Results: Toxicity analysis revealed no adverse effects on liver or kidneys with any of the tested formulations after 60 days. Immune cell perturbations were observed at early time points following iron oxide nanoparticle injection but normalized by the study endpoint. Biodistribution analysis demonstrated that the nanoparticle coating dictated their accumulation across various organs, with significant tumor accumulation observed for pegylated iron oxide nanoparticles and Venofer^®.

Conclusion: Iron oxide nanoparticle formulations exert a transient effect on the host immune system and some exhibit tumor accumulation, suggesting their potential for further development in cancer imaging and treatment.