Archives of Toxicology最新文献

This Letter to the Editor addresses the recent step by the International Agency for Research on Cancer (IARC) to reclassify pure talc from Group 2B "Possibly carcinogenic to humans" to Group 2A "Probably carcinogenic to humans". This change was made by IARC not based on any new data, but by reassessing previous studies, including an inhalation study on rats and mice performed in the 1980s under the auspices of the National Toxicology Program (NTP). The NTP study, however, found evidence of tumorigenicity in rats only, but not in mice. This contradicts the toxicological principle of "at least two species" for extrapolating carcinogenicity status from animals to humans. Benign and malignant pheochromocytoma, a rare condition identified in the adrenal medulla of rats in multiple NTP studies, played a special role in the IARC talc reclassification, being evaluated as the "unusual" finding requiring a precautionary approach. The Letter argues that combined benign, malignant, and complex pheochromocytoma in rats is irrelevant for the assessment of talc carcinogenicity in humans. However, with the exclusion of pheochromocytoma argumentation, the need for talc reclassification appears to be highly questionable.

Scorpion venom contains a diverse array of bioactive compounds, including peptides, proteins, enzymes, and alkaloids, which hold significant medicinal potential despite their toxicity due to interactions with voltage-gated sodium, potassium, and calcium channels affecting the autonomic nervous system. A comprehensive study analyzing literature from esteemed scientific databases (2000-2025) evaluates the structural and functional properties of these venom components. Enzymes and proteins exhibit anticancer properties through apoptosis induction, angiogenesis inhibition, and immune modulation, while ion channel modulators show promise in treating neurological disorders, pain, and cardiac arrhythmias. Antimicrobial peptides demonstrate high efficacy against multidrug-resistant (MDR) bacteria. Certain alkaloids also offer antioxidant and immunoregulatory benefits. A pioneering study on advanced nano-systems derived from scorpion venom has highlighted their potential to enhance drug delivery and therapeutic efficacy. Translational promise is further supported by advancements in recombinant expression, structure-activity relationship investigations, and innovative delivery strategies, despite challenges such as toxicity and stability. Scorpion venom thus represents a rich source of compounds with significant medicinal and biological applications.

The development of reliable predictive models for nephrotoxic agents remains a critical challenge in drug development, given safety concerns associated with kidney toxicity. Conventional molecular descriptors generally fail to capture essential spatial and electronic features necessary for accurate nephrotoxicity prediction, underscoring the need for novel descriptor approaches. This study presents a novel projection-based method for nephrotoxicity prediction by converting chemical structures into 2D maps for deep learning via 3D spatial transformation to enhance both feature representation and model performance. Both Mollweide and Equirectangular projections were utilized to transform 3D molecular geometries into optimized 2D representations. The 2D molecular maps incorporated three key molecular properties to display the information of atom-based projections showing atomic positions and identities, electrostatic projections visualizing charge distribution, and vdW projections illustrating molecular steric potentials. The Mollweide projection based on atom color demonstrated superior predictive performance, achieving 83% predictive accuracy with an AUC of 0.86, establishing it as the most effective CNN model. The electrostatic and vdW projections transformed atomic spatial data into electrostatically and sterically informative maps, enabling more nuanced molecular pattern recognition and enhanced representation. The reliability of the model was validated through different methods, including independent verification on test set combined with five-fold cross validation as well as comparisons with traditional descriptor-based models using the benchmarking method. Our findings demonstrate that projection-based molecular representations show strong potential for nephrotoxicity screening, opening new possibilities for toxicology prediction and drug safety advancement.

Phencyclidine (PCP), historically known as "angel dust," and its analogues (3-HO-PCP, 3-MeO-PCP, 4-MeO-PCP, 3-HO-PCE, 3-MeO-PCE, 4-MeO-PCE) are dissociative new psychoactive substances with high abuse potential and limited experimental safety data. An integrated in silico workflow (STopTox, admetSAR 3.0, ADMETlab 3.0, ACD/Labs Percepta, Toxtree, ProTox 3.0, OCHEM, TEST, VEGA QSAR) was applied to profile acute toxicity and key hazard domains. Across platforms, rat oral LD₅₀ values for PCP-type analogues were consistently in the ~ 200-630 mg/kg range (Percepta 210-800 mg/kg, TEST 197-628 mg/kg, VEGA 278-368 mg/kg, ProTox ~ 348-404 mg/kg), indicating moderate acute toxicity by the oral route; substantially lower LD₅₀ values were predicted for intravenous exposure in mice (~ 25-59 mg/kg). Qualitative models (STopTox, ADMETlab, admetSAR) classified all compounds as acutely toxic by the oral route (e.g., STopTox oral toxicity confidence ~ 77-92%) and commonly predicted inhalation/dermal risks depending on the analogue; admetSAR assigned EPA Category III for acute oral toxicity. Organ-specific effects (Percepta; ADMETlab) highlighted the lungs, liver, and blood as prominent targets (e.g., lungs 0.89-0.93, liver up to 0.91, blood up to 0.85), with gastrointestinal involvement (up to 0.82) and generally lower kidney probabilities (~ 0.09-0.70). Cardiotoxicity signals included predicted hERG inhibition with Percepta IC₅₀ ~ 4.9-12.3 µM and high probabilities of hERG blockade in ADMETlab/admetSAR, supporting potential QT-prolongation risk. Genotoxicity predictions were consistently negative across Percepta, OCHEM, ADMETlab, admetSAR, and VEGA. Eye/skin irritation potential was notable for phenolic analogues, with Percepta indicating high probabilities for 3-HO-PCP and 3-HO-PCE (eye ~ 88-90%, skin ~ 96%), while other tools showed model-dependent variability. Endocrine screening suggested at most weak-to-moderate ER-α interactions, with the highest probability for 3-HO-PCP (LogRBA >  - 3). Overall, convergent multi-tool evidence indicates moderate acute toxicity, cardiotoxicity signals, and multi-organ risk for PCP analogues, while mutagenicity appears unlikely. These results provide mechanistic and quantitative context to inform clinical management, forensic interpretation, and risk assessment of this NPS class.

Triclosan (TCS), a broad-spectrum lipophilic antiseptic, is frequently found in household and healthcare supplies. Its increased use during the COVID-19 pandemic has led to significant accumulation in soil and aquatic environments. In humans, TCS predominantly accumulates in the liver, while little is known about the molecular processes promoting TCS-induced hepatic damage. Adverse outcome pathways (AOPs) offer a structured toxicological framework linking molecular initiating events to adverse health outcomes. To examine how TCS exposure relates to liver fibrosis, we developed an AOP framework and established an offspring rat model subjected to lifelong TCS exposure. Through the milk and placenta, the offspring rats were exposed to TCS. After weaning, they received 0, 10, and 50 mg/kg doses until day 60. Our findings indicate that lifelong TCS exposure increased hepatic transforming growth factor-β (TGF-β1) levels and then modulates the advanced glycation end products (AGEs) and their receptor (RAGE) pathway (AGEs-RAGE pathway) to promote collagen production, causing extracellular matrix deposition and hepatic fibrosis. The reliability of the AOP framework was validated by the significant decrease in the markers linked to fibrosis-related expression following this two-part inhibition. This framework received a "high" rating based on the Organization for Economic Cooperation and Development (OECD User Manual) assessment guidelines, by integrating this framework with in vitro and in vivo experiments. These findings offer a basis for future risk assessment and therapeutic strategies targeting TCS-induced liver fibrosis.

Desalkylgidazepam, an active gidazepam metabolite, first appeared on the illicit drug market in 2022 and has been detected in polydrug intoxication cases. Since both benzodiazepines and their metabolites can result from gidazepam metabolism, it is important to identify markers that specifically indicate consumption of each compound. We therefore investigated the human metabolism of gidazepam and desalkylgidazepam by incubating them with human hepatocytes and analyzing the resulting samples, along with human blood from a confirmed desalkylgidazepam-positive case, using liquid chromatography-high-resolution mass spectrometry. To further assess their pharmacological profile, we examined the activity of gidazepam, desalkylgidazepam, and their potential (3R)- and (3S)-hydroxy metabolites at γ-aminobutyric acid A (GABA_AR) and 18 kDa translocator protein (TSPO) receptors in silico, using AutoDock Tools and UCSF Chimera. Gidazepam was metabolized through N-desalkylation (yielding desalkylgidazepam), N-acetylation, and N-glucuronidation. Conversely, desalkylgidazepam was subjected to hydroxylation and subsequent O-glucuronidation reactions. Notably, gidazepam demonstrated a lower affinity at GABA_AR's prominent α₁/γ₂ site compared to desalkylgidazepam and its (3R)- and (3S)-hydroxy metabolites. However, its interaction with the transmembrane domains of the α₁β₂ subunit may account for its anxiolytic effects. For the TSPO receptor, gidazepam and 3-hydroxy desalkylgidazepam metabolites showed higher binding affinity, whereas desalkylgidazepam did not bind to TSPO. Our findings suggest blood markers specific to gidazepam, namely gidazepam-N-glucuronide and N-acetyl gidazepam, are essential for confirming gidazepam consumption. In addition, in silico modelling supports the hypothesis that gidazepam functions as a prodrug via GABA_AR and as an agonist at TSPO. Further research is necessary to clarify designer benzodiazepine activity at TSPO.

Fluoride plays a dual role in dental health-preventing caries at optimal levels but causing fluorosis when excessive. While most animal studies focus on young mice, age-related susceptibility to fluoride remains poorly understood. This study presents the first comprehensive analysis of developmental stage-dependent differences in fluoride toxicity, focusing on enamel formation and systemic fluoride clearance. Male C57BL/6J mice-adolescent (5-9 weeks) and mature (16-20 weeks)-were exposed to fluoride in drinking water (0, 50, 100, or 125 ppm) for 6 weeks. Adolescent mice developed pronounced dental fluorosis, characterized by chalky white incisors, elevated Quantitative Light-induced Fluorescence (QLF) values, reduced enamel microhardness, and lower enamel mineral density (EMD). Histological analysis revealed disrupted ameloblast morphology, reduced KLK4 expression, and aprismatic enamel, with more severe effects in adolescents. In contrast, mature mice exhibited minimal changes in QLF, enamel hardness, and EMD. Systemic fluoride analysis showed significantly lower serum and urinary fluoride levels in adolescent mice compared to mature mice, indicating reduced excretion and increased tissue accumulation. These findings demonstrate that younger mice are more vulnerable to fluoride-induced enamel defects due to lower clearance than mature mice. This study provides critical evidence of age-related differences in fluoride toxicity, revealing heightened vulnerability during developmental stages. Our findings have significant public health implications, supporting the need for age-specific fluoride exposure guidelines to balance caries prevention and developmental fluoride toxicity.

Drug biotransformation and bioactivation play a pivotal role in drug discovery, driving the development of analytical methods to investigate xenobiotic metabolism. However, the identification of drug metabolism products (i.e., drug metabolites) remains challenging. Drug metabolites are difficult to predict, and they are often missed without prior knowledge of the drug's metabolic fate. Untargeted approaches overcome this requirement, but demand strategies for metabolite identification. In this study, we developed a computational workflow, using high resolution LC-MS/MS metabolomics data, integrating BioTransformer and SIRIUS for the prediction and putative identification of drug metabolite structures. We challenged our workflow to the analysis of human metabolites from 6 well-known drugs, administered to primary human hepatocytes and human liver microsomes: amitriptyline (10 µM), carbamazepine (12.5 µM), cyclophosphamide (20 µM), fipronil (20 µM), phenytoin (50 µM), and verapamil (6 µM). Of the drugs' metabolites, 62-100% were found using this computational approach. Furthermore, 4 new metabolite structures (1 amitriptyline metabolite and 3 verapamil metabolites) were proposed using de novo predictions in SIRIUS. This strategy proved efficient in accelerating the study of drug metabolism, potentially avoiding tedious manual metabolite identification. In sum, we demonstrate that this computational workflow holds potential in automating metabolite identification, expanding metabolite coverage, and elucidating metabolites of newly developed drugs.

FOXN family genes (FOXNs) have a significant role in the progression of various malignancies; nevertheless, the relationship between their genetic variations and the risk of bladder cancer is yet insufficiently comprehended. This study included 580 bladder cancer patients and 1,101 healthy controls, evaluated for 8,695 single nucleotide polymorphisms (SNPs) in FOXNs. The rs10484024 T > C variant in FOXN3 was identified as a significant risk factor for bladder cancer (OR = 1.18, 95% CI: 1.02-1.36, P = 2.72 × 10^- 2). Further investigation reveals a strong interaction between this locus and smoking (P_interaction = 3.50 × 10^- 2), and bladder cancer risk is much higher in smokers carrying the C allele (OR = 1.93, 95% CI: 1.39-2.71, P = 1.13 × 10^- 4). Functional annotation results suggest that rs10484024 is likely reducing FOXN3 expression by affecting the remote regulation of RNA-binding protein binding sites and enhancers/promoters. The TCGA study, in conjunction with GSE3167, confirmed that the dysregulation of FOXN3 expression was associated with altered mutation frequency in KMT2C somatic cells and the modulation of cell cycle-related pathways. The data suggest that rs10484024 may promote bladder cancer by regulating FOXN3 expression and worsening cell cycle dysregulation and somatic mutation accumulation. This study established, for the first time, an association between genetic variation in the FOXN3 gene and bladder cancer risk, demonstrating a substantial interaction with smoking, suggesting that FOXN3 may serve as a novel biomarker and intervention target for bladder cancer.