Archives of Toxicology最新文献

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.

Human in vitro liver tissue models have evolved to maintain hallmarks of hepatocellular function for extended periods with potential to model aspects of cholestasis for drug and chemical safety applications. Microphysiological systems (MPS) have been suggested as promising new approaches to model liver physiology and predict chemical-induced cholestasis in humans. This study comprehensively compared both basal function and toxicant-induced effects in 2D cultures and three liver MPS (i.e., 2-lane OrganoPlate, 3-lane OrganoPlate and PhysioMimix LC12) that were seeded with either HepaRG cells, primary human hepatocytes (PHH), or human induced pluripotent stem cell (iPSC)-derived hepatocytes. PHH and iPSC-derived hepatocytes (iHeps) were tested up to 7 days while HepaRG were evaluated over 30 days. Albumin, urea, CYP3A4 activity, and bile acids were measured. HepaRG and PHH showed comparable function in 2D and PhysioMimix LC12, with albumin higher for HepaRG and urea higher for PHH. HepaRG maintained production of biomarkers for up to 30 days in both 2D and PhysioMimix LC12. In both OrganoPlate models, HepaRG produced higher levels of albumin and urea as compared to iHeps; still, HepaRG function in OrganoPlate was lower than that in 2D or PhysioMimix LC12. Bile acid synthesis (after 7 days) was much higher with PHH in the PhysioMimix LC12 as compared to 2D PHH or 2D HepaRG. Upon exposure to cholestatic agents (bosentan, 2-octynoic acid, α-naphthyl isocyanate), robust CYP3A4 induction was observed in HepaRG and PHH treated with bosentan and α-naphthylisocyanate. Only in PhysioMimix LC12, both HepaRG and PHH, all compounds elicited decreased bile acid release into cell culture medium, a biomarker for cholestasis. In summary, the hepatocyte functional markers (CYP3A4, albumin, urea) were comparable between PHH and HepaRG in 2D and PhysioMimix LC12 MPS. However, the effects of cholestatic agents on PHH and HepaRG, specifically, bile acid release were detected only in the PhysioMimix LC12 with PHH showing more consistent responses compared to HepaRG.

Healthy maternal metabolism is critical during pregnancy and lactation to support fetal development and protect against environmental toxins. Polychlorinated biphenyl 11 (PCB 11), a lower-chlorinated, non-legacy congener, is detected in human serum, including pregnant women and children; however, its impact during these sensitive life stages remains poorly understood. This study presents the first comprehensive hepatic proteome analysis of mouse dams exposed to PCB 11 during pregnancy and lactation. Female C57BL/6 J mice received daily oral doses of PCB 11 (0, 1.0 or 6.0 mg/kg) prior to conception through lactation. At postpartum day 21, brain, liver, and serum samples were analyzed for PCB 11 and its metabolites, and hepatic proteomic changes were assessed. Low detection of PCB 11 and its metabolites was observed in tissues, suggesting rapid clearance. Metabolite screening revealed OH-PCB 11, PCB 11 sulfate, and OH-PCB 11 sulfate metabolites in serum. Global proteomics identified significant alterations in hepatic protein expression, including downregulation of cytochrome P450 enzymes, solute carriers, and enzymes involved in fatty acid and steroid metabolism. Pathway enrichment analyses indicated disruptions in xenobiotic metabolism and endocrine pathways. These findings suggest that PCB 11 exposure during pregnancy and lactation impairs hepatic detoxification and metabolic capacity, potentially compromising maternal and offspring health. This work highlights the need for further investigation into the long-term consequences of PCB 11 exposure during pregnancy and lactation.

Snake envenomation, a neglected tropical disease, presents complex and species-dependent systemic pathophysiology. Here, we conduct an integrated proteomic and in vivo toxicological assessment of venoms from ten medically significant Chinese snakes. Our proteomic analysis delineated the venom composition of the ten snake species. Viperidae venoms were rich in snake venom metalloproteinases and phospholipase A₂, consistent with their hemorrhagic and myotoxic effects, while elapidae venoms were dominated by three-finger toxin and phospholipase A₂. Furthermore, we identified that the colubrid Rhabdophis tigrinus possesses a unique venom arsenal primarily composed of three-finger toxin (33.1%) and phospholipase A₂ (30.8%). In vivo toxicity assessment in mice via four administration routes (subcutaneous, intramuscular, intraperitoneal, intravenous) demonstrated that venom lethality was highly route-dependent, with elapid venoms (particularly Bungarus multicinctus, intravenous median lethal dose = 0.16 mg/kg) being an order of magnitude more potent than viperid venoms. Notably, the injection route critically modulated the toxicological manifestations; for instance, intramuscular injection accentuated local tissue damage, while intravenous injection exacerbated coagulopathy. This multi-omics study systematically links the specific toxin arsenals of these ten venoms to distinct pathological phenotypes observed via different clinically relevant routes, providing a valuable resource for understanding venom toxicity mechanisms and guiding clinical management of snakebite.

Branched polyethyleneimine (BPEI) is a cationic polymer widely utilized in household products (e.g., fragrances, antimicrobial sprays, and deodorants) due to its unique physicochemical properties, such as cationic nature, hydrophilicity, and strong adsorption capacity. Despite its broad utility, concerns regarding its biodistribution and potential toxicity remain unresolved. In this study, we employed positron emission tomography (PET) imaging with ⁶⁴Cu-labeled-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetracetic acid (DOTA)-conjugated BPEI (⁶⁴Cu-DOTA-BPEI) to evaluate the biodistribution and pulmonary toxicity of BPEI in rats following intratracheal instillation. Quantitative biodistribution analyses and PET imaging showed that ⁶⁴Cu-DOTA-BPEI deposited in the lung at 37 MBq/rat exhibited high pulmonary retention, with about 65% initial dose at 72 h post-instillation. BPEI deposited in the lung showed limited clearance after systemic absorption, with the hepatobiliary system being the primary route, accounting for about 10-20% cumulative clearance up to 72 h. BPEI at 24 h post-instillation (15, 30, 60, and 90 µg/rat) produced a dose-dependent acute lung inflammation, characterized by neutrophilia and eosinophilia. Although inflammation reactions were resolved by 14 days after a single instillation, its long retention in the lung and high cytotoxic potential imply that repeated exposures can cause chronic lung diseases. These findings highlight the need for careful safety evaluation of household products containing BPEI, especially when inhaled as aerosols, due to its prolonged pulmonary retention and high cytotoxic potential.