Search Results (165)

Alternaria mycotoxins represent a significant and emerging concern in the field of food safety due to their widespread occurrence in diverse food and feed commodities, including cereals, tomatoes, oilseeds, and dried fruits. Among these, alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and altertoxin-I (ATX-I) are the most frequently detected, often co-occurring at varying concentrations, thereby increasing the complexity of exposure and risk assessment. The gastrointestinal tract (GIT) is a crucial target of these toxins, as well as the liver, particularly considering its detoxifying role. Nevertheless, despite being a source of possible gastrointestinal and hepatic toxicity, there is still scarce data on the toxicokinetics of Alternaria toxins, on their mode of action, and respective toxic effects. To date, in vitro studies have shown that different Alternaria mycotoxins exhibit diverse toxicological effects, which may be dependent on their chemical structure. AOH and ATX-I have shown genotoxicity and cytotoxicity, mainly through interaction with the DNA and apoptosis, respectively. Tentoxin (TEN) has displayed hepatotoxic potential via impairment of detoxification pathways, and altenuene (ALT) has revealed lower toxicity. In vivo, AME and ATX-II revealed genotoxicity, while AOH and ATX-I showed context-dependent variability in their effects. Altogether, this review emphasizes that there is still a great lack of knowledge on these mycotoxins and an urgent need for more comprehensive toxicological and occurrence data to support proper risk assessment and, ultimately, regulatory decision-making. Full article

Aristolochic acid I (AAI) is widely recognized as a genotoxic and cytotoxic compound. To rationally propose detoxification strategies, it is essential to fully elucidate the in vivo disposition of AAI. Nevertheless, the toxicokinetic characteristics of AAI, particularly the possible involvement of the recirculation process, remain incompletely understood. In this research, toxicokinetics of AAI was studied following a single oral administration of AAI in Fisher rats (10, 30 and 100 mg/kg, n = 6). A method of ultra-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS) was developed to achieve the quantitation of AAI in rat plasma. Plasma concentration–time profiles and kinetic parameters were analyzed to characterize the toxicokinetic behavior of AAI. A secondary elevation was observed in the plasma concentration–time profiles of AAI, suggesting the existence of AAI reabsorption. The non-linear elimination kinetics of AAI might be attributed to capacity-limited excretion via bile. Additionally, the biliary excretion of AAI and several key metabolites was also explored through qualitative analysis of bile samples. For the first time, AAI-O-glucuronide was identified in bile, providing further support for enterohepatic recirculation (EHR)-mediated reabsorption of AAI. In conclusion, these findings provided solid evidence for EHR-mediated reabsorption of AAI in rats. The recirculation process might be a key mechanism responsible for the prolonged retention of AAI. In the future, detoxification strategies targeting the EHR process could be effective approaches to minimize the systemic exposure of AAI. Full article

MDM hydantoin (MDMH), a formaldehyde-releasing preservative widely used in cosmetics, poses potential health risks due to its conversion to formaldehyde and systemically absorbed metabolites. Current safety assessments lack quantitative exposure data due to rapid degradation of MDMH in biological matrices. In the present study, we developed a validated LC-MS/MS assay for simultaneous determination of MDMH and its stable metabolite DMH in rat plasma, and characterized their toxicokinetics using population modeling following intravenous and transdermal administration. MDMH exhibited extremely rapid elimination (t_1/2 = 0.4 ± 0.1 min) with near-complete conversion to DMH (97.6 ± 9.6%), while DMH demonstrated prolonged retention (t_1/2 = 174.2 ± 12.2 min) and complete bioavailability (100.9 ± 18.0%) after transdermal application. Population modeling estimated that 84% (relative standard error: 42.8%) of applied MDMH undergoes cutaneous absorption and metabolism to DMH and formaldehyde within skin tissues. This study demonstrates that stable metabolite monitoring combined with population modeling enables toxicokinetic characterization of rapidly degrading compounds following dermal exposure. Full article

Background: Slow-transit constipation (STC) lacks durable and safe prokinetics. Deglycosylated-azithromycin (Deg-AZM), a novel small-molecule transgelin agonist that restores colonic motility in STC, has been approved for clinical trials in 2024. Objectives: This study aimed to assess the genetic toxicity and embryo–fetal development (EFD) toxicity of Deg-AZM through a series of standardized non-clinical safety studies. Methods: We conducted Ames, in vivo micronucleus, and chromosomal aberration tests to evaluate genotoxicity. Acute and 28-day repeated-dose oral toxicity studies were performed in Sprague-Dawley rats. EFD toxicity was assessed in pregnant rats administered Deg-AZM from gestation day (GD) 6 to 15. Toxicokinetic analyses were integrated into repeated-dose and EFD studies. Results: Deg-AZM demonstrated no mutagenic potential in the bacterial reverse-mutation assay at concentrations up to 2500 µg/plate (with metabolic activation) or 150 µg/plate (without metabolic activation). No clastogenic effects were observed in micronucleus or chromosomal aberration assays. The median lethal dose (LD₅₀) exceeded 1600 mg/kg in acute oral toxicity. In the 28-day study, no adverse effects were observed at doses up to 600 mg/kg, though mild hematological and hepatic changes were noted at high doses, all of which were reversible. In the EFD study, Deg-AZM did not induce maternal toxicity, teratogenicity, or adverse fetal outcomes at doses up to 600 mg/kg. Conclusions: Deg-AZM demonstrates a favorable safety profile with no evidence of genetic toxicity or developmental harm at pharmacologically relevant doses, supporting its further development as a therapeutic agent for STC. Full article

The present study aimed to establish a physiologically based toxicokinetic (PBTK) model to investigate the absorption, retention, and transport of inhaled nano-sized titanium dioxide (TiO₂-NPs) particles in rats, thereby providing a basis for understanding the absorption, distribution, and elimination mechanisms of TiO₂-NPs in various organs. A detailed respiratory module and the Hill coefficient equation were adopted in the PBTK model. Calibration and validation of the model were conducted using the only two available inhalation biodistribution datasets for TiO₂-NPs found in the literature, encompassing different doses and exposure conditions. The overall fit with both datasets was acceptable with R² value of 0.95 in respiratory system and 0.88 in the secondary organs. The sensitivity analysis indicated that the alveolar–interstitial transfer rate (K_{alv_inter}) and tissue–blood distribution coefficients (P_lu, P_li, P_ki) significantly influenced the retention of TiO₂-NPs in pulmonary regions and distribution to secondary organs, with these parameters exhibiting time-dependent behavior. The PBTK model demonstrates a good predictive performance for TiO₂-NPs content in all rat organs, with simulated values consistently ranging within 0.5- to 2-fold of the measured data. In last, we developed a PBTK model that can well predict the in vivo distribution of inhaled TiO₂-NPs and provided a novel computational tool for cross-species extrapolation of human inhalation exposure and subsequent biodistribution. Full article

Background: Slow transit constipation (STC) represents a refractory gastrointestinal disorder with limited therapeutic options. Deglycosylated azithromycin (Deg-AZM) is a small molecule Transgelin agonist effective against STC, which has been approved for 2024 clinical trials. Objectives: This study comprehensively evaluated the cardiac safety (hERG inhibition), acute cardiovascular–respiratory effects, and single/repeated-dose toxicity of Deg-AZM in Beagle dogs to de-risk clinical translation. Methods: Using automated patch-clamp (hERG-HEK293 cells; 0.1–1000 μM), telemetric monitoring in Beagles (3/8/24 mg/kg; Latin square design), and GLP-compliant toxicity studies (single-dose: 150–300 mg/kg; 28-day: 5–50 mg/kg/day), we assessed functional, biochemical, histopathological, and toxicokinetic parameters. Results: Deg-AZM showed negligible hERG inhibition (maximum 21.3% at 1000 μM). Transient PR prolongation (24 mg/kg; resolved by 4 h) and respiratory rate reduction (8–24 mg/kg; resolved by 2 h) occurred at supratherapeutic doses. Single-dose toxicity revealed one mortality at 300 mg/kg (acute cardiac ischemia), while 28-day studies identified fully reversible myocardial vacuolation at 50 mg/kg. Toxicokinetics demonstrated dose-proportional exposure (AUC and C_max) and low accumulation (accumulation factors ≤ 1.5). No hematological, coagulation, or hepatic toxicity was observed. Conclusions: With absent hERG liability and manageable transient physiological effects, Deg-AZM exhibited a favorable preclinical safety profile supporting its clinical development for STC. Full article

Trifluoroacetic acid (TFA) is a persistent degradation product of widely used fluorinated compounds such as hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluorocarbons (HCFCs) and hydrochlorofluoroolefins. Its chemical stability, water solubility, and environmental persistence raise concerns about potential human and ecological risks. To provide an overview of current knowledge on TFA, we conducted a literature search (PubMed and Scopus, December 2024–January 2025) focusing on its environmental fate, human exposure, toxicokinetic, ecotoxicology, and regulation. A narrative approach was applied, prioritizing recent and high-quality evidence. TFA is ubiquitous in air, water, food, and consumer products. Human exposure occurs mainly through ingestion and inhalation. It is rapidly absorbed and excreted mostly unchanged in urine, with limited metabolic transformation. Though not bioaccumulated in fat, its environmental persistence and ongoing exposure raise concerns about long-term systemic effects. Ecotoxicological data show chronic toxicity in aquatic and terrestrial species, with environmental concentrations often exceeding safety thresholds. Currently, no binding EU limit exists for TFA, although several countries have proposed drinking water guidelines. TFA represents an emerging environmental contaminant with potential human health and ecological impacts. Strengthened monitoring, long-term toxicological studies, and precautionary regulatory action are urgently needed. Full article

Per- and polyfluoroalkyl substances (PFAS) have been found worldwide in water, soil, plants, and animals, including humans. A primary route of exposure for humans and animals to PFAS is through the diet and drinking water. Perfluorooctane sulfonate (PFOS), a long-chain PFAS with a relatively long half-life, has been associated with adverse health effects in humans and laboratory animals. There are few toxicokinetic studies on PFOS in domestic livestock raised for human food consumption, which are critical for assessing human food safety. This work aimed to develop a simple daily accumulation model (DAM) for predicting PFOS residues in edible beef cattle muscle. A one-compartment toxicokinetic model in a spreadsheet format was developed using simple calculations to account for daily PFAS into and out of the animal. The DAM was used to simulate two case studies to predict resultant PFOS residues in edible beef cattle tissues. The results demonstrated that the model can reasonably predict PFOS concentrations in beef cattle muscle in a real-world scenario. The DAM was then used to simulate dietary PFOS exposure in beef cattle throughout a typical lifespan in order to derive a generic bioaccumulation factor. The DAM is expected to work well for other PFAS in beef cattle, PFAS in other livestock species raised for meat, and other chemical contaminants with relatively long half-lives. Full article

Background: Citrinin (CIT) is a mycotoxin produced by various fungi contaminating stored cereals and fruits. While biomonitoring and food occurrence data indicate widespread exposure, its public health risks remain unclear due to the lack of human toxicokinetic (TK) data. Methods: A UHPLC-MS/MS method was validated for CIT quantification in capillary blood (VAMS Mitra^® tips), feces, and urine obtaining LLOQs ≤ 0.05 ng/mL. A human TK study was conducted following a single oral bolus of 200 ng/kg bw CIT. Individual capillary blood (VAMS Mitra^® tips), feces, and urine samples were collected for 48 h after exposure. Samples were analyzed to determine CIT’s TK profile. Results: TK modeling was performed using a multi-compartmental structure with a hierarchical Bayesian population approach, allowing robust parameter estimation despite the lack of standards for CIT metabolites. Conclusions: The derived TK parameters align with preliminary human data and significantly advance CIT exposure assessment via biomonitoring. A human inter-individual toxicokinetic variability (HK_AF) of 1.92 was calculated based on the derived AUC, indicating that EFSA’s current default uncertainty factor for TK variability is adequately protective for at least 95% of the population. Full article

Cadmium is widely recognized as an important environmental toxicant that may give rise to kidney dysfunction, bone disease, and cancer in humans and animals. Kidney dysfunction occurs at very low exposures and is often considered as the most sensitive or critical effect. Cadmium exposures of concern occur in many countries. In low- and middle-income countries with small-scale mining, excessive exposure to cadmium and other metals occurs in occupational and environmental settings. This is of particular importance in view of the growing demand for metals in global climate change mitigation. Since the 1970s, the present authors have contributed evidence concerning the role of metallothionein and other factors in influencing the toxicokinetics and toxicity of cadmium, particularly as it relates to the development of adverse effects on kidneys in humans and animals. The findings gave a background to the development of biomarkers employed in epidemiological studies, demonstrating the important role of metallothionein in protection against cadmium-induced kidney dysfunction in humans. Studies in cadmium-exposed population groups demonstrated how biomarkers of kidney dysfunction changed during 8 years after drastic lowering of environmental cadmium exposure. Other epidemiological studies showed the impact of a good zinc status in lowering the prevalence of cadmium-related kidney dysfunction. Increased susceptibility to Cd-induced kidney dysfunction was shown in a population with high exposure to inorganic arsenic when compared with a group with low such exposure. Several national and international organizations have used part of the reviewed information, but the metallothionein-related biomarkers and the interaction effects have not been fully considered. We hope that these data sets will also be included and improve risk assessments and preventive measures. Full article

High-resolution accurate mass non-targeted analysis (NTA) is a useful discovery tool for metabolite characterization of in vivo dosing studies since it enables detection of both predicted and unexpected biotransformation products. We used NTA to investigate biotransformation of perfluorohexanesulfonamide (PFHxSA) in plasma and liver from male and female Sprague Dawley rats after a 5-day repeat exposure study. PFHxSA is an emerging per- and polyfluoroalkyl substance (PFAS) with unknown toxicity and a potentially reactive headgroup. NTA revealed the presence of predicted in vivo biotransformation products (BP) such as perfluorohexane sulfonic acid (PFHxS) and perfluorohexanesulfinic acid (PFHxSi). PFHxSi also has unknown toxicity and has not, to our knowledge, been previously reported as a PFHxSA BP in mammals. Multiple perfluoroalkyl ether sulfonamides, associated BPs, and novel PFAS were also detected in rat plasma and liver. We observed sex-specific distributions of the dosed compound and BPs, suggesting different toxicokinetics and biological responses. The presence of a complex mixture of predicted and unexpected PFAS in plasma and liver not only mimics the complexity of environmental exposure but also highlights the need for toxicity testing with mixtures and a more complete assessment of dosing solution purity. Full article

The development of alternative methods that link cellular and predictive toxicity to high-level toxicity is a key focus of current research within the framework of the 3Rs in animal experimentation. In this context, this study aimed to evaluate the previously developed in vitro approach using the zebrafish liver cell line (ZFL) for assessing bioaccumulation and biotransformation of the compound BDE-47, which is more hydrophobic than phenanthrene, and is the compound used in the previous study. For this purpose, experimentally, the internal concentrations in the cells (C_cell) and the exposure medium of both BDE-47 and its main metabolites were quantified at different exposure times by GC-MS. Additionally, the free bioavailable concentration (C_free) was determined with a solid-phase microextraction (SPME) experiment. With the aim of refine models, C_cell and C_free were also estimated using a predictive chemical distribution model (MBM). Bioconcentration factors (BCFs) were determined by relating all these values, as well as by toxicokinetic fitting and by in vitro–in vivo extrapolation modelling (IVIVE). The results showed a high concordance with the values obtained in vivo. Moreover, the study highlighted the importance of experimentally determining C_free and C_cell, as the predicted values can vary depending on the chemical, thereby influencing the BCF outcome. This variation occurs because models do not account for the absorption and biotransformation kinetics of the compounds. The data presented may contribute to refining predictive models. Full article

The widespread availability and pseudo-persistence of typical psychiatric pharmaceuticals (PDs) can have serious impacts on aquatic ecosystems and even human health. However, the toxicokinetics of typical PDs and the corresponding enzymatic biomarker responses are unclear. In this study, eight typical PDs [carbamazepine (CBZ), citalopram (CIT), sertraline (SER), venlafaxine (VLF), amitriptyline (AMT), chlorpromazine (CPM), quetiapine (QTP) and clozapine (CLZ)] were selected to study the uptake, depuration and biological effects of PDs in Daphnia magna. The results found that the uptake rates (K_u) were in the sequence of VLF < QTP < CBZ < CLZ < CIT < AMT < SER < CPM, while the depuration rates (K_d) were in the order of CLZ < AMT < CIT < SER < QTP < CBZ < CPM < VLF. Correspondingly, the bioconcentration factors (BCFs) followed on as VLF < QTP < CBZ < CIT < AMT < CLZ < SER < CPM. Both pH-dependent octanol–water partition coefficients (log D_ow) and liposome–water partition coefficients (log D_lip-w) exhibited positive correlations with the log BCF of PDs (p < 0.05), indicating the important roles of ionization degree and biological phospholipid contents on bioconcentration. Superoxide dismutase (SOD) activities were evidently induced in the SER and CPM groups, while ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST) activities were significantly induced only in the CBZ group. Acetylcholinesterase (AChE) activity was obviously induced by CBZ, SER and AMT, with levels 1.73, 1.62 and 2.44 times that of the control group (p < 0.05). The K_u of PDs, oxidative stress and metabolic level of D. magna combine to affect BCF levels together. In conclusion, this study contributes to a better understanding of the toxicokinetics and biochemical responses of PDs in D. magna and potential mechanisms of action, which may allow for a better assessment of their environmental health risks to aquatic ecosystems. Full article

Silver nanoparticles (AgNPs) have emerged as promising agents in cancer diagnostics and/or therapy, demonstrating a lot of possible pharmacological actions. However, understanding the pharmacokinetics and safety profiles of nanoparticles, which is crucial for their clinical application, still raises many questions. Studies indicate that AgNPs can accumulate in tumour tissues, improving drug delivery and specificity. However, their interaction with biological systems necessitates thorough safety evaluations. Classical methods for assessing AgNPs’ safety include cytotoxicity assays, genotoxicity tests, and histopathological examinations. However, novel techniques are emerging, such as advanced imaging and biomarker analysis, offering more precise toxicity assessments. Prediction models, including computational simulations and in silico analyses, are being developed to forecast AgNPs’ toxicity profiles. These models aim to reduce reliance on animal testing and expedite the evaluation process. To mitigate potential risks associated with nanoparticle-based therapies, strategies such as surface modification, controlled release systems, and targeted delivery are being explored. These methods aim to enhance therapeutic efficacy while minimizing adverse effects. The main aim of this review article is to describe AgNPs from the point of view of their pharmacokinetic/toxicokinetic profile in the light of modern knowledge. Special attention will be given to novel methods for assessing the safety and toxicity profiles of AgNPs, providing insights into their interactions with cancer therapies and their potential clinical applications. Full article

This study investigated the effects of acrylamide on the growth, neurobehavioral responses, gut integrity, microbial composition, and toxicokinetics of black soldier fly larvae (BSFL). Larvae were exposed to acrylamide-contaminated diets at 0.05, 0.5, and 5 mg/kg (dry weight) to assess dose-dependent impacts. Results revealed that acrylamide exposure delayed larval growth peaks and reduced maximum weights by 6.17–76.01% (12–18 days). Additionally, crawling speed decreased significantly at ≥0.5 mg/kg, indicating neurotoxicity. Trypan blue staining demonstrated dose-dependent midgut damage (2.22% in control vs. 25.56% at 5 mg/kg), correlating with compromised nutrient absorption. Gut microbiota analysis showed enrichment of pathogenic genera (e.g., Escherichia-Shigella) and suppression of beneficial taxa (e.g., Klebsiella), alongside reduced metabolic and immune-related pathways via Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Toxicokinetic modeling revealed bioaccumulation, with bioaccumulation factors (BAF) inversely related to substrate concentration (18.67 at 0.05 mg/kg vs. 2.90 at 5 mg/kg). Elimination half-lives (DT₅₀) varied from 3.25 to 8.22 days, suggesting concentration-dependent detoxification efficiency. These findings highlight acrylamide’s multifaceted toxicity in BSFL, emphasizing risks in waste valorization and insect-based feed production. This study underscores the need for substrate safety protocols to ensure sustainable applications of BSFL in the circular bioeconomy. Full article