Journal of Xenobiotics最新文献

This study investigated water quality, metal ion concentrations, and antibiotic residues specifically enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP), across six American shad (Alosa sapidissima) aquaculture sites over a one-year period. Water and sediment samples were analyzed to determine contamination levels, and ENR-degrading bacteria were isolated from the culture environment to explore their potential use in bioremediation. Findings showed that NH₃-N and total suspended solids (TSS) exceeded recommended standards at all sampling sites. Elevated levels of Li, Na (except S1), Fe, Ni (except S2 and S4), Sr, and Cu were found at site S3. Site S5 recorded the highest concentrations of Al, As, and Pb, while Cd was most abundant at S6. In sediments, S5 showed higher levels of Mg, K (except S3), Ca, Cr, Mn, Fe, Ni, As, Pb, Cu, and Zn (except S3). ENR and CIP were detected in all water and sediment samples, with a 100% detection rate. The highest ENR (16.68-3215.95 mg·kg^-1) and CIP (3.90-459.60 mg·kg^-1) concentrations in water occurred at site S6, following a seasonal pattern of autumn > winter > summer > spring. In sediments, the maximum ENR (41.43-133.67 mg·kg^-1) and CIP (12.36-23.71 mg·kg^-1) levels were observed in spring. Two ENR-degrading bacterial strains were successfully isolated and identified as Enterococcus and Bacillus. Optimal degradation was achieved at 30 °C, pH 8.0, 6% inoculum, and 3000 Lux, resulting in a 64.2% reduction in ENR after 72 h. Under slightly different conditions (25 °C, pH 10), degradation reached 58.5%. This study provides an efficient strain resource for the bioremediation of ENR pollution in the aquaculture water of American shad.

Curcumin (CUR), atractylodin (ATD), α-mangostin (αMG), ethyl-p-methoxycinnamate (EPMC), ligustilide (LIG), and β-eudesmol (BEU) are commonly used in Thai traditional medicine formulations. This study evaluated the cytotoxic effects of these compounds in HepG2 liver cancer cells and ReNcell VM neural progenitor cells using the resazurin assay, as well as their potential for hERG inhibition in hERG-overexpressing HEK293 cells, utilizing the automated patch-clamp technique. αMG and CUR significantly reduced HepG2 cell viability (IC₅₀ = 5.5 and 21 µM, respectively). In undifferentiated ReNcell VM cells, αMG was the most potent inhibitor of cell viability (IC₅₀ = 2.1 µM), followed by CUR (IC₅₀ = 21.1 µM), while in differentiated ReNcell VM cells, only αMG exhibited significant neurotoxicity (IC₅₀ = 6.0 µM). Other compounds showed no significant effects on these cells. ATD, BEU, LIG, and EPMC demonstrated low inhibition of hERG channels (IC₅₀ = 26.4, 33.4, 37.3, and 53 µM, respectively), while CUR and αMG displayed weak inhibitory effects (IC50 > 100 µM). αMG may have cytotoxic effects on hepatocytes and neurons at concentrations much higher than when used as medicine or food supplements. At regular clinical doses, αMG, ATD, BEU, EPMC, LIG, and CUR are unlikely to cause significant side effects. However, if these compounds are considered for drug development, their potential effects on hERG channels should be carefully assessed to avoid possible cardiotoxicity. Pharmacokinetics, both preclinical and clinical studies, are necessary to understand the relationship between the plasma concentration profile of EPMC and its potential risks for hepatotoxicity, neurotoxicity, cardiotoxicity, and drug interactions.

Irregular use of antibiotics is widespread in Nigeria, which has been reported to be associated with the prevalence of antibiotic resistance. As antibiotics have been reported to be associated with declining male infertility in animal models, we investigated the association between exposure to antibiotics and sperm quality. The study was a prospective case-control study involving 136 infertile men and 154 fertile men recruited from five hospitals in southern Nigeria. Semen analysis was carried out, while Liquid Chromatography Mass Spectrometry was used to assay for various antibiotics in urinary samples. Three antibiotics showed an independent association with sperm quality in the regression analysis. Urinary ampicillin was associated with more than a 3 mL decline in sperm count in the cases, with no significant effects shown in the control group. Similarly, a significant association of urinary chloramphenicol with sperm motility and sperm morphology was shown in cases of infertility. In contrast, an independent association of urinary tetracycline with increased sperm motility in men with infertility was found, but no significant association was shown in fertile men. We conclude that urinary antibiotics-ampicillin, tetracycline, and chloramphenicol-may be associated with varying sperm characteristics and sperm quality in Nigerian men.

People are exposed to pesticides daily through food, drinking water, and the environment, both in urban and rural settings. These chemicals, while offering economic and agricultural benefits through pest control and increased productivity, may pose a growing risk to human health and ecosystem biodiversity. While the European regulatory framework offers a robust foundation for risk assessment, significant limitations persist, especially in addressing cumulative exposure, low-dose effects, and chemical mixtures. This review focuses on selected scientific and regulatory challenges by reviewing recent European Food Safety Authority (EFSA) conclusions, Organization for Economic Co-operation and Development (OECD) test guidelines updates, and current European legislative approaches. Particular attention is given to the regulation of endocrine-disrupting and reprotoxic substances, highlighting progress and remaining gaps in implementation. A brief mention will also be made of immuno-toxic substances, for which no specific hazard class has yet been established. Building on official reports and peer-reviewed literature, this review provides a structured evaluation of the scientific and regulatory landscape, including underexplored issues like the transition to animal-free toxicology and integration of biomonitoring with health data. The goal is to propose realistic, evidence-based improvements to current frameworks using integrated, interdisciplinary approaches that connect toxicology, policy, and implementation science. A shift to a holistic, systems-based, and precautionary paradigm is vital to address emerging challenges and ensure strong protection of health and environment, as well as supporting the needs of the agricultural sector.

A four-year survey was conducted to monitor the presence of multiple pesticide residues contaminating tomatoes, with the aim of evaluating the potential health and environmental risks. A multiresidue liquid chromatography-triple mass spectrometry with a multiple reaction monitoring (LC-MS/MS-MRM) method was fully validated and used to test 252 pesticides in 360 samples analysed. According to SANTE guidelines, the proposed method was considered suitable for the purpose. Dietary risk assessment was conducted using the Hazard Quotient (HQ) approach and the European Food Safety Authority (EFSA) Pesticide Residue Intake Model; meanwhile, the cumulative environmental risk assessment was conducted using the Concentration Addition (CA) and Independent Action (IA) methods. Data obtained revealed multiple contaminations in most fields examined over the years. Twenty-two pesticide residues were identified, comprising 68.2% fungicides, 27.3% insecticides, and the remaining 4.5% acaricides. Higher levels were detected for Boscalid in 2022 in three fields, with an average value of 0.42 mg/kg. Multi-residue contamination occurred each year; the lowest abundance was detected in 2023 (3.9%), and the highest in 2022 (12.3%), with 5 pesticide residues as the maximum number of compounds detected in one sample in 2022. The consumer risk assessment identified no potential health concerns for adults or toddlers, and the combined risk was considered acceptable. The environmental assessment showed maximum cumulative ratio (MCR) values that were always ≥1, indicating a contribution to the toxicity of the mixture, only slightly higher than that of the single compound with the highest toxicity. The results of this study highlight the critical need to include cumulative dietary exposure assessments in pesticide risk evaluations, especially for food products that are susceptible to contamination by multiple residues.

Mitochondria play crucial roles in various cellular functions, including ATP production, apoptosis, and calcium homeostasis. Signaling pathways and hormones such as estrogens regulate the mitochondrial network through genetic, epigenetic, and metabolic processes. Estrogens increase the efficiency of mitochondrial oxidative phosphorylation by preventing uncoupling. Upon reaching menopause, when estrogen levels decrease, impaired mitochondrial function (uncoupled oxidative phosphorylation, lower ATP yields) is observed. Like all hormones in the body, estrogens undergo metabolic processing, resulting in estrogenic degradation metabolites (EDMs). These metabolites can form adducts with genomic and mitochondrial DNA and are of particular interest due to their potential role as carcinogens. Given that estradiol influences mitochondrial function, it is possible that EDMs may have an impact on heart mitochondria. To investigate this, we used isolated heart mitochondria from control and oophorectomized (mimicking menopausal stage) female Wistar rats of the same age. We found that mitochondria exposed to EDMs exhibited reduced coupling of oxidative phosphorylation and diminished ATP production, while increasing reactive oxygen species generation. Furthermore, these effects were significantly stronger in mitochondria from oophorectomized rats than in mitochondria from control (intact) rats. In addition, mitochondrial oxidative phosphorylation complex activities were differentially affected: complex I and ATPase activities decreased, while complex IV remained unaffected. We propose that exposure to EDMs promotes mitochondrial dysfunction in rats and that these effects are exacerbated by oophorectomy, a procedure commonly used to model the effects of menopause in women.

In this study, we evaluated the cytotoxicity and antioxidant activity of the soil ciliate Rigidohymena tetracirrata (Gellért, 1942) Berger 2011, exposed to single and bimetallic mixtures of heavy metals (HMs) for 24 h. Ecotoxicological tests showed LC₂₀ values of 0.16, 19.86 and 0.68 mg L^-1 to Copper (Cu), Zinc (Zn), and Cadmium (Cd), respectively, and LC₅₀ values of 0.25, 44.12 and 1.12 mg L^-1, respectively. Furthermore, it was observed that the mixture of Cd and Zn exhibited antagonism in comparison to other mixtures, (Cd + Cu and Cu + Zn). In the total phenolic content (TPC) assay, a higher phenolic content was observed for the LC₂₀ of extracellular Cu (p ≤ 0.01) and the LC₂₀ of intracellular Cd (p ≤ 0.001). The LC₅₀ values for Cd and Zn in both extracellular and intracellular contents demonstrated increased α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging activity with significant values of p ≤ 0.05, respectively. Regarding hydroxyl scavenging activity (HRSA), the LC₅₀ of extracellular Cd (p ≤ 0.001) and LC₅₀ of intracellular Cu (p ≤ 0.001) exhibited higher antioxidant activity. Therefore, the present study suggests that R. tetracirrata holds considerable potential as bioindicators and could be used as a model organism in ecotoxicological studies of soil polluted by HMs.

Bisphenol (BP) compounds are widely present in the environment, primarily due to their use as plastic additives. These substances involve health risks, particularly as endocrine disruptors. While the general population is chronically exposed, patients with end-stage chronic kidney disease undergoing hemodialysis (HD-CKD) represent a particularly vulnerable group. This is due to both impaired renal clearance of circulating BPs and potential contamination from plastic-containing dialyzers used in extracorporeal blood circulation. In this longitudinal study, from the 35 HD-CKD patients initially selected, 25 changed their conventional dialyzers to BPA-free dialyzers for 6 months. Blood serum samples were collected, at baseline and after the intervention, to quantify levels of five BP analogues: Bisphenol A (BPA), Bisphenol AF (BPAF), Bisphenol F (BPF), Bisphenol B (BPB), and Bisphenol S (BPS). Genotoxicity was assessed using the comet assay and the micronucleus test on peripheral white blood cells. Among the analyzed BPs, only BPAF showed a statistically significant reduction when using BPA-free dialyzers. In terms of genotoxicity, a significant decrease was observed only in primary DNA damage (mainly DNA strand breaks), with no notable changes in chromosomal damage. This is the first study to detect multiple BP analogues in HD-CKD patients, beyond BPA, and to associate human exposure to BPs with DNA damage biomarkers. The observed reduction in DNA damage in parallel with decreased BPAF levels highlights the importance of monitoring and minimizing BP exposure of this high-risk population.

Due to their visible photoluminescence (PL) at room temperature, porous silicon particles (PSps) have gained interest for their potential biomedical applications, making them promising biological markers for in vivo or in vitro use. This study explores the PL evolution and stabilization of PSps following a two-step oxidation process involving air annealing and chemical oxidation in deionized water. PS layers were fabricated by electrochemical etching of p⁺-Si wafers and then annealed in air at 300 °C and 600 °C for five minutes. The layers were then stored in deionized water and sonicated to produce PSps. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to analyze the morphology and composition of the particles, and spectrofluorimetry was used to monitor the PL over several weeks. Samples annealed at 300 °C exhibited a transition from nearly complete PL quenching to strong yellow-red emission. In contrast, the 600 °C sample showed no PL emission. The cytotoxicity of the PSps was evaluated using an MTT assay on human endothelial cells (EA.Hy926) with PSps and polyethylene glycol (PEG)-coated PSps at concentrations of (3.5-125 µg/mL) in both serum-free and fetal bovine serum (FBS)-containing media over 24, 48, and 72 h. Cell viability was significantly affected by both exposure time and particle concentration; however, this effect was prevented under conditions mimicking the physiological plasma environment.

Toxicokinetic (TK) properties are essential in the framework of chemical risk assessment and drug discovery. Specifically, a TK profile provides information about the fate of chemicals in the human body. In this context, Quantitative Structure-Activity Relationship (QSAR) models are convenient computational tools for predicting TK properties. Here, we developed QSAR models to predict two TK properties: oral bioavailability and volume of distribution at steady state (VD_ss). We collected and curated two large sets of 1712 and 1591 chemicals for oral bioavailability and VD_ss, respectively, and compared regression and classification (binary and multiclass) models with the application of several machine learning algorithms. The best predictive performance of the models for regression (R) prediction was characterized by a Q²_F3 of 0.34 with the R-CatBoost model for oral bioavailability and a geometric mean fold error (GMFE) of 2.35 with the R-RF model for VD_ss. The models were then applied to a list of potential endocrine-disrupting chemicals (EDCs), highlighting chemicals with a high probability of posing a risk to human health due to their TK profiles. Based on the results obtained, insights into the structural determinants of TK properties for EDCs are further discussed.