Journal of Applied Toxicology最新文献

This work presents the first demonstration of a tube-based droplet microfluidic implementation of the Ames test, bridging single-droplet resolution with regulatory genotoxicity testing. The Ames test is a cornerstone assay for detecting mutagenicity, but conventional plate- and well-based formats suffer from high reagent consumption, low throughput, and limited automation. We report a droplet-based microfluidic Ames test assay using Salmonella typhimurium TA98, combining nanoliter compartmentalization with multiparameter optical detection. Cell density screening identified an optimal inoculum range of 10⁶-10⁷ cells/mL that maximized sensitivity while limiting spontaneous revertants. Dose-response analysis with the reference mutagen 4-nitro-o-phenylenediamine (4-NOPD) revealed clear increases in the fraction of droplets with growth of revertants, followed by a cytotoxic suppression at ≥ 8 μg/mL. A threshold-based evaluation enabled robust quantification of stochastic mutation events at single-droplet resolution. Compared with the classical fluctuation assay, the microfluidic format reduced reagent consumption by > 90%, generated statistically powerful datasets within 48 h, and eliminated subjective scoring. This study establishes segmented-flow microfluidics as a scalable, sensitive, and resource-efficient platform for mutagenicity testing, with applications in regulatory toxicology, environmental monitoring, and high-throughput chemical screening.

Taizhou City in Zhejiang Province was once one of China's largest e-waste-polluted areas. We assessed the effects of perinatal exposure to multiple heavy metals and dioxins on serum steroid levels in children from this area. We recruited 42 pairs of mothers and infants, collected breast milk and blood samples from the children, and detected dioxins and heavy metals in the breast milk, as well as steroid hormones in the serum. We employed multiple analytical approaches, including multivariable linear regression (MLR) model and Bayesian kernel machine regression (BKMR) models, to investigate the relationship between heavy metals, dioxins, and the serum steroid hormone levels in these children. In a separate exposure model using MLR, total polychlorinated dibenzofurans (PCDFs) (β: -0.930, 95% CI: -1.837, -0.023) and total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs) (β: -0.578, 95% CI: -1.142, -0.013) were negatively associated with DHEA. Within the MLR mixed exposure model, a negative association was observed between cadmium (Cd) and progesterone (β: -0.225, 95% CI: -0.447, -0.004), while a positive association was found between 2,3,7,8-TeCDD (TCDD) and dehydroepiandrosterone (DHEA) (β: 0.841, 95% CI: 0.196, 1.485). However, based on the BKMR results, these associations were attenuated. Perinatal exposure to heavy metals and dioxins may disrupt sex hormone levels and may have an impact on later reproductive health.

A widely used antibacterial drug, triclosan (TCS), is becoming more commonly acknowledged as an emergent aquatic pollutant with the potential to disrupt hormones. The physiological, biochemical and histological consequences of long-term TCS exposure in Oreochromis niloticus were assessed in this study. For 15, 30 and 45 days, adult fish were exposed to three sublethal doses of TCS (0.146, 0.219 and 0.438 mg L^-1). To ascertain reproductive and hepatic responses, growth indices, hepatosomatic index (HSI), gonadosomatic index (GSI), plasma vitellogenin (VTG) levels and gonadal histopathology were evaluated. The results showed significant increases in HSI and decreases in GSI, indicating hepatic enlargement and gonadal suppression, along with concentration-dependent declines in body weight and total length. Biochemical investigations revealed significant changes in VTG synthesis, with males displaying a brief increase followed by suppression and females showing a dose and time-dependent reduction, indicating a dualistic, sex-specific endocrine response. Reproductive impairment was confirmed by histopathological testing, which revealed severe degenerative alterations in gonadal tissues, including necrosis, vacuolation, interstitial cell infiltration and follicular atresia. Potential effects on breeding fitness, offspring production and population stability are suggested by the incapacity of O. niloticus to tolerate TCS-induced stress during the spawning period. All of these results point to triclosan being a strong endocrine and cytotoxic drug that interferes with the hepatic and gonadal physiology of O. niloticus. The study highlights the critical need for more stringent regulation and monitoring of this molecule in aquatic habitats, as well as the ecological risk connected to persistent TCS contamination.

Sphaeranthus amaranthoides, a lesser-known species of the Asteraceae family, has shown promising medicinal properties, prompting investigation into its cytotoxic and pro-apoptotic effects on human cancer cells. This study evaluated aqueous, methanol, ethyl acetate, and hexane leaf extracts for selective anticancer activity. Normal Vero cells and cancer cell lines AGS (gastric) and HT-29 (colorectal) were exposed to Sa-EAE extract, and GC-MS analysis identified key bioactive compounds, including methyl 10,13-dimethyltetradecanoate, 3,7,11,15-tetramethyl-2-hexadecen-1-ol, and 1,3,5-triazine derivatives. The extract showed selective cytotoxicity against AGS cells while sparing normal Vero cells. Apoptosis was evidenced by mitochondrial-membrane depolarization (ΔΨm), cytochrome c release, activation of Caspase-9 and Caspase-3, LDH leakage, and modulation of the Bcl-2/Bax ratio. Apoptotic morphology was confirmed via AO/EB and PI staining. Flow cytometry revealed G₀/G₁ cell cycle arrest, with downregulation of Cyclin D1 and CDK4 and upregulation of p21 and p27. These findings indicate that Sa-EAE exerts dual effects of mitochondrial-mediated apoptosis and G₀/G₁ arrest in gastric cancer cells, with minimal toxicity to normal cells, supporting its potential as a therapeutic candidate for further in vivo validation.

Gold is used in different fields showing great promise in various biomedical applications like nanotechnology, oncology, and drug delivery. Meanwhile, its effects on some biological systems of male Wistar rats remain unclear. The aim of this study was first to investigate the impact of Allochrysine solution after its intraperitoneal administration to male Wistar rats on their nutritional status. Second, the biodistribution of gold in the liver, the testes, and the brain was investigated, and the 24-h urine samples were studied as well. Third, the biochemical evaluation of hepatic and renal functions was performed. Our results showed that gold altered the nutritional status of rats. The quantitative study allowed the measurement of very high levels of gold in 24-h urine samples, in the testes, in the liver, and in the brain. The biochemical study of blood parameters showed that gold induced hyperglycemia and toxicity in the liver (e.g., ALT, AST, ALP, and TB) of treated rats. The study of urine showed excretion of elevated urine output with high specific gravity. The absolute and relative creatinine clearance were significantly higher in the gold-treated group. Our results suggest that gold is capable of crossing the blood-brain barrier and the blood-testis barrier. In the brain, gold stimulated a significant weight loss and reduced food intake, leading to modification in their nutritional status. The hepatic and kidney tissues concentrated gold in order to eliminate the metal, via biliary and urinary excretion, respectively. These organs regulated gold concentration and enhanced its elimination to facilitate detoxification.

Synthetic food dyes are widely used in Ghana, yet their ecological effects on freshwater ecosystems remain understudied. This study investigated the acute toxicity of five commonly used synthetic food dyes (tartrazine, allura red, sunset yellow, carmoisine, and green S) on two bioindicators, Daphnia magna and Lemna minor, following OECD 202 (2006) and OECD TG 221 protocols. The physicochemical analysis suggested that synthetic dyes, even in dilute form, can alter water chemistry. Although the electrical conductivity (EC), salinity, and total dissolved solids (TDS) values for sunset yellow were relatively low (8.12 mS/cm, 7.50 psu, and 2.98 g/L, respectively), tartrazine, carmoisine, and green S recorded high levels of EC, TDS, and salinity. Levels of Cd and Hg in all the dyes were below the detection limit (<0.001 mg/L). Carmoisine, however, recorded 0.003 mg/L for Cd. Levels of Cr, Pb, Fe, and Mn were above the limits for food dyes (≤0.002, ≤0.043, and ≤0.006 mg/L), raising environmental concern. The EC₅₀ showed that allura red is the most toxic, and tartrazine is the least toxic. IC₅₀ showed that green S is the most toxic and sunset yellow is the least toxic. All the dyes showed potential toxicity, and when released into the environment without treatment, they will have adverse effects on the aquatic environment. Bioaccumulation potential revealed that Pb, Mn, As, and Hg were accumulated in daphnia, whereas Cr, Cd, and Fe were not due to their low solubility, ionic competition, and strict cleansing mechanisms by daphnia. These findings emphasize the ecological risks of unregulated dye pollution in Ghanaian waters and highlight the importance of region-specific ecotoxicological data to guide environmental policies, regulations, and sustainable wastewater management practices.

This study aims to screen potential regulatory targets for atherosclerosis (AS) through bioinformatics and explore the mechanism of these targets in ox-LDL-induced injury in HUVECs, thereby providing novel therapeutic targets for AS. The GEO dataset GSE43292 was obtained. Differentially expressed genes were screened using the limma package. AS-related genes were identified via LASSO regression and SVM algorithms. ssGSEA was performed to detect relative immune cell expression, followed by correlation analysis between AS-related genes and immune cells. MPP6 and NEGR1 were screened as AS-related genes. MPP6 and NEGR1 showed negative correlations with most immune cells. After 100 μg/mL ox-LDL treatment, HUVECs showed reduced HUVEC viability, increased apoptosis, enhanced LDH release, and upregulated TNF-α, IL-6, and IL-1β. Protein-protein interaction networks of predicted transcription factors were constructed, and scores were assigned via the maximal clique centrality method. The results identified EP300 as the transcription factor with the highest score. MPP6, NEGR1, and EP300 were detected by RT-qPCR and Western blot. Overexpression of MPP6/NEGR1 alleviated ox-LDL-induced HUVEC injury. EP300 bound to MPP6/NEGR1 promoters to suppress their expression, and EP300 knockdown alleviated ox-LDL-induced HUVEC injury. In conclusion, EP300 exacerbates ox-LDL-induced HUVEC injury by binding to MPP6/NEGR1 promoters and suppressing their expression.

Three-dimensional, self-organizing structures derived from stem cells, known as organoids, represent a groundbreaking advancement in preclinical drug development. Organoid-based platforms advance preclinical testing by providing an accurate representation of human tissue architecture and genetics, surpassing traditional two-dimensional cultures and animal models in testing both drug safety and efficacy. Researchers are shifting toward organoid-based systems as primary components of new approach methodologies, as global regulatory bodies increasingly acknowledge animal testing limitations. This review delivers an exhaustive examination of organoid technologies and their applications in drug testing. Our study explores current methods used to model toxic responses in different organs-such as the liver, kidney, and heart-while highlighting how personalized and disease-specific organoids can enhance the accuracy of efficacy testing. Our investigation also examines regulatory frameworks and outlines the path toward organoid platform standardization and validation before their integration into drug development processes. Complex neural organoids show great promise but continue to face significant challenges, including biological variability, a lack of universal standards, and ethical concerns. The combination of organoid technology with microengineering techniques, artificial intelligence-based analysis, and high-throughput screening methods represents a transformative change in translational medicine. Organoid-based systems represent both scientific breakthroughs and ethical necessities, as they provide human-specific data while reducing dependence on animal testing. If organoid development progresses with regulatory approval, it could fundamentally transform drug discovery and safety evaluation methods.