Journal of Applied Toxicology最新文献

Titanium dioxide nanoparticles (TiO₂ NPs) can induce the cell cycle arrest in spermatogonia, and the JAK2/STAT3 signaling pathway plays a pivotal role in cell cycle progression, but the specific upstream regulatory mechanisms are not completely clarified. The purpose of this study was to investigate whether CXCL13 regulated the JAK2/STAT3 signaling pathway to participate in cell cycle arrest after mouse spermatogonia cell line (GC-1) exposure to TiO₂ NPs. The GC-1 cells were treated with TiO₂ NPs at different concentrations (0, 10, 20, 30, and 40 μg/mL) for 24 h to detect cell viability, cell cycle distribution, CXCL13 protein, JAK2/STAT3 pathway-related proteins, and cell cycle-related proteins. The CXCL13 recombinant protein was used to verify the role of CXCL13 in cell cycle and JAK2/STAT3 signaling pathway. TiO₂ NPs inhibited cell viability; regulated cell cycle-related proteins including remarkably decreased Cyclin D1, CDK4, Cyclin E1, and CDK2 as well as increased p21; and induced cell cycle arrest at the G0/G1 phase. TiO₂ NPs inhibited the levels of CXCL13 protein and weakened the activation of the JAK2/STAT3 signaling pathway by reducing the levels of p-JAK2/JAK2 and p-STAT3/STAT3 proteins. Furthermore, CXCL13 mitigated the suppression of the JAK2/STAT3 signaling pathway and the G0/G1 cell cycle arrest caused by TiO₂ NPs. Taken together, TiO₂ NPs downregulated the expression of CXCL13 to inhibit the activation of downstream JAK2/STAT3 signaling pathway, eventually inducing cell cycle arrest at the G0/G1 phase. These results provide a novel insight for complemented understanding of the mechanisms of TiO₂ NPs-induced cell cycle arrest in GC-1 cells.

N-Nitrosodimethylamine (NDMA) is a known water disinfection byproduct (DBP) characterized as a potent hepatotoxin, promutagen, and probable human carcinogen; this is because of the metabolites associated with its biotransformation. The metabolism of NDMA produces formaldehyde, another alkylating agent and DBP. Both compounds are generated from natural and anthropogenic sources, but the safety restrictions applied to NDMA do not extend to the uses of formaldehyde. Hence, potential health and ecological risks are of concern. Due to limited information on the long-term effects of exposure to these compounds at environmentally relevant concentrations, this work aimed to compare the transgenerational reproductive and developmental toxicity of separate exposures to NDMA or its metabolite formaldehyde in Drosophila melanogaster over four generations. The parental flies were fed NDMA or formaldehyde (1.19E-06 to 5 mM) for 48 h during the third larval instar. Subsequent offspring (F1-F3) were grown under compound-free conditions. In the parental generation, both exposures modified the time to emergence and reduced the number of progenies. NDMA, but not formaldehyde, was lethal, affected fertility, and weakly induced malformations. In the next generations, both exposures induced malformed flies and modified the number of offspring. Reproductive toxicity and malformations were maintained for at least three generations, suggesting that detrimental effects could extend to unexposed offspring. This is the first study reporting the associated individual transgenerational effects on reproduction and development between NDMA and its metabolite formaldehyde in D. melanogaster, highlighting the relevance of evaluating multiple generations to accurately determine the health and environmental risks of pollutants.

Collagens are biofunctional proteins that have been widely used in many fields, including biomedical, cosmetics, and skin care for their value in maintaining the integrity of cellular membranes. Collagens are also commonly consumed in foods and provide a source of protein and amino acids. As part of the safety assessment for this particular recombinant humanized type III (RHTypeIII) collagen produced by Komagataella phaffii SMD1168-2COL3, a series of toxicological tests were conducted. This collagen has ≥ 90% amino acid sequence homology to bovine and porcine collagen. The RHTypeIII collagen showed no evidence of genotoxic potential in a battery of tests. It was not toxic in an acute oral study, with no effects at 10 g/kg BW. The RHTypeIII collagen was not developmentally toxic in Sprague Dawley (SD) rat, and the NOAEL was 4.5 g/kg BW/day. In a 90-day oral gavage study in rats, there were no adverse findings observed; therefore, the high dose level (4.5 g/kg BW/day) was considered the NOAEL. The protein sequence was subjected to homology searches against the AllergenOnline database (sliding 80-amino acid windows and full sequence searches). From the 80-amino acid alignment searches, 23 significant matches were identified (> 35% identity and E value < 1 × 10^-7) to allergens of bovine, fish, anisakis, feverfew pollen, ragweed pollen, and wheat origin. Although matches were identified, further assessment of the in silico results combined with a literature review demonstrates that the risk of allergenic cross-reactivity for this collagen is low. These results demonstrate RHTypeIII collagen is not toxic and unlikely to present a risk of allergy when used as a food ingredient.

Arsenic (As), a highly toxic metalloid, is present throughout our environment as a result of both natural and human-related activities. Furthermore, As exposure could lead to a persistent inflammatory response, which may facilitate the pathogenesis of several diseases in various organs. This study was performed to investigate the As-induced inflammatory response and the underlying molecular mechanisms in vitro. Further, the anti-inflammatory effects of a natural dietary polyphenol tannic acid (TA) were also explored. In human normal bronchial (BEAS-2B), adenocarcinoma alveolar basal (A549), and murine macrophages (J774) cell lines, a trivalent form of As (as As³⁺) exposure markedly induced the expression of various pro-inflammatory mediators (cytokines and chemokines). Additionally, it was found that As³⁺ exposure induced reactive oxygen species (ROS) generation and activation of the nuclear factor-kappa B (NF-kB) p65 and extracellular signal-regulated kinase (ERK)1/2 pathways in BEAS-2B cells. As expected, the blockade of either ERK1/2 (PD98059) or NF-kB p65 (IMD0354), or both pathways attenuated As³⁺-induced pro-inflammatory mediators release. Interestingly, pre-treatment with ROS inhibitor N-acetylcysteine (NAC) attenuated activation of ERK/NF-kB pathways, suggesting that ROS have a critical role in pathway's activation and subsequent inflammatory response. Further, TA pre-treatment effectively attenuated As³⁺-induced inflammatory response by suppressing ROS production and ERK/NF-kB signaling pathways activation. Therefore, this study provides scientific evidence for the anti-inflammatory activities of TA and the underlying molecular mechanisms.

Crude oil contamination has been shown to impair reproduction in aquatic animals through carcinogenic and genotoxic properties. Here, we assessed the endocrine-disrupting function of crude oil on male reproductive system based on testicular histology, sex steroid hormones, and fertility endpoints in adult male goldfish (Carassius auratus), which were exposed to 0.02- to 2-mg/L crude oil for 21 days (Experiment #1) or to 5- to 250-mg/L crude oil for 9 days (Experiment #2). The crude oil contained 0.22-mg/L nickel (Ni), 1.10-mg/L vanadium (V), and 12.87-mg/L polycyclic aromatic hydrocarbons (PAHs). Twenty-four hours after adding crude oil, the sum of PAHs ranged from 0.30 to 2.28 μg/L in the aquaria containing 0.02- and 250-mg/L crude oil, respectively. Water analyses for heavy metals in Experiment #2 showed high concentrations (mg/L) of Ni (0.07-0-09) and V (0.10-0.21). For both experiments, exposure to crude oil did not impact gonadosomatic index; however, testes showed histopathological defects including hyperplasia or hypertrophy of Sertoli cells, depletion of the Leydig cells, necrosis of germ cells, and fibrosis of lobular wall. In Experiment #1, sperm production and motility, testosterone (T), and 17β-estradiol (E₂) were not significantly different among treatments. In Experiment #2, the number of spermiating males decreased by ~50% following exposure to 250-mg/L crude oil. Sperm production, motility kinematics, T, and the T/E₂ ratio significantly decreased in males exposed to ≥ 50-mg/L crude oil; however, E₂ remained unchanged. Results show crude oil-induced imbalance of sex steroid hormones disrupts spermatogenesis resulting in diminished sperm production and motility.

Dihydroartemisinin (DHA) is an effective antimalarial drug with potential antitumor efficacy, yet toxicological information is limited. The present study was designed to evaluate the potential toxicity of oral DHA. DHA was administered orally by gavage to SD rats at doses of 0, 25, 50, and 75/60 mg/kg b.w./day for 28 days, followed by a 4-week recovery period. Concomitant toxicokinetics was also evaluated. Due to potential toxicity affecting survival, only the female top dose was adjusted from 75 to 60 mg/kg on study day 14 (D14). Female rats in the low-dose group and male rats in the low- and medium-dose groups did not show any signs of toxicity. In contrast, male rats in the high-dose group and female rats in the medium- and high-dose groups showed significant toxic effects, including weight loss, hair loss, and gastrointestinal reactions (soft stools, perianal dirt, and fecal abnormalities). At the end of administration, female rats in the 75/60 (dose-adjusted) mg/kg dose group had significantly higher reticulocytes (Ret% and RETIC) and alanine aminotransferase (ALT), increased liver weights, and significantly lower hemoglobin (HGB). In addition, histopathology showed mild vacuolation of hepatocytes. These findings suggest that female rats have a greater toxic response than males, and toxicokinetics further demonstrate this sex difference. However, the toxic effects of DHA were reversed at the end of the 4-week recovery period. Therefore, the liver was identified as the primary target organ. The no-observed-adverse-effect-level (NOAEL) was 25 and 50 mg/kg b.w./day in female and male rats, respectively.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder caused by the interaction of genetic and complex environmental factors. The prevalence of autism has dramatically increased in countries and regions undergoing rapid industrialization and urbanization. Recent studies have shown that particulate matter (PM) in air pollution affects the development of neurons and disrupts the function of the nervous system, leading to behavioral and cognitive problems and increasing the risk of ASD. However, research on the mechanism of environmental factors and ASD is still in its infancy. On this basis, we conducted a literature search and analysis to review epidemiological studies on the correlation between fine particulate matter (PM_2.5) and inhalable particulate matter (PM₁₀) and ASD. The signaling pathways and pathogenic mechanisms of PM in synaptic injury and neuroinflammation are presented, and the mechanism of the ASD candidate gene SHANK3 was reviewed. Additionally, the different sites of action of different particles in animal models and humans were highlighted, and the differences of their effects on the pathogenesis of ASD were explained. We summarized the aetiology and mechanisms of PM-induced autism and look forward to future research breakthroughs in improved assessment methods, multidisciplinary alliances and high-tech innovations.

The clinical application of cantharidin (CTD) is seriously limited due to its nephrotoxicity. Therefore, this study aims to investigate sensitive biomarkers for the evaluation and prediction of nephrotoxicity induced by CTD in rat. A total of 80 rats were randomly divided into four groups: control group and three doses of CTD groups. After 0, 1, 5, 15, and 28 days of intragastric administration, rat serum and urine were collected for biochemical indexes, then serum was used for metabolomic analyses, and rat kidney was collected for pathological and ultrastructural observation. The levels of serum crea (Scr), blood urea nitrogen (BUN), urea, urine crea (Ucrea), and urinary microalbumin (UmALB) were significantly increased after administration of different doses of CTD (p < 0.05). Additionally, histopathology and cell ultrastructure observation of kidney showed significant cell inflammatory infiltration and glomerular edema. Seven metabolic biomarkers including 6-hydroxymelatonin were significantly disturbed by CTD. The CatBoost Classifier prediction model was used to establish the CTD nephrotoxicity prediction model, and the prediction accuracy and precision were 0.645 and 0.640, respectively. Moreover, 6-hydroxymelatonin was found to be most useful biomarkers for evaluating the CTD nephrotoxicity. Finally, the seven metabolic biomarkers were found mainly involved in pyruvate metabolism, pantothenate and CoA biosynthesis.

Resorcinol-formaldehyde aerogel (RFa) is a unique nanomaterial composed of polymer nanoparticles with a three-dimensional network structure. Our previous studies have demonstrated its application in the separation and purification of alkaloids, and we are exploring its application potential as the drug delivery carrier. Therefore, it is necessary to comprehensively understand the in vivo toxicity profile of RFa and evaluate its oral biosafety. In this work, we systematically evaluated the in vivo acute toxicity and subchronic oral toxicity of RFa in both male and female Kunming mice. During the 14-day acute toxicity test, the dose administered (M = 580 mg/kg) was converted from the clinical dose of adsorbed alkaloids on RFa. The mice were gavaged only once and were observed continuously for 14 days. There were no abnormalities, and pathological changes in the major organs (heart, liver, spleen, lungs, kidneys, testes, and ovaries) were detected, followed by the 12-week subchronic toxicity test at the dose of 1/4M, 1/2M, and M. All mice were administered orally once daily and regularly observed throughout the experimental period. As a result, no abnormalities were found in body weights, food intake, and organ coefficients. Tissue section revealed no pathological changes in the major organs. In addition, there were no significant differences in hematological, blood biochemical, and coagulation parameters in both male and female mice compared to control group. These results showed that RFa was well tolerated at these dosage levels and did not cause significant toxic effects in Kunming mice. This study, as part of a broad research program on the biosafety of aerogel nanomaterials, provided the biosafety assurance for the subsequent study of RFa in biomedical applications.

Lactiplantibacillus plantarum is a Gram-positive, bacilli-shaped bacterium commonly found in fermented foods and the human gastrointestinal tract. Heat-treatment of L. plantarum OLL2712 prior to consumption has been found to have positive health effects. However, a full toxicological evaluation of heat-treated L. plantarum OLL2712 cells (heat-treated OLL2712) has not been conducted. In this regard, heat-treated OLL2712 was evaluated for use as an ingredient in food and dietary supplements using a panel of toxicological tests including genotoxic and subchronic studies. Heat-treated OLL2712 did not show any genotoxicity based on an in vitro mammalian chromosomal aberration test and in vivo mouse micronucleus assay up to 8.0 × 10⁹ cells/mL and 6.4 × 10¹² cells/kg, respectively. In the acute oral toxicity study, no toxic effects were observed at 5 × 10¹¹ cells/kg body weight. In the 13-week subchronic toxicity study, rats were administered (via gavage) heat-treated OLL2712 at concentrations of 0.5 × 10¹¹, 1.5 × 10¹¹, and 5 × 10¹¹ cells/kg body weight. Administration did not significantly impact mortality, body weight, food consumption, ophthalmology, hematology, clinical chemistry, coagulation, urinalysis, and macroscopic or microscopic findings. The no-observed-adverse-effect level of heat-treated OLL2712 in both sexes was 5 × 10¹¹ cells/kg body weight/day, the highest dose tested.