Current Research in Toxicology最新文献

Current treatments for chronic obstructive pulmonary disease (COPD), a common respiratory condition, include oxygen therapy and steroids for temporary relief. In this study, we established a rat model of cigarette smoke (CS)-induced COPD and investigated the benefits of a hydrogen-oxygen generator in this model. CS-exposed rats were treated using either a hydrogen-oxygen generator or a steroid. A hydrogen-oxygen generator reduced the neutrophil, lymphocyte, and eosinophil counts compared to natural recovery, whereas steroid treatment increased the total white blood cell, neutrophil, lymphocyte, monocyte and eosinophil counts. Furthermore, the mean linear intercept and the mean alveolar number were 59.8%, and 188.3%, respectively, after treatment with the generator, compared to the values observed with natural recovery. Finally, the generator increased the tricuspid annular plane systolic excursion values by 113.1% compared with the values in natural recovery. Our findings indicate successful establishment of a rat model of CS-induced COPD and demonstrate the potential benefits of using a hydrogen-oxygen generator for COPD patients.

Ectopic lipid deposition in the hepatocyte plays an important role in the development of nonalcoholic fatty liver disease (NAFLD), which has become one of the most common causes of chronic liver disease worldwide yet no approved drugs are currently available. In this study, a cell-based method was developed to screen potential drugs with low toxicity that inhibit lipid accumulation. In the same 96-well plate, cytotoxicity was measured using CCK8 assay, followed by lipid content detection using BODIPY 493/503 via fluorometry assay, a lipid droplet-specific fluorescent dye commonly used in microscopy and flow cytometry, but not previously reported in fluorometry. Lipid content was normalized to DAPI staining to control for cell number. The results of this assay were highly consistent with the fluorescence microscopy, with significantly lower intra-group variability in detecting lipid accumulation induced by free fatty acids in Huh7 cells. Validation was conducted using 10 well documented steatotic compounds and 5 negative controls, all of which were correctly identified by the assay. In addition, the inhibitory effect of ML261, a well-known inhibitor of hepatic lipid droplets formation, was also confirmed by the assay both in AML12 cells and Hepa1-6 cells. To our knowledge, this study is the first to quantify lipid droplets using BODIPY 493/503 by fluorometry assay, and to demonstrate that CCK8 does not interfere with subsequent BODIPY 493/503 staining, both of which will reduce the cost and increase the efficiency. In conclusion, the method is simple, reliable, efficient and does not rely on expensive instruments, making it an easily generalizable approach to identify potential drug candidates for NAFLD treatment.

Rotenone is a natural compound from plants. It is widely used in pesticides because of highly toxic to insects and fish. However, lots of research has reported that rotenone has neurotoxic effects in humans. It is confirmed there is a correlation between rotenone exposure and Parkinson's disease (PD). Therefore, the role of gut microbiota and related metabolic pathways was investigated in rotenone-induced neurotoxicity. The results showed that the abundance of gut microbiota changed significantly. The differential metabolites were enriched in the nicotinate and nicotinamide metabolism pathways, which had the greatest impact on the entire metabolic system. The contents of acetic acid and butyric acid in intestinal tissues decreased significantly. Additionally, Interleukin-6 (IL-6), Tumor necrosis factor alpha (TNF-α) and vasoactive intestinal peptide (VIP) were significantly up-regulated, while gastrin (GAS) and Ghrelin were significantly down-regulated. Expression of intestinal tight junction protein was significantly reduced. Moreover, nicotinamide adenine dinucleotide (NAD⁺), a the product of the nicotinate/nicotinamide pathways, decreased significantly. And the expression levels of nicotinamide phosphoribosyl transferase (NAMPT) and Solute Carrier Family 25 Member 51 (SLC25A51) also reduced significantly. Therefore, gut microbiota was influenced obviously in rats exposed to rotenone, leading to a decrease of acetic acid and butyric acid contents, which might in turn affect the change of intestinal barrier permeability and induce inflammatory reactions. Meanwhile, the nicotinate/nicotinamide metabolic pathways might play an important role in rats exposed to rotenone.

Exposure to alcohol can induce different degrees of damage to various tissues and organs, and brain is the most vulnerable part affected by alcohol. However, there is no detailed report on whether intermittent alcohol exposure can result in pathological changes in the hypothalamus of adolescent rats and the detailed mechanism. This study investigated pathological changes in the hypothalamus, probed the levels of inflammatory factors, and detected the expression of proteins related to endoplasmic reticulum stress (ERS) to determine whether ERS is involved in the injury process of the hypothalamus and the protective mechanism of L-3-n-butylphthalide (L-NBP). The results showed that intermittent alcohol exposure induced hypothalamic nerve injury, including cell apoptosis, increased the levels of inflammatory factors, and upregulated the expression of glucose-regulated protein 78 (GRP78), p-Inositol Requiring Enzyme 1α (p-IRE1α), apoptosis signal-regulating kinase 1 (ASK1), and p-c-Jun N-terminal kinase (p-JNK)). Tauroursodeoxycholic acid (TUDCA), an ERS inhibitor, significantly reduced the pathological damage described above. The increases in the levels of inflammatory factors, pathological injury, and increased levels of proteins associated with the IRE1α-ASK1-JNK pathway were alleviated by L-NBP. The present study indicated that intermittent alcohol exposure could lead to hypothalamic cell apoptosis in adolescent rats and L-NBP could alleviate the above injury by inhibiting the IRE1α-ASK1-JNK pathway. Abbreviations: Ang-2, Angiopoietin-2; ASK1, Apoptosis signal-regulating kinase 1; ER, Endoplasmic reticulum; ERS, Endoplasmic reticulum stress; ELISA, Enzyme-linked immunosorbent assay; GFAP, Glial fibrillary acidic protein; GRP78, Glucose-regulated protein 78; IBA1, Ionized calcium binding adapter molecule 1; i.p., Intraperitoneal; IRE1α, Inositol Requiring Enzyme 1α; JNK, c-Jun N-terminal kinase; L-NBP, L-3-n-butylphthalide; PND, Postnatal day; PVDF, Polyvinylidene difluoride; SDS-PAGE, Sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TRAF2, TNF-receptor associated factor 2; TUDCA, Tauroursodeoxycholic acid; VEGF, Vascular endothelial growth factor.

Elevated manganese (Mn) exposure has been implicated in a broad spectrum of neurological disorders, including motor dysfunction and cognitive deficits. Previous studies have demonstrated that Mn induces neurotoxicity by disrupting the integrity of the blood-brain barrier (BBB), a critical regulator in maintaining central nervous system homeostasis and a contributing factor in the pathogenesis of numerous neurological disorders. However, the precise molecular mechanisms underlying Mn-induced BBB disruption and its role in facilitating neurotoxicity remain incompletely understood. The primary objectives of this study were to elucidate the mechanisms underlying the relationship between Mn exposure and BBB tight junction proteins (TJPs), and to further investigate potential neuroprotective strategies for mitigating Mn-induced cognitive impairments. In this investigation, we developed Mn exposure models utilizing both murine subjects and cell culture systems to elucidate the mechanisms underlying TJPs involvement and to assess the potential neuroprotective effects of gastrodin (GAS), a bioactive compound extracted from traditional Chinese medicine. Our findings revealed a significant reduction in TJPs expression, both in vivo and in vitro, in Mn-induced BBB disruption. The overexpression of Occludin (OCLN), a crucial component of TJPs, mitigated Mn-induced BBB damage. GAS administration effectively attenuated Mn-induced disruption of the BBB, enhanced the expression of TJPs, and mitigated Mn-induced cognitive dysfunctions, potentially through the modulation of the RhoA/ROCK2 signaling pathway. This research sought to advance our understanding of the molecular pathways involved in Mn-mediated BBB disruption and to identify novel therapeutic approaches for mitigating the deleterious effects of Mn exposure on cognitive function.

Opioids have been the primary method used to manage pain for hundreds of years, however the increasing prescription rate of these drugs in the modern world has led to a public health crisis of overdose related deaths. Naloxone is the current standard treatment for opioid overdose rescue, but it has not been fully investigated for potential off-target toxicity effects. The current methods for pharmaceutical development do not correlate well with pre-clinical animal studies compared to clinical results, creating a need for improved methods for therapeutic evaluation. Microphysiological systems (MPS) are a rapidly growing field, and the FDA has accepted this area of research to address this concern, offering a promising alternative to traditional animal models. This study establishes a novel multi-organ MPS model of acute opioid overdose and rescue to investigate the efficacy and off-target toxicity of naloxone in combination with opioids. By integrating primary human and human induced pluripotent stem cell (hiPSC)-derived cells, including preBötzinger complex neurons, liver, cardiac, and skeletal muscle components, this study establishes a novel functional multi-organ MPS model of acute opioid overdose and rescue to investigate the efficacy and off-target toxicity of naloxone in combination with opioids, with clinically relevant functional readouts of organ function. The system was able to successfully exhibit opioid overdose using methadone, as well as rescue using naloxone evidenced by the neuronal component activity. In addition to efficacy, the multi-organ platform was able to characterize potential off-target toxicity effects of naloxone, specifically in the cardiac component.

The anthraquinone dye Alizarin Red S (ARS) is used for marking live animals, specifically as a tool for monitoring the stock of the endangered European eel by marking caught fish with ARS before releasing the eels back into the wild. As ARS can be found in recaptured eels even years later, knowledge of potential health hazards of ARS is essential for assessing the food safety of eels marked with ARS. As the compound class of anthraquinones is known for their genotoxic and carcinogenic properties, concerns were raised regarding the food safety of marked eels. Up to now, no data for characterizing the hazard potential of ARS is available. In this study, we aimed at closing this data gap. We tested ARS in liver (HepG2), cervix (HeLa) and lymphoblast (TK-6) cells and identified HepG2 cells as the cell line most sensitive to ARS-induced cytotoxicity. We then investigated oxidative stress, DNA strand breaks, and micronucleus formation in these cells and did not observe effects at sub-cytotoxic concentrations.

Mechanistically based non-animal methods for assessing skin sensitization hazard have been developed, but are not considered sufficient, individually, to conclusively define the skin sensitization potential or potency of a chemical. This resulted in the development of defined approaches (DAs), as documented in OECD TG 497, for combining information sources in a prescriptive manner to provide a determination of risk or potency. However, there are currently no DAs within OECD TG 497 that can derive a point of departure (POD) for risk assessment. The Skin Allergy Risk Assessment - Integrated Chemical Environment (SARA-ICE) DA for skin sensitization is a Bayesian statistical model that estimates a human-relevant metric of sensitizer potency, the ED₀₁, an estimate of the human predictive patch test dermal dose at which there is 1% chance of inducing sensitization, which can be used in a risk assessment paradigm. The model accounts for variability of input data and explicitly quantifies uncertainty. SARA-ICE derives the ED₀₁ from a variety of in vitro and in vivo test method data and is built upon historical human, murine, and in vitro test data for 434 chemicals. In addition to the ED₀₁ POD SARA-ICE DA also provides a Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classification probability for GHS subcategories 1A, 1B and not classified (NC). Here we describe the SARA-ICE model and its evaluation, including performance versus benchmark PODs. In addition, via a case study with isothiazolinones (ITs), we demonstrate the utility of SARA-ICE for integrating different data inputs and compare the ED₀₁ for six ITs to existing historical data.

The present study describes the "fit for purpose" testing and the independent product-specific GMP validation of the monocyte activation test (MAT) to detect pyrogenic and pro-inflammatory contaminants, MAT Method A, Quantitative Test (European Pharmacopoeia, Ph. Eur. chapter 2.6.30, 2017). A fit for purpose study was carried out to ensure that the chosen MAT set-up (cryopreserved PBMC, IL-6 detection) can reliably discriminate between batches of product containing pyrogenic contaminants below the contaminants limit concentration, CLC, from batches containing pyrogenic contaminants above the CLC. Such testing is carried out once, before the chosen MAT set-up is used for subsequent product testing to show that the incidence of false positives (pyrogen-negative (CLC) batches) and - especially - false negatives (pyrogen-positive (>CLC) testing as pyrogen-negative (