Toxicology Mechanisms and Methods最新文献

In biomedical research, the fruit fly (Drosophila melanogaster) is among the most effective and flexible model organisms. Through the use of the Drosophila model, molecular mechanisms of human diseases can be investigated and candidate pharmaceuticals can be screened. White rot fungus Inonotus obliquus is a member of the family Hymenochaetaceae. Due to its multifaceted pharmacological effects, this fungus has been the subject of scientific investigation. Nevertheless, the precise mechanisms by which Inonotus obliquus treats diseases remain unclear. In this study, we prepared an aqueous extract derived from Inonotus obliquus and demonstrated that it effectively prevented the negative impacts of inflammatory agents on flies, including overproliferation and overdifferentiation of intestinal progenitor cells and decreased survival rate. Furthermore, elevated reactive oxygen species levels and cell death were alleviated by Inonotus obliquus aqueous extract, suggesting that this extract inhibited intestinal inflammation. Additionally, Inonotus obliquus aqueous extract had an impact on the insulin pathway, as it alleviated growth defects in flies that were fed a high-sugar diet and in chico mutants. In addition, we determined the composition of Inonotus obliquus aqueous extract and conducted a network pharmacology analysis in order to identify prospective key compounds and targets. In brief, Inonotus obliquus aqueous extract exhibited considerable potential as a therapeutic intervention for human diseases. Our research has established a foundational framework that supports the potential clinical implementation of Inonotus obliquus.

Chronic exposure to manganese compounds leads to accumulation of the manganese in the basal ganglia and hippocampus. High levels of manganese in these structures lead to oxidative stress, neuroinflammation, imbalance of brain neurotransmitters, and hyperactivation of calpains mediating neurotoxicity and causing motor and cognitive impairment. The purpose of this work was to study the effect of excess manganese chloride intake on rats' spatial memory and on dopamine-β-hydroxylase (DβH) activity under conditions of calpain activity suppression. Rats were divided into 3 groups of 10 animals each. Group 1 received MnCl₂ (30 days, 5 mg/kg/day, intranasally), group 2 received MnCl₂ (30 days, 5 mg/kg/day, intranasally) and calpain inhibitor Cast (184-210) (30 days, 5 µg/kg/day, intranasally), and group 3 received sterile saline (30 days in a volume of 20 μl, intranasally). The spatial working memory was assessed using Morris water maze test. DβH activity was determined by HPLC. We have shown that in response to excessive intake of MnCl₂, there was a development of cognitive impairments in rats, which was accompanied by a decrease in DβH activity in the hippocampus. The severity of cognitive impairment was reduced by inhibiting the activity of m-calpain. The protective effect of calpain inhibitors was achieved not through an effect on DβH activity. Thus, the development of therapeutic regimens for the treatment of manganism using dopaminomimetics and/or by inhibiting calpains, must be performed taking into account the manganese-induced decrease of DβH activity and the inability to influence this process with calpain inhibitors.

Malignant melanoma is the most aggressive type of skin cancer with increasing incidence rates worldwide. On the other hand, watercress is a rich source of phenethyl isothiocyanate (PEITC), among others, which has been widely investigated for its anticancer properties against various cancers. In the present study, we evaluated the role of a watercress extract in modulating apoptotic induction in an in vitro model of human malignant melanoma consisting of melanoma (A375, COLO-679, COLO-800), non-melanoma epidermoid carcinoma (A431) and immortalized, non-tumorigenic keratinocyte (HaCaT) cells. Moreover, the chemical composition of the watercress extract was characterized through UPLC MS/MS and other analytical methodologies. In addition, cytotoxicity was assessed by the alamar blue assay whereas apoptosis was determined, initially, by a multiplex activity assay kit (measuring levels of activated caspases -3, -8 and -9) as well as by qRT-PCR for the identification of major genes regulating apoptosis. In addition, protein expression levels were evaluated by western immunoblotting. Our data indicate that the extract contains various phytochemicals (e.g. phenolics, flavonoids, pigments, etc.) while isothiocyanates (ITCs; especially PEITC) were the most abundant. In addition, the extract was shown to exert a significant time- and dose-dependent cytotoxicity against all malignant melanoma cell lines while non-melanoma and non-tumorigenic cells exhibited significant resistance. Finally, expression profiling revealed a number of genes (and corresponding proteins) being implicated in regulating apoptotic induction through activation of the intrinsic apoptotic cascade. Overall, our data indicate the potential of PEITC as a promising anti-cancer agent in the clinical management of human malignant melanoma.

Rotenone is a pesticide that causes complex I inhibition and is widely known to induce motor disability and experimental Parkinson's disease (PD) in rodents. Evidence suggests a crucial role for sirtuin/nuclear factor-kappaB/nod-like receptor family, pyrin domain-containing 3 (SIRT1/NFκB/NLRP3) signaling and inflammation in PD and rotenone neurotoxicity. Hesperetin (C16H14O6) is a citrus flavonoid with documented anti-inflammatory activity. We investigated the value of hesperetin in delaying rotenone-induced PD in mice and the possible modulation of inflammatory burden. PD was induced in mice via rotenone injections. Groups were assigned as a vehicle, PD, or PD + hesperetin (50 or 100 mg/kg) and compared for the motor function, protein level (by ELISA), and gene expression (by real-time PCR) of the target proteins, histopathology, and immunohistochemistry for tyrosine hydroxylase enzyme. Hesperetin (50 or 100 mg/kg) alleviated the motor disability and the striatal dopamine level and decreased the expression of NLRP3 and NF-κB but increased SIRT1 expression (p < 0.05). Further, it enhanced the neural viability and significantly decreased neural degeneration in the substantia nigra, hippocampus, and cerebral cortex (p < 0.05). Taken together, we propose that hesperetin mediates its neuroprotective function via alleviating modulation of the SIRT1/NFκB/NLRP3 pathway. Therefore, hesperetin might delay the PD progression.

The harmful effects of PM_2.5 on human health, including an increased risk of chronic kidney disease (CKD), have raised a lot of attention, but the underlying mechanisms are unclear. We used the Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) to simulate the inhalation of PM_2.5 in the real environment and established an animal model by exposing C57BL/6 mice to filtered air (FA) and Particulate Matter (PM_2.5) for 8 weeks. PM_2.5 impaired the renal function of the mice, and the renal tubules underwent destructive changes. Analysis of NHANES data showed a correlation between reduced kidney function and higher blood levels of PM_2.5 components, polychlorinated biphenyls (PCBs) and dioxins, which are Aryl hydrocarbon Receptor (AhR) ligands. PM_2.5 exposure induced higher levels of AhR and CYP1A1 and oxidative stress as evidenced by the higher levels of ROS, MDA, and GSSG in kidneys of mice. PM_2.5 exposure led to AhR overexpression and nuclear translocation in proximal renal tubular epithelial cells. Inhibition of AhR reduced CYP1A1 expression and PM_2.5-increased levels of ROS, MDA and GSSG. Our study suggested metformin can mitigate PM_2.5-induced oxidative stress by inhibiting the AhR/CYP1A1 pathway. These findings illuminated the role of AhR/CYP1A1 pathway in PM_2.5-induced kidney injury and the protective effect of metformin on PM_2.5-induced cellular damage, offering new insights for air pollution-related renal diseases.

Introduction: Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) exposition has been associated with health problems. Therefore, this research evaluated genotoxicity induced in male mice strain CD-1 exposed to benzo[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) and their interaction with Fe, Pb, and Al.

Methods: Groups of animals were exposed intraperitoneally to HM, PAHs, and mixtures of both. Peripheral blood samples were taken from 0 to 96 h at 24 h intervals; genotoxicity was determined by micronucleus tests and comet assay. Additionally, toxicity and viability were evaluated.

Results: HM and PAHs individually were genotoxic. About toxicity, only Al altered polychromatic erythrocytes number and did not change leukocytes viability. Concerning mixtures, Fe + B[a]P, Fe + B[a]A, Pb + B[a]P increased genotoxicity. There were no changes with Pb + B[a]A. Finally, Al mixtures with both PAHs damage was decreased.

Conclusions: Exposure to HM and PAH caused genetic damage. Fe, Al, and B[a]A, established a genotoxic potential. Every metal can interact with PAHs in different ways. Also, the micronucleus test and the comet assay demonstrated their high capacity and reliability to determine the genotoxic potential of the compounds evaluated in this work.

Cooking oil fumes (COFs) are widely acknowledged as substantial contributors to indoor air pollution, having detrimental effects on human health. Despite the existence of commercialized in vitro aerosol exposure platforms, assessment risks of aerosol pollutants are primarily evaluated based on multiwell plate experiments by trapping and redissolving aerosols to conduct comprehensive in vitro immersion exposure manner. Therefore, an innovative real-time exposure system for COF aerosol was constructed, featuring a self-designed microfluidic chip as its focal component. The chip was used to assess toxicological effects of in vitro exposure to COF aerosol on cells cultured at the gas-liquid interface. Meanwhile, we used transcriptomics to analyze genes that exhibited differential expression in cells induced by COF aerosol. The findings indicated that the MAPK signaling pathway, known for its involvement in inflammatory response and oxidative stress, played a crucial role in the biological effects induced by COF aerosol. Biomarkers associated with inflammatory response and oxidative stress exhibited corresponding alterations. Furthermore, the concentration of COF aerosol exposure and post-exposure duration exert decisive effects on these biomarkers. Thus, the study suggests that COF can induce oxidative stress and inflammatory response in BEAS-2B cells, potentially exerting a discernible impact on human health.

Cyclosporine A (CsA) has shown efficacy against immunity-related diseases despite its toxicity in various organs, including the liver, emphasizing the need to elucidate its underlying hepatotoxicity mechanism. This study aimed to capture the alterations in genome-wide expression over time and the subsequent perturbations of corresponding pathways across species. Six data from humans, mice, and rats, including animal liver tissue, human liver microtissues, and two liver cell lines exposed to CsA toxic dose, were used. The microtissue exposed to CsA for 10 d was analyzed to obtain dynamically differentially expressed genes (DEGs). Single-time points data at 1, 3, 5, 7, and 28 d of different species were used to provide additional evidence. Using liver microtissue-based longitudinal design, DEGs that were consistently up- or down-regulated over time were captured, and the well-known mechanism involved in CsA toxicity was elucidated. Thirty DEGs that consistently changed in longitudinal data were also altered in 28-d rat in-house data with concordant expression. Some genes (e.g. TUBB2A, PLIN2, APOB) showed good concordance with identified DEGs in 1-d and 7-d mouse data. Pathway analysis revealed up-regulations of protein processing, asparagine N-linked glycosylation, and cargo concentration in the endoplasmic reticulum. Furthermore, the down-regulations of pathways related to biological oxidations and metabolite and lipid metabolism were elucidated. These pathways were also enriched in single-time-point data and conserved across species, implying their biological significance and generalizability. Overall, the human organoids-based longitudinal design coupled with cross-species validation provides temporal molecular change tracking, aiding mechanistic elucidation and biologically relevant biomarker discovery.

Professional painters represent an occupational population group that deserves attention for study in the field of occupational toxicology due to the wide range of complex chemical mixtures they are exposed to. It is imperative to underscore that the International Agency for Research on Cancer has classified commercial painting as a high-risk occupation for the development of cancer. Given this context, the primary objective of the present study was to conduct a systematic review aimed at addressing the following question: are car painters at occupational risk regarding potential genotoxicity? To address this question, a selection process was undertaken, with three reviewers carefully selecting, reading, and analyzing full manuscripts from 26 studies included in this review. The technical rigor of these studies underwent meticulous scrutiny, culminating in the classification of six studies as Strong, eight as Moderate, and 12 as Weak, predicated on the extent of confounders considered. Taken together, the findings suggest that chemical substances from paints may indeed pose a risk of genotoxicity for professionals in this field, as all studies indicated genotoxicity among professional painters through various tests.

The waterpipe works by placing tobacco in a bowl with holes at the bottom, which is connected to a tube leading to a water-filled container. Upon heating the tobacco product with hot charcoal placed atop it, the emanating smoke is inhaled by the user via a hose linked to the water receptacle. The aim of this literature review is to evaluate whether the use of waterpipes can indeed induce genotoxicity in mammalian cells in vivo. Additionally, the study aims to assess the quality of the included research articles on this topic to ensure the reliability of the findings. We performed comprehensive searches in PubMed, SCOPUS, and Web of Science to identify relevant articles published until July 2024. The findings confirmed that waterpipe smoke induces genetic damage. This assertion is supported by the fact that 11 studies (out of 15) received a Strong or Moderate assessment categorization, suggesting that the majority of studies adhered to most technical standards, thereby enhancing the reliability of the research findings. Regarding the types of DNA damage reported, DNA strand breaks, chromosome damage and oxidative DNA damage were found in this review. Taken together, this study holds significant importance in assessing the efficacy of genotoxicity assays in detecting DNA damage due to waterpipe smoke and the comet and micronucleus assays are suitable biomarkers for biomonitoring people who use waterpipe.