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Electronic cigarettes (ECIGs) have always been promoted as safer alternatives to combustible cigarettes. However, a growing amount of literature shows that while ECIGs do not involve combustion-derived toxicants, thermal degradation of the main constituents of ECIG liquid produces toxicants such as carbonyls. In this study, we report the detection of phenolic compounds in ECIG aerosols using a novel analytical method. The introduced method relies on liquid-liquid extraction to separate phenols from the major constituents of ECIG aerosol propylene glycol (PG) and vegetable glycerol (VG). Phenol emissions from ECIGs were tested at different powers, puff durations, PG/VG ratios, nicotine benzoate concentrations, and flow rates to assess the influence of these operating parameters on phenol formation. The performance metrics showed that the analytical method has high specificity and reliability to separate and quantify phenolic compounds in ECIG aerosols. Increasing power and puff duration significantly increased conditions that lead to a higher temperature and greater thermal degradation.Drug-induced toxicity has, in many cases, been linked to oxidative metabolism resulting in the formation of reactive metabolites and subsequent covalent binding to biomolecules. Two structurally related antipsychotic drugs, clozapine (CLZ) and olanzapine (OLZ), are known to form similar nitrenium ion reactive metabolites. CLZ-derived reactive metabolites have been linked to agranulocytosis and hepatotoxicity. We have studied the oxidative metabolism of CLZ and OLZ as well as two known metabolites of CLZ, desmethyl-CLZ (DCLZ), and CLZ-N-oxide (CLZ-NO), using in vitro rat liver microsomal (RLM) incubations with glutathione (GSH) trapping of reactive metabolites and liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). Reactive metabolite binding to selected standard peptides and recombinant purified human proteins was also evaluated. Bottom-up proteomics was performed using two complementary proteases, prefractionation of peptides followed by LC-HRMS/MS for elucidating modifications of target proteins. Induced RLM was selected to form reactive metabolites enzymatically to assess the complex profile of reactive metabolite structures and their binding potential to standard human proteins. Multiple oxidative metabolites and several different GSH adducts were found for CLZ and OLZ. Modification sites were characterized on human glutathione S-transferase (hGST) alpha 1 (OLZ-modified at Cys112), hGST mu 2 (OLZ at Cys115), and hGST pi (CLZ, DCLZ, CLZ-NO and OLZ at Cys170), human microsomal GST 1 (hMGST1, CLZ and OLZ at Cys50), and human serum albumin (hSA, CLZ at Cys34). Furthermore, two modified rat proteins, microsomal GST 1 (CLZ and OLZ at Cys50) and one CYP (OLZ-modified, multiple possible isoforms), from RLM background were also characterized. In addition, direct effects of the reactive metabolite modifications on proteins were observed, including differences in protease cleavage specificity, chromatographic behavior, and charge-state distributions.The use of medicinal plants concomitantly with conventional drugs can result in herb-drug interactions that cause fluctuations in drug bioavailability and consequent therapeutic failure and/or toxic effects. The CYP superfamily of enzymes plays an important role in herb-drug interactions. Among CYP enzymes, CYP3A4 and CYP2D6 are the most relevant since they metabolize about 50% and 30% of the drugs on the market, respectively. Thus, the main goal of this study was to evaluate the occurrence of in vitro interactions between medicinal plant extracts and drug substrates of CYP3A4 and CYP2D6 enzymes. Standardized extracts from nine medicinal plants (Bauhinia forficata, Cecropia glaziovii, Cimicifuga racemosa, Cynara scolymus, Echinacea sp., Ginkgo biloba, Glycine max, Ilex paraguariensis, and Matricaria recutita) were evaluated for their potential interactions mediated by CYP3A4 and CYP2D6 enzymes. Among the extracts tested, C. glaziovii (red embaúba) showed the most relevant inhibitory effects of CYP3A4 and CYP2D6 activity, while I. paraguariensis (yerba mate) inhibited CYP3A4 activity. Both extracts were chemically analyzed by UPLC-MS/MS, and these inhibitory effects could lead to clinically potential and relevant interactions with the drug substrates of these isoenzymes.Balkan endemic nephropathy (BEN) is a slowly progressive interstitial fibrotic disease affecting numerous people living along the Danube River in the Balkan Peninsula, of which aristolochic acids (AAs) produced naturally in Aristolochia plants are key etiological agents. However, the exposure biology of the disease remains poorly understood. Initially, the high incidence of BEN in the Balkan Peninsula was thought to occur through ingestion of bread prepared from flour made with wheat grains comingled with the seeds of Aristolochia clematitis L., an AA-containing weed that grows abundantly in the wheat fields of the affected areas. In this study, by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, we show for the first time that vegetables, in particular root vegetables of endemic areas, are extensively contaminated with AAs taken up through root absorption from the AA-tainted soil. Furthermore, we found a pH dependence of the n-octanol/water partition coefficient (Kow) of AAs, which resulted in a dramatically higher hydrophobicity-driven plant uptake efficiency of AAs into food crops in endemic areas, characterized by higher acidity levels, compared to non-endemic areas. We believe the results of this study have significantly unraveled the mystery surrounding the uneven distribution of BEN incidence.We have previously shown that phenyl saligenin phosphate (PSP), an organophosphorus compound which is classed as a weak inhibitor of acetylcholinesterase, triggered cytotoxicity in mitotic and differentiated H9c2 cardiomyoblasts. The aim of this study was to assess whether sublethal concentrations of PSP could disrupt the morphology of differentiating rat H9c2 cardiomyoblasts and human-induced pluripotent stem-cell-derived cardiomyocyte progenitor cells (hiPSC-CMs) and to assess the underlying cytoskeletal changes. PSP-induced changes in protein expression were monitored via Western blotting, immunocytochemistry, and proteomic analysis. PSP-mediated cytotoxicity was determined by measuring MTT reduction, LDH release, and caspase-3 activity. Sublethal exposure to PSP (3 μM) induced morphological changes in differentiating H9c2 cells (7, 9, and 13 days), reflected by reduced numbers of spindle-shaped cells. Moreover, this treatment (7 days) attenuated the expression of the cytoskeletal proteins cardiac troponin I, tropomyosin-1, and α-actin. Further proteomic analysis identified nine proteins (e.g., heat shock protein 90-β and calumenin) which were down-regulated by PSP exposure in H9c2 cells. To assess the cytotoxic effects of organophosphorus compounds in a human cell model, we determined their effects on human-induced pluripotent stem-cell-derived cardiomyocyte progenitor cells. Chlorpyrifos and diazinon-induced cytotoxicity (48 h) was evident only at concentrations >100 μM. By contrast, PSP exhibited cytotoxicity in hiPSC-CMs at a concentration of 25 μM following 48 h exposure. Finally, sublethal exposure to PSP (3 μM; 7 days) induced morphological changes and decreased the expression of cardiac troponin I, tropomyosin-1, and α-actin in hiPSC-CMs. In summary, our data suggest cardiomyocyte morphology is disrupted in both cell models by sublethal concentrations of PSP via modulation of cytoskeletal protein expression.Predicting the structures of metabolites formed in humans can provide advantageous insights for the development of drugs and other compounds. Here we present GLORYx, which integrates machine learning-based site of metabolism (SoM) prediction with reaction rule sets to predict and rank the structures of metabolites that could potentially be formed by phase 1 and/or phase 2 metabolism. selleck compound GLORYx extends the approach from our previously developed tool GLORY, which predicted metabolite structures for cytochrome P450-mediated metabolism only. A robust approach to ranking the predicted metabolites is attained by using the SoM probabilities predicted by the FAME 3 machine learning models to score the predicted metabolites. On a manually curated test data set containing both phase 1 and phase 2 metabolites, GLORYx achieves a recall of 77% and an area under the receiver operating characteristic curve (AUC) of 0.79. Separate analysis of performance on a large amount of freely available phase 1 and phase 2 metabolite data indicates that achieving a meaningful ranking of predicted metabolites is more difficult for phase 2 than for phase 1 metabolites. GLORYx is freely available as a web server at https//nerdd.zbh.uni-hamburg.de/ and is also provided as a software package upon request. The data sets as well as all the reaction rules from this work are also made freely available.The concern about titanium dioxide nanoparticles (TiO2-NPs) toxicity and their possible harmful effects on human health has increased. Their biological impact is related to some key physicochemical properties, that is, particle size, charge, crystallinity, shape, and agglomeration state. However, the understanding of the influence of such features on TiO2-NP toxicity remains quite limited. In this study, cytotoxicity, proinflammatory response, and oxidative stress caused by five types of TiO2-NPs with different physicochemical properties were investigated on A549 cells used either as monoculture or in co-culture with macrophages differentiated from the human monocytic THP-1 cells. We tailored bulk and surface TiO2 physicochemical properties and differentiated NPs for size/specific surface area, shape, agglomeration state, and surface functionalization/charge (aminopropyltriethoxysilane). An impact on the cytotoxicity and to a lesser extent on the proinflammatory responses depending on cell type was observed, namely, smaller, large-agglomerated TiO2-NPs were shown to be less toxic than P25, whereas rod-shaped TiO2-NPs were found to be more toxic. Besides, the positively charged particle was slightly more toxic than the negatively charged one. Contrarily, TiO2-NPs, whatever their physicochemical properties, did not induce significant ROS production in both cell systems compared to nontreated control groups. These results may contribute to a better understanding of TiO2-NPs toxicity in relation with their physicochemical features.Recent studies have raised concerns about e-cigarette liquid inhalation toxicity by reporting the presence of chemicals with European Union CLP toxicity classification. In this scenario, the regulatory context is still developing and is not yet up to date with vaping current reality. Due to the paucity of toxicological studies, robust data regarding which components in e-liquids exhibit potential toxicities, are still inconsistent. In this study we applied computational methods for estimating the toxicity of poorly studied chemicals as a useful tool for predicting the acute toxicity of chemicals contained in e-liquids. The purpose of this study was 3-fold (a) to provide a lower tier assessment of the potential health concerns associated with e-liquid ingredients, (b) to prioritize e-liquid ingredients by calculating the e-tox index, and (c) to estimate acute toxicity of e-liquid mixtures. QSAR models were generated using QSARINS software to fill the acute toxicity data gap of 264 e-liquid ingredients. As a second step, the potential acute toxicity of e-liquids mixtures was evaluated.
Homepage: https://www.selleckchem.com/products/pf-9366.html
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