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British Journal of Pharmacology Sep 2022HERG blocking drugs known for their propensity to trigger Torsades de Pointes (TdP) were reported to induce a sympatho-vagal coactivation and to enhance High Frequency...
BACKGROUND AND PURPOSE
HERG blocking drugs known for their propensity to trigger Torsades de Pointes (TdP) were reported to induce a sympatho-vagal coactivation and to enhance High Frequency heart rate (HFHR) and QT oscillations (HFQT) in telemetric data. The present work aimed to characterize the underlying mechanism(s) leading to these autonomic changes.
EXPERIMENTAL APPROACH
Effects of 15 torsadogenic hERG blocking drugs (astemizole, chlorpromazine, cisapride, droperidol, ibutilide, dofetilide, haloperidol, moxifloxacin, pimozide, quinidine, risperidone, sotalol, sertindole, terfenadine, and thioridazine) were assessed by telemetry in beagle dogs. Haemodynamic effects on diastolic and systolic arterial pressure were analysed from the first doses causing QTc prolongation and/or HFQT oscillations enhancement. Autonomic control changes were analysed using the high frequency autonomic modulation (HFAM) model.
KEY RESULTS
Except for moxifloxacin and quinidine, all torsadogenic hERG blockers induced parasympathetic activation or sympatho-vagal coactivation combined with enhancement of HFQT oscillations. These autonomic effects result from reflex compensatory mechanisms in response to mild haemodynamic side effects. These haemodynamic mechanisms were characterized by transient HR acceleration during HF oscillations. A phenomenon of concealed QT prolongation was unmasked for several torsadogenic hERG blockers under β-adrenoceptor blockade with atenolol. Resulting enhancement of HFQT oscillations was shown to contribute directly to triggering dofetilide-induced ventricular arrhythmias.
CONCLUSION AND IMPLICATIONS
This work supports for the first time a contribution of haemodynamic side properties to ventricular arrhythmias triggered by torsadogenic hERG blocking drugs. These haemodynamic side effects may constitute a second component of their arrhythmic profile, acting as a trigger alongside their intrinsic arrhythmogenic electrophysiological properties.
Topics: Animals; Arrhythmias, Cardiac; Dogs; Drug-Related Side Effects and Adverse Reactions; Electrocardiography; Ether-A-Go-Go Potassium Channels; Heart Rate; Long QT Syndrome; Moxifloxacin; Quinidine; Reflex; Torsades de Pointes
PubMed: 35751378
DOI: 10.1111/bph.15905 -
ACS Omega Jun 2022Novel drug development is a time-consuming process with relatively high debilitating costs. To overcome this problem, computational drug repositioning approaches are...
Exploration of Potential Ewing Sarcoma Drugs from FDA-Approved Pharmaceuticals through Computational Drug Repositioning, Pharmacogenomics, Molecular Docking, and MD Simulation Studies.
Novel drug development is a time-consuming process with relatively high debilitating costs. To overcome this problem, computational drug repositioning approaches are being used to predict the possible therapeutic scaffolds against different diseases. In the current study, computational drug repositioning approaches were employed to fetch the promising drugs from the pool of FDA-approved drugs against Ewing sarcoma. The binding interaction patterns and conformational behaviors of screened drugs within the active region of Ewing sarcoma protein (EWS) were confirmed through molecular docking profiles. Furthermore, pharmacogenomics analysis was employed to check the possible associations of selected drugs with Ewing sarcoma genes. Moreover, the stability behavior of selected docked complexes (drugs-EWS) was checked by molecular dynamics simulations. Taken together, astemizole, sulfinpyrazone, and pranlukast exhibited a result comparable to pazopanib and can be used as a possible therapeutic agent in the treatment of Ewing sarcoma.
PubMed: 35721972
DOI: 10.1021/acsomega.2c00518 -
The Journal of Pharmacology and... Aug 2022Infigratinib (INF) is a fibroblast growth factor receptor inhibitor that was recently United States Food and Drug Administration-approved for the treatment of advanced...
Identification of Infigratinib as a Potent Reversible Inhibitor and Mechanism-Based Inactivator of CYP2J2: Nascent Evidence for a Potential In Vivo Metabolic Drug-Drug Interaction with Rivaroxaban.
Infigratinib (INF) is a fibroblast growth factor receptor inhibitor that was recently United States Food and Drug Administration-approved for the treatment of advanced or metastatic cholangiocarcinoma. We previously established that INF inhibited and inactivated cytochrome P450 3A4 (CYP3A4). Here, in a follow up to our previous study, we identified for the first time that INF also elicited potent competitive inhibition and mechanism-based inactivation of CYP2J2 with kinetic parameters , , , and a partition ratio of 1.94 M, 0.10 M, 0.026 minute, and ∼3, respectively, when rivaroxaban was harnessed as the probe substrate. Inactivation was revealed to exhibit cofactor-dependency and was attenuated by an alternative substrate (astemizole) and direct inhibitor (nilotinib) of CYP2J2. Additionally, the nature of inactivation was unlikely to be pseudo-irreversible and instead arose from covalent modification due to the lack of substantial enzyme activity recovery after dialysis and chemical oxidation, as well as the lack of a resolvable Soret band in spectral scans. Glutathione trapping confirmed that the identity of the putative reactive intermediate implicated in the covalent inactivation of both CYP2J2 and CYP3A4 was identical and likely attributable to an electrophilic -benzoquinonediimine intermediate of INF. Finally, mechanistic static modeling revealed that by integrating the previously arcane inhibition and inactivation kinetic parameters of CYP2J2-mediated rivaroxaban hydroxylation by INF illuminated in this work, together with those previously documented for CYP3A4, a 49% increase in the systemic exposure of rivaroxaban was projected. Our modeling results predicted a potential risk of metabolic drug-drug interactions between the clinically relevant combination of rivaroxaban and INF in the setting of cancer. SIGNIFICANCE STATEMENT: This study reported that INF elicits potent reversible inhibition and mechanism-based inactivation of CYP2J2. Furthermore, static modelling predicted that its coadministration with the direct oral anticoagulant rivaroxaban may potentially culminate in a metabolic drug-drug interaction (DDI) leading to an increased risk of major bleeding. As rivaroxaban is steadily gaining prominence as the anticoagulant of choice in the treatment of cancer-associated venous thromboembolism, the DDI projections reported here are clinically relevant and warrant further investigation via physiologically based pharmacokinetic modelling and simulation.
Topics: Anticoagulants; Cytochrome P-450 CYP2J2; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Drug Interactions; Phenylurea Compounds; Pyrimidines; Rivaroxaban
PubMed: 35640957
DOI: 10.1124/jpet.122.001222 -
Annals of Medicine and Surgery (2012) Jun 2022Cardiac toxicity is a very seldom documented side effect of Pheniramine. Although second-generation antihistamines such as terfenadine and astemizole have been linked to...
Cardiac toxicity is a very seldom documented side effect of Pheniramine. Although second-generation antihistamines such as terfenadine and astemizole have been linked to cardiac injury, the incidence of SVT after Pheniramine treatment on adult clinical dose is currently unknown. In this case, we present a 22-year-old girl who developed adenosine-resistant supraventricular tachycardia (SVT) after being given pheniramine due to a bean allergy. It is crucial to know that symptomatic SVT could occur with therapeutic doses of pheniramine. This case highlights the importance of a comprehensive drug evaluation in emergency situations to identify the underlying etiologies and prompt treatment commencement. It also emphasizes the significance of assessing and choosing acute drugs for each patient admitted to the emergency unit to ensure the start of a newer medication if necessary.
PubMed: 35600167
DOI: 10.1016/j.amsu.2022.103621 -
Methods in Molecular Biology (Clifton,... 2022Human ether-a-go-go-related gene (hERG) channel plays an essential role in the repolarization of the cardiac action potential. Genetic mutations and some chemicals/drugs...
Human ether-a-go-go-related gene (hERG) channel plays an essential role in the repolarization of the cardiac action potential. Genetic mutations and some chemicals/drugs interfere with hERG channel activity, which may prolong the QT interval and potentially cause long QT syndrome. The FluxOR™ thallium flux assay performed in two cell lines, U2OS and HEK293, with stable hERG expression can be used to identify compounds that inhibit hERG channel activity. This chapter describes a cell-based hERG channel inhibition assay that has been optimized and performed in a 1536-well plate format. The homogeneous and robust assay can be used to identify compounds that inhibit hERG channel activity.
Topics: Action Potentials; Ether-A-Go-Go Potassium Channels; HEK293 Cells; Humans; Long QT Syndrome; Research Design
PubMed: 35294752
DOI: 10.1007/978-1-0716-2213-1_3 -
Se Pu = Chinese Journal of... Mar 2022An accurate mass database and a method based on ultra high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry...
[Rapid screening and identification of 167 illegally added medicines in herbal tea by ultra high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry].
An accurate mass database and a method based on ultra high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry (UHPLC-Orbitrap HRMS) were developed. These were applied in the screening and identification of illegally added medicines in herbal tea. Based on investigations, 167 medicines were selected to build an accurate MS database; these medicines included antipyretic analgesics, glucocorticoids, antibiotics, and antihistamines, among other categories. The database was established using Orbitrap HRMS and TraceFinder software. The database carried information on all selected compounds, including the molecular formula, accurate mass of precursor ions and fragment ions, retention time, and mass spectra. The samples were ultrasonically extracted with a 50% (v/v) methanol aqueous solution. The extracted solutions were separated using a Waters XBrigde BEH C18 column (100 mm×2.1 mm, 2.5 μm). As the mobile phases, 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid were used, with gradient elution. The sample solutions were analyzed by Orbitrap HRMS in the full-scan MS and data-dependent MS/MS acquisition modes (Full MS/dd-MS). Positive and negative polarity data were simultaneously acquired. Some parameters were optimized to increase the peak intensity and sensitivity of all compounds. The resolutions in the full-MS scan and dd-MS scan were set to 70000 and 17500, respectively. In the full-MS mode, scanning was performed in the range of m/z 100 to 1000. In the MS/MS mode, the normalized collision energy (NEC) was set to 20%, 40%, and 60% for each compound. The inclusion list was not used during the measurement, and the dynamic exclusion time was set to 10.0 s. The loop count was set to 5. After acquiring the sample data with these conditions using Orbitrap MS, they were imported into TraceFinder software, through which the sample information was extracted and automatically matched with the information on compounds in the MS database. Screening and identification were conducted by comparing the retention times as well as the exact masses of precursor ions and fragment ions that were experimentally measured. If the errors between the experimentally and theoretically obtained masses of the precursor ions were below 5×10 and the deviations in retention times were less than 20 s, then suspicious positive compounds might be identified. Furthermore, if such compounds possess more than one similar fragment ion with a mass tolerance below 5×10, and exhibit similar ion distributions in the MS/MS profiles (compared to those in the database), they could be confirmed to be the same. The validation result showed that all compounds had good linear relationships, with correlation coefficients (r) greater than 0.99. Because pefloxacin, norfloxacin, desloratadine, astemizole and clindamycin had background interference, the method was not suitable for their quantification. Following experiments using three spiked concentrations, the recoveries of the rest 162 compounds were found to be in the range of 66.4%-118.1%, and the relative standard deviations (RSDs, n=6), in the range of 0.1%-16.1%. When the limit of detection (LOD) was 0.2 mg/kg, 83 compounds were detected, while when the LOD was 1.0 mg/kg, 167 compounds were detected. All compounds were matched successfully to the standard added sample with the MS database in TraceFinder software. To lower the likelihood of false positive and false negative results, a quality control method was recommended. The method was applied to analyze 245 herbal tea samples, among which 12 positive samples were detected. Thirteen positive compounds were found, including acetaminophen, diclofenac sodium, chlorpheniramine, brompheniramine, dexamethasone, dexamethasone 21-acetate, prednisone, prednisone 21-acetate, metronidazole, erythromycin, ciprofloxacin, amantadine, and dextromethorphan. In particular, amantadine, dextromethorphan, brompheniramine, and ciprofloxacin were newly detected, compared to standard methods. The developed method is rapid and accurate, and will be useful in the high-throughput screening of illegally added medicines in herbal tea.
Topics: Chromatography, High Pressure Liquid; Limit of Detection; Static Electricity; Tandem Mass Spectrometry; Teas, Herbal
PubMed: 35243835
DOI: 10.3724/SP.J.1123.2021.07006 -
International Journal of Molecular... Dec 2021Apicomplexan parasites, such as , spp., spp., and spp., cause significant morbidity and mortality. Existing treatments are problematic due to toxicity and the...
Apicomplexan parasites, such as , spp., spp., and spp., cause significant morbidity and mortality. Existing treatments are problematic due to toxicity and the emergence of drug-resistant parasites. Because protozoan tubulin can be selectively disrupted by small molecules to inhibit parasite growth, we assembled an in vitro testing cascade to fully delineate effects of candidate tubulin-targeting drugs on and vertebrate host cells. Using this analysis, we evaluated clemastine, an antihistamine that has been previously shown to inhibit growth by competitively binding to the CCT/TRiC tubulin chaperone as a proof-of-concept. We concurrently analyzed astemizole, a distinct antihistamine that blocks heme detoxification in . Both drugs have EC values of ~2 µM and do not demonstrate cytotoxicity or vertebrate microtubule disruption at this concentration. Parasite subpellicular microtubules are shortened by treatment with either clemastine or astemizole but not after treatment with pyrimethamine, indicating that this effect is not a general response to antiparasitic drugs. Immunoblot quantification indicates that the total α-tubulin concentration of 0.02 pg/tachyzoite does not change with clemastine treatment. In conclusion, the testing cascade allows profiling of small-molecule effects on both parasite and vertebrate cell viability and microtubule integrity.
Topics: Animals; Antiparasitic Agents; Apicoplasts; Cells, Cultured; Clemastine; Histamine Antagonists; Humans; Microtubules; Parasites; Protozoan Proteins; Tubulin
PubMed: 35008492
DOI: 10.3390/ijms23010068 -
Microsystems & Nanoengineering 2021Cardiovascular disease (CVD) is the number one cause of death in humans. Arrhythmia induced by gene mutations, heart disease, or hERG K channel inhibitors is a serious...
Cardiovascular disease (CVD) is the number one cause of death in humans. Arrhythmia induced by gene mutations, heart disease, or hERG K channel inhibitors is a serious CVD that can lead to sudden death or heart failure. Conventional cardiomyocyte-based biosensors can record extracellular potentials and mechanical beating signals. However, parameter extraction and examination by the naked eye are the traditional methods for analyzing arrhythmic beats, and it is difficult to achieve automated and efficient arrhythmic recognition with these methods. In this work, we developed a unique automated template matching (ATM) cardiomyocyte beating model to achieve arrhythmic recognition at the single beat level with an interdigitated electrode impedance detection system. The ATM model was established based on a rhythmic template with a data length that was dynamically adjusted to match the data length of the target beat by spline interpolation. The performance of the ATM model under long-term astemizole, droperidol, and sertindole treatment at different doses was determined. The results indicated that the ATM model based on a random rhythmic template of a signal segment obtained after astemizole treatment presented a higher recognition accuracy (100% for astemizole treatment and 99.14% for droperidol and sertindole treatment) than the ATM model based on arrhythmic multitemplates. We believe this highly specific ATM method based on a cardiomyocyte beating model has the potential to be used for arrhythmia screening in the fields of cardiology and pharmacology.
PubMed: 34567738
DOI: 10.1038/s41378-021-00251-4 -
ACS Medicinal Chemistry Letters Aug 2021In the context of drug repositioning and expanding the existing structure-activity relationship around astemizole (AST), a new series of analogues were designed,...
In the context of drug repositioning and expanding the existing structure-activity relationship around astemizole (AST), a new series of analogues were designed, synthesized, and evaluated for their antiplasmodium activity. Among 46 analogues tested, compounds , , and displayed high activities against asexual blood stage parasites (NF54 IC = 0.025-0.043 μM), whereas amide compound additionally showed activity against late-stage gametocytes (stage IV/V; LG IC = 0.6 ± 0.1 μM) and 860-fold higher selectivity over hERG (, SI = 43) compared to AST. Several analogues displaying high solubility (Sol > 100 μM) and low cytoxicity in the Chinese hamster ovary (SI > 148) cell line have also been identified.
PubMed: 34413963
DOI: 10.1021/acsmedchemlett.1c00328 -
Journal of Translational Medicine May 2021Circular RNAs (circRNAs) are a new class of noncoding RNAs that have gained increased attention in human tumor research. However, the identification and function of...
BACKGROUND
Circular RNAs (circRNAs) are a new class of noncoding RNAs that have gained increased attention in human tumor research. However, the identification and function of circRNAs are largely unknown in the context of gastric cancer (GC). This study aims to identify novel circRNAs and determine their action networks in GC.
METHODS
A comprehensive strategy of data mining, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and computational biology were conducted to discover novel circRNAs and to explore their potential mechanisms in GC. Promising therapeutic drugs for GC were determined by connectivity map (CMap) analysis.
RESULTS
Six overlapped differentially expressed circRNAs (DECs) were screened from selected microarray and RNA-Seq datasets of GC, and the six DECs were then validated by sanger sequencing and RNase R treatment. Subsequent RT-qPCR analysis of GC samples confirmed decreased expressions of the six DECs (hsa_circ_0000390, hsa_circ_0000615, hsa_circ_0001438, hsa_circ_0002190, hsa_circ_0002449 and hsa_circ_0003120), all of which accumulated preferentially in the cytoplasm. MiRNA binding sites and AGO2 occupation of the six circRNAs were predicted using online databases, and circRNA-miRNA interactions including the six circRNAs and 33 miRNAs were determined. Then, 5320 target genes of the above 33 miRNAs and 1492 differently expressed genes (DEGs) from The Cancer Genome Atlas (TCGA) database were identified. After intersecting the miRNA target genes and the 889 downregulated DEGs, 320 overlapped target genes were acquired. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that these target genes were related to two critical tumor-associated signaling pathways. A protein-protein interaction network with the 320 target genes was constructed using STRING, and fifteen hubgenes (ATF3, BTG2, DUSP1, EGR1, FGF2, FOSB, GNAO1, GNAI1, GNAZ, GNG7, ITPR1, ITPKB, JUND, NR4A3, PRKCB) in the network were identified. Finally, bioactive chemicals (including vorinostat, trichostatin A and astemizole) based on the fifteen hubgenes were identifed as therapeutic agents for GC through the CMap analysis.
CONCLUSIONS
This study provides a novel insight for further exploration of the pathogenesis and therapy of GC from the circRNA-miRNA-mRNA network perspective.
Topics: Computational Biology; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gi-Go; Humans; Immediate-Early Proteins; MicroRNAs; RNA, Circular; RNA, Messenger; Stomach Neoplasms; Tumor Suppressor Proteins
PubMed: 34049561
DOI: 10.1186/s12967-021-02903-5