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Methods in Enzymology 2023The biosynthesis of cardiac glycosides, broadly classified as cardenolides and bufadienolides, has evolved repeatedly among flowering plants. Individual species can...
The biosynthesis of cardiac glycosides, broadly classified as cardenolides and bufadienolides, has evolved repeatedly among flowering plants. Individual species can produce dozens or even hundreds of structurally distinct cardiac glycosides. Although all cardiac glycosides exhibit biological activity by inhibiting the function of the essential Na/K-ATPase in animal cells, they differ in their level of inhibitory activity. For within- and between-species comparisons of cardiac glycosides to address ecological and evolutionary questions, it is necessary to not only quantify their relative abundance, but also their effectiveness in inhibiting the activity of different animal Na/K-ATPases. Here we describe protocols for characterizing the amount and toxicity of cardenolides from plant samples and the degree of insect Na/K-ATPase tolerance to inhibition: (1) an HPLC-based assay to quantify the abundance of individual cardenolides in plant extracts, (2) an assay to quantify inhibition of Na/K-ATPase activity by plant extracts, and (3) extraction of insect Na/K-ATPases for inhibition assays.
Topics: Animals; Cardenolides; Chromatography, High Pressure Liquid; Sodium-Potassium-Exchanging ATPase; Cardiac Glycosides; Plant Extracts
PubMed: 36710014
DOI: 10.1016/bs.mie.2022.08.003 -
Biomedical Chromatography : BMC Mar 2022A sensitive and specific ultra-performance liquid chromatographic-tandem mass spectrometric method was developed and validated to simultaneously determine periplocin,...
Simultaneous determination of periplocin, periplocymarin, periplogenin, periplocoside M and periplocoside N of Cortex Periplocae in rat plasma and its application to a pharmacokinetic study.
A sensitive and specific ultra-performance liquid chromatographic-tandem mass spectrometric method was developed and validated to simultaneously determine periplocin, periplocymarin (PM), periplogenin (PG), periplocoside M (PSM) and periplocoside N (PSN) in rat plasma. Acetonitrile was employed to precipitate plasma with appropriate sensitivity and acceptable matrix effects. Chromatographic separation was performed using a Waters HSS T3 column with a gradient elution using water and acetonitrile both containing 0.1% formic acid and 0.1 mm ammonium formate within 8 min. Detection was performed in positive ionization mode using multiple reaction monitoring. The method was fully validated in terms of selectivity, linearity, accuracy, precision, recovery, matrix effects and stability. Using this method, the concentrations of periplocin, PM, PG, PSM and PSN were established after oral administration of Cortex Periplocae extract to rats, and the pharmacokinetic characteristics of periplocin, PM, PG, PSM and PSN were assessed. Generally, PM, PG, PSM and PSN were eliminated slowly and their half-lives were all >8 h. In addition, the systemic exposure of PSM showed significant differences between genders with more than 10 times higher area under the concentration-time curve in female rats than in male rats. The findings of this study provide useful information for further research on Cortex Periplocae.
Topics: Administration, Oral; Animals; Cardiac Glycosides; Chromatography, High Pressure Liquid; Digitoxigenin; Female; Male; Rats; Reproducibility of Results; Saponins; Tandem Mass Spectrometry
PubMed: 34816469
DOI: 10.1002/bmc.5283 -
Journal of the American Society For... May 2021Ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) is an economical and indispensable tool in natural...
Ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) is an economical and indispensable tool in natural product research to investigate novel metabolites, biomarker discovery, chemical diversity exploration, and structure elucidation. In this study, the structural analysis of 38 naturally occurring cardiac glycosides (CGs) in various tissues of was achieved by the extensive use of mass spectrometry. The chemical diversity of CGs was described on the basis of characteristic MS/MS fragmentation patterns, accurate mass measurement, and published scientific information on CGs from . It was observed that only six genins, ., Δanhydrogitoxigenin, Δadynerigenin, gitoxigenin, oleandrigenin, digitoxigenin, and adynerigenine, produce 38 diverse chemical structures of CGs. Among them, 20 were identified as diastereomers having a difference in a sugar (l-oleandrose, β-d-diginose, and β-d-sarmentose) unit. However, the differentiation of diastereomeric CGs was not possible by only MS/MS fragments. Thus, the diastereomer's chromatographic elution order was assigned on the basis of the relative retention time (RRt) of two reference standards (odoroside A and oleandrin) among their diastereomers. Besides this, the in-source fragmentation of CGs and the MS/MS of / 325 and 323 disaccharide daughter ions also exposed the intrinsic structure information on the sugar units. The daughter ions / 162, 145, 113, 95, and 85 in MS/MS spectra indicated the abundance of l-oleandrose, β-d-diginose, and β-d-sarmentose sugars. At the same time, / 161, 143, 129, and 87 product ions confirmed the presence of a β-d-digitalose unit. As a result, the UPLC-ESI/TQD system was successfully utilized for the structure characterization of CGs in tissues.
Topics: Cardenolides; Cardiac Glycosides; Chromatography, High Pressure Liquid; Digitoxigenin; Molecular Structure; Nerium; Stereoisomerism; Tandem Mass Spectrometry
PubMed: 33818079
DOI: 10.1021/jasms.1c00017 -
Clinical Therapeutics May 2021Dronedarone may increase digoxin plasma levels through inhibition of P-glycoprotein. Using real-world data, we evaluated the risk of digitalis intoxication in...
PURPOSE
Dronedarone may increase digoxin plasma levels through inhibition of P-glycoprotein. Using real-world data, we evaluated the risk of digitalis intoxication in concomitant users of dronedarone and digoxin compared digoxin-alone users.
METHODS
We used the Clinformatics DataMart, a US claims database, to identify adult patients with atrial fibrillation (AF) or atrial flutter (AFL) who concomitantly used dronedarone and digoxin and those who used digoxin alone between July 2009 and March 2016. Digitalis intoxication during follow-up until March 2016 was ascertained using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). Adjusted hazard ratios (HR) for digitalis intoxication in concomitant users versus users of digoxin alone were estimated, controlling for age, sex, cohort entry year, number of medical encounters for AF or AFL, history of congestive heart failure, diabetes, hypertension, stroke, myocardial infarction, renal failure, use of drugs interacting with digoxin, and digoxin dose.
FINDINGS
Overall, 524 concomitant users and 32,459 users of digoxin alone were identified, among which 3 and 301 events of digitalis intoxication occurred during follow-up, respectively. Incidence rates were 17.25 and 9.17 cases per 1000 person-years, respectively. The adjusted HR for digitalis intoxication in concomitant users versus users of digoxin alone was 1.56 (95% CI, 0.50-4.88; P = 0.45). When digitalis intoxication was defined by ICD-9-CM and ICD-10-CM codes accompanied by laboratory testing for digoxin/digitoxin or hospitalization within 30 days, no events occurred in the concomitant users and 40 events occurred in the users of digoxin alone (incidence rate of 1.22 cases per 1000 person-years).
IMPLICATIONS
Concomitant use of dronedarone and digoxin was uncommon in this study, and no significant increase in the risk of digitalis intoxication with concomitant use was found.
Topics: Adult; Atrial Fibrillation; Atrial Flutter; Digitalis; Digoxin; Dronedarone; Humans
PubMed: 33888353
DOI: 10.1016/j.clinthera.2021.03.014 -
Endocrine, Metabolic & Immune Disorders... 2020The ability of an aqueous extract of the sclerotia of Pleurotus tuberregium to modulate hematological parameters was investigated in normal and alloxan treated rabbits.
OBJECTIVE
The ability of an aqueous extract of the sclerotia of Pleurotus tuberregium to modulate hematological parameters was investigated in normal and alloxan treated rabbits.
METHODS
The extract was subjected to atomic absorption spectrophotometric and flame ionization detector-coupled-gas chromatographic (GC-FID) analysis. Diabetes mellitus was induced by a 120 mg/kg body weight intravenous injection of alloxan. Metformin was orally administered at 50 mg/kg, while the extract was administered (both to normal and diabetic rabbits) at 100, 200 and 300 mg/kg.
RESULTS
Analysis of the extract showed that it had high contents of calcium, magnesium, manganese and potassium. Eleven known glycosides were detected, comprising mainly of amygdalin (37.7%), digoxin (14.4%), dhurrin (14.0%), linamarin (13.6%), prunasin (10.8%) and digitoxin (8.4%). Also detected were twelve known saponins, consisting mainly of sapogenin (40.3%) and neochlorogenin (21.8%); and twelve known lignans, consisting mainly of matairesinol (59.7%), secoisolariciresinol (20.9%) and lariciresinol (14.9%). Compared to the Diabetic control, the hematocrit, hemoglobin concentration, mean cell hemoglobin, mean cell hemoglobin concentration, mean corpuscular volume, red cell distribution width; and red cell, total white cell, lymphocytes, granulocytes and platelet counts of the treated groups were significantly (p<0.05) higher.
CONCLUSION
The above result showed that the extract had a positive effect on the hemopoietic system of the treated animals, at least at the doses at which it was administered in this study.
Topics: Alloxan; Animals; Biological Factors; Blood Glucose; Blood Platelets; Diabetes Mellitus, Experimental; Erythrocytes; Hemoglobins; Leukocytes; Pleurotus; Rabbits; Water
PubMed: 31544706
DOI: 10.2174/1871530319666190809155506 -
Chinese Journal of Integrative Medicine Sep 2020To select potential molecules that can target viral spike proteins, which may potentially interrupt the interaction between the human angiotension-converting enzyme 2...
OBJECTIVE
To select potential molecules that can target viral spike proteins, which may potentially interrupt the interaction between the human angiotension-converting enzyme 2 (ACE2) receptor and viral spike protein by virtual screening.
METHODS
The three-dimensional (3D)-coordinate file of the receptor-binding domain (RBD)-ACE2 complex for searching a suitable docking pocket was firstly downloaded and prepared. Secondly, approximately 15,000 molecular candidates were prepared, including US Food and Drug Administration (FDA)-approved drugs from DrugBank and natural compounds from Traditional Chinese Medicine Systems Pharmacology (TCMSP), for the docking process. Then, virtual screening was performed and the binding energy in Autodock Vina was calculated. Finally, the top 20 molecules with high binding energy and their Chinese medicine (CM) herb sources were listed in this paper.
RESULTS
It was found that digitoxin, a cardiac glycoside in DrugBank and bisindigotin in TCMSP had the highest docking scores. Interestingly, two of the CM herbs containing the natural compounds that had relatively high binding scores, Forsythiae fructus and Isatidis radix, are components of Lianhua Qingwen (), a CM formula reportedly exerting activity against severe acute respiratory syndrome (SARS)-Cov-2. Moreover, raltegravir, an HIV integrase inhibitor, was found to have a relatively high binding score.
CONCLUSIONS
A class of compounds, which are from FDA-approved drugs and CM natural compounds, that had high binding energy with RBD of the viral spike protein. Our work provides potential candidates for other researchers to identify inhibitors to prevent SARS-CoV-2 infection, and highlights the importance of CM and integrative application of CM and Western medicine on treating COVID-19.
Topics: COVID-19; China; Computer Simulation; Coronavirus Infections; Drug Repositioning; Drugs, Chinese Herbal; Glycoproteins; Humans; Imaging, Three-Dimensional; Mass Screening; Molecular Docking Simulation; Pandemics; Peptidyl-Dipeptidase A; Pneumonia, Viral; Protein Binding; United States; United States Food and Drug Administration
PubMed: 32740825
DOI: 10.1007/s11655-020-3427-6 -
Molecules (Basel, Switzerland) Sep 2022The SARS-CoV-2 targets were evaluated for a set of FDA-approved drugs using a combination of drug repositioning and rigorous computational modeling methodologies such as...
In Silico Study towards Repositioning of FDA-Approved Drug Candidates for Anticoronaviral Therapy: Molecular Docking, Molecular Dynamics and Binding Free Energy Calculations.
The SARS-CoV-2 targets were evaluated for a set of FDA-approved drugs using a combination of drug repositioning and rigorous computational modeling methodologies such as molecular docking and molecular dynamics (MD) simulations followed by binding free energy calculations. Six FDA-approved drugs including, Ouabain, Digitoxin, Digoxin, Proscillaridin, Salinomycin and Niclosamide with promising anti-SARS-CoV-2 activity were screened in silico against four SARS-CoV-2 proteins-papain-like protease (PLpro), RNA-dependent RNA polymerase (RdRp), SARS-CoV-2 main protease (Mpro), and adaptor-associated kinase 1 (AAK1)-in an attempt to define their promising targets. The applied computational techniques suggest that all the tested drugs exhibited excellent binding patterns with higher scores and stable complexes compared to the native protein cocrystallized inhibitors. Ouabain was suggested to act as a dual inhibitor for both PLpro and Mpro enzymes, while Digitoxin bonded perfectly to RdRp. In addition, Salinomycin targeted PLpro. Particularly, Niclosamide was found to target AAK1 with greater affinity compared to the reference drug. Our study provides comprehensive molecular-level insights for identifying or designing novel anti-COVID-19 drugs.
Topics: Antiviral Agents; COVID-19; Cysteine Endopeptidases; Digitoxin; Digoxin; Drug Repositioning; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Niclosamide; Ouabain; Papain; Proscillaridin; RNA-Dependent RNA Polymerase; SARS-CoV-2
PubMed: 36144718
DOI: 10.3390/molecules27185988 -
Anti-cancer Agents in Medicinal... 2021Periplogenin (PPG), a natural compound isolated from traditional Chinese herb Cortex Periplocae, has been reported to possess anti-inflammatory and anti-cancer...
BACKGROUND
Periplogenin (PPG), a natural compound isolated from traditional Chinese herb Cortex Periplocae, has been reported to possess anti-inflammatory and anti-cancer properties.
OBJECTIVE
The present study aims to investigate the antitumor effects of PPG and the underlying mechanism in human colorectal cancer cells.
METHODS
The inhibition of cell growth in vitro was assessed by MTT assay. The induction of apoptosis and the ROS production induced by PPG was investigated by flow cytometry analysis. Western blotting was applied to measure the protein expression. Small interference RNA (siRNA) and a specific pharmacological inhibitor were used to knock down or inhibit the expression of related genes.
RESULTS
PPG was able to cause the production of ROS, inhibit the cancer cell growth and induce apoptosis. Nacetylcysteine was able to inhibit ROS production and apoptosis. PPG up-regulated the protein levels of BIP, peIF2α and CHOP as well as IRE1α and p-JNK, and down-regulated the protein level of p-ASK1, all of which were reversed by N-acetylcysteine. Importantly, knockdown of CHOP or JNK protein level attenuated the PPGelicited apoptosis.
CONCLUSION
PPG-induced apoptosis was regulated by ROS-mediated BIP/eIF2α/CHOP and BIP/ASK1/JNK signaling pathways in colon cancer cells, suggesting that PPG is a promising therapeutic agent for the treatment of human colon cancer.
Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Digitoxigenin; Drug Discovery; Endoplasmic Reticulum; Endoribonucleases; Eukaryotic Initiation Factor-2; Gene Expression Regulation; Humans; MAP Kinase Kinase Kinase 5; MAP Kinase Signaling System; Periploca; Plant Extracts; Protein Serine-Threonine Kinases; Reactive Oxygen Species
PubMed: 32640963
DOI: 10.2174/1871520620666200708104559 -
Cancers Aug 2021The high mortality of OvCa is caused by the wide dissemination of cancer within the abdominal cavity. OvCa cells metastasize to the peritoneum, which is covered by...
The high mortality of OvCa is caused by the wide dissemination of cancer within the abdominal cavity. OvCa cells metastasize to the peritoneum, which is covered by mesothelial cells, and invade into the underlying stroma, composed of extracellular matrices (ECM) and stromal cells. In a study using a three-dimensional quantitative high-throughput screening platform (3D-qHTS), we found that β-escin, a component of horse chestnut seed extract, inhibited OvCa adhesion/invasion. Here, we determine whether β-escin and structurally similar compounds have a therapeutic potential against OvCa metastasis. Different sources of β-escin and horse chestnut seed extract inhibited OvCa cell adhesion/invasion, both in vitro and in vivo. From a collection of 160 structurally similar compounds to β-escin, we found that cardiac glycosides inhibited OvCa cell adhesion/invasion and proliferation in vitro, and inhibited adhesion/invasion and metastasis in vivo. Mechanistically, β-escin and the cardiac glycosides inhibited ECM production in mesothelial cells and fibroblasts. The oral administration of β-escin inhibited metastasis in both OvCa prevention and intervention mouse models. Specifically, β-escin inhibited ECM production in the omental tumors. Additionally, the production of HIF1α-targeted proteins, lactate dehydrogenase A, and hexokinase 2 in omental tumors was blocked by β-escin. This study reveals that the natural compound β-escin has a therapeutic potential because of its ability to prevent OvCa dissemination by targeting both cancer and stromal cells in the OvCa tumor microenvironment.
PubMed: 34439084
DOI: 10.3390/cancers13163931 -
Microbial Pathogenesis Aug 2022Urinary tract infections (UTIs) are a serious health concern worldwide. Treatment of UTIs is becoming a challenge as uropathogenic Escherichia coli (UPEC), which is the...
Urinary tract infections (UTIs) are a serious health concern worldwide. Treatment of UTIs is becoming a challenge as uropathogenic Escherichia coli (UPEC), which is the most common etiological agent, has developed resistance to the main classes of antibiotics. Small molecules that interfere with metabolic processes rather than growth are attractive alternatives to conventional antibiotics. Repurposing of already known drugs for treating infectious diseases could be an attractive avenue for finding novel therapeutics against infections caused by UPEC. Virtual screenings enable the rapid and economical identification of target ligands from large libraries of compounds, reducing the cost and time of traditional drug discovery. Moreover, the drugs that have been approved by the FDA have low cytotoxicity and good pharmacological characteristics. In this work, we targeted the HisC enzyme of the histidine biosynthetic pathway as enzymes of this pathway are absent in humans. We screened the library of FDA-approved drugs against HisC via molecular docking, and four hits (Docetaxel, Suramin, Digitoxin, and Nystatin) showing the highest binding energy were selected. These were further tested for antibacterial activity, which was observed only for Docetaxel (MIC value of 640 μg/ml); therefore, Docetaxel was further tested for its efficacy in vivo in murine catheter UTI model and antibiofilm activity using crystal violet staining and scanning electron microscopy. Docetaxel inhibited biofilm formation and reduced the bacterial load in urine, kidney, and bladder. Docking studies revealed that Docetaxel acts by blocking the binding site of HisC to the native substrate by competitive inhibition. Docetaxel may be a potential new inhibitor for UPEC with antibacterial and antibiofilm capability.
Topics: Animals; Anti-Bacterial Agents; Docetaxel; Drug Repositioning; Escherichia coli Infections; Humans; Mice; Molecular Docking Simulation; Urinary Tract Infections; Uropathogenic Escherichia coli
PubMed: 35781005
DOI: 10.1016/j.micpath.2022.105665