15 results on '"Chern CY"'
Search Results
2. The angiogenesis-modulating effects of coumarin-derivatives.
- Author
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Huang HT, Huang CY, Lee CJ, Sun BJ, Jhang ZW, Wen CC, Wang YH, Li TS, Chern CY, and Chen YH
- Subjects
- Animals, Biological Assay, Chickens, Coumarins pharmacology, Mammals, Angiogenesis, Zebrafish
- Abstract
Coumarin is a natural compound that is rich in plants. Coumarin and its derivates were reported to have many biological activities, such as anti-bacterial, anti-tumor, and anti-coagulation. In this study, we examined the angiogenic modulating activities of six previously synthesized coumarin derivatives (Compound #1-#6) in zebrafish embryos and further confirmed them in a chick model. According to the survival rate in a zebrafish model, Compound #1 (100 %), #2 (82.5-100 %), and #4 (100 %) showed much less toxicity than Compound #3 (19.2-100 %), #5 (0-100 %), and #6 (0-100 %). Using a green blood vessel fluorescent transgenic fish Tg(fli1:egfp) to record the angiogenesis-modulating effects of Compound #1, #2, and #4, we found that Compound #2 had the highest effects in interfering intersegmental vessel growth, subintestinal vein growth, and caudal vein plexus remodeling. Chick chorioallantoic membrane (CAM) assay also showed that Compound #2 exposure led to a reduction of blood vessel growth. Real-time PCR experiments revealed that Compound #2 significantly changed the expression of vascular growth-related genes flt1, cdh5, and nrp1a in zebrafish. Based on our data from zebrafish and chick models, a new coumarin-derivative (Compound #2) possesses anti-angiogenic activity with low toxicity, but further investigation in mammal models is asked to confirm our findings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
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3. Coumarin Derivatives Inhibit ADP-Induced Platelet Activation and Aggregation.
- Author
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Lu PH, Liao TH, Chen YH, Hsu YL, Kuo CY, Chan CC, Wang LK, Chern CY, and Tsai FM
- Subjects
- Adenosine Diphosphate pharmacology, Blood Platelets, Coumarins pharmacology, Platelet Aggregation Inhibitors pharmacology, Platelet Glycoprotein GPIIb-IIIa Complex pharmacology, Platelet Activation, Platelet Aggregation
- Abstract
Coumarin was first discovered in Tonka bean and then widely in other plants. Coumarin has an anticoagulant effect, and its derivative, warfarin, is a vitamin K analogue that inhibits the synthesis of clotting factors and is more widely used in the clinical treatment of endovascular embolism. At present, many artificial chemical synthesis methods can be used to modify the structure of coumarin to develop many effective drugs with low toxicity. In this study, we investigated the effects of six coumarin derivatives on the platelet aggregation induced by adenosine diphosphate (ADP). We found that the six coumarin derivatives inhibited the active form of GPIIb/IIIa on platelets and hence inhibit platelet aggregation. We found that 7-hydroxy-3-phenyl 4H-chromen-4-one (7-hydroxyflavone) had the most severe effect. In addition, we further analyzed the downstream signal transduction of the ADP receptor, including the release of calcium ions and the regulation of cAMP, which were inhibited by the six coumarin derivatives selected in this study. These results suggest that coumarin derivatives inhibit coagulation by inhibiting the synthesis of coagulation factors and they may also inhibit platelet aggregation.
- Published
- 2022
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4. An octimibate derivative, Oxa17, enhances cholesterol efflux and exerts anti-inflammatory and atheroprotective effects in experimental atherosclerosis.
- Author
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Tsui PF, Chern CY, Lien CF, Lin FY, Tsai CS, Tsai MC, and Lin CS
- Subjects
- Animals, Anti-Inflammatory Agents chemistry, Anti-Inflammatory Agents pharmacology, Atherosclerosis etiology, Diet, High-Fat adverse effects, Dose-Response Relationship, Drug, Humans, Imidazoles chemistry, Imidazoles pharmacology, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, THP-1 Cells, Anti-Inflammatory Agents therapeutic use, Atherosclerosis metabolism, Atherosclerosis prevention & control, Cholesterol metabolism, Imidazoles therapeutic use
- Abstract
Atherosclerotic cardiovascular diseases (ASCVDs), associated with vascular inflammation and lipid dysregulation, are responsible for high morbidity and mortality rates globally. For ASCVD treatment, cholesterol efflux plays an atheroprotective role in ameliorating inflammation and lipid dysregulation. To develop a multidisciplinary agent for promoting cholesterol efflux, octimibate derivatives were screened and investigated for the expression of ATP-binding cassette transporter A1 (ABCA1). Western blotting and qPCR analysis were conducted to determine the molecular mechanism associated with ABCA1 expression in THP-1 macrophages; results revealed that Oxa17, an octimibate derivative, enhanced ABCA1 expression through liver X receptors alpha (LXRα) activation but not through the microRNA pathway. We also investigated the role of Oxa17 in high-fat diet (HFD)-fed mice used as an in vivo atherosclerosis-prone model. In ldlr
-/- mice, Oxa17 increased plasma high-density lipoprotein (HDL) and reduced plaque formation in the aorta. Plaque stability improved via reduction of macrophage accumulation and via narrowing of the necrotic core size under Oxa17 treatment. Our study demonstrates that Oxa17 is a novel and potential agent for ASCVD treatment with atheroprotective and anti-inflammatory properties., (Copyright © 2021 Elsevier Inc. All rights reserved.)- Published
- 2021
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5. Targeting HR Repair as a Synthetic Lethal Approach to Increase DNA Damage Sensitivity by a RAD52 Inhibitor in BRCA2-Deficient Cancer Cells.
- Author
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Tseng WC, Chen CY, Chern CY, Wang CA, Lee WC, Chi YC, Cheng SF, Kuo YT, Chiu YC, Tseng ST, Lin PY, Liou SJ, Li YC, and Chen CC
- Subjects
- Animals, Antineoplastic Agents pharmacology, Apoptosis, BRCA2 Protein genetics, Breast Neoplasms metabolism, Breast Neoplasms pathology, Cell Proliferation, DNA Repair, Female, Humans, Irinotecan pharmacology, Mice, Mice, Nude, Mutation, Topoisomerase I Inhibitors pharmacology, Tumor Cells, Cultured, Xenograft Model Antitumor Assays, BRCA2 Protein deficiency, Breast Neoplasms drug therapy, Curcumin pharmacology, DNA Damage, Gene Expression Regulation, Neoplastic drug effects, Homologous Recombination, Rad52 DNA Repair and Recombination Protein antagonists & inhibitors
- Abstract
BRCA mutation, one of the most common types of mutations in breast and ovarian cancer, has been suggested to be synthetically lethal with depletion of RAD52. Pharmacologically inhibiting RAD52 specifically eradicates BRCA-deficient cancer cells. In this study, we demonstrated that curcumin, a plant polyphenol, sensitizes BRCA2-deficient cells to CPT-11 by impairing RAD52 recombinase in MCF7 cells. More specifically, in MCF7-siBRCA2 cells, curcumin reduced homologous recombination, resulting in tumor growth suppression. Furthermore, a BRCA2-deficient cell line, Capan1, became resistant to CPT-11 when BRCA2 was reintroduced. In vivo, xenograft model studies showed that curcumin combined with CPT-11 reduced the growth of BRCA2-knockout MCF7 tumors but not MCF7 tumors. In conclusion, our data indicate that curcumin, which has RAD52 inhibitor activity, is a promising candidate for sensitizing BRCA2-deficient cells to DNA damage-based cancer therapies.
- Published
- 2021
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6. A chalcone derivative, 1m-6, exhibits atheroprotective effects by increasing cholesterol efflux and reducing inflammation-induced endothelial dysfunction.
- Author
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Chen LW, Tsai MC, Chern CY, Tsao TP, Lin FY, Chen SJ, Tsui PF, Liu YW, Lu HJ, Wu WL, Lin WS, Tsai CS, and Lin CS
- Subjects
- ATP Binding Cassette Transporter 1 genetics, Animals, Cholesterol, Inflammation drug therapy, Mice, Mice, Knockout, Atherosclerosis drug therapy, Atherosclerosis prevention & control, Chalcone pharmacology, Chalcones pharmacology
- Abstract
Background and Purpose: Atherosclerosis, resulting from lipid dysregulation and vascular inflammation, causes atherosclerotic cardiovascular disease (ASCVD), which contributes to morbidity and mortality worldwide. Chalcone and its derivatives possess beneficial properties, including anti-inflammatory, antioxidant and antitumour activity with unknown cardioprotective effects. We aimed to develop an effective chalcone derivative with antiatherogenic potential., Experimental Approach: Human THP-1 cells and HUVECs were used as in vitro models. Western blots and real-time PCRs were performed to quantify protein, mRNA and miRNA expressions. The cholesterol efflux capacity was assayed by
3 H labelling of cholesterol. LDL receptor knockout (Ldlr-/- ) mice fed a high-fat diet were used as an in vivo atherogenesis model. Haematoxylin and eosin and oil red O staining were used to analyse plaque formation., Key Results: Using ATP-binding cassette transporter A1 (ABCA1) expression we identified the chalcone derivative, 1m-6, which enhances ABCA1 expression and promotes cholesterol efflux in THP-1 macrophages. Moreover, 1m-6 stabilizes ABCA1 mRNA and suppresses the expression of potential ABCA1-regulating miRNAs through nuclear factor erythroid 2-related factor 2 (Nrf2)/haem oxygenase-1 (HO-1) signalling. Additionally, 1m-6 significantly inhibits TNF-α-induced expression of adhesion molecules, vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1), plus production of proinflammatory cytokines via inhibition of JAK/STAT3 activation and the modulation of Nrf2/HO-1 signalling in HUVECs. In atherosclerosis-prone mice, 1m-6 significantly reduces lipid accumulation and atherosclerotic plaque formation., Conclusion and Implications: Our study demonstrates that 1m-6 produces promising atheroprotective effects by enhancing cholesterol efflux and suppressing inflammation-induced endothelial dysfunction, which opens a new avenue for treating ASCVD., Linked Articles: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc., (© 2020 The British Pharmacological Society.)- Published
- 2020
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7. Discovery of T-1101 tosylate as a first-in-class clinical candidate for Hec1/Nek2 inhibition in cancer therapy.
- Author
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Chuang SH, Lee YE, Huang LYL, Chen CK, Lai CL, Lin YH, Yang JY, Yang SC, Chang LH, Chen CH, Liu CW, Lin HS, Lee YR, Huang KP, Fu KC, Jen HM, Lai JY, Jian PS, Wang YC, Hsueh WY, Tsai PY, Hong WH, Chang CC, Wu DZ, Wu J, Chen MH, Yu KM, Chern CY, Chang JM, Lau JYN, and Huang JJ
- Subjects
- Animals, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Cell Line, Tumor, Cell Proliferation drug effects, Cytoskeletal Proteins metabolism, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, Humans, K562 Cells, Liver Neoplasms, Experimental drug therapy, Liver Neoplasms, Experimental metabolism, Liver Neoplasms, Experimental pathology, Mice, Mice, SCID, Molecular Docking Simulation, Molecular Structure, NIMA-Related Kinases metabolism, Protein Kinase Inhibitors chemical synthesis, Protein Kinase Inhibitors chemistry, Structure-Activity Relationship, Tissue Distribution, Antineoplastic Agents pharmacology, Cytoskeletal Proteins antagonists & inhibitors, Drug Discovery, NIMA-Related Kinases antagonists & inhibitors, Protein Kinase Inhibitors pharmacology
- Abstract
Highly expressed in cancer 1 (Hec1) plays an essential role in mitosis and is correlated with cancer formation, progression, and survival. Phosphorylation of Hec1 by Nek2 kinase is essential for its mitotic function, thus any disruption of Hec1/Nek2 protein-protein interaction has potential for cancer therapy. We have developed T-1101 tosylate (9j tosylate, 9j formerly known as TAI-95), optimized from 4-aryl-N-pyridinylcarbonyl-2-aminothiazole of scaffold 9 by introducing various C-4' substituents to enhance potency and water solubility, as a first-in-class oral clinical candidate for Hec1 inhibition with potential for cancer therapy. T-1101 has good oral absorption, along with potent in vitro antiproliferative activity (IC
50 : 14.8-21.5 nM). It can achieve high concentrations in Huh-7 and MDA-MB-231 tumor tissues, and showed promise in antitumor activity in mice bearing human tumor xenografts of liver cancer (Huh-7), as well as of breast cancer (BT474, MDA-MB-231, and MCF7) with oral administration. Oral co-administration of T-1101 halved the dose of sorafenib (25 mg/kg to 12.5 mg/kg) required to exhibit comparable in vivo activity towards Huh-7 xenografts. Cellular events resulting from Hec1/Nek2 inhibition with T-1101 treatment include Nek2 degradation, chromosomal misalignment, and apoptotic cell death. A combination of T-1101 with either of doxorubicin, paclitaxel, and topotecan in select cancer cells also resulted in synergistic effects. Inactivity of T-1101 on non-cancerous cells, a panel of kinases, and hERG demonstrates cancer specificity, target specificity, and cardiac safety, respectively. Subsequent salt screening showed that T-1101 tosylate has good oral AUC (62.5 μM·h), bioavailability (F = 77.4%), and thermal stability. T-1101 tosylate is currently in phase I clinical trials as an orally administered drug for cancer therapy., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.Y.N. Lau is a cofounder and shareholder of Taivex Therapeutics Corporation. The other authors declare no competing financial interest., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)- Published
- 2020
- Full Text
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8. Chalcone Derivatives Enhance ATP-Binding Cassette Transporters A1 in Human THP-1 Macrophages.
- Author
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Teng IJ, Tsai MC, Shih SF, Tsuei BF, Chang H, Chuang YP, Lin CS, Chern CY, and Chen SJ
- Subjects
- Chalcones chemistry, Gene Expression Regulation drug effects, Humans, Liver X Receptors genetics, Macrophages drug effects, MicroRNAs genetics, Molecular Structure, Signal Transduction drug effects, THP-1 Cells, ATP Binding Cassette Transporter 1 genetics, Chalcones chemical synthesis, Chalcones pharmacology, Macrophages cytology, Up-Regulation
- Abstract
Atherosclerosis is a process of imbalanced lipid metabolism in the vascular walls. The underlying pathology mainly involves the deposition of oxidized lipids in the endothelium and the accumulation of cholesterol in macrophages. Macrophages export excessive cholesterol (cholesterol efflux) through ATP-binding cassette transporter A1 (ABCA1) to counter the progression of atherosclerosis. We synthesized novel chalcone derivatives and assessed their effects and the underlying mechanisms on ABCA1 expression in macrophages. Human THP-1 macrophages were treated with synthetic chalcone derivatives for 24 h. In Western blot and flow cytometry analyses, a chalcone derivative, ( E )- 1-(3,4-diisopropoxyphenyl)-3-(4-isopropoxy-3-methoxyphenyl)prop- 2-en-1-one ( 1m ), was observed to significantly enhance ABCA1 protein expression in THP-1 cells (10 µM, 24 h). Levels of mRNA of ABCA1 and liver X receptor alpha (LXRα) were quantified using a real-time quantitative polymerase chain reaction technique and were found to be significantly increased after treatment with the novel chalcone derivative 1m . Several microRNAs, including miR155, miR758, miR10b, miR145, miR33, and miR106b, which functionally inhibit ABCA1 expression were suppressed after treatment with 1m. Collectively, 1m increases ABCA1 expression in human THP-1 macrophages. The mechanisms involve the activation of the LXRα-ABCA1 pathway and suppression of certain microRNAs that regulate ABCA1 expression.
- Published
- 2018
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9. Pro-Angiogenic Effects of Chalcone Derivatives in Zebrafish Embryos in Vivo.
- Author
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Chen YH, Chang CY, Chang CF, Chen PC, Lee YT, Chern CY, and Tsai JN
- Subjects
- Angiogenesis Inducing Agents chemical synthesis, Animals, Animals, Genetically Modified, Chalcones chemical synthesis, Embryo, Nonmammalian, Genes, Reporter, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, Molecular Structure, Morphogenesis drug effects, Structure-Activity Relationship, Vascular Endothelial Growth Factor A genetics, Vascular Endothelial Growth Factor A metabolism, Zebrafish, Zebrafish Proteins genetics, Zebrafish Proteins metabolism, Angiogenesis Inducing Agents pharmacology, Chalcones pharmacology, Gene Expression Regulation, Developmental, Neovascularization, Physiologic drug effects, Vascular Endothelial Growth Factor A agonists, Zebrafish Proteins agonists
- Abstract
The aim of this study was to investigate novel chalcones with potent angiogenic activities in vivo. Chalcone-based derivatives were evaluated using a transgenic zebrafish line with fluorescent vessels to real-time monitor the effect on angiogenesis. Results showed that the chalcone analogues did not possess anti-angiogenic effect on zebrafish vasculatures; instead, some of them displayed potent pro-angiogenic effects on the formation of the sub-intestinal vein. Similar pro-angiogenic effects can also be seen on wild type zebrafish embryos. Moreover, the expression of vegfa, the major regulator for angiogenesis, was also upregulated in their treatment. Taken together, we have synthesized and identified a series of novel chalcone-based derivatives as potent in vivo pro-angiogenic compounds. These novel compounds hold potential for therapeutic angiogenesis.
- Published
- 2015
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10. Synthesis of analogues of gingerol and shogaol, the active pungent principles from the rhizomes of Zingiber officinale and evaluation of their anti-platelet aggregation effects.
- Author
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Shih HC, Chern CY, Kuo PC, Wu YC, Chan YY, Liao YR, Teng CM, and Wu TS
- Subjects
- Animals, Catechols chemical synthesis, Dose-Response Relationship, Drug, Drug Evaluation, Preclinical, Fatty Alcohols chemical synthesis, Hydrogenation, Models, Chemical, Molecular Structure, Oxidation-Reduction, Plant Extracts chemistry, Plant Extracts pharmacology, Platelet Aggregation drug effects, Platelet Aggregation Inhibitors chemical synthesis, Platelet Count, Rabbits, Catechols pharmacology, Fatty Alcohols pharmacology, Zingiber officinale chemistry, Platelet Aggregation Inhibitors pharmacology, Rhizome chemistry
- Abstract
The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b) exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads.
- Published
- 2014
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11. Toxicity assessments of chalcone and some synthetic chalcone analogues in a zebrafish model.
- Author
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Lee YT, Fong TH, Chen HM, Chang CY, Wang YH, Chern CY, and Chen YH
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- Animals, Embryo, Nonmammalian drug effects, Embryonic Development drug effects, Muscle Fibers, Skeletal drug effects, Muscle, Skeletal abnormalities, Zebrafish, Abnormalities, Drug-Induced pathology, Chalcone analogs & derivatives, Chalcone toxicity, Muscle Fibers, Skeletal pathology, Teratogens toxicity
- Abstract
The aim of this study was to investigate the in vivo toxicities of some novel synthetic chalcones. Chalcone and four chalcone analogues 1a-d were evaluated using zebrafish embryos following antibody staining to visualize their morphological changes and muscle fiber alignment. Results showed that embryos treated with 3'-hydroxychalcone (compound 1b) displayed a high percentage of muscle defects (96.6%), especially myofibril misalignment. Ultrastructural analysis revealed that compound 1b-treated embryos displayed many muscle defect phenotypes, including breakage and collapse of myofibrils, reduced cell numbers, and disorganized thick (myosin) and thin (actin) filaments. Taken together, our results provide in vivo evidence of the myotoxic effects of the synthesized chalcone analogues on developing zebrafish embryos.
- Published
- 2014
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12. Evaluation of the anti-inflammatory effect of chalcone and chalcone analogues in a zebrafish model.
- Author
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Chen YH, Wang WH, Wang YH, Lin ZY, Wen CC, and Chern CY
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- Animal Fins surgery, Animals, Anti-Inflammatory Agents chemical synthesis, Anti-Inflammatory Agents chemistry, Chalcone chemical synthesis, Chalcone chemistry, Larva drug effects, Larva enzymology, Models, Animal, Neutrophil Infiltration drug effects, Peroxidase metabolism, Wound Healing drug effects, Anti-Inflammatory Agents pharmacology, Chalcone analogs & derivatives, Chalcone pharmacology, Zebrafish metabolism
- Abstract
The aim of this study was to investigate novel chalcones with potent anti-inflammatory activities in vivo. Chalcone and two chalcone analogues (compound 5 and 9) were evaluated using a caudal fin-wounded transgenic zebrafish line "Tg(mpx:gfp)" to visualize the effect of neutrophil recruitment dynamically. Results showed that treatment with compound 9 not only affected wound-induced neutrophil recruitment, but also affected Mpx enzymatic activity. Moreover, protein expression levels of pro-inflammatory factors (Mpx, NFκB, and TNFα) were also regulated by compound 9. Taken together, our results provide in vivo evidence of the anti-inflammatory effects of synthesized chalcone analogues on wound-induced inflammation.
- Published
- 2013
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13. The effect of prostacyclin agonists on the differentiation of phorbol ester treated human erythroleukemia cells.
- Author
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Shen HW, Chen YL, Chern CY, and Kan WM
- Subjects
- Acetates agonists, Epoprostenol analogs & derivatives, Humans, Leukemia, Erythroblastic, Acute pathology, Oxazoles agonists, Thrombopoiesis drug effects, Cell Differentiation drug effects, Epoprostenol agonists, Leukemia, Erythroblastic, Acute drug therapy, Phorbol Esters pharmacology
- Abstract
Phorbol-12-myristate-13-acetate (PMA) induces megakaryocytopoeisis in human erythroleukemia (HEL) cells which is characterized by the increase in cell size, increase in nuclear polyploidization and expression of megakaryocyte marker, CD41. However, upon treatment with 100 nM of selective prostacyclin (IP) agonist beraprost inhibits the induced differentiation. Moreover, selective non-prostanoid IP agonist, BMY 45778 prevents PMA induced megakaryocytopoeisis in HEL cells similarly, while prostaglandin E(2) and specific EP(3) agonist sulprostone have no effect. Thus, IP receptor is involved. Furthermore, adenylate cyclase activator forskolin and cAMP analog dibutyryl-cAMP also prevented PMA induced megakaryocytopoeisis in HEL cells. Thus, IP agonists inhibition of PMA induced megakaryocytopoeisis in HEL cells may involve a cAMP dependent pathway.
- Published
- 2007
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14. Inhibition of superoxide anion and elastase release in human neutrophils by 3'-isopropoxychalcone via a cAMP-dependent pathway.
- Author
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Hwang TL, Yeh SH, Leu YL, Chern CY, and Hsu HC
- Subjects
- 3',5'-Cyclic-AMP Phosphodiesterases metabolism, Adenylyl Cyclases metabolism, Adult, Calcium metabolism, Cell Degranulation, Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors, Cyclic AMP-Dependent Protein Kinases metabolism, Dose-Response Relationship, Drug, Female, Humans, In Vitro Techniques, Isoquinolines pharmacology, Leukocyte Elastase antagonists & inhibitors, Male, N-Formylmethionine Leucyl-Phenylalanine, Neutrophils enzymology, Protein Kinase Inhibitors pharmacology, Respiratory Burst, Sulfonamides pharmacology, Superoxides metabolism, Anti-Inflammatory Agents pharmacology, Chalcones pharmacology, Cyclic AMP metabolism, Leukocyte Elastase metabolism, Neutrophils drug effects, Phosphodiesterase Inhibitors pharmacology, Superoxides antagonists & inhibitors
- Abstract
1 Chalcone is abundantly present in the plant kingdom and has various biological activities such as anti-inflammatory and antioxidant. In this study, the semisynthetic chalcone derivative, 3'-isopropoxychalcone (H2O7D), was demonstrated to inhibit the generation of superoxide and the release of elastase, as well as to accelerate resequestration of cytosolic calcium in formyl-L-methionyl-L-leucyl-L-phenylalanine-activated human neutrophils. 2 H2O7D displayed no antioxidant or superoxide-scavenging ability, and it failed to alter the subcellular NADPH oxidase activity. 3 H2O7D induced a substantial increase in cAMP but not cGMP levels. The elevation of cAMP formation by H2O7D was inhibited by adenosine deaminase (ADA). Furthermore, The inhibitory effects of H2O7D were reversed by protein kinase (PK)A inhibitors, as well as ADA and a selective A2a-receptor antagonist. 4 H2O7D inhibited phosphodiesterase (PDE) activities, but it did not alter adenylyl cyclase and soluble guanylyl cyclase activities. These results show that the cAMP-elevating effect of H2O7D results from the inhibition of PDE activity and not from the stimulation of cyclase function. Consistent with this, H2O7D potentiated the PGE(1)-caused inhibitory effects and cAMP formation. 5 In summary, these results indicate that the inhibitory effect of H2O7D is cAMP/PKA dependent, and that it occurs through inhibition of cAMP PDE, which potentiates the autocrine functions of endogenous adenosine. Inhibition of respiratory burst and degranulation in human neutrophils may give this drug the potential to protect against the progression of inflammation.
- Published
- 2006
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15. Naphthoquinone esters from the root of Rhinacanthus nasutus.
- Author
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Wu TS, Hsu HC, Wu PL, Leu YL, Chan YY, Chern CY, Yeh MY, and Tien HJ
- Subjects
- Antihypertensive Agents chemistry, Antihypertensive Agents isolation & purification, Antiviral Agents chemistry, Esters chemistry, Magnetic Resonance Spectroscopy, Naphthoquinones chemistry, Antiviral Agents isolation & purification, Esters isolation & purification, Naphthoquinones isolation & purification, Plants, Medicinal chemistry
- Abstract
Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.
- Published
- 1998
- Full Text
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