Lipoxygenase is a protein with non-heme iron atom, which has been discovered in many animals and plants. Lipoxygenase which has a close relationship with human tumors, inflammatory diseases, asthma, arteriosclerosis, and toxic action of chemicals could not only di-oxygenate endogenous polyunsaturated fatty acid to yield bioactive factors such as leukotrienes(LTs), but also has co-oxidation activity to activate xenobiotics. Lipoxygenase inhibitors include hydroxamic acid derivatives, nordihydroguaiaretic acid, flavonoids, FLAP inhibitors and so on. All of them can effectively restrain the catalytic action of lipoxygenase. Literatures demonstrate that the inhibitors can block the formation of relevant bioactive factors and toxic products of xenobiotics clinically which are used to prevent and cure the relevant diseases to keep people healthy.
Animals ; Flavonoids ; pharmacology ; Humans ; Leukotrienes ; metabolism ; Lipoxygenase Inhibitors ; pharmacology ; Masoprocol ; pharmacology ; Oxidation-Reduction ; Xenobiotics ; metabolism

BACKGROUND: To evaluate the role of free fatty acids on the ischemic myocardium, influences of various free fatty acids upon transmembrane action potential and ATP-sensitive K+(KATP) channel activity were examined in the ventricular myocardium and single cardiac myocytes. METHODS: KATP channel activities were measured in the enzymatically (collagenase) isolated single rat ventricular cardiac myocytes by the method of the excised inside-out and the cell-attached patch clamp, and transmembrane action potentials were recorded using the conventional 3M-KCl microelectode techniques in the rat ventricular myocardium. RESULTS: Free fatty acids [FFAs; arachidonic acid (AA), linoleic acid (LA) and lysophosphatidylcholine (LPC)] reduced the KATP channel activity in a dose-dependent manner in the inside-out patch, and 50%-inhibition concentrations (IC50) were 88 +/- 11.2, 49 +/- 12.5, and 188 +/- 17.4 M respectively. Both frequency of channel opening and the mean open-burst duration were markedly decreased, but the amplitude of single channel currents were not changed by the FFAs. AA (50 micrometer) and LPC (50 micrometer) did not affect the dinitrophenol (DNP, 50 micrometer)-induced KATP channel activity, whereas LA (50 micrometer) had a tendency to reduce the activity. The channel inhibition effects by 10 micrometer AA in the inside-out patch were significantly augmented by diclofenac (10 micrometer), but was not changed by nordihydroguaiaretic acid. FFAs never stimulated KATP channel activity, even in the inside-out patch where KATP channel activity reduced in the presence of internal ATP (100 micrometer). Time for 90% repolarization (APD90) significantly increased during superfusion of the FFAs, to 22 (50 micrometer AA), 24 (50 micrometer LA), and 18 (50 micrometer LPC) % from those of the contol at the time of 10 min superfusion, but the other action potential characteristics were not changed by the FFAs. AA (10 micrometer) attenuated cromakalim (10 micrometer)-induced APD90 shortening effects. CONCLUSION: It was inferred that FFAs inhibit the KATP channel activity directly by themselves and/or indirectly by their metabolites in the rat ventricular cardiomyocytes, and therefore, duration of action potential lengthens to be a burden over the ischemic myocardium accounting for the injury of myocardium at the late stage of ischemia.
Action Potentials* ; Adenosine Triphosphate ; Animals ; Arachidonic Acid ; Cromakalim ; Diclofenac ; Fatty Acids, Nonesterified* ; Ischemia ; Linoleic Acid ; Lysophosphatidylcholines ; Masoprocol ; Myocardium* ; Myocytes, Cardiac ; Potassium Channels* ; Potassium* ; Rats*

This study is to investigate whether the synthesized chiral compound Nordy has influence on the function of endothelial progenitor cells (EPCs) from human umbilical cord blood induced by vascular endothelial growth factor (VEGF). EPCs were isolated from human umbilical cord blood by density gradient centrifugation. After cultured for 7 -10 days, EPCs were prepared for detecting effect of Nordy on proliferation, migration and tubule-forming activity in Matrigel induced by VEGF. Incubation of EPCs with 100 micromol L(-1) Nordy for 24 h initially inhibited the proliferative capacity of EPCs induced by VEGF (P <0.05). Moreover, 25 -50 micromol L(-1) Nordy also exhibited inhibitory effect at 48 -72 h. In addition, 25 - 100 micromol L(-1) Nordy impaired EPCs migratory and tubule-forming capacity in vitro (P < 0.05). Nordy could inhibit in EPCs the functions of proliferation, migration and tubulogenesis induced by VEGF in vitro, which might be a possible mechanism of its anti-EPCs effects.
Antineoplastic Agents ; pharmacology ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Endothelial Cells ; cytology ; Fetal Blood ; cytology ; Humans ; Masoprocol ; analogs & derivatives ; pharmacology ; Neovascularization, Physiologic ; drug effects ; Stem Cells ; cytology ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors

Platelet-activating factor (PAF) enhanced interleukin-1 (IL-1) activity by the interaction with a specific receptor in rat alveolar macrophages. In this study, we investigated the role of endogenous arachidonate metabolites and intracellular calcium mobilization in the PAF-induced IL-1 activity. Alveolar macrophages were preincubated with 5-lipoxygenase and cyclooxygenase inhibitors 30 min before the addition of PAF and lipopolysaccharide (LPS). After 24 h culture, IL-1 activity was measured in the supernate of sample using the thymocyte proliferation assay. Inhibition of 5-lipoxygenase by nordihydroguaiaretic acid and AA-861 completely blocked the PAF-induced enhancement of IL-1 activity with IC50 of 2 micrometer and 5 micrometer, respectively. In contrast, the inhibition of cyclooxygenase pathway by indomethacin and ibuprofen resulted in the potentiation in PAF-induced IL-1 activity with maximal effect at 1 micrometer and 5 micrometer, respectively. In addition, leukotriene B4 and prostaglandin E2 production were observed in PAF-stimulated alveolar macrophage culture. As could be expected, 5-lipoxygenase and cyclooxygenase inhibitors abolished PAFstimulated leukotriene B4 and prostaglandin E2 production, respectively. The effects of PAF on intracellular calcium mobilization in alveolar macrophages were evaluated using the calcium-sensitive dye fura-2 at the single cell level. PAF at any dose between 10-16 and 10-8M did not increase intracellular calcium. Furthermore, there was no effective change of intracellular calcium level when PAF was added to alveolar macrophages in the presence of LPS or LPS + LTB4, and 4, 24 and 48h after treatment of these stimulants. Together, the results indicate that IL-1 activity induced by PAF is differently regulated through subsequent induction of endogenous 5-lpoxygenase and cyclooxygenase pathways, but not dependent on calcium signalling pathway.
Animals ; Arachidonate 5-Lipoxygenase ; Calcium ; Cyclooxygenase Inhibitors ; Dinoprostone ; Fura-2 ; Ibuprofen ; Indomethacin ; Inhibitory Concentration 50 ; Interleukin-1* ; Leukotriene B4 ; Lipoxygenase Inhibitors ; Macrophages, Alveolar* ; Masoprocol ; Prostaglandin-Endoperoxide Synthases ; Rats ; Thymocytes

Nordy is a synthesized chrial compound. To investigate the effects of nordy (25 - 100 micromol x L(-1)) on the function of formylpeptide receptor (FPR) of malignant human glioma cells, human glioblastoma cell line U87 was used to detect its proliferation, migration, calcium mobilization, vascular endothelial growth factor (VEGF) mRNA and protein levels after activation of FPR by its agonist N-formyl-methionyl-leucyl-phenylalanine (fMLF). Cell proliferation, migration ability, VEGF mRNA, VEGF protein and calcium mobilization were evaluated by cell counting, chemotaxis assay, RT-PCR, ELISA and spectrometry. Nordy (50 - 100 micromol x L(-1)) potently inhibited the proliferation, migration and calcium mobilization of U87 cells induced by fMLF (P < 0.05). Moreover, 100 micromol x L(-1) nordy showed a significantly impaired VEGF mRNA expression and protein secretion induced by fMLF (P < 0.05). Nordy could inhibit FPR functioning in glioma cell proliferation, migration and angiogenesis, which might be a possible mechanism of its anti-cancer effects.
Antineoplastic Agents ; pharmacology ; Calcium ; metabolism ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Enzyme-Linked Immunosorbent Assay ; Glioblastoma ; genetics ; metabolism ; pathology ; Humans ; Masoprocol ; analogs & derivatives ; pharmacology ; N-Formylmethionine Leucyl-Phenylalanine ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Formyl Peptide ; agonists ; metabolism ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Spectrophotometry ; methods ; Vascular Endothelial Growth Factor A ; biosynthesis ; genetics

The aim of the present study is to investigate the role of nordihydroguaiaretic acid (NDGA) on inflammatory cells accumulation after focal cerebral ischemia and the underlying mechanism. Focal cerebral ischemia was induced by 30 min of middle cerebral artery occlusion (MCAO) followed by 72 h of reperfusion. NDGA (5 and 10 mg/kg) was administered intraperitoneally 30 min, 2, 24, 48 h after reperfusion, respectively. The brain injuries were observed by neurological and histological examination. Endogenous IgG exudation, neutrophils and macrophages/microglia accumulation, and intercellular adhesion molecule-1 (ICAM-1) protein expression were determined by immunohistochemistry 72 h after reperfusion. ICAM-1 mRNA was determined by RT-PCR 72 h after reperfusion. The catalysates of 5-lipoxygenase (5-LOX), leukotriene B4 (LTB4) and cysteinyl leukotrienes (CysLTs), were evaluated by ELISA 3 h after reperfusion. The results showed that NDGA ameliorated neurological dysfunction, decreased infarct volume, and inhibited endogenous IgG exudation, neutrophils infiltration, ICAM-1 mRNA and protein expression 72 h after reperfusion. Moreover, NDGA reduced the levels of LTB4 and CysLTs 3 h after reperfusion. However, NDGA did not reduce the accumulation of macrophages/microglia 72 h after reperfusion. These results suggest that NDGA decreases neutrophil infiltration in the subacute phase of focal cerebral ischemia via inhibiting 5-LOX activation.
Animals ; Arachidonate 5-Lipoxygenase ; metabolism ; Brain Ischemia ; complications ; physiopathology ; Immunoglobulin G ; immunology ; Inflammation ; etiology ; physiopathology ; prevention & control ; Intercellular Adhesion Molecule-1 ; genetics ; metabolism ; Leukotriene B4 ; metabolism ; Lipoxygenase Inhibitors ; pharmacology ; Male ; Masoprocol ; pharmacology ; Neutrophils ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; prevention & control

OBJECTIVETo explore effects of nordy on biological behaviors of human malignant glioblastoma cell line U87MG in vitro and transplanted tumor in vivo, and to identify the differential proteome upon Nordy induced differentiation.

METHODSGlioblastoma U87MG cells were induced to differentiate by synthetic lipoxygenase inhibitor, Nordy. The drug was also given via peritoneal injection to nude mice (27 mg/kg body weight) bearing orthotopic transplanted tumors of U87MG cells in the brain. The tumor volumes and GFAP expression were measured. Total proteins of U87MG cells after Nordy treatment were analysed by two-dimensional gel electrophoresis. PDQuest 7.1 computer software was used to compare protein profiles of the treated cells with that of untreated control. Differentially expressed proteins were then selected and characterized by matrix assisted laser desorption ionization-time of flight-mass spectrometry. The functional aspects of these proteins were analyzed by bioinformatics.

RESULTSNordy suppressed both the proliferation of U87MG cells in vitro and the tumor growth of orthotopic transplanted tumors in vivo (P < 0.01). The differentially expressed proteins induced by Nordy included proliferation-associated gene A, alternative splicing factor ASF-3, eukaryotic translation initiation factor 5A, coffilin 1 (non-muscle), beta galactoside binding lectin, glyceraldehyde-3-phosphate dehydrogenase, enolase 1 and an unknown protein.

CONCLUSIONSNordy promotes the differentiation of glioblastoma cells, by which it may serve as a therapeutic agent. Various proteins identified during Nordy-induced differentiation are involved in the cell proliferation, metabolism, differentiation, apoptosis and gene transcription.

Animals ; Antineoplastic Agents ; pharmacology ; Brain Neoplasms ; metabolism ; pathology ; Cell Differentiation ; Cell Line, Tumor ; Cell Proliferation ; Female ; Gene Expression Regulation, Neoplastic ; Glial Fibrillary Acidic Protein ; metabolism ; Glioblastoma ; metabolism ; pathology ; Humans ; Lipoxygenase Inhibitors ; pharmacology ; Male ; Masoprocol ; analogs & derivatives ; pharmacology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Protein Array Analysis ; Proteome ; genetics ; metabolism ; Proteomics ; methods ; Random Allocation ; Tumor Burden