title: Interactive inhibitory effects of formoterol and montelukast on activated human neutrophils.
abstract: The research question addressed in the current study was: do formoterol (1 and 10 nM) and montelukast (2 μM) possess interactive inhibitory effects on activated human neutrophils, particularly in relation to alterations in cyclic AMP and cytosolic Ca²(+) fluxes? Isolated human blood neutrophils were activated with the chemoattractant N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) (1 μM) in combination with cytochalasin B (CB; 3 μM). Fura-2-acetoxymethyl ester-based spectrofluorimetry, lucigenin-enhanced chemiluminescence, colorimetric and flow cytometric procedures were used to measure cytosolic Ca²(+) fluxes, production of superoxide, elastase release and beta-2 integrin (CR3) expression, respectively, while cyclic AMP and leukotriene (LT)B₄ were assayed using competitive binding ELISA procedures. Activation of the cells with fMLP/CB resulted in abrupt and sustained increases in cytosolic Ca²(+), as well as release of elastase and production of superoxide and LTB₄, and expression of CR3, all of which were attenuated by formoterol and montelukast individually, and especially by the combination of these agents. These anti-inflammatory effects of each agent, as well as the combination, were associated with significant increases in cyclic AMP. The findings of the current study may explain the efficacy of montelukast and formoterol when used in combination with inhaled corticosteroids in the treatment of severe asthma, possibly by controlling neutrophil-driven inflammation of the airways.
authors.affiliation: Medical Research Council Unit for Inflammation and Immunity, Dept of Immunology, Faculty of HealthSciences, University of Pretoria, Pretoria, South Africa.
authors.forename: C M
authors.initials: CM
authors.lastname: Gravett
authors.forename: A J
authors.initials: AJ
authors.lastname: Theron
authors.forename: H C
authors.initials: HC
authors.lastname: Steel
authors.forename: G R
authors.initials: GR
authors.lastname: Tintinger
authors.forename: R
authors.initials: R
authors.lastname: Cockeran
authors.forename: C
authors.initials: C
authors.lastname: Feldman
authors.forename: R
authors.initials: R
authors.lastname: Anderson
mesh_terms: D000085:Acetates / Q000494:pharmacology*; D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology*; D000328:Adult; D000420:Albuterol / Q000494:pharmacology; D018821:CD18 Antigens / Q000032:analysis; D015220:Calcium Channels / Q000187:drug effects; D000242:Cyclic AMP / Q000032:analysis; D003521:Cyclopropanes; D003571:Cytochalasin B / Q000494:pharmacology; D004347:Drug Interactions; D004983:Ethanolamines / Q000494:pharmacology*; D000068759:Formoterol Fumarate; D006801:Humans; D020024:Leukotriene Antagonists / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000032:analysis; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects*; D010196:Pancreatic Elastase / Q000032:analysis / Q000378:metabolism; D011804:Quinolines / Q000494:pharmacology*; D020889:Rolipram / Q000494:pharmacology; D013440:Sulfides; D013481:Superoxides / Q000032:analysis
chemical_list: D000085:Acetates; D058666:Adrenergic beta-2 Receptor Agonists; D018821:CD18 Antigens; D015220:Calcium Channels; D003521:Cyclopropanes; D004983:Ethanolamines; D020024:Leukotriene Antagonists; D011804:Quinolines; D013440:Sulfides; D013481:Superoxides; D007975:Leukotriene B4; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D000242:Cyclic AMP; D010196:Pancreatic Elastase; D020889:Rolipram; C093875:montelukast; D000420:Albuterol; D000068759:Formoterol Fumarate