title: Effect of three flavonoids, 5,7,3',4'-tetrahydroxy-3-methoxy flavone, luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophil.
abstract: The effect of three flavonoids, 5,7,3',4'-tetrahydoxy-3-methoxy flavone (THMF), luteolin, and quercetin, on the stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils were investigated. When the cells were preincubated with these flavonoids, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was significantly suppressed, showing a dependence on amounts of the flavonoid. The suppressing effect of the flavonoid was THMF > luteolin > quercetin. These flavonoids also suppressed the superoxide generation induced by phorbol 12-myristate 13-acetate. In this case also, THMF was more effective than luteolin and quercetin. On the other hand, the superoxide generation induced by arachidonic acid was markedly suppressed by quercetin. The suppressing effect was quercetin >> THMF > luteolin. THMF, luteolin, and quercetin significantly suppressed tyrosyl phosphorylation of 80.1-, 58.0-, and 45.0-kDa proteins in fMLP-treated human neutrophils. The suppression depended on the concentration of the flavonoids, and the inhibition of tyrosyl phosphorylation was in parallel to that of the fMLP-induced superoxide generation, respectively. While luteolin and quercetin showed a weak hemolytic activity at 2.5 mM, THMF showed almost no hemolytic activity even at 5 mM, suggesting an advantage of THMF for its clinical use.
authors.affiliation: Department of Anesthesia, Kochi Medical School, Kohasu, Kochi, 783-8505, Japan.
authors.forename: H W
authors.initials: HW
authors.lastname: Lu
authors.forename: K
authors.initials: K
authors.lastname: Sugahara
authors.forename: Y
authors.initials: Y
authors.lastname: Sagara
authors.forename: N
authors.initials: N
authors.lastname: Masuoka
authors.forename: Y
authors.initials: Y
authors.lastname: Asaka
authors.forename: M
authors.initials: M
authors.lastname: Manabe
authors.forename: H
authors.initials: H
authors.lastname: Kodama
mesh_terms: D016718:Arachidonic Acid / Q000494:pharmacology; D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D047311:Luteolin; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D010766:Phosphorylation; D011794:Quercetin / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
chemical_list: C436444:5,7,3',4'-tetrahydroxy-3-methoxy flavone; D001798:Blood Proteins; D005419:Flavonoids; D013481:Superoxides; D016718:Arachidonic Acid; D014443:Tyrosine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D011794:Quercetin; D047311:Luteolin; D013755:Tetradecanoylphorbol Acetate