BACKGROUND: Flavonoids have a variety of activities including anti-allergic activities, and are known to inhibit histamine release from human basophils and murine mast cells. OBJECTIVE: The effects of luteolin, a flavone, on the immunoglobulin (Ig) E-mediated allergic mediator release from human cultured mast cells (HCMCs) were investigated and compared with those of baicalein and quercetin. METHODS: HCMCs were sensitized with IgE, and then treated with flavonoids before challenge with antihuman IgE. The amount of released mediators was determined as was mobilization of intracellular Ca2+ concentration, protein kinase C (PKC) translocation and phosphorylation of intracellular proteins were detected after anti-IgE stimulation. RESULTS: Luteolin, baicalein and quercetin inhibited the release of histamine, leukotrienes (LTs), prostaglandin D2 (PGD2), and granulocyte macrophage-colony stimulating factor (GM-CSF) from HCMC in a concentration-dependent manner. Additionally, the three flavonoids inhibited A23187-induced histamine release. As concerns Ca2+ signalling, luteolin and quercetin inhibited Ca2+ influx strongly, although baicalein did slightly. With regard to PKC signalling, luteolin and quercetin inhibited PKC translocation and PKC activity strongly, although baicalein did slightly. The suppression of Ca2+ and PKC signallings might contribute to the inhibition of mediator release. The activation of extracellular signal-regulated kinases (ERKs) and c-Jun NH2-terminal kinase (JNK), that were activated just before the release of LTs and PGD2 and GM-CSF mRNA expression in IgE-mediated signal transduction events, were clearly suppressed by luteolin and quercetin. In contrast, the flavonoids did not affect the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway. CONCLUSION: These results indicate that luteolin is a potent inhibitor of human mast cell activation through the inhibition of Ca2+ influx and PKC activation.
BACKGROUND:Flavonoids have a variety of activities including anti-allergic activities, and are known to inhibit histamine release from human basophils and murine mast cells. OBJECTIVE: The effects of luteolin, a flavone, on the immunoglobulin (Ig) E-mediated allergic mediator release from human cultured mast cells (HCMCs) were investigated and compared with those of baicalein and quercetin. METHODS:HCMCs were sensitized with IgE, and then treated with flavonoids before challenge with antihuman IgE. The amount of released mediators was determined as was mobilization of intracellular Ca2+ concentration, protein kinase C (PKC) translocation and phosphorylation of intracellular proteins were detected after anti-IgE stimulation. RESULTS:Luteolin, baicalein and quercetin inhibited the release of histamine, leukotrienes (LTs), prostaglandin D2 (PGD2), and granulocyte macrophage-colony stimulating factor (GM-CSF) from HCMC in a concentration-dependent manner. Additionally, the three flavonoids inhibited A23187-induced histamine release. As concerns Ca2+ signalling, luteolin and quercetin inhibited Ca2+ influx strongly, although baicalein did slightly. With regard to PKC signalling, luteolin and quercetin inhibited PKC translocation and PKC activity strongly, although baicalein did slightly. The suppression of Ca2+ and PKC signallings might contribute to the inhibition of mediator release. The activation of extracellular signal-regulated kinases (ERKs) and c-Jun NH2-terminal kinase (JNK), that were activated just before the release of LTs and PGD2 and GM-CSF mRNA expression in IgE-mediated signal transduction events, were clearly suppressed by luteolin and quercetin. In contrast, the flavonoids did not affect the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway. CONCLUSION: These results indicate that luteolin is a potent inhibitor of human mast cell activation through the inhibition of Ca2+ influx and PKC activation.
Authors: Suparna Nanua; Suzanna M Zick; Juan E Andrade; Umadevi S Sajjan; John R Burgess; Nicholas W Lukacs; Marc B Hershenson Journal: Am J Respir Cell Mol Biol Date: 2006-06-22 Impact factor: 6.914
Authors: D Kempuraj; M Tagen; B P Iliopoulou; A Clemons; M Vasiadi; W Boucher; M House; A Wolfberg; T C Theoharides Journal: Br J Pharmacol Date: 2008-09-22 Impact factor: 8.739
Authors: N Sismanopoulos; D-A Delivanis; D Mavrommati; E Hatziagelaki; P Conti; T C Theoharides Journal: Allergy Date: 2012-10-16 Impact factor: 13.146