Curcumin, a constituent of curry, suppresses IgE-mediated allergic response and mast cell activation at the level of Syk.
ABSTRACT Activation of mast cells through the high-affinity receptor for IgE (FcepsilonRI) underlies atopic allergic reactions. Curcumin can block this activation, but the mechanism and the effects of curcumin on IgE-mediated allergic reactions are unknown.
We sought to determine the antiallergic activity of curcumin in vivo and its mechanism of action in mast cells.
The antiallergic activity of curcumin was evaluated in mast cell cultures and the passive cutaneous anaphylaxis model. The effects of curcumin on mast cell signaling events were examined by using immunoblotting, immunoprecipitation, RT-PCR, and other molecular biologic approaches.
Curcumin inhibited antigen-mediated activation of mast cells and passive cutaneous anaphylaxis in mice. Suppression of degranulation and secretion of TNF-alpha and IL-4 was apparent at concentrations as low as 3 micromol/L curcumin in activated mast cells. Similar concentrations of curcumin suppressed Syk-dependent phosphorylations of the adaptor proteins linker of activated T cells and Grb2-associated binder 2, which are critical for mast cell activation. Although curcumin did not inhibit the phosphorylation of Syk itself, it directly inhibited Syk kinase activity in vitro. Further downstream, activating phosphorylations of Akt and the mitogen-activated protein kinases p38, p44/42 (extracellular signal-regulated kinase 1/2), and c-Jun N-terminal kinase, which are critical for the production of inflammatory cytokines, were also inhibited.
Curcumin inhibits Syk kinase-dependent signaling events in mast cells and might thus contribute to its antiallergic activity. Therefore curcumin might be useful for the treatment of mast cell-related immediate and delayed allergic diseases.
- SourceAvailable from: ocean.kisti.re.kr[Show abstract] [Hide abstract]
ABSTRACT: TREK-1 channel is a member of the two-pore domain potassium (K2P) channel family that is regulated by intracellular pH, membrane stretch, polyunsaturated fatty acids, temperature, and some neuroprotectant agents. TREK-1 channel can influence neuronal excitability by regulating leakage of potassium ions and resting membrane potential. TREK-1 channel has been shown to be overexpressed in prostate cancer cells. Although the importance of these properties, relatively little is known about flavonoid effects in the regulations of TREK-1 channel. The purpose of the study was to screening of flavonoids as the TREK-1 channel modulator using one of electrophysiological techniques such as excised inside-out patch configuration. We demonstrated blocking effect on TREK-1 channel by flavonoids such as epigallocatechin-3-gallate (EGCG), curcumin and quercetin in CHO cells transiently expressing TREK-1 channel. The inhibition of TREK-1 channel by quercetin and curcumin was reversible, whereas EGCG was little reversible. Quercetin, EGCG and curcumin decreased the relative channel activity to 73%, 91% and 94%, respectively. The half-inhibitory concentration (IC50) of curcumin, quercetin and EGCG was , and in CHO cells expressing TREK-1 channel, respectively. These results indicate that flavonoids might regulate TREK-1 and this regulation might be one of the pharmacological actions of flavonoid in nervous systems and cancer cells.Journal of the Korea Academia-Industrial cooperation Society. 01/2011; 12(6).
- [Show abstract] [Hide abstract]
ABSTRACT: Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin D2 (PGD2) and 5-lipoxygenase (5-LO) dependent leukotriene C4 (LTC4) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular Ca(2+) influx via phospholipase Cγ1 (PLCγ1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-κB (NF-κB) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum LTC4, PGD2, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.Biomolecules and Therapeutics 01/2014; 22(1):27-34. · 0.79 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Aceriphyllum rossii contains an abundant source of natural flavonoids with potential antioxidant, anticancer and anti-inflammatory properties. However, the effect of Aceriphyllum rossii extract (ARE) on immunoglobulin E-mediated allergic responses remains unknown. In the present study, the effects of ARE and its active compounds, quercetin and kaempferol, on IgE-mediated rat basophilic leukemia mast cell activation and passive cutaneous anaphylaxis (PCA) were investigated. ARE, quercetin, and kaempferol inhibited secretion of β-hexosaminidase and histamine, and reduced the production and mRNA expression of interleukin-4 and tumor necrosis factor-α. ARE also decreased the production of prostaglandin E2 and leukotriene B4 and expression of cyclooxygenase 2 and 5-lipoxygenase. Furthermore, ARE, quercetin, and kaempferol inhibited IgE-mediated phosphorylation of Syk, phospholipase Cγ, protein kinase C (PKC)μ, and the mitogen-activated protein kinases, extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase. ARE, quercetin, and kaempferol markedly suppressed mast cell-dependent PCA in IgE-sensitized mice. These results indicate that ARE and its active constituents, quercetin and kaempferol, may be a useful therapy for immediate-type hypersensitivity.Journal of Agricultural and Food Chemistry 04/2014; · 3.11 Impact Factor