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.
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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. 06/2011; 12(6).
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ABSTRACT: Antiallergic activities of 10 lactic acid bacteria strains prepared from Mongolian dairy products as orally administered probiotics were examined in three murine type I allergy models (compound 48/80 stimulation, passive cutaneous anaphylaxis reaction, and ovalbumin sensitization models). Among the 10, only Lactobacillus plantarum strain 06CC2 significantly alleviated allergic symptoms in all three models and reduced the levels of total IgE, ovalbumin-specific IgE, and histamine in the sera of ovalbumin-sensitized mice. In vitro study, interferon-γ and interleukin-4 secretions from spleen cells of ovalbumin-sensitized mice administered the 06CC2 strain were significantly enhanced and suppressed, respectively, in the presence of ovalbumin. In Peyer's patches of ovalbumin-sensitized mice, strain 06CC2 significantly enhanced mRNA expressions of interferon-γ and interleukin-12 receptor β2, but suppressed that of the interleukin-4. Thus, strain 06CC2 probably promoted Th1 immunity through intestinal immunity and improved the Th1/Th2 balance in type I allergic mice, resulting in alleviation of allergic symptoms.Journal of Functional Foods 07/2014; 9:60–69. · 4.48 Impact Factor
- Journal of Functional Foods 04/2013; 5(2):763-772. · 4.48 Impact Factor