Britanin Suppresses IgE/Ag-Induced Mast Cell Activation by Inhibiting the Syk Pathway

The aim of this study was to determine whether britanin, isolated from the flowers of Inula japonica (Inulae Flos), modulates the generation of allergic inflammatory mediators in activated mast cells. To understand the biological activity of britanin, the authors investigated its effects on the generation of prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and degranulation in IgE/Ag-induced bone marrow-derived mast cells (BMMCs). Britanin dose dependently inhibited degranulation and the generations of PGD2 and LTC4 in BMMCs. Biochemical analyses of IgE/Ag-mediated signaling pathways demonstrated that britanin suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes, including phospholipase Cgamma1 (PLCgamma1)-mediated calcium influx, the activation of mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase and p38), and the nuclear factor-kappaB (NF-kappaB) pathway. Taken together, the findings of this study suggest britanin suppresses degranulation and eicosanoid generation by inhibiting the Syk-dependent pathway and britanin might be useful for the treatment of allergic inflammatory diseases.

Curcumin Inhibits the Activation of Immunoglobulin E-Mediated Mast Cells and Passive Systemic Anaphylaxis in Mice by Reducing Serum Eicosanoid and Histamine Levels

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 Ca2+ influx via phospholipase Cgamma1 (PLCgamma1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappaB (NF-kappaB) 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.

Curcumin Inhibits the Activation of Immunoglobulin E-Mediated Mast Cells and Passive Systemic Anaphylaxis in Mice by Reducing Serum Eicosanoid and Histamine Levels

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 Ca2+ influx via phospholipase Cgamma1 (PLCgamma1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappaB (NF-kappaB) 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.

Emodin Isolated from Polygoni cuspidati Radix Inhibits TNF-alpha and IL-6 Release by Blockading NF-kappaB and MAP Kinase Pathways in Mast Cells Stimulated with PMA Plus A23187

Emodin, a naturally occurring anthraquinone derivative isolated from Polygoni cuspidati radix, has several beneficial pharmacologic effects, which include anti-cancer, anti-diabetic, and anti-inflammatory activities. In this study, the authors examined the effect of emodin on the production of proinflammatory cytokines, such as, tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, in mouse bone marrow-derived mast cells (BMMCs) stimulated with phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187. To investigate the mechanism responsible for the regulation of pro-inflammatory cytokine production by emodin, the authors assessed its effects on the activations of transcriptional factor nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein kinases (MAPKs). Emodin attenuated the nuclear translocation of (NF)-kappaB p65 and its DNA-binding activity by reducing the phosphorylation and degradation of IkappaBalpha and the phosphorylation of IkappaB kinase B (IKK). Furthermore, emodin dose-dependently attenuated the phosphorylations of MAPKs, such as, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAP kinase, and the stress-activated protein kinases (SAPK)/c-Jun-N-terminal kinase (JNK). Taken together, the findings of this study suggest that the anti-inflammatory effects of emodin on PMA plus A23187-stimulated BMMCs are mediated via the inhibition of NF-kappaB activation and of the MAPK pathway.

Flowers of Inula japonica Attenuate Inflammatory Responses

BACKGROUND: The flowers of Inula japonica (Inulae Flos) have long been used in traditional medicine for the treatment of inflammatory diseases. In the present study, we investigated the anti-inflammatory properties of Inulae Flos Extract (IFE). METHODS: The anti-inflammatory effects of IFE against nitric oxide (NO), PGE2, TNF-alpha, and IL-6 release, as well as NF-kappa B and MAP kinase activation were evaluated in RAW 264.7 cells. RESULTS: IFE inhibited the production of NO and the expression of inducible nitric oxide synthase (iNOS) in LPS-stimulated RAW264.7 cells. In addition, IFE reduced the release of pro-inflammatory cytokines, such as TNF-alpha and IL-6. Furthermore, IFE inhibited the NF-kappa B activation induced by LPS, which was associated with the abrogation of I kappa B-alpha degradation and subsequent decreases in nuclear p65 and p50 levels. Moreover, the phosphorylation of ERK, JNK, and p38 MAP kinases in LPS-stimulated RAW 264.7 cells was suppressed by IFE in a dose-dependent manner. CONCLUSION: These results suggest that the anti-inflammation activities of IFE might be attributed to the inhibition of NO, iNOS and cytokine expression through the down-regulation of NF-kappa B activation via suppression of I kappa B alpha and MAP kinase phosphorylation in macrophages.

Development of a Mass Production Method of Platelet Activating Factor Acetylhydrolase

Platelet activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent lipid mediator in a variety of physiological events. PAF is also involved in various pathological events including allergy and inflammation. PAF-acetylhydrolase (PAF-AH) hydrolyzes PAF to produce inactive lyso-PAF. Thus, overproduction of PAF-AF will be useful for the therapeutic valuation of the enzyme. In this study, we established an overproduction method of bovine PAF-AH in Escherichia coli system. We used bovine mammary gland for cDNA cloning. The cDNA had two mismatches of amino acid sequences (Thr-247 to Met and Ile-431 to Thr) compared with the previously reported PAF-AH cDNA (bovine spleen, NM_174578). The recombinant PAF-AH of 43 kDa in molecular size reacted with human PAF-AH polyclonal antibody and showed a strong PAF-AH enzyme activity in an in vitro assay system. The recombinant PAF-AH produced by this study can be applied for various experiments including in vivo models to test its protective activity against PAF-related diseases.

Methyl-beta-cyclodextrin inhibits cell growth and cell cycle arrest via a prostaglandin E(2) independent pathway

Methyl-beta-cyclodextrin, a cyclic oligosaccharide known for its interaction with the plasma membrane induces several events in cells including cell growth and anti-tumor activity. In this study, we have investigated the possible role of cyclooxygenase 2 (COX-2) in cell growth arrest induced by methyl-beta-cyclodextrin in Raw264.7 macrophage cells. Methyl-beta-cyclodextrin inhibited cell growth and arrested the cell cycle, and this cell cycle arrest reduced the population of cells in the S phase, and concomitantly reduced cyclin A and D expressions. Methyl-beta-cyclodextrin in a dose- and time-dependent manner, also induced COX-2 expression, prostaglandin E(2) (PGE(2)) synthesis, and COX-2 promoter activity. Pretreatment of cells with NS398, a COX-2 specific inhibitor completely blocked PGE(2) synthesis induced by methyl-beta-cyclodextrin, however inhibition on cell proliferation and cell cycle arrest was not effected, suggesting non-association of COX-2 in the cell cycle arrest. These results suggest that methyl-beta-cyclodextrin induced cell growth inhibition and cell cycle arrest in Raw264.7 cells may be mediated by cyclin A and D1 expression.

Phospholipase A2 as an Index of Disease Activity in Rheumatoid Arthritis / 대한류마티스학회지

OBJECTIVES: A limited retrospective study of patients with rheumatoid arthritis (RA) found that serum phospholipase A2 (PLA2) activity correlates with disease activity. To assess the strength of this relationship we investigated prospectively 25 patients with RA using a double blind approach. METHODS: Twenty five patients who fulfilled the 1987 American College of Rheumatology criteria for RA had clinical and laboratory assessments. PLA2 activity was measured before and after treatment of 3 months in patients with RA. Fourteen healthy individuals were also enrolled as controls. PLA2 activity was assayed using E.coli membrane phospholipid substrate labelled with[14C]-oleic acid. RESULTS: 1) Serum PLA2 activity was significantly higher in patients with RA than that of normal healthy controls (p<0.001). 2) In Patients with RA, synovial fluid PLA2 activity was higher than serum PLA2 activity, and a positive correlation between PLA2 in synovial fluids and matched sera was found in these patients (p<0.05). 3) After treatment, PLA2 activity was significantly decreased with improvement of clinical(morning stiffness and Ritchie index) and laboratory(ESR, CRP and rheumatoid factor)assessments (p<0.001). 4) Among the clinical and laboratory markers of disease activity, ESR showed the best correlation with serum PLA2 activity (r=0.493, p<0.05). 5) In the patients who did not respond clinically to treatment (n=5), there was no significant decrease in PLA2 activity. CONCLUSION: PLA2 activity significantly correlates with RA activity and may serve as an index of disease activity in RA.