scholarly journals Inhibitory Effect of Methyleugenol on IgE-Mediated Allergic Inflammation in RBL-2H3 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Feng Tang ◽  
Feilong Chen ◽  
Xiao Ling ◽  
Yao Huang ◽  
Xiaomei Zheng ◽  
...  

Allergic diseases, such as asthma and allergic rhinitis, are common. Therefore, the discovery of therapeutic drugs for these conditions is essential. Methyleugenol (ME) is a natural compound with antiallergic, antianaphylactic, antinociceptive, and anti-inflammatory effects. This study examined the antiallergic effect of ME on IgE-mediated inflammatory responses and its antiallergy mechanism in the mast cell line, RBL-2H3. We found that ME significantly inhibited the release ofβ-hexosaminidase, tumor necrosis factor- (TNF-)α, and interleukin- (IL-) 4, and was not cytotoxic at the tested concentrations (0–100 μM). Additionally, ME markedly reduced the production of the proinflammatory lipid mediators prostaglandin E2(PGE2), prostaglandin D2(PGD2), leukotriene B4(LTB4), and leukotriene C4(LTC4). We further evaluated the effect of ME on the early stages of the FcεRI cascade. ME significantly inhibited Syk phosphorylation and expression but had no effect on Lyn. Furthermore, it suppressed ERK1/2, p38, and JNK phosphorylation, which is implicated in proinflammatory cytokine expression. ME also decreased cytosolic phospholipase A2(cPLA2) and 5-lipoxygenase (5-LO) phosphorylation and cyclooxygenase-2 (COX-2) expression. These results suggest that ME inhibits allergic response by suppressing the activation of Syk, ERK1/2, p38, JNK, cPLA2, and 5-LO. Furthermore, the strong inhibition of COX-2 expression may also contribute to the antiallergic action of ME. Our study provides further information about the biological functions of ME.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Toshiaki Ara ◽  
Norio Sogawa

We previously demonstrated that a kampo medicine, kakkonto, decreases lipopolysaccharide- (LPS-) induced prostaglandin E2 (PGE2) production by human gingival fibroblasts. In this study, we examined the herbs constituting kakkonto that exhibit this effect. Shokyo strongly and concentration dependently and kanzo and keihi moderately decreased LPS-induced PGE2 production. Shokyo did not alter cyclooxygenase-2 (COX-2) activity, cytosolic phospholipase A2 (cPLA2), annexin 1 and COX-2 expression, and LPS-induced extracellular signal-regulated kinase (ERK) phosphorylation. Kanzo inhibited COX-2 activity but increased annexin 1 and COX-2 expression and did not alter LPS-induced ERK phosphorylation. Keihi inhibited COX-2 activity and LPS-induced ERK phosphorylation but slightly increased COX-2 expression and did not alter cPLA2 and annexin 1 expression. These results suggest that the mechanism of shokyo is through the inhibition of cPLA2 activity, and that of kanzo and keihi is through the inhibition of COX-2 activity and indirect inhibition of cPLA2 activity. Therefore, it is possible that shokyo and kakkonto are clinically useful for the improvement of inflammatory responses.


2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
So Hyun Jo ◽  
Yun Jung Lee ◽  
Dae Gill Kang ◽  
Ho Sub Lee ◽  
Dae Ki Kim ◽  
...  

IgE-mediated mast cell degranulation and excessive Th2 cells activation are major features of various allergic diseases.Sohamhyoong-tanghas been reported to have anti-inflammatory and antibacterial effects. In this study, we investigated the inhibitory effect ofSohamhyoong-tangextract (SHHTE) on allergic symptoms and inflammatory responses in ovalbumin- (OVA-) sensitized BALB/c mice. The mice were sensitized with OVA and alum at 2-week intervals and then orally given SHHTE for 13 days followed by intradermal OVA injection. Administration of SHHTE significantly reduced edema formation and inflammatory-cell infiltration in ear tissues. Total and OVA-specific IgEs as well as proinflammatory cytokine TNF-αand Th2-associated cytokine IL-4 levels were lower in the SHHTE-treated group than in the vehicle. SHHTE treatment significantly suppressed both mRNA and protein levels of IL-4 and IL-5 in OVA-stimulated splenocytes. SHHTE decreased Th1 (IFN-γ) and Th17 (IL-17a) cytokine mRNA expression but increased Treg cytokines (IL-10 and TGF-β1). Moreover, SHHTE significantly inhibited degranulation of RBL-2H3 cell line in a dose-dependent manner. Thus, SHHTE efficiently inhibited the allergic symptoms in an OVA-sensitized mouse model and its action may correlate with the suppression of IgE production by increasing IL-10 and TGF-β1, which can limit the function of other T helper cells and prevent the release of inflammatory mediators from mast cells. These results suggest that SHHTE could be a therapeutic agent for treating various allergic diseases.


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Eun-Ho Lee ◽  
Young-Je Cho

AbstractThis study confirmed the association with inflammation-related proteins, mediators, and cytokines using saucerneol D from Saururus chinensis leaf, a useful ingredient increased through elicitor treatment. To confirm the anti-inflammatory effect, saucerneol D were treated with lipopolysaccharide, which induces pro-inflammatory factors in Raw 264.7 cell. The pro-inflammatory influences were measured by dint of chemical assay and western blotting as well as ELISA. As a result, the content of saucerneol D was changed when eicitor was treated by various concentration (1.5, and 3 mg/mL) in S. chinensis leaves. In addition, the expression levels of hyaluronidase and pro-inflammatory-related factors [nitric oxide (NO), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2)] were regulated according to the saucerneol D content in the elicitor-treated and non-treated groups. Therefore, after confirming that saucerneol D has an inhibitory effect on pro-inflammatory-related factors, saucerneol D was adjusted by concentration and compared with the control substance to verify the efficacy. Saucerneol D was adjusted to a concentration that did not toxic to macrophages through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Saucerneol D controlled at various concentrations inhibited iNOS and COX-2 proteins. NO produced by iNOS activity, prostaglandin E2 (PGE2), an inflammatory mediator produced by COX-2 activity, and pro-inflammatory cytokines [interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α)] were significantly suppressed. Therefore, it was confirmed that saucerneol D, an active ingredient increased by the elicitor treatment, could be used as a functional material that controls inflammatory factors.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hiroyuki Kitamura ◽  
Hiroko Urano ◽  
Toshiaki Ara

Periodontal disease is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss in severe clinical cases. The chemical mediator prostaglandin E2 (PGE2) and cytokines such as interleukin- (IL-)6 and IL-8 have been known to play important roles in inflammatory responses and tissue degradation. In the present study, we investigated the effects of a kampo medicine, kakkonto (TJ-1), on the production of prostaglandin E2 (PGE2), IL-6, and IL-8 by human gingival fibroblasts (HGFs) treated with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Kakkonto concentration dependently suppressed LPS-induced PGE2 production but did not alter basal PGE2 levels. In contrast, kakkonto significantly increased LPS-induced IL-6 and IL-8 production. Kakkonto decreased cyclooxygenase- (COX-)1 activity to approximately 70% at 1 mg/mL but did not affect COX-2 activity. Kakkonto did not affect cytoplasmic phospholipase A2 (cPLA2), annexin1, or LPS-induced COX-2 expression. Kakkonto suppressed LPS-induced extracellular signal-regulated kinase (ERK) phosphorylation, which is known to lead to ERK activation and cPLA2 phosphorylation. These results suggest that kakkonto decreased PGE2 production by inhibition of ERK phosphorylation which leads to inhibition of cPLA2 phosphorylation and its activation. Therefore, kakkonto may be useful to improve gingival inflammation in periodontal disease.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Bona Linke ◽  
Yannick Schreiber ◽  
Bettina Picard-Willems ◽  
Patrick Slattery ◽  
Rolf M. Nüsing ◽  
...  

Platelets are well known for their role in hemostasis and are also increasingly recognized for their roles in the innate immune system during inflammation and their regulation of macrophage activation. Here, we aimed to study the influence of platelets on the production of inflammatory mediators by monocytes and macrophages. Analyzing cocultures of platelets and murine bone marrow-derived macrophages or human monocytes, we found that collagen-activated platelets release high amounts of prostaglandin E2(PGE2) that leads to an increased interleukin- (IL-) 10 release and a decreased tumor necrosis factor (TNF)αsecretion out of the monocytes or macrophages. Platelet PGE2mediated the upregulation of IL-10 in both cell types via the PGE2receptor EP2. Notably, PGE2-mediated IL-10 synthesis was also mediated by EP4 in murine macrophages. Inhibition of TNFαsynthesis via EP2 and EP4, but not EP1, was mediated by IL-10, since blockade of the IL-10 receptor abolished the inhibitory effect of both receptors on TNFαrelease. This platelet-mediated cross-regulation between PGE2and cytokines reveals one mechanism how monocytes and macrophages can attenuate excessive inflammatory responses induced by activated platelets in order to limit inflammatory processes.


2005 ◽  
Vol 288 (6) ◽  
pp. R1774-R1782 ◽  
Author(s):  
Adam Sapirstein ◽  
Hideyuki Saito ◽  
Sarah J. Texel ◽  
Tarek A. Samad ◽  
Eileen O’Leary ◽  
...  

The products of arachidonic acid metabolism are key mediators of inflammatory responses in the central nervous system, and yet we do not know the mechanisms of their regulation. The phospholipase A2 enzymes are sources of cellular arachidonic acid, and the enzymes cyclooxygenase-2 (COX-2) and microsomal PGE synthase-1 (mPGES-1) are essential for the synthesis of inflammatory PGE2 in the brain. These studies seek to determine the function of cytosolic phospholipase A2α (cPLA2α) in inflammatory PGE2 production in the brain. We wondered whether cPLA2α functions in inflammation to produce arachidonic acid or to modulate levels of COX-2 or mPGES-1. We investigated these questions in the brains of wild-type mice and mice deficient in cPLA2α (cPLA2α−/−) after systemic administration of LPS. cPLA2α−/− mice had significantly less brain COX-2 mRNA and protein expression in response to LPS than wild-type mice. The reduction in COX-2 was most apparent in the cells of the cerebral blood vessels and the leptomeninges. The brain PGE2 concentration of untreated cPLA2α−/− mice was equal to their wild-type littermates. After LPS treatment, however, the brain concentration of PGE2 was significantly less in cPLA2α−/− than in cPLA2α+/+ mice (24.4 ± 3.8 vs. 49.3 ± 11.6 ng/g). In contrast to COX-2, mPGES-1 RNA levels increased equally in both mouse genotypes, and mPGES-1 protein was unaltered 6 h after LPS. We conclude that cPLA2α regulates COX-2 levels and modulates inflammatory PGE2 levels. These results indicate that cPLA2α inhibition is a novel anti-inflammatory strategy that modulates, but does not completely prevent, eicosanoid responses.


2003 ◽  
Vol 228 (7) ◽  
pp. 786-794 ◽  
Author(s):  
Wieslaw Kozak ◽  
David M. Aronoff ◽  
Olivier Boutaud ◽  
Anna Kozak

Cytochrome P-450 monooxygenase (epoxygenase)-derived arachidonic acid (AA) metabolites, including 11,12-epoxyeicosatrienoic acid (11,12-EET), possess anti-inflammatory and antipyretic properties. Prostaglandin E2 (PGE2), a cyclooxygenase (COX)-derived metabolite of AA, is a well-defined mediator of fever and inflammation. We have tested the hypothesis that 11,12-EET attenuates synthesis of PGE2 in monocytes, which are the cells that are indispensable for induction of fever and initiation of inflammation. Monocytes isolated from freshly collected rat blood were stimulated with lipopolysaccharide (LPS; 100 ng/2 × 105 cells) to induce COX-2 and stimulate generation of PGE2. SKF-525A, an inhibitor of epoxygenases, significantly augmented the lipopolysaccharide-provoked synthesis of PGE2 in cell culture in a concentration-dependent manner. It did not affect, however, elevation of the expression of COX-2 protein in monocytes stimulated with LPS. 11,12-EET also did not affect the induction of COX-2 in monocytes incubated with lipopolysaccharide. However, 11,12-EET suppressed, in a concentration-dependent fashion, the generation of PGE2 in incubates. Preincubation of a murine COX-2 preparation for 0–5 min with three concentrations of 11,12-EET (1, 5, and 10 μM) inhibited the oxygenation of [14C]-labeled AA by the enzyme. The inhibitory effect of 11,12-EET on COX-2 was time-and-concentration-dependent, suggesting a mechanism-based inhibition. Based on these data, we conclude that 11,12-EET suppresses generation of PGE2 in monocytes via modulating the activity of COX-2. These data support the hypothesis that epoxygenasederived AA metabolites constitute a negative feedback on the enhanced synthesis of prostaglandins upon inflammation.


2012 ◽  
Vol 40 (06) ◽  
pp. 1257-1270 ◽  
Author(s):  
Hui-Hun Kim ◽  
Jin-Su Yoo ◽  
Tae-Yong Shin ◽  
Sang-Hyun Kim

Allergic inflammatory diseases such as food allergy, asthma, sinusitis, and atopic dermatitis are increasing worldwide. In this study, we investigated the effects of aqueous extract of Mosla chinensis Max. (AMC) on mast cell-mediated allergic inflammation and studied the possible mechanism of this action. AMC inhibited compound 48/80-induced systemic and immunoglobulin E (IgE)-mediated local anaphylaxis. AMC reduced intracellular calcium levels and downstream histamine release from rat peritoneal mast cells activated by compound 48/80 or IgE. In addition, AMC decreased gene expression and secretion of proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 in human mast cells. The inhibitory effect of AMC on cytokine expression was nuclear factor (NF)-κB dependent. Our results indicate that AMC inhibits mast cell-mediated allergic inflammatory reaction by suppressing histamine release and expression of proinflammatory cytokines and the involvement of calcium and NF-κB in these effects. AMC might be a possible therapeutic candidate for allergic inflammatory disorders.


2010 ◽  
Vol 88 (4) ◽  
pp. 603-609 ◽  
Author(s):  
Zhigang Xu ◽  
Ming Zhang ◽  
Xiaoyan Lv ◽  
Dan Xiang ◽  
Xuewen Zhang ◽  
...  

Celecoxib is a selective inhibitor of cyclooxygenase-2 (COX-2). It may reduce the risk of cancer formation by affecting the metabolism of arachidonic acid (AA), which has been implicated in the development of cancer. Accordingly, this study was designed to determine the effects of celecoxib on the AA pathway in mouse hepatoma H22 cells. Celecoxib was found to inhibit the proliferation of H22 cells in a dose- and time-dependent manner. Low doses (50 and 100 µmol·L–1) of celecoxib caused an increase in the expression of cytosolic phospholipase A2 (cPLA2), but did not affect the expression of COX-2 in terms of the mRNA and protein levels. Surprisingly, the amount of AA was elevated and the level of prostaglandin E2 (PGE2) was unaltered in the culture supernatant. At higher celecoxib doses (200 and 400 µmol·L–1), the mRNA and protein of both COX-2 and cPLA2 were inhibited. The concentration of AA was increased, and PGE2 level was depressed in H22 cells. The ratio of AA to PGE2 was increased in a dose-dependent manner. Our findings suggest that the imbalance between AA and PGE2, characterized by increased AA at a low dosage and decreased PGE2 at a high dosage of celecoxib, was an important indicator of cytotoxicity of celecoxib on H22 cells.


Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 804 ◽  
Author(s):  
Haidong Wei ◽  
Chun Li ◽  
Hongwei Xin ◽  
Shuang Li ◽  
Yanju Bi ◽  
...  

Keel fracture has negative effects on the health and welfare of laying hens. We investigated effects of keel fracture on stress, inflammation, and the orexin system in laying hens. Ninety 17-week-old Lohmann white laying hens were palpated and euthanatized at 42 weeks old, and marked as normal keel (NK)/fractured keel (FK) from absence/presence of keel fracture. Serum, brain, liver, and abdominal-muscle samples were collected from 10 NK and 10 FK hens to determine the stress and inflammatory responses and the activity of orexin systems by corticosterone content, expression of heat shock proteins (TNF-α 60, 70, 90), and inflammatory factors (tumor necrosis factor (TNF)-α, nuclear factor-kappa Bp65 (NF-κBp65), inducible nitric oxide synthase (iNOS), prostaglandin E synthases (PTGEs), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β)), orexin (ORX), and orexin-receptor 1/2 (ORXR1/ORXR2). The FK hens had higher serum corticosterone content, Hsps, and inflammatory factor mRNA expression levels than NK hens, although levels of iNOS in the liver and TNF-α in the muscle were similar. Protein levels of Hsp70 and Hsp90 in the brain and liver, iNOS and COX-2 in the liver, NF-κBp65, iNOS, and COX-2 in the brain of FK hens were increased compared with NK hens. Furthermore, FK hens had lower mRNA expression of ORX, ORXR1, and ORXR2 than NK hens. Therefore, keel fracture causes stress and inflammation, and inhibits the expression of the orexin system in laying hens.


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