Ear Swelling Response Research Articles

Repeatedly administered antidepressant drugs modulate humoral and cellular immune response in mice through action on macrophages.

Depression is associated with an altered immune response, which could be normalized by antidepressant drugs. However, little is known about the influence of antidepressants on the peripheral immune response and function of macrophages in individuals not suffering from depression. Our studies were aimed at determining the influence of antidepressant drugs on the humoral and cellular immune response in mice. Mice were treated intraperitoneally with imipramine, fluoxetine, venlafaxine, or moclobemide and contact immunized with trinitrophenyl hapten followed by elicitation and measurement of contact sensitivity by ear swelling response. Peritoneal macrophages from drug-treated mice were either pulsed with sheep erythrocytes or conjugated with trinitrophenyl and transferred into naive recipients to induce humoral or contact sensitivity response, respectively. Secretion of reactive oxygen intermediates, nitric oxide, and cytokines by macrophages from drug-treated mice was assessed, respectively, in chemiluminometry, Griess-based colorimetry and enzyme-linked immunosorbent assay, and the expression of macrophage surface markers was analyzed cytometrically. Treatment of mice with fluoxetine, venlafaxine, and moclobemide results in suppression of humoral and cell-mediated immunity with a reduction of the release of macrophage proinflammatory mediators and the expression of antigen-presentation markers. In contrast, treatment with imipramine enhanced the humoral immune response and macrophage secretory activity but slightly suppressed active contact sensitivity. Our studies demonstrated that systemically delivered antidepressant drugs modulate the peripheral humoral and cell-mediated immune responses, mostly through their action on macrophages. Imipramine was rather proinflammatory, whereas other tested drugs expressed immunosuppressive potential. Current observations may be applied to new therapeutic strategies dedicated to various disorders associated with excessive inflammation.

A novel compound 2-(4-{2-[(phenylthio)acetyl]carbonohydrazonoyl}phenoxy)acetamide downregulates TSLP through blocking of caspase-1/NF-κB pathways

Thymic stromal lymphopoietin (TSLP) is regarded as the main factor responsible for the pathogenesis of allergic disorders such as atopic dermatitis, chronic obstructive pulmonary diseases, and allergic rhinitis. As part of our continuing search for novel anti-inflammatory compounds, 2-(4-{2-[(phenylthio)acetyl]carbonohydrazonoyl}phenoxy)acetamide (PA) was analyzed. In the present study, we examined how PA regulates the mRNA expression and production of TSLP in the human mast cell line, HMC-1 cells. Computer-aided docking simulation, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, caspase-1 assay, and Western blotting were used to investigate the effects of PA. PA decreased the mRNA expression and production of TSLP in HMC-1 cells. PA (1μM) inhibited the TSLP production up to 87.710±5.201%. PA also improved the activation and phosphorylation of nuclear factor-κB as well as the degradation and phosphorylation of IκBα. Caspase-1 activation was up-regulated in activated HMC-1 cells, whereas caspase-1 activation was down-regulated by PA. Finally, PA inhibited ear swelling response induced by phorbol myristate acetate in mice. These results indicate that PA would be effective to treat inflammatory and atopic disorders through the down-regulations of TSLP.

Identification of Biological and Pharmaceutical Mast Cell‐ and Basophil‐Related Targets

Identification of Biological and Pharmaceutical Mast Cell‐ and Basophil‐Related Targets

보중익기탕(補中益氣湯)이 접촉성 과민반응에 미치는 영향(影響)

Objective : The water extract of Bojungikgi-tang (BTE) composed with Ginseng Radix, Astragali Radix, Angelicae gigantis Radix, Atractylodes Rhizoma alba, Aurantii nobilis Pericarpium, Glycyrrhizae Radix, Cimicifuga Rhizoma, and Bupleuri Radix and it has been traditionally used for chronic diseases or weakness after illness in oriental countries. However, little is known about the effects of aqueous extract of BTE on trimellitic anhydride (TMA)-induced contact hypersensitivity (CHS). Therefore, the aim of this study was to investigate the effects of BTE on TMA-induced CHS in BALB/c mice.Methods : In this study, the extract of BTE was prepared by extracting with distilled water at 100℃ for 2.5 h. The extract was freeze-dried following filtration through 0.45 μm filter. Mice were orally administrated with or without BTE extract of different doses (25-200 ㎎/㎏/day) for 28 days. During the challenge period, mice were externally applied with different doses of BTE extract one time per day 30 min before TMA treatment. I examined the effects of BTE on the serum levels of IgE, IgG1, IgG2a, and IgG2b, nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in isolated peritoneal macrophages, Th2 cytokine production in isolated spleen cells, ear swelling responses, and the leukocyte infiltration induced by TMA.Results : The orally and externally administration of BTE dose-dependently reduced the serum levels of hapten-specific immunoglobulin E (IgE), IgG1 titer, and PGE₂ production as well as ear swelling responses and leukocyte infiltration in TMA-induced BALB/c mice. The levels of NO and PGE₂ production from peritoneal macrophages stimulated with TMA-BSA were markedly suppressed by pretreatment with BTE in a concentration dependent manner. Furthermore, the levels of Th2 cytokines (IL-4, IL-5, IL-13) production from spleen cells stimulated with ConA were markedly suppressed by BTE treatment in a concentration dependent manner.Conclusions : These results suggest that BTE treatment suppresses chronic contact hypersensitivity, and it can be assumed that the suppression of ear swelling, serum IgE, NO and PGE₂ levels, leukocyte infiltration, and Th2 cytokines in an animal model. Therefore, these properties may contribute to the strong anti-CHS response effect of BTE.

Inhibitory function of NKT cells during early induction phase of nickel allergy

Until now, metal allergies have been regarded as a Th1-type immune response. However, because the contribution of a Th2-type immune response has been suggested by clinical findings, we previously examined the Th2-type immune response during the development of metal allergies using a GATA-3 transgenic (GATA-3 Tg) mouse model. As a result, a Th2-type immunization reaction was suggested to be involved in the early phase of metal allergies.Recently, the involvement of NKT cells in metal allergies has been suggested. We examined this possibility using the activation of NKT cells and an NKT cell-deficient mouse model to determine the contribution of NKT cells to nickel allergy in the present study. In NKT cell-deficient mice, ear swelling was remarkably increased, compared with that in control mice. Also, in mice that had been treated with α-galactosylceramide (α-GalCer) to activate NKT cells, the ear swelling response was remarkably inhibited, compared with that in untreated mice. These facts show that NKT cells are involved in the inhibition of nickel allergy-induced ear swelling responses.

Sasa veitchii extracts suppress 2,4-dinitrofluorobenzene-induced contact hypersensitivity in mice

ABSTRACTWe examined the therapeutic effect of the extract from Sasa veitchii leaves (Sasa extract: SE) on the allergic skin inflammation model. SE derived from 0.141 g (low dose) or 0.562 g (high dose) of the leaves was administered orally for 15 days. High dose of SE suppressed ear swelling response induced by repeated 2,4-dinitrofluorobenzene (DNFB) paintings, and both low and high doses of SE reduced infiltration of immune cells into the ear dermis. Although the number of T cells, Treg, CD4+T cells and CD8+T cells in draining lymph nodes (dLNs) was not changed by SE, IFN-γ secretion from dLN induced by concanavalin A or 2,4-dinitrobenzenesulfonic acid was suppressed by a high dose of SE while IL-10 levels remained unchanged. These results suggest that SE suppresses allergic skin inflammation via reducing IFN-γ secreted from immune cells, especially T cells.

Dietary Vitamin D Increases Percentages and Function of Regulatory T Cells in the Skin-Draining Lymph Nodes and Suppresses Dermal Inflammation.

Skin inflammatory responses in individuals with allergic dermatitis may be suppressed by dietary vitamin D through induction and upregulation of the suppressive activity of regulatory T (TReg) cells. Vitamin D may also promote TReg cell tropism to dermal sites. In the current study, we examined the capacity of dietary vitamin D3 to modulate skin inflammation and the numbers and activity of TReg cells in skin and other sites including lungs, spleen, and blood. In female BALB/c mice, dietary vitamin D3 suppressed the effector phase of a biphasic ear swelling response induced by dinitrofluorobenzene in comparison vitamin D3-deficient female BALB/c mice. Vitamin D3 increased the percentage of TReg (CD3+CD4+CD25+Foxp3+) cells in the skin-draining lymph nodes (SDLN). The suppressive activity of TReg cells in the SDLN, mesenteric lymph nodes, spleen, and blood was upregulated by vitamin D3. However, there was no difference in the expression of the naturally occurring TReg cell marker, neuropilin, nor the expression of CCR4 or CCR10 (skin-tropic chemokine receptors) on TReg cells in skin, SDLN, lungs, and airway-draining lymph nodes. These data suggest that dietary vitamin D3 increased the percentages and suppressive activity of TReg cells in the SDLN, which are poised to suppress dermal inflammation.

Bcl-3 puts the brakes on contact hypersensitivity.

B-cell lymphoma (Bcl)-3 is a nonclassical member of the IκB protein family known to interact with transcriptionally inactive NF-κB1 and NF-κB2 homodimers to modulate gene expression. Besides its action as an oncoprotein, Bcl-3 has been shown to have both proinflammatory and anti-inflammatory functions depending on the cell-type affected. In this issue of the European Journal of Immunology, Tassi etal. [Eur. J. Immunol. 2015. 45: 1059-1068] report that Bcl-3 inhibits the production of the proinflammatory chemokines CXCL9 and CXCL10 in keratinocytes, thereby restricting the influx of CD8(+) effector T cells in a mouse model of allergic contact dermatitis. In addition, mice with a global deficiency of Bcl-3 show enhanced ear swelling responses in the late phase of contact hypersensitivity responses. Besides keratinocytes, other radioresistant cell types appear to also utilize Bcl-3 to dampen the inflammatory response. This Commentary will discuss the evidence supporting Bcl-3 as a critical player in limiting inflammation during the later stages of contact hypersensitivity.

FcRγ promotes contact hypersensitivity to oxazolone without affecting the contact sensitisation process in B6 mice.

The process of sensitisation by specific contact allergens is indispensable for the induction of allergic contact dermatitis. Oxazolone is a well-characterised contact allergen. Previous studies suggested that immune cells bearing the FcRγ subunit are essential for oxazolone-induced contact hypersensitivity, but the biological functions of the FcRγ subunit in the process of sensitisation to oxazolone remain unknown. In this study, we show that FcRγ deficiency decreases ear-swelling responses to oxazolone in mice. However, we found that oxazolone-sensitised FcRγ(-/-) mice and oxazolone-sensitised wild-type (WT) mice have comparable numbers of CD11c(+) MHCII(hi) dendritic cells (DCs) in their draining lymph nodes (LNs). In addition, oxazolone-sensitised LN cells from both FcRγ(-/-) and WT mice showed considerable production of interferon-gamma (IFNγ), interleukin-4 (IL-4) and IL-17A upon oxazolone-keyhole limpet haemocyanin loading. Consistent with these data, oxazolone-sensitised FcRγ(-/-) and FcRγ(+/+) LN cells conferred contact hypersensitivity to WT naïve mice challenged with the hapten. Our findings clearly indicate that, in an experimental mouse model, the FcRγ subunit positively regulates contact hypersensitivity to oxazolone without affecting the contact sensitisation process.

Cannabinoid 1 receptors in keratinocytes attenuate fluorescein isothiocyanate-induced mouse atopic-like dermatitis.

Atopic dermatitis is a chronic inflammatory disease characterized by an impaired epidermal barrier function combined with a chronic Th2-type inflammatory response and an intense pruritus. Here, we used an experimental mouse model for Th2-type contact hypersensitivity (CHS) to fluorescein isothiocyanate (FITC) to investigate the potential role of cannabinoid 1 receptors (CB1) in the pathophysiology of mouse atopic-like dermatitis. Mice lacking CB1 receptors globally (Cnr1(-/-) ) or specifically in keratinocytes (KC-Cnr1(-/-) ) as well as wild-type (WT) control mice were sensitized and challenged with FITC. We examined ear swelling responses, transepidermal water loss, Th2-type skin inflammatory responses and serum IgE levels. Both Cnr1(-/-) and KC-Cnr1(-/-) showed enhanced CHS responses to FITC and a delayed epidermal barrier repair when compared with WT mice. mRNA levels for IL-4, thymic stromal lymphopoietin (TSLP) and CCL8, as well as eosinophil activity, were significantly increased in inflamed ear tissue of FITC-challenged Cnr1(-/-) and KC-Cnr1(-/-) mice. Importantly, CB1 receptor-deficient keratinocytes secreted increased levels of TSLP, a proinflammatory mediator that drives Th2-type skin inflammation in atopic dermatitis, under basal and Th2-type inflammatory conditions. Taken together, our results demonstrate that CB1 receptors in keratinocytes help to maintain epidermal barrier homoeostasis and attenuate Th2-type allergic inflammatory responses. Based on our work, we propose that enhanced epidermal allergen penetrance cooperates with increased production of TSLP and CCL8 by epidermal keratinocytes for the induction of type 2 CD4+ T helper cells. Our results place keratinocytes at the cross-roads of outside-in and inside-out pathophysiologic mechanisms of atopic dermatitis.

Two distinct subsets of skin-infiltrating memory T cells, TRM and TEM, define cutaneous immune responses against systemically-administered soluble antigens (IRC9P.702)

Abstract Cutaneous immune reactions to soluble antigens, such as drugs, are common, but their precise pathomechanism remains unclarified. To this end, we newly developed a murine model for skin eruptions against soluble antigens using ovalbumin (OVA)-specific TCR transgenic line, OT1. OT1 T cells were adoptively transferred to naïve mice and were immunized with OVA/CFA. Five days later, a skin inflammation was induced to the right ear with topical PMA treatment, which induced skin-resident memory T cells (TRM). Two weeks after PMA-painting, a large number of CD103+CD69+ OT1-TRM were found in the epidermis of PMA-painted site, whereas only a marginal number of OT1 T cells were detected in the untreated left ear. Then, OVA peptide was injected intravenously, which exhibited immediate ear swelling response only in the right ear where OT1-TRM exist in the epidermis. Five days after the systemic administration of OVA peptide, CD44+CD62L- effector memory OT1 T cells (TEM) were significantly increased in the blood and, intriguingly, were detected in the dermis of the untreated left ear. In addition, a repeated intravenous administration of OVA peptide developed chronic necrotic skin lesion even without extrinsic stimuli. These observations implicate respective roles of TRM and TEM in cutaneous immune responses: antigen-specific TRM in the epidermis cause immediate and localized skin eruptions, whereas TEM infiltrate from the blood into the dermis and induce chronic disseminated dermatoses.

Dendritic Cell Motility and T Cell Activation Requires Regulation of Rho-Cofilin Signaling by the Rho-GTPase Activating Protein Myosin IXb

Directed migration of stimulated dendritic cells (DCs) to secondary lymphoid organs and their interaction with Ag-specific T cells is a prerequisite for the induction of primary immune responses. In this article, we show that murine DCs that lack myosin IXB (Myo9b), a motorized negative regulator of RhoA signaling, exhibit increased Rho signaling activity and downstream acto-myosin contractility, and inactivation of the Rho target protein cofilin, an actin-depolymerizing factor. On a functional level, Myo9b(-/-) DCs showed impaired directed migratory activity both in vitro and in vivo. Moreover, despite unaltered Ag presentation and costimulatory capabilities, Myo9b(-/-) DCs were poor T cell stimulators in vitro in a three-dimensional collagen matrix and in vivo, associated with altered DC-T cell contact dynamics and T cell polarization. Accordingly, Myo9b(-/-) mice showed an attenuated ear-swelling response in a model of contact hypersensitivity. The impaired migratory and T cell stimulatory capacity of Myo9b(-/-) DCs was restored in large part by pharmacological activation of cofilin. Taken together, these results identify Myo9b as a negative key regulator of the Rho/RhoA effector Rho-kinase [Rho-associated coiled-coil-forming kinase (ROCK)]/LIM domain kinase signaling pathway in DCs, which controls cofilin inactivation and myosin II activation and, therefore may control, in part, the induction of adaptive immune responses.

IgE-mediated mast cell responses are inhibited by thymol-mediated, activation-induced cell death in skin inflammation

Mast cells play a critical role in inflammatory skin diseases through releasing proinflammatory mediators; however, few therapies directly target these cells. In 1878, the use of topical thymol, a now recognized potent agonist for transient receptor potential channels, was first described to treat eczema and psoriasis. We sought to determine the mechanisms through which thymol can alter skin inflammation. We examined the effect of topical thymol on IgE-dependent responses using a mast cell-dependent passive cutaneous anaphylaxis (PCA) model, as well as in vitro-cultured mast cells. Thymol dose-dependently inhibited PCA when administered topically 24 hours before antigen challenge but provoked an ear-swelling response directly on application. This direct effect was associated with local mast cell degranulation and was absent in histamine-deficient mice. However, unlike with PCA responses, there was no late-phase swelling. In vitro thymol directly triggered calcium flux in mast cells through transient receptor potential channel activation, along with degranulation and cytokine transcription. However, no cytokine protein was produced. Instead, thymol induced a significant increase in apoptotic cell death that was seen both in vitro and in vivo. We propose that the efficacy of thymol in reducing IgE-dependent responses is through promotion of activation-induced apoptotic cell death of mast cells and that this likely explains the clinical benefits observed in early clinical reports.

The role of neutrophils and G-CSF in DNFB-induced contact hypersensitivity in mice.

Neutrophils are thought to play an important role during contact hypersensitivity (CHS) in mice, a notion which is supported by studies in which neutrophils are depleted by monoclonal antibodies (mAb). Here, we show that administration of the commonly used anti-mouse Ly6G/C mAb (clone RB6.8C5) leads to depletion of not only neutrophils but also a population of monocytes and macrophages. In contrast, depletion using a Ly6G-specific mAb (clone 1A8) only leads to depletion of neutrophils. We demonstrate that the anti-Ly6G/C mAb suppresses the inflammatory response to a higher extent than the anti-Ly6G mAb suggesting that the impact of neutrophil-depletion in the CHS model may have been overstated when based on protocols using the anti-Ly6G/C mAb. Still, the role of neutrophils in CHS is substantiated as we demonstrate that G-CSF is an important regulator of neutrophil mobilization and effector function in CHS. Indeed, G-CSF was detectable both in the inflamed tissue and in serum during the immune response and we show that blocking G-CSF results in a reduced number of neutrophils in the blood and an attenuation of the ear-swelling response in the tissue. In conclusion, this study supports that neutrophils are important drivers of inflammation in the DNFB-induced CHS model and shows that G-CSF is a significant factor in mobilizing neutrophils during the response.

A comparison of the effects of dexamethasone-pharmacopuncture and dexamethasone-oral administration based on traditional Korean medicine theory on anaphylactic reaction in mice

Pharmacopuncture, or herbal acupuncture, is a new form of therapy derived from combinations of two traditional therapeutic methods, herbal medicine and acupuncture therapy. To compare the efficacy between dexamethasone-pharmacopuncture (DP) and dexamethasone-oral administration (DO), the effect of DP was investigated in murine models. Anti-anaphylactic effects of dexamethasone treatments were investigated in compound 48/80-induced systemic anaphylactic reaction, ear swelling response, and passive cutaneous anaphylaxis (PCA). DP treatment significantly inhibited the compound 48/80-induced systemic anaphylactic reaction, ear swelling response, and PCA. The effects between DP and DO were on a similar level. These results indicate that DP can be used as an alternative method for DO in case of emergency.

Collagen hydrolysate inhibits zymosan-induced inflammation

During the past years, evidence accumulated showing that glycine comprises anti-inflammatory activities. These effects occur, at least in part, via the activation of glycine-gated chloride channels (GlyR). Glycine is one of the major structural units of collagen, making up about 30% of the amino acids. This study aims to investigate the anti-inflammatory potential of collagen hydrolysate (CH) using the zymosan-induced ear-skin inflammation mouse model. After oral intake of 12.5, 25 or 50 mg CH the plasma levels of glycine increased in a concentration-dependent manner. CH was able to counteract zymosan-induced ear-skin inflammation locally (ear swelling) as well as systemically (IL-6 production by lipopolysaccharide (LPS)-stimulated whole blood cells). The LPS-stimulated IL-6 production in whole blood correlated positively with the ear swelling response. This correlation was abolished by strychnine (a glycine receptor antagonist), indicating the involvement of GlyR. Collectively, these data show that CH is able to modulate inflammatory responses both locally as well as systemically. This effect might be constituted by inhibiting pro-inflammatory cytokine production via GlyR.

Interleukin-5 Plays a Key Role in Mouse Strain- Dependent Susceptibility to Contact Hypersensitivity through Its Effects on Initiator B Cells

Background: Elicitation of contact hypersensitivity requires antigen-specific immunoglobulin M (IgM) antibodies that trigger recruitment of effector T cells to the local tissue. These antigen-specific IgM antibodies are produced by B-1-like ‘initiator B cells'. In this study, we compared susceptibility to hapten-induced contact hypersensitivity between BALB/c and C57BL/6 mice. Methods: BALB/c and C57BL/6 mice were sensitized by painting oxazolone onto the skin and were challenged on the ears with the same hapten on day 4. Ear thickness and serum hapten-specific IgM levels were measured at 24 h post-challenge. Peritoneal cells were harvested and the numbers of B cell subpopulations were counted. Interleukin (IL)-5 was intraperitoneally injected into BALB/c and C57BL/6 mice, and the change in numbers of B cell subpopulations and serum IgM levels was monitored. Results: Oxazolone induced stronger ear swelling and specific IgM responses in BALB/c mice than in C57BL/6 mice. BALB/c mice had higher numbers of peritoneal B-1 cells than C57BL/6 mice at steady state. IL-5 injection increased the number of peritoneal B-1 cells and serum IgM levels more significantly in BALB/ mice than in C57BL/6 mice. Conclusions: BALB/c mice exhibit higher susceptibility to hapten-induced contact hypersensitivity than C57BL/6 mice, most likely because they have a higher number of B-1 cells, leading to massive production of hapten-specific IgM antibodies upon contact sensitization. The differences in the number of B-1 cells and IgM responses between the two strains of mice may be attributed to the difference in responsiveness of B-1 cells to IL-5.

Temporal effect of local hyperthermia on murine contact hypersensitivity

Background The sensitization and elicitation phases are involved in the immunopathogenesis of contact hypersensitivity (CHS). Langerhans cells (LCs) are believed to play pivotal roles in the sensitization stage of CHS. Local hyperthermia on skin induces the migration as well as maturation of epidermal LCs. Although fever-range whole body hyperthermia and local hyperthermia at 43°C prior to sensitization were reported to suppress CHS, the effects of different temperatures and the timing sequence of local hyperthermia on CHS have not been tackled. Methods Local hyperthermia was applied to murine dorsal skin 3 days prior to, concurrent with, or 2 days post sensitization with fluorescein isothiocyanate (FITC) in BALB/c mice. Local hyperthermia temperatures at 37°C, 39°C, 41°C and 43°C were applied to mouse dorsal skin and the severity of CHS was calculated by measuring the swelling response of the challenged ears. Results Local hyperthermia at 39°C, 41°C and 43°C prior to sensitization reduced the severity of CHS, as compared with that at 37°C. The suppression of CHS was temperature dependant in that higher temperature had a stronger effect. On the contrary, the hyperthermia treatments, either concurrent with or post-sensitization, resulted in an enhanced temperature-dependant ear swelling response. Conclusions The severity of murine CHS could be influenced by local hyperthermia at the sensitization stage in a temperature dependant manner. The temporal effect of local hyperthermia suggested a novel factor in interpreting the severity of allergic contact dermatitis.

Inhibitory Effects of BiRyuChe-Bang on Mast Cell-Mediated Allergic Reactions and Inflammatory Cytokines Production

BiRyuChe-bang (BRC) is a Korean prescription medicine, which has been used to treat allergic rhinitis at Kyung Hee Medical Center. In this work, we investigated the effects of BRC on mast cell-mediated allergic reactions and inflammatory cytokines production, and identified the active component of BRC. Histamine release was measured from rat peritoneal mast cells (RPMCs). Ear swelling and passive cutaneous anaphylaxis (PCA) were examined in mouse models. Phorbol 12-myristate 13-acetate (PMA) plus A23187-induced inflammatory cytokines production was measured using enzyme-linked immunosorbent assay. Reverse transcriptase-polymerase chain reaction was used for the expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8. Activation of nuclear factor (NF)-κB was analyzed by Western blotting. BRC significantly inhibited the compound 48/80-induced ear swelling response, histamine release from RPMCs, PCA activated by anti-dinitrophenyl IgE, and PMA plus A23187-induced inflammatory cytokines production (p < 0.05). In addition, BRC dose-dependently inhibited the mRNA expressions of TNF-α, IL-6, and IL-8 as well as the activation of NF-κB in a human mast cell line, HMC-1 cells. BRC inhibited the levels of TNF-α and IL-6 in mice induced with PCA. Several components of BRC, such as 1,8-Cineole, Linalool, Linalyl acetate, α-Pinene, and α-Terpineol, significantly inhibited the release of histamine from RPMCs (p < 0.05). Among these components, Linalyl acetate was the most effective for inhibiting histamine release. These results indicate that BRC has a potential regulatory effect on allergic and inflammatory reactions mediated by mast cells.

Macrophage Activation - Mediated Hydrogen Peroxide Generation by the Royal Sun Medicinal Mushroom Agaricus brasiliensis (Higher Basidiomycetes)

Agaricus brasiliensis has been demonstrated to have potent antitumor activity. The activity is postulated to act through mediation of the host immune system. We have reported that A. brasiliensis extract (ABE) inhibited compound 48/80 induced a systemic anaphylaxis-like reaction, ear swelling response, and passive cutaneous anaphylaxis-like reaction in mice. There is some recent information available on the mechanism of antiallergic effects resulting from oral administration of ABE. However, information regarding how ABE may activate macrophages through intestinal epithelial cells is still limited. To clarify the mechanism of macrophages activation by ABE, a gut in vitro model constructed of Caco-2 and RAW264.7 cells was applied. Treatment of ABE to the apical compartment resulted in significant increases in tumor necrosis factor (TNF)-α production in the basolateral compartment. Moreover, addition of catalase to the basolateral compartment before ABE treatment suppressed TNF-α production completely, but the addition of superoxide dismutase did not suppress this at all. These data suggest that ABE could potentiate hydrogen peroxide emissions from Caco-2 cells into the basolateral side and activate macrophages, which is important in the immune system.