Expression of SARS-CoV-2 receptor angiotensin-converting enzyme 2 by activating protein-1 in human mast cells.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection activates mast cells and induces a cytokine storm, leading to severe Coronavirus disease in 2019 (COVID-19). SARS-CoV-2 employs angiotensin-converting enzyme 2 (ACE2) for cell entry. In the present study, the expression of ACE2 and its mechanism in activated mast cells were studied utilizing the human mast cell line, HMC-1 cells and it was elucidated whether dexamethasone used as a treatment for COVID-19 could regulate ACE2 expression. Here we documented for the first time that levels of ACE2 were increased by stimulation of phorbol 12-myristate 13-acetate and A23187 (PMACI) in HMC-1 cells. Increased levels of ACE2 were significantly diminished by treatment with Wortmannin, SP600125, SB203580, PD98059, or SR11302. The expression of ACE2 was most significantly reduced by the activating protein (AP)-1 inhibitor SR11302. PMACI stimulation enhanced the expression of the transcription factor AP-1 for ACE2. In addition, levels of transmembrane protease/serine subfamily member 2 (TMPRSS2) and tryptase were increased in PMACI-stimulated HMC-1 cells. However, dexamethasone significantly lowered levels of ACE2, TMPRSS2, and tryptase generated by PMACI. Treatment with dexamethasone also reduced activation of signaling molecules linked to ACE2 expression. According to these findings, levels of ACE2 were up-regulated through activation of AP-1 in mast cells, suggesting that suppressing ACE2 levels in mast cells would be a therapeutic approach to lessen the harm caused by COVID-19.

TSLP up-regulates inflammatory responses through induction of autophagy in T cells.

Thymic stromal lymphopoietin (TSLP), a type I cytokine belonging to the IL-2 cytokine family, promotes Th2-mediated inflammatory responses. The aim of this study is to investigate whether TSLP increases inflammatory responses via induction of autophagy using a murine T cell lymphoma cell line, EL4 cells, and lipopolysaccharide (LPS)-injected mice. TSLP increased expression levels of autophagy-related factors, such as Beclin-1, LC3-II, p62, Atg5, and lysosome associated membrane protein 1/2, whereas these factors increased by TSLP disappeared by neutralization of TSLP in EL4 cells. TSLP activated JAK1/JAK2/STAT5/JNK/PI3K, while the blockade of JAK1/JAK2/STAT5/JNK/PI3K signaling pathways reduced the expression levels of Beclin-1, LC3-II, and p62 in TSLP-stimulated EL4 cells. In addition, TSLP simultaneously increased levels of inflammatory cytokines via induction of autophagy by activation of JAK1/JAK2/STAT5/JNK/PI3K signaling pathways. In an LPS-induced acute liver injury (ALI) mouse model, exogenous TSLP increased expression levels of Beclin-1 and LC3-II, whereas functional deficiency of TSLP by TSLP siRNA resulted in lower expression of Beclin-1, LC3-II, and inflammatory cytokines, impairing their ability to form autophagosomes in ALI mice. Thus, our findings show a new role of TSLP between autophagy and inflammatory responses. In conclusion, regulating TSLP-induced autophagy may be a potential therapeutic strategy for inflammatory responses.

Euscaphic acid relieves fatigue by enhancing anti-oxidative and anti-inflammatory effects.

BACKGROUND: Oxidative stress and inflammation are involved in chronic fatigue. Euscaphic acid (EA) is an active compound of Eriobotrya japonica (Loquat) and has anti-oxidative effect. METHODS: The goal of present study is to prove whether EA could relieve fatigue through enhancing anti-oxidant and anti-inflammatory effects in in vitro/in vivo models. RESULTS: EA notably improved activity of superoxide dismutase (SOD) and catalase (CAT), while EA reduced levels of malondiadehyde (MDA) and inflammatory cytokines without cytotoxicity in H2O2-stimulated in myoblast cell line, C2C12 cells. EA significantly reduced levels of fatigue-causing factors such as lactate dehydrogenase (LDH) and creatin kinase (CK), while EA significantly incresed levels of anti-fatigue-related factor, glycogen compared to the H2O2-stimulated C2C12 cells. In treadmill stress test (TST), EA significantly enhanced activities of SOD and CAT as well as exhaustive time and decreased levels of MDA and inflammatory cytokines. After TST, levels of free fatty acid, citrate synthase, and muscle glycogen were notably enhanced by oral administration of EA, but EA decreased levels of lactate, LDH, cortisol, aspartate aminotransferase, alanine transaminase, CK, glucose, and blood urea nitrogen compared to the control group. Furthermore, in forced swimming test, EA significantly increased levels of anti-fatigue-related factors and decreased excessive accumulations of fatigue-causing factors. CONCLUSIONS: Therefore, the results indicate that potent anti-fatigue effect of EA can be achieved via the improvement of anti-oxidative and anti-inflammatory properties, and this study will provide scientific data for EA to be developed as a novel and efficient component in anti-fatigue health functional food.

RANKL down-regulates the mast cell proliferation through inducing senescence.

An increase in the number of mast cells could contribute to inflammatory diseases and pathologic conditions. A receptor activator of NF-κB ligand (RANKL)/RANK system is one of the key signaling pathways accelerating mast cell-mediated allergic inflammatory reactions. However, the biological functions of RANKL in mast cell proliferation remains to be clarified. The aim of the present study is to clarify the role of RANKL in mast cell proliferation. Surprisingly, RANKL remarkably reduced the proliferation of human mast cell line, HMC-1 cells through the inhibition of murine double minute 2 (MDM2) and Ki-67 mRNA expressions in a dose-dependent manner. RANKL significantly reduced cell viability, whereas it increased cellular senescence via increasing levels of p53, phosphorylated(p)-p53, p21, and p16 and decreasing levels of retinoblastoma protein (pRb) and p-pRb in HMC-1 cells. Even in rat peritoneal mast cells, RANKL induced cellular senescence by increasing filamentous-actin polymerization. In addition, RANKL remarkably reduced thymic stromal lymphopoietin (TSLP)-induced mast cell proliferation via the downregulation of MDM2 and Ki-67. RANKL decreased levels of p-signal transducer and activator of transcription 6 in TSLP-stimulated HMC-1 cells. The mast cell growth factor, interleukin-13 was remarkably down-regulated by treatment with RANKL in TSLP-stimulated HMC-1 cells. Furthermore, RANKL increased the number of senescence-associated ß-galactosidase-stained cells and protein levels of p53, p-p53, and p21 in TSLP-stimulated HMC-1 cells. These data suggest that RANKL down-regulates mast cell proliferation by inducing senescence.

Exposure of ovalbumin during pregnancy prevents the development of allergic rhinitis in offspring through the induction of mast cell autophagy.

Most allergic disease studies have focused on postnatal chemical or microbial exposure. Recent studies have indicated that allergic diseases are associated with the immunological interaction between the mother and her offspring, but the relevant mechanisms are unclear. The aim of this study was to assess whether maternal exposure to allergens during pregnancy could affect allergic rhinitis (AR) in the offspring. Compared with offspring of naïve mothers, offspring of ovalbumin (OVA)-exposed mothers exhibited a significant reduction in AR clinical symptoms and levels of histamine, IgE, T helper type-2(Th2) cytokines, thymic stromal lymphopoietin, cyclooxygenase-2, chemokines, infiltration of inflammatory cell, and activity of caspase-1. Interestingly, we observed that offspring of OVA-exposed mothers regulated OVA-induced Th2 responses by inducing autophagy in mast cells. Our data demonstrated that maternal exposure to OVA during pregnancy decreased allergic sensitivity in offspring, suggesting that the vertical transmission of maternal immune responses may be involved. These findings have important implications in the regulation of AR. Furthermore, we propose that the autophagy of mast cells may be a potential target for AR prevention or treatment.

A calcium channel blocker, manoalide exerts an anti-allergic inflammatory effect through attenuating NF-κB activity.

BACKGROUND: Many people are troubled by allergic inflammation including ocular allergic diseases, anaphylaxis, allergic rhinitis, atopic dermatitis, and eczema. Consequently, finding medications for use in allergic inflammation therapy is crucial in human health. Manoalide, a marine natural product isolated as an anti-bacterial metabolite from Luffariella variabilis, is a calcium channel blocker. However, its latent ability as an anti-allergic inflammatory agent has not yet been reported. Our research aimed to elucidate whether manoalide exerts an anti-allergic inflammatory effect in the human mast cell line, HMC-1. METHODS: Herein, we investigated the immunoregulatory effects and molecular mechanisms of manoalide in HMC-1 cells. RESULTS: Manoalide significantly alleviated secretion of the inflammatory cytokines interleukin (IL)-1ß, thymic stromal lymphopoietin, tumor necrosis factor-α, IL-6, and IL-8 via blockage of caspase-1 without cytotoxicity in activated HMC-1 cells. Activation of nuclear factor-κB increased by mast cell stimulation was attenuated by treatment with manoalide. In addition, we demonstrated that manoalide treatment remarkably attenuated the activation of mitogen-activated protein kinases in activated-HMC-1 cells. CONCLUSIONS: Taken together, our findings indicate manoalide has an anti-allergic inflammatory role, and we propose that manoalide might have potential as a novel anti-allergic inflammatory agent.

Sulforaphane mitigates mast cell-mediated allergic inflammatory reactions in in silico simulation and in vitro models.

Objectives: Sulforaphane, a major ingredient isolated from Brassica oleracea var. italica (broccoli), is known to exhibit anti-inflammatory, anti-cancer, and anti-diabetic effects. In this study, we employed an in vitro model of phorbol 12-myristate 13-acetate and a23187 (PMACI)-stimulated human mast cells (HMC-1 cells) to investigate the anti-allergic inflammatory effects and mechanisms of sulforaphane and Brassica oleracea var. italica extracts.Methods: Cytokine levels were measured by ELISA and quantitative real-time-PCR methods. Caspase-1 activity was determined by caspase-1 assay. Binding mode of sulforaphane within caspase-1 was determined by molecular docking simulation. Protein expression was determined by Western blotting.Results: Water extract of Brassica oleracea var. italica (WE) significantly reduced thymic stromal lymphopoietin (TSLP) secretion and caspase-1 activity on activated HMC-1 cells. In the molecular docking simulation and in vitro caspase-1 assays, sulforaphane regulated caspase-1 activity by docking with the identical binding site of caspase-1. Sulforaphane significantly inhibited the levels of inflammatory mediators including TSLP, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-8 in a dose-dependent manner. Immunoblotting experiments revealed that sulforaphane and WE reduced translocation of NF-κBp65 into the nucleus and phosphorylation of IκBα in the cytosol. Furthermore, phosphorylation of mitogen-activated protein kinases (MAPK) was down-regulated by treatment with sulforaphane or WE.Conclusion: Our findings suggest that sulforaphane and WE have anti-allergic inflammatory effects by intercepting caspase-1/NF-κB/MAPKs signaling pathways.

Effects of Resveratrol on Thymic Stromal Lymphopoietin Expression in Mast Cells.

Background and objectives: Cytokine thymic stromal lymphopoietin (TSLP) plays a pivotal role in the pathogenesis of atopic diseases such as atopic dermatitis, allergic rhinitis, and asthma. Resveratrol (RSV) exerts various pharmacological effects such as antioxidant, anti-inflammatory, neuroprotective, and anticancer. Although, it has been verified the beneficial effects of RSV on various subjects, the effect of RSV on thymic stromal lymphopoietin (TSLP) regulation has not been elucidated. Materials and Methods: Here, we examined how RSV regulates TSLP in HMC-1 cells. Enzyme-linked immunosorbent assay, real-time polymerase chain reaction, Western blotting, and calcium assay were performed to evaluate the effect of RSV. Results: TSLP production and mRNA expression were reduced by RSV. RSV down-regulated nuclear factor-κB activation, IκBα phosphorylation as well as activation of receptor-interacting protein2 and caspase-1 in HMC-1 cells. In addition, RSV treatment decreased the up-regulation of intracellular calcium in HMC-1 cells. Conclusions: These results suggest that RSV might be useful for the treatment of atopic diseases through blocking of TSLP.

The ameliorative effect of AST2017-01 in an ovalbumin-induced allergic rhinitis animal model.

OBJECTIVE: AST2017-01 is developed to be used for treatment and prevention of allergic diseases and composed of processed-Cordyceps militaris and processed-Rumex crispus. But, effect of AST2017-01 remains unclear in an allergic rhinitis (AR). So, this study aimed to explore the effects of AST2017-01 in ovalbumin (OVA)-induced AR animal model. METHODS: OVA-induced AR animals were orally administered AST2017-01 and chrysophanol, an active component of AST2017-01 for 10 days. RESULTS: In mice with AR, AST2017-01 and chrysophanol markedly decreased number of rubs, IgE, histamine, thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin (IL)-1ß, IL-4, IL-5, and IL-13 in serum or nasal mucosa tissues. Moreover, activities and protein levels of caspase-1 were markedly diminished by oral administration of AST2017-01 and chrysophanol. Declines of macrophage inflammatory protein-2, intercellular adhesion molecules-1, eosinophil, and mast cells were also noted in nasal mucosa tissues of AST2017-01 and chrysophanol groups. CONCLUSIONS: Taken together, these findings indicate that AST2017-01 has an anti-allergic effect as a therapeutic agent or functional food for treating and preventing AR.

Chrysophanol, an anthraquinone from AST2017-01, possesses the anti-proliferative effect through increasing p53 protein levels in human mast cells.

OBJECTIVE: Natural products are well known as the source of drugs in the treatment of allergic inflammation. Chrysophanol, an anthraquinone from the AST2017-01 extract, showed a beneficial anti-inflammatory effect on activated human mast cells in our previous study. However, a regulatory effect of AST2017-01 and chrysophanol on mast cell proliferation induced by thymic stromal lymphopoietin (TSLP) remains unclear. The present study determined the anti-proliferative effect and the fundamental mechanism of AST2017-01 and chrysophanol in mast cells. METHODS: We evaluated an anti-proliferative effect of AST2017-01 and chrysophanol in TSLP-stimulated human mast cell line, HMC-1. RESULTS: Without cytotoxicity, AST2017-01 and chrysophanol decreased mast cells growth and Ki67 mRNA expression increased by TSLP. AST2017-01 and chrysophanol enhanced expressions of p53 and Bax, whereas inhibited expression of Bcl-2. AST2017-01 and chrysophanol restored caspase-3 activity which was decreased by TSLP. AST2017-01 and chrysophanol suppressed expressions of murine double minute-2 protein and phosphorylated-signal transducer and activator of transcription six which are associated with the regulation of p53 protein. AST2017-01 and chrysophanol decreased levels of interleukin (IL)-13, IL-6, and tumor necrosis factor-α. Moreover, AST2017-01 and chrysophanol reduced mRNA expressions of TSLP receptor and IL-7 receptor α. CONCLUSIONS: Therefore, this study proposes that AST2017-01 and chrysophanol may be promising candidates for the development of potent anti-inflammatory or health functional foods.

Use of Physcion to Improve Atopic Dermatitis-Like Skin Lesions through Blocking of Thymic Stromal Lymphopoietin.

Physcion is well known for the treatment of carcinoma. However, the therapeutic effect of physcion on atopic dermatitis (AD) through the inhibition of thymic stromal lymphopoietin (TSLP) level remains largely unknown. In this study, we investigated the anti-AD effect of physcion using HMC-1 cells, splenocytes, and a murine model. Treatment with physcion decreased production and mRNA expression levels of TSLP, IL-6, TNF-ɑ, and IL-1ß in activated HMC-1 cells. Physcion reduced the expression levels of RIP2/caspase-1 and phospho (p)ERK/pJNK/pp38 in activated HMC-1 cells. Physcion suppressed the expression levels of pIKKß/NF-κB/pIkB in activated HMC-1 cells. Moreover, physcion attenuated the production levels of TSLP, IL-4, IL-6, TNF-, and IFN-γ from activated splenocytes. Oral administration of physcion improved the severity of 2,4-dinitrochlorobenzene-induced AD-like lesional skin through reducing infiltration of inflammatory cells and mast cells, and the protein and mRNA levels of TSLP, IL-4, and IL-6 in the lesional skin tissues. Physcion attenuated histamine, IgE, TSLP, IL-4, IL-6, and TNF- levels in serum. In addition, physcion inhibited caspase-1 activation in the lesional skin tissues. These findings indicate that physcion could ameliorate AD-like skin lesions by inhibiting TSLP levels via caspase-1/MAPKs/NF-kB signalings, which would provide experimental evidence of the therapeutic potential of physcion for AD.

Inhibitory effect of naringenin via IL-13 level regulation on thymic stromal lymphopoietin-induced inflammatory reactions.

Naringenin (NG) has various beneficial properties, such as anti-cancer and anti-inflammatory effects. Thymic stromal lymphopoietin (TSLP) induces mast cell proliferation and inflammatory reactions. The aim of this study was to investigate the regulatory effect of NG on TSLP-induced mast cell proliferation and inflammatory reactions using human mast cell line (HMC-1) cells. HMC-1 cells were pre-treated with NG and then treated with TSLP. HMC-1 cells proliferation was determined by quantifying bromodeoxyuridine incorporation. Levels of anti-apoptotic and pro-apoptotic factors were analyzed by western blot analysis. The productions and mRNA expressions of interleukin (IL)-13 and tumour necrosis factor-α (TNF-α) were analyzed by ELISA and quantitative real-time PCR. We found that NG significantly attenuated HMC-1 cells proliferation and Ki-67 mRNA expression promoted by TSLP. NG significantly suppressed mRNA expression of TSLP receptor and IL-7 receptor α in TSLP-treated HMC-1 cells. NG significantly down-regulated levels of phosphorylated-signal transducer and activation of transcription 6 and murine double-minute 2 in TSLP-treated HMC-1 cells, up-regulated levels of cleaved poly ADP-ribose polymerase and p53 in TSLP-treated HMC-1 cells. Furthermore, NG significantly decreased the productions and mRNA expressions of IL-13 and TNF-α in TSLP-treated HMC-1 cells. These results suggest NG has an inhibitory effect on mast cell-mediated allergic inflammatory reactions.

Functions of the Signal Transducer and Activator of Transcription 6 in a Behavioral Animal Model of Depression.

AIMS: Depression is one of the most common inflammatory and mental disorders. Signal transducer and activator of transcription 6 (STAT6) plays a crucial role in the pathology of mental disorders as well as inflammatory diseases. METHODS: Here we determined the role of STAT6 in the pathogenesis of depression using STAT6-deficient mice in a forced swimming test. RESULTS: The immobility time was significantly decreased in STAT6-deficient mice compared to wild-type mice without alteration of locomotor activity. STAT6-deficient mice exhibited a significantly enhancing dopamine and 5-hydroxytryptamine (5-HT, serotonin) in brain. In addition, the expression of serotonin transporter in the hippocampus was markedly downregulated in STAT6-deficient mice. These results provide the first evidence that STAT6 affects depressive-like behavior through downregulating monoamines, including dopamine and 5-HT in the hippocampus of brain. CONCLUSIONS: In conclusion, identification of STAT6 signaling pathways on depression might open new perspectives for antidepressant therapies.

Anticancer agent ABT-737 possesses anti-atopic dermatitis activity via blockade of caspase-1 in atopic dermatitis in vitro and in vivo models.

OBJECTIVE: Previous studies reported that depletion of Bcl-2 has a protective effect against allergic diseases. Furthermore, recently our study showed that anticancer drug has antiallergic inflammatory effect. An anticancer agent ABT-737 is an inhibitor of Bcl-2 and has an anti-inflammatory effect. However, the antiallergic inflammatory activity of ABT-737 is still unknown. Here, we aimed to explore the anti-atopic dermatitis (AD) activity and the mechanism of ABT-737 in AD models. MATERIALS AND METHODS: HaCaT cells were used for in vitro experiments. To evaluate the effect of ABT-737 in vivo model, BalB/c mice were orally administered ABT-737 for 6 weeks in 2,4-dinitrofluorobenzene (DNFB)-induced AD-like murine model. Major assays were enzyme-linked immunosorbent assay, reverse transcription-PCR, caspase-1 assay, histamine assay, and H&E staining. RESULTS: ABT-737 significantly decreased thymic stromal lymphopoietin (TSLP) secretion and caspase-1 activity in activated HaCaT cells. In DNFB-induced AD mice, oral administration of ABT-737 alleviated clinical severity and scratching behavior. ABT-737 decreased levels of AD-related biomarkers including IgE, histamine, TSLP, and inflammatory cytokines. In addition, ABT significantly reduced caspase-1 activity in skin lesions of AD mice. DISCUSSION AND CONCLUSIONS: ABT-737 elicited an anti-AD activity via suppression of caspase-1 activation in AD in vitro and in vivo models. Therefore, this study provides important information regarding the use of anticancer drugs for controlling allergic inflammatory diseases.

Cordycepin ameliorates skin inflammation in a DNFB-challenged murine model of atopic dermatitis.

OBJECTIVES: Atopic dermatitis (AD) is an allergic and inflammatory skin disorder caused by a combination of itching and skin sensitization by allergens. This article investigated whether cordycepin modulates AD symptoms by using an AD murine model. MATERIAL AND METHODS: We evaluated a regulatory effect and specific molecular mechanism of cordycepin on AD induced by the repeated local exposure of 2,4-dinitrochlorobenzene to dorsal skin of mice. Blood or AD-like skin lesions samples were removed for histopathologic analysis, enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and Western blot analyses. RESULTS: Oral administration of cordycepin decreased duration of scratching behavior and serum levels of histamine and immunoglobulin E increased by DNFB challenge. Cordycepin attenuated clinical symptoms and epidermis thickness of AD mice. In addition, cordycepin reduced thymic stromal lymphopoietin (TSLP), interleukin (IL)-4, IL-6, and tumor necrosis factor-α levels in the serum of AD mice. Cordycepin-attenuated infiltrations of mast cells and eosinophils with decreases in TSLP, macrophage inflammatory protein-2, and intercellular adhesion molecule-1 protein levels in AD-like skin lesions. Messenger RNA expressions of TSLP, thymus and activation-regulated chemokine/CCL17, and C-C chemokine receptor type 3 in AD-like skin lesions were also suppressed by cordycepin. Cordycepin inhibited caspase-1 expressions and activities in AD-like skin lesions. CONCLUSIONS: In conclusion, this study demonstrates that cordycepin ameliorates AD symptoms, suggesting that cordycepin might be a candidate to treat allergic skin diseases.

Anti-inflammatory effects of Artemisia scoparia and its active constituent, 3,5-dicaffeoyl-epi-quinic acid against activated mast cells.

OBJECTIVES: Artemisia scoparia Waldst. et Kit. (AS) has been used to treat inflammation, urticaria and hepatitis. However, the scientific studies of AS and its active compound for inflammatory reactions in activated human mast cell line, HMC-1 cells have not yet been elucidated. MATERIALS AND METHODS: Here, we isolated 3,5-dicaffeoyl-epi-quinic acid (DEQA) from AS butanol fraction. The anti-inflammatory effect of AS and its new active compound, DEQA was examined in HMC-1 cells by studying the following markers: phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-induced thymic stromal lymphopoietin (TSLP), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 secretion and mRNA expression by ELISA and RT-PCR, respectively. Furthermore, mechanism related to anti-inflammatory was examined by Western blotting. RESULTS: We reported that AS and its new active compound, DEQA significantly reduced TSLP, TNF-α, IL-1ß and IL-6 production levels through the reduction of caspase-1 activity. The mRNA expression of these inflammatory cytokine was also reduced via blocking nuclear factor-κB nuclear translocation by AS and DEQA. In addition, AS significantly reduced phosphorylated-c-Jun N-terminal kinase level and DEQA significantly reduced both phosphorylated-c-Jun N-terminal kinase and -p38 mitogen-activated protein kinase levels. CONCLUSIONS: Therefore, these results indicated that AS and its active compound, DEQA may improve mast cell-mediated inflammatory diseases.

Effects of Linalyl Acetate on Thymic Stromal Lymphopoietin Production in Mast Cells.

Thymic stromal lymphopoietin (TSLP) is an important factor responsible for the pathogenesis of allergic diseases, such as atopic dermatitis and asthma. Because linalyl acetate (LA) possesses a wide range of pharmacological properties, being antispasmodic, anti-inflammatory, and anti-hyperpigmentation, we hypothesized that LA could inhibit TSLP. Therefore, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, caspase-1 assay, Western blot analysis, fluorescent analyses of the intracellular calcium levels, and the phorbol myristate acetate (PMA)-induced edema model were used to investigate how LA inhibits the production of TSLP in HMC-1 cells. LA reduced the production and mRNA expression of TSLP in HMC-1 cells. LA also inhibited the activation of nuclear factor-κB and degradation of IκBα. PMA plus A23187 stimulation up-regulated caspase-1 activity in HMC-1 cells; however, this up-regulated caspase-1 activity was down-regulated by LA. Finally, LA decreased intracellular calcium levels in HMC-1 cells as well as PMA-induced ear swelling responses in mice. Taken together, these results suggest that LA would be beneficial to treatment of atopic and inflammatory diseases by reducing TSLP.

Di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), an anticancer agent, exerts an anti-inflammatory effect in activated human mast cells.

OBJECTIVE: Inflammation has been closely associated with the development and progression of cancer. Previously, we reported that mast cells play a critical role in tumor growth. The purpose of this study is to investigate the anti-inflammatory effect of an anticancer agent, di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), on an activated human mast cell line, in this case HMC-1 cells. METHODS: We evaluated the effect and specific molecular mechanism of Dp44mT on phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI) using HMC-1 cells. RESULTS: Here, we demonstrated that Dp44mT significantly decreased the protein levels of hypoxia-inducible factor-1α and vascular endothelial growth factor without exposing activated HMC-1 cells to any cytotoxicity. In activated mast cells, Dp44mT mitigated the strong production and mRNA expression of inflammatory cytokines, in this case, interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, and thymic stromal lymphopoietin, through a blockade of caspase-1 and nuclear factor-κB activities. Furthermore, phosphorylations of the mitogen-activated protein kinase family included in inflammatory signaling cascades were significantly inhibited by a Dp44mT treatment. CONCLUSIONS: Overall, our results indicate that the anticancer agent Dp44mT has an anti-inflammatory effect and may be of therapeutic importance for the treatment of mast cell-mediated inflammatory diseases.

ß-eudesmol suppresses allergic reactions via inhibiting mast cell degranulation.

The regulatory effect of ß-eudesmol, which is an active constituent of Pyeongwee-San (KMP6), is evaluated for allergic reactions induced by mast cell degranulation. Phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cell line, HMC-1 cells, and compound 48/80-stimulated rat peritoneal mast cells (RPMCs) are used as the in vitro models; mice models of systemic anaphylaxis, ear swelling, and IgE-dependent passive cutaneous anaphylaxis (PCA) are used as the in vivo allergic models. The results demonstrate that ß-eudesmol suppressed the histamine and tryptase releases from the PMA plus calcium ionophore A23187-stimulated HMC-1 cells. ß-eudesmol inhibits the expression and activity of histidine decarboxylase in the activated HMC-1 cells. In addition, ß-eudesmol inhibits the levels of histamine and tryptase released from the compound 48/80-stimulated RPMCs. Furthermore, ß-eudesmol decreases the intracellular calcium level in the activated RPMCs. ß-eudesmol also decreases the compound 48/80-induced mortality and ear swelling response. ß-eudesmol suppresses the serum levels of histamine, IgE, interleukin (IL)-1ß, IL-4, IL-5, IL-6, IL-13, and vascular endothelial growth factor (VEGF) under PCA mice as well as PCA reactions. Therefore, the results from this study indicate the potential of ß-eudesmol as an anti-allergic drug with respect to its pharmacological properties against mast cell-mediated allergic reactions.

Anti-inflammatory effects of a traditional Korean medicine: Ojayeonjonghwan.

OBJECTIVE: To study the anti-inflammatory properties of OJ. CONTEXT: Ojayeonjonghwan (OJ) is a traditional Korean prescription, which has been widely used for the treatment of prostatitis. However, no scientific study has been performed of the anti-inflammatory effects of OJ. MATERIALS AND METHODS: Peritoneal macrophages were isolated 3-4 days after injecting a C57BL/6J mouse with thioglycollate. They were then treated with OJ water extract (0.01, 0.1, and 1 mg/mL) for 1 h and stimulated with lipopolysaccharide (LPS) for different times. Nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and proinflammatory cytokine levels were determined by NO assay, Western blotting, RT-PCR and ELISA. RESULTS: NO generation and iNOS induction were increased in the LPS-activated mouse peritoneal macrophages. However, NO generation and iNOS induction by LPS were suppressed by treatment with OJ for the first time. The IC50 value of OJ with respect to NO production was 0.09 mg/mL. OJ did not influence LPS-stimulated COX-2 induction, but did significantly decrease LPS-stimulated secretions and mRNA expressions of tumour necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß. Inhibition rates of TNF-α, IL-6, and IL-1ß at an OJ concentration of 1 mg/mL were 77%, 88%, and 50%, respectively. OJ also suppressed the LPS-induced nuclear translocation of NF-κB. High-performance liquid chromatography showed schizandrin and gomisin A are major components of OJ. CONCLUSIONS: OJ reduces inflammatory response, and this probably explains its positive impact on the prostatitis associated inflammation.