Genuine traditional Korean medicine,Naju Jjok (Chung-Dae,Polygonum tinctorium) improves 2,4-dinitrofluorobenzene-induced atopic dermatitis-like lesional skin

PurposeNaju Jjok (NJJ, Polygonum tinctorium) is a clear heat and release toxin medicinal. It has been used to treat various inflammatory diseases and as a dye in clothing in traditional Korean medicine. However, the effect of NJJ on atopic dermatitis (AD) has not been elucidated. Therefore, we examined whether NJJ would have an inhibitory effect on AD using the mimic AD murine model and in vitro model.MethodsWe treated NJJ on 2,4-dinitrofluorobenzene (DNFB)-induced AD-like skin lesions in NC/Nga mice, phorbol myristate acetate/calcium ionophore A23187-stimulated human mast cell line (HMC-1) cells, and anti-CD3/anti-CD28-stimulated splenocytes. Histological analysis, ELISA, PCR, and Western blot analysis were performed.ResultsThe oral administration with NJJ suppressed the total clinical severity in DNFB-induced AD-like lesional skin. NJJ significantly suppressed the levels of inflammatory mRNA and protein in AD-like lesional skin. NJJ significantly suppressed the levels of IgE and interleukin-4 in the serum of DNFB-induced AD mice. The expression of mast cells-derived caspase-1 was suppressed by NJJ in AD-like lesional skin. In addition, topical application with NJJ improved clinical symptoms in DNFB-induced AD mice. The topical application with NJJ significantly suppressed the levels of IgE and histamine in the serum of DNFB-induced AD mice. NJJ suppressed the production and mRNA expression of TSLP by blockade of caspase-1 signal pathway in the activated HMC-1 cells. Furthermore, NJJ significantly decreased the production of tumor necrosis factor-α from the stimulated splenocytes.ConclusionsIn conclusion, these results propose curative potential of natural dye, NJJ by showing the scientific evidence on anti-AD effect of NJJ which has been used traditionally.     

Rosmarinic acid and ursolic acid alleviate deficits in cognition,synaptic regulation and adult hippocampal neurogenesis in an Aβ1-42-induced mouse model of Alzheimer's disease

BackgroundRosmarinus officinalis, commonly known as rosemary, is a medicinal herb that presents significant biological properties such as antimicrobial, antioxidant, anti-inflammatory, anti-diabetic and anti-depressant activities. Recent findings correlate impaired adult neurogenesis, which is crucial for the maintenance of synaptic plasticity and hippocampal functioning, synaptic regulation with the pathological hallmarks of Alzheimer's disease (AD). These observations call for the need to developing compounds that promote neurogenesis and alleviates deficits in cognition and synaptic regulation.Purpose and study designThe present study was conducted to determine the proneurogenic effects of R. officinalis and its active compounds (ursolic acid and rosmarinic acid) in comparison to Donepezil in an Aβ_1-42-induced mouse model of AD.MethodsBALB/c mice were divided into ten groups. Half were injected with Aβ_1-42 in the hippocampus through stereotaxic surgery to generate the disease groups. The other half received control injections. Each set of five groups were administered orally with vehicle, an ethanolic extract of R. officinalis, ursolic acid, rosmarinic acid or donepezil. Behavior analysis included the Morris water maze test, the novel object recognition test and the Elevated plus maze. The mice were then sacrificed and the hippocampal tissue was processed for immunohistochemistry and gene expression analysis.ResultsThe results show a protective effect by rosmarinic acid and ursolic acid in reversing the deficits in spatial and recognition memory as well as changes in anxiety induced by Aβ_1-42. The neuronal density and the expression levels of neurogenic (Ki67, NeuN and DCX) and synaptic (Syn I, II, III, Synaptophysin and PSD-95) markers were also normalized upon treatment with rosmarinic and ursolic acid.ConclusionOur findings indicate the potential of R. officinalis and its active compounds as therapeutic agents against Aβ_1-42-induced neurotoxicity in AD.     

Topical treatment with mastic (resin from Pistacia lentiscus) elicits anti-inflammatory and anti-pruritic responses by modulating keratinocyte activation in a mouse model of allergic dermatitis

BackgroundAs the number of patients with skin allergies, including atopic dermatitis, has increased rapidly, therapeutic options such as anti-IL-31 antibody and Janus kinase inhibitor have been developed recently. However, many concerns remain regarding the adverse effects and cost of these drugs; therefore, development of supplements that could support the effect of therapeutic agents is always required.PurposeThe aim of this study was to develop preventive and supportive options for skin allergies by focusing on a natural product called “Mastic”. Methods: Initially, the anti-inflammatory and anti-pruritic responses of 3% and 30% Mastic topical treatment were investigated in a mouse model of allergic contact dermatitis, generated by topical application of toluene-2,4-diisocyanate (TDI), a hapten that induces type 2 helper T cells. After itch behaviour and ear-swelling response were monitored, serum, auricular lymph nodes, and skin tissues were collected to analyse immunocyte differentiation, cytokine determination, and histological changes.ResultsOur findings indicated that topical treatment with mastic significantly ameliorated ear swelling, itch behaviour, immunocyte infiltration, and cytokine production. Histological evaluation confirmed the occurrence of anti-inflammatory responses. The anti-inflammatory and anti-pruritic effects of topical treatment with mastic (3% and 5%) were further confirmed in a mouse model of atopic dermatitis which was generated by topical application of TDI in NC/Nga mice. Thickness of the back skin, AD score, transepidermal water loss (TEWL), and itch behaviour were measured weekly, and immunocyte differentiation, cytokine determination, and histological changes were also analysed. Mastic treatment significantly attenuated the skin thickness, AD score, TEWL, and itch behaviour. Corroborated reduction was observed in the numbers of T cells and IgE-B cells, as well as in pro-inflammatory cytokine production. The reproducibility of the effects of mastic was confirmed with 1% mastic ointment in a setting similar to the AD mouse model. In vitro evaluation of keratinocytes indicated that mastic pre-exposure induced a significant dose-dependent decrease in cytokine production.ConclusionOur findings thus demonstrate that topical treatment with mastic significantly ameliorate inflammatory and pruritic responses in a mouse model of allergic dermatitis.     

Rosa davurica Pall. improves DNCB-induced atopic dermatitis in mice and regulated TNF-Alpa/IFN-gamma-induced skin inflammatory responses in HaCaT cells

PurposeRosa davurica Pall., is mainly distributed in Korea, Japan, northeastern China, southeastern Siberia, and eastern Asia. It has been extensively used to treat various kinds of diseases by reason of the significant antioxidant, antiviral and anti-inflammatory activities. However, the pharmacological mechanism of Rosa davurica Pall. in atopic dermatitis (AD) is still ill defined and poorly understood. This study was to examine the anti-inflammatory effects and its mechanism on AD of Rosa davurica Pall. leaves (RDL).MethodsTo evaluate the therapeutic potential of RDL against AD, we have investigated the effects of RDL on the inflammatory reactions and the productions of inflammatory chemokines and cytokines that were induced by tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) in HaCaT cells. Futhermore, we examined the effects of RDL on the signaling pathways of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB). For the in-vivo studies, RDL extract was topically applied to the dinitrochlorobenzene (DNCB)-induced AD mice, then its therapeutic effect was evaluated physiologically and morphologically.ResultsAfter the stimulation of HaCaT cells with TNF-α/IFN-γ, RDL considerably reduced the release of inflammatory mediators such as nitric oxide (NO), PEG₂ and other cytokines. RDL also reduced the phosphorylations of MAPK and NF-κB in TNF-α/IFN-γ-stimulated HaCaT cells. In vivo topical application of RDL to DNCB-induced AD mice significantly reduced the dorsal skin and ear thickness, clinical dermatitis severity, and mast cells. Treatment with RDL also markedly decreased the levels of serum IgE, IL-6 and the number of WBCs in the blood.ConclusionOur studies indicate that RDL inhibits the AD-like skin lesions by modulating skin inflammation. Consequently, these results suggest that RDL may be served as a possible alternative therapeutic treatment for skin disorder such as AD.     

I. inflexus (Thunb.) Kudo extract improves atopic dermatitis and depressive-like behavior in DfE-induced atopic dermatitis-like disease

BackgroundAtopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease, which is caused by several genetic, immunological, and environmental factors. In addition to skin manifestations, AD is associated with an increased risk of depression and suicidal ideation. Furthermore, this association is underappreciated and therefore insufficiently studied.Hypothesis/PurposeWe investigated the association between AD and depression and the effect of I. inflexus (Thunb.) Kudo extract (IIE) treatment in a Dermatophagoides farinae extract (DfE)-induced mouse model of AD.Study DesignWe evaluated the effects of IIE on depressive behavior in AD mice using four experimental groups: normal (untreated), AD mice (untreated Dfe-induced), IIE-treated (Dfe-induced AD mice), and positive control (tacrolimus-treated Dfe-induced AD mice).MethodsAn AD model was established by the application of 4% sodium dodecyl sulfate to the shaved dorsal neck skin and ears of NC/Nga mice 1 h before application of 100 mg DfE twice per week for 3 weeks. After the first week of DfE application, mice were treated with IIE every day for the remaining 2 weeks. We performed behavioral testing, histology, ELISA, and western blotting to assess depressive-like behavior and neuroinflammatory responses and to measure IgE, histamine, corticosterone, and serotonin levels.ResultsCompared with normal mice, AD mice showed more scratching behavior, increased ear swelling, and higher serum levels of IgE and histamine. AD mice also exhibited evidence of depressive-like behavior in the open-field and sucrose preference tests as well as altered serum corticosterone and brain serotonin concentrations. Histopathological analyses revealed increased infiltration of inflammatory cells and mast cells into the skin and ear tissue and elevated microglia activation and neuroinflammatory response in the brains of AD mice. Topical application of IIE reversed the effects of AD on scratching behavior, ear swelling, open-field locomotion, sucrose preference, and levels of IgE, histamine, corticosterone, serotonin, and inflammatory markers. Moreover, IIE treatment reduced inflammatory cytokine responses in keratinocyte cells.ConclusionIIE is a candidate anti-AD therapy due to its ability to exert neuroprotective and antidepressant effects.     

Suppressive effect of 1,4-anhydro-4-seleno-D-talitol (SeTal) on atopic dermatitis-like skin lesions in mice through regulation of inflammatory mediators

BackgroundAtopic dermatitis (AD) is a multifactorial chronic inflammatory disease that affects ∼20 % of children and 3% of adults globally and is generally treated by the topical application of steroidal drugs that have undesirable side-effects. The development of alternative therapies is therefore an important objective. The present study investigated the effects of topical treatment with a novel water-soluble selenium-containing carbohydrate derivative (4-anhydro-4-seleno-D-tatitol, SeTal) on the symptoms and inflammatory parameters in an AD mouse model.MethodsMice were sensitized by applying 2,4-dinitrochlorobenzene (DNCB) to their dorsal skin on days 1–3, then further challenged on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. SeTal (1 and 2%) or hydrocortisone (1%) was applied topically to the backs of the mice from days 14–29, and skin severity scores and scratching behavior determined on day 30. The mice were euthanized, and their ears and dorsal skin removed to quantify inflammatory parameters, edema, myeloperoxidase (MPO) activity, and AD-associated cytokines (tumor necrosis factor alpha (TNF-α), interleukins (IL)-18, and IL-33).ResultsDNCB treatment induced skin lesions and increased the scratching behavior, ear edema, MPO activity (ear and dorsal skin), and cytokine levels in dorsal skin. Topical application of SeTal improved inflammatory markers (cytokine levels and MPO activity), cutaneous severity scores, and scratching behavior.ConclusionThe efficacy of SeTal was satisfactory in the analyzed parameters, showing similar or better results than hydrocortisone. SeTal appears to be therapeutically advantageous for the treatment and control of AD.     

Silencing of H4R inhibits the production of IL-1β through SAPK/JNK signaling in human mast cells

Context: Mast cell (MC) activation through H4R releases various inflammatory mediators which are associated with allergic asthma.

Objectives: To investigate the siRNA-mediated gene silencing effect of H4R on human mast cells (HMCs) functions and the activation of stress-activated protein kinases (SAPK)/jun amino-terminal kinases (JNK) signaling pathways for the release of ineterleukin-1β (IL-1β) in HMCs.

Materials and methods: H4R expression was analyzed by RT-PCR and western blotting in human mast cell line-1 (HMC-1) cells and H4RsiRNA transfected cells. The effect of H4RsiRNA and H4R-antagonist on H4R mediated MC functions such as intracellular Ca²⁺ release, degranulation, IL-6 and IL-1β release, and the activation SAPK/JNK signaling pathways were studied. HMC-1 cells were stimulated with 10?μM of histamine (His) and 4-methylhistamine (4-MH) and pretreated individually with H4R-antagonist JNJ7777120 (JNJ), histamine H1 receptor (H1R)-antagonist mepyramine, and signaling molecule inhibitors SP600125 (SP) and Bay117082.

Results: We found that the HMC-1 cells expressed H4R and H4RsiRNA treatment down regulated the H4R expression in HMC-1 cells. Both His and 4-MH induced the intracellular Ca²⁺ release and degranulation whereas; H4R siRNA and JNJ inhibited the effect. Furthermore, the activation of H4R caused the phosphorylation of SAPK/JNK pathways. H4R gene silencing and pretreatment with SP and JNJ decreased His and 4-MH induced phosphorylation of SAPK/JNK. We found that the activation of H4R caused the release of IL-1β (124.22?pg/ml) and IL-6 (122.50?pg/ml) on HMC-1 cells. Whereas, SAPK/JNK inhibitor (68.36?pg/ml) inhibited the H4R mediated IL-1β release.

Conclusions: Taken together, the silencing of H4R inhibited the H4R mediated MC functions and SAPK/JNK phosphorylation. Furthermore, the H4R activation utilized SAPK/JNK signaling pathway for IL-1β release in HMC-1 cells.     

Anti-Inflammatory Activity of S. Marianum and N. Sativa Extracts on Macrophages

Background:Nigella sativa (N. sativa) and Silybum marianum (S. marianum) are used to regulate macrophage polarization in lipopolysaccharide-induced RAW 264.7 cells and thioglycollate-elicited peritoneal inflammation.Methods:Cytotoxicity assays and acute toxicity tests were performed to investigate the safe dose and toxicity of the prepared extracts. Also, nitric oxide production was determined by Griess assay on RAW264.7 and peritoneal macrophage supernatants. After RNA extraction from macrophages, real-time PCR was performed to measure the relative gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, transforming growth factor (TGF)-β, and IL-10. Finally, regulatory T cells (Treg cells) were counted by flow cytometry.Results:S. marianum methanolic extract (SME), N. sativa ethanolic extract (NEE), and their mixture (SME+NEE) decreased NO levels significantly in RAW264.7 and peritoneal murine macrophages. N. sativa ethanolic extract significantly increased IL-10 gene expression and significantly decreased IL-6 and TNF-α expression in RAW264.7 cells. In mixture-treated peritoneal macrophages, IL-10 and TGF-β expression were significantly increased, while IL-6 and TNF-α were significantly decreased. Also, the percentage of Treg cells was significantly greater in the mixture-treated cells than in controls.Conclusion:These results suggest that an SME and NEE mixture has anti-inflammatory and immunomodulatory activities and may be useful in the treatment of diseases of immunopathologic origin characterized by macrophage hyperactivation.Key Words: Cytokine, Inflammation, Nigella sativa, Nitric oxide, Silybum marianum     

Oral Administration of p-Hydroxycinnamic Acid Attenuates Atopic Dermatitis by Downregulating Th1 and Th2 Cytokine Production and Keratinocyte Activation

Atopic dermatitis (AD) is a complex disease that is caused by various factors, including environmental change, genetic defects, and immune imbalance. We previously showed that p-hydroxycinnamic acid (HCA) isolated from the roots of Curcuma longa inhibits T-cell activation without inducing cell death. Here, we demonstrated that oral administration of HCA in a mouse model of ear AD attenuates the following local and systemic AD manifestations: ear thickening, immune-cell infiltration, production of AD-promoting immunoregulatory cytokines in ear tissues, increased spleen and draining lymph node size and weight, increased pro-inflammatory cytokine production by draining lymph nodes, and elevated serum immunoglobulin production. HCA treatment of CD4⁺ T cells in vitro suppressed their proliferation and differentiation into Th1 or Th2 and their Th1 and Th2 cytokine production. HCA treatment of keratinocytes lowered their production of the pro-inflammatory cytokines that drive either Th1 or Th2 responses in AD. Thus, HCA may be of therapeutic potential for AD as it acts by suppressing keratinocyte activation and downregulating T-cell differentiation and cytokine production.     

Antidiabetic potential of gallic acid from Emblica officinalis: Improved glucose transporters and insulin sensitivity through PPAR-γ and Akt signaling

BackgroundNature has gifted a variety of vital phytochemicals having potential therapeutic application against various ailments. Emblica officinalis (E. officinalis), an ancient plant, has long been used as a remedy for diabetes and cardiovascular complications, and presence of abundant amount of gallic acid could be accountable for its medicinal potential.PurposeThe study was aimed to determine the in-vivo and in-vitro anti-diabetic potential of gallic acid and fruit juice of E. officinalis. Molecular mechanism of gallic acid as well as fruit juice of E. officinalis for anti-diabetic potential has also been revealed.Experimental study designAnti-diabetic potential of E. officinalis and gallic acid was evaluated in 3T3-L1 preadipocytes and various animal models like db/db mice and fructose administered rats. PPAR-γ expression and glucose translocation were observed using western blot and PCR techniques.ResultsTreatment of E. officinalis fruit juice and gallic acid facilitated their glucose homeostasis; improved insulin sensitivity; reduced obesity; abridged elevated blood pressure and declined cholesterol level, and also induced adipogenesis in 3T3-L1 adipocytes. Mechanistically, treatment increased expression of PPAR-γ through activation of C/EBPs and simultaneously increased Glut4 translocation in 3T3-L1 adipocytes. Moreover, gallic acid treatment increased insulin sensitivity through activation of Akt rather than AMPK signaling pathway while fruit juice of E. officinalis showed dual activation, Akt and AMPK as well.ConclusionThese findings reveal the role of gallic acid in E. officinalis mediated antidiabetic potential, and delineate the upregulation of pAkt, PPAR-γ and Glut4 in gallic acid mediated antidiabetic activity, thus providing potential therapy for diabetes and related disorders.     

The involvement of TRPA1 channel activation in the inflammatory response evoked by topical application of cinnamaldehyde to mice

AimsIn the present work, we characterize the inflammatory process induced by the topical application of cinnamaldehyde on the skin of mice and verify the participation of transient receptor potential A1 TRPA1 receptors in this process.Main methodsWe measured mouse ear edema and sensitization/desensitization after topical application of cinnamaldehyde or/and capsaicin. We also quantified cellular infiltration through myeloperoxidase (MPO) activity and histological and immunohistochemical analyses and evaluated the expression of TRPV1 and TRPA1 by western blot.Key findingsCinnamaldehyde induced ear edema in mice (1–6 μg/ear) with a maximum effect of 4 μg/ear. Cinnamaldehyde promoted leukocyte infiltration as detected by increasing MPO activity and confirmed by histological analyses. The edema and cellular infiltration evoked by the application of 4 μg/ear of cinnamaldehyde were prevented by topical application of ruthenium red, a non-selective TRP antagonist as well as camphor and HC030031, two TRPA1 receptor antagonists. Cinnamaldehyde-induced edema, but not cellular infiltration, was prevented by topical application of the tachykinin NK1 antagonist, aprepitant, indicating a neuropeptide release phenomenon in this process. Additionally, we observed that repeated topical applications of cinnamaldehyde did not induce changes in sensitization or desensitization with respect to the edema response. Interestingly, repeated treatment with the TRPV1 agonist, capsaicin, abrogated it edematogenic response, confirming the desensitization process and partially decreasing the cinnamaldehyde-induced edema, suggesting the involvement of capsaicin-sensitive fibers.SignificanceOur data demonstrate that the topical application of cinnamaldehyde produces an inflammatory response that is dependent on TRPA1 receptor stimulation.     

Anti-atopic dermatitis effects of Parasenecio auriculatus via simultaneous inhibition of multiple inflammatory pathways

The treatment of atopic dermatitis (AD) is challenging due to its complex etiology. From epidermal disruption to chronic inflammation, various cells and inflammatory pathways contribute to the progression of AD. As with immunosuppressants, general inhibition of inflammatory pathways can be effective, but this approach is not suitable for long-term treatment due to its side effects. This study aimed to identify a plant extract (PE) with anti-inflammatory effects on multiple cell types involved in AD development and provide relevant mechanistic evidence. Degranulation was measured in RBL-2H3 cells to screen 30 PEs native to South Korea. To investigate the anti-inflammatory effects of Parasenecio auriculatus var. matsumurana Nakai extract (PAE) in AD, production of cytokines and nitric oxide, activation status of FcεRI and TLR4 signaling, cell-cell junction, and cell viability were evaluated using qRT-PCR, western blotting, confocal microscopy, Griess system, and an MTT assay in RBL-2H3, HEK293, RAW264.7, and HaCaT cells. For in vivo experiments, a DNCB-induced AD mouse model was constructed, and hematoxylin and eosin, periodic acid-Schiff, toluidine blue, and F4/80-staining were performed. The chemical constituents of PAE were analyzed by HPLC-MS. By measuring the anti-degranulation effects of 30 PEs in RBL-2H3 cells, we found that Paeonia lactiflora Pall., PA, and Rehmannia glutinosa (Gaertn.) Libosch. ex Steud. show an inhibitory activity of more than 50%. Of these, PAE most dramatically and consistently suppressed cytokine expression, including IL-4, IL-9, IL-13, and TNF-α. PAE potently inhibited FcεRI signaling, which mechanistically supports its basophil-stabilizing effects, and PAE downregulated cytokines and NO production in macrophages via perturbation of toll-like receptor signaling. Moreover, PAE suppressed cytokine production in keratinocytes and upregulated the expression of tight junction molecules ZO-1 and occludin. In a DNCB-induced AD mouse model, the topical application of PAE significantly improved atopic index scores, immune cell infiltration, cytokine expression, abnormal activation of signaling molecules in FcεRI and TLR signaling, and damaged skin structure compared with dexamethasone. The anti-inflammatory effect of PAE was mainly due to integerrimine. Our findings suggest that PAE could potently inhibit multi-inflammatory cells involved in AD development, synergistically block the propagation of inflammatory responses, and thus alleviate AD symptoms.     

Bioactive monoterpene indole alkaloids from Nauclea officinalis

Two new monoterpene indole alkaloids, naucleaoffines A (1) and B (2), together with six known alkaloids (3–8), were isolated from the stems and leaves of Nauclea officinalis. The structures of 1 and 2 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with the data reported in literature. All isolated compounds were evaluated for their anti-inflammatory activities and anti-HIV-1 activities. Compounds 1–8 exhibited significant inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC₅₀ values comparable to that of hydrocortisone. In addition, compounds 1–8 showed significant anti-HIV-1 activities with EC₅₀ ranged from 0.06 to 2.08 µM. These findings suggest that the discoveries of these indole alkaloids with significant anti-inflammatory activities and anti-HIV-1 activities isolated from N. officinalis could be of great importance to the development of new anti-inflammatory and anti-HIV agents.     

Scrophularia buergeriana attenuates allergic inflammation by reducing NF-κB activation

BackgroundScrophularia buergeriana Miq. (Scrophulariaceae) (SB) has been used as an oriental medicine for the treatment of inflammatory diseases, such as neuritis and pharyngolaryngitis.PurposeWe explored the therapeutic effects of S. buergeriana ethanol extract (SBE) on airway inflammation in ovalbumin (OVA)-induced asthmatic mice and lipopolysaccharide (LPS)-stimulated RAW264.7 cells.MethodsMice were intraperitoneally injected with OVA on days 0 and 14 to elevate the immune response. On days 21 to 23, the mice were challenged with OVA solution and SBE (20 and 40 mg/kg) was administered daily by oral gavage from days 18 to 23. RAW264.7 cells were pretreated with SBE 1 h before LPS stimulation.ResultsSBE administration effectively suppressed inflammatory cell infiltration, the expression of interleukin (IL)-5, IL-13, and IL-17, immunoglobulin E, and airway hyperresponsiveness in an OVA-induced allergic asthma model. A reduction in histological alterations, including airway inflammation and mucus hypersecretion, was observed. These effects of SBE were accompanied by a decrease in matrix metalloproteinase-9 (MMP-9) expression and nuclear factor kappa B (NF-κB) phosphorylation. These responses were observed in LPS-stimulated RAW264.7 cells. SBE treatment reduced the mRNA expression of tumor necrosis factor (TNF)-α, IL-6, and MMP-9, and NF-κB phosphorylation, in LPS-stimulated RAW264.7 cells.ConclusionOur results indicated that SBE effectively attenuated airway inflammation in an OVA-induced allergic asthma model. These properties of SBE were thought to be involved in the suppression of NF-κB phosphorylation, suggesting that the material has the potential to regulate the development of allergic asthma.     

Effect of H4R antagonist N-(2-aminoethyl)-5-chloro-1H-indol-2-carboxamides and 5-chloro-2-(piperazin-1-ylmethyl)-1H-benzimidazole on histamine and 4-methylhistamine-induced mast cell response

Context: The histamine plays a decisive role in acute and chronic inflammatory responses and is regulated through its four types of distinct receptors designated from H1 to H4. Recently histamine 4 receptor (H4R) antagonists have been reported to possess various pharmacological effects against various allergic diseases.

Objective: To investigate the inhibitory effect of N-(2-aminoethyl)-5-chloro-1H-indol-2-carboxamide (Compound A) and 5-chloro-2-(piperazin-1-ylmethyl)-1H-benzimidazole (Compound L) on H4R-mediated calcium mobilization, cytokine IL-13 production, ERK1/2, Akt and NF-κB activation in human mastocytoma cells-1 (HMC-1).

Materials and methods: Compounds A and L were synthesized chemically and their inhibitory effect on intracellular calcium release was analyzed by Fluo-4 calcium assay, cytokine measurement through ELISA and activation of signaling molecules by western blot.

Results: Pre-treatment with compounds A and L significantly reduced the H4R-mediated intracellular calcium release. Histamine and 4-methylhistamine (4-MH) induced Th2 cytokine IL-13 production in HMC-1 cells, was inhibited by compound A (77.61%, 74.25% at 1?μM concentration) and compound L (79.63%, 81.70% at 1?μM concentration). Furthermore, histamine induced the phosphorylation of ERK1/2, Akt and NF-κB was suppressed by compounds A and L at varying levels, ERK1/2 (88%, 86%), Akt (88%, 89%) and NF-κB (89%, 87%) in HMC-1 cells.

Discussion and conclusions: Taken together these data demonstrate that compound A and compound L may block H4R-mediated downstream signaling events.