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.     

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.     

7,8,4′-Trihydroxyisoflavone Attenuates DNCB-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice

Atopic dermatitis (AD) is characterized by chronic highly pruritic and relapsing inflammatory skin lesions. Despite its growing prevalence, therapeutic treatments remain limited. Natural immune modulators from herbal extracts or derivatives may be useful for treating AD symptoms. This study examined the effect of 7,8,4′-trihydroxyisoflavone (7,8,4′-THIF), a metabolite of soy isoflavone daidzin, on AD-like symptoms. Repeated epicutaneous application of 2,4-dinitrochlorobenzene (DNCB) was performed on the ear and dorsal skin of NC/Nga mice to induce AD-like symptoms and skin lesions, and 7,8,4′-THIF (200 and 400 nmol) or tacrolimus (100 µg) was applied topically for 3 weeks to assess their anti-pruritic effects. We found that 7,8,4′-THIF alleviated DNCB-induced AD-like symptoms as quantified by skin lesion, dermatitis score, ear thickness, and scratching behavior. Histopathological analysis demonstrated that 7,8,4′-THIF decreased DNCB-induced eosinophil and mast cell infiltration into skin lesions. We also found that 7,8,4′-THIF significantly alleviated DNCB-induced loss of water through the epidermal layer. In addition to reducing the DNCB-induced increase in serum IgE, 7,8,4′-THIF also lowered skin lesion levels of the chemokine thymus and activation regulated chemokine; Th2 cytokines interleukin (IL)-4, IL-5, and IL-13; and Th1 cytokines IL-12 and interferon-γ. These results suggest that 7,8,4′-THIF might be a potential therapeutic candidate for the treatment of atopic dermatitis.     

Arjunolic acid protects against DNCB-induced atopic dermatitis-like symptoms in mice by restoring a normal cytokine balance

Purpose

Atopic dermatitis (AD) is a chronically relapsing, pruritic, eczematous skin disorder accompanying allergic inflammation. AD is triggered by oxidative stress and immune imbalance. The effect of oral arjunolic acid (AA) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in mice was investigated.

Methods

Repeated epicutaneous application of DNCB to the ear and shaved dorsal skin of mice was performed to induce AD-like symptoms and skin lesions: 250mg/kg AA was given orally for three weeks to assess its anti-pruritic effects. Serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-10, immunoglobulin (Ig)E and caspase-3 were assessed by ELISA.

Results

We found that AA alleviated DNCB-induced AD-like symptoms as quantified by skin lesions, dermatitis score, ear thickness and scratching behavior. Levels of reactive oxygen species in the AA group were significantly inhibited compared with those in the DNCB group. In parallel, AA blocked a DNCBinduced reduction in serum levels of IL-4 and IL-10 associated with an attenuation of DNCB-induced increases in serum TNF-α, IL-6, IgE and caspase-3.

Conclusions

The results indicate that AA suppresses DNCB-induced AD in mice via redox balance and immune modulation, and could be a safe clinical treatment for AD.

     

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.     

Effects of topical application of a tri-herb formula on inflammatory dry-skin condition in mice with oxazolone-induced atopic dermatitis

BackgroundAtopic dermatitis (AD) is a chronic relapsing inflammatory and pruritic skin disease, affecting 10-20% of the population worldwide. Paeonia suffruticosa Andrews (Paeoniaceae) (Cortex Moutan) and Mentha haplocalyx Briq. (Labiatae) (Herba Menthae) have shown beneficial effects on AD. Calendula officinalis L. (Asteraceae) is commonly used for treating skin rashes and wounds.PurposeIn the present study, a three-herbs formula including Cortex Moutan and Herba Menthae, together with C. officinalis at 1:1:1 weight ratio was used as a topical agent and its therapeutic effects on AD was investigated.MethodsIn vitro effects of individual herbs and three-herbs formula (0.125–1 mg/ml) were examined using cytokine release assay on human mast HMC-1 cells, inflammation test on murine macrophage RAW cells and human keratinocyte (HaCaT) cells, and migration scratch assay on human umbilical vein endothelial cells (HUVEC). The contributing functional pathway of three-herbs formula in AD was explored using Western Blot assay in HMC-1 cells. Oxazolone-induced AD-like mice model was also used to investigate the in vivo therapeutic effect of the topical application of the three-herbs formula.ResultsHerba Menthae, Cortex Moutan, and three-herbs formula significantly reduced the production of IL-6 and tumor necrosis factor (TNF)-α in HMC-1 cells, inhibited the expression of IL-6, IL-8 and CCL2 in TNF-α/IFN-γ stimulated HaCaT cells, and suppressed the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. Moreover, Herba Menthae and three-herbs formula significantly suppressed CCL2 and TNF-α production in LPS-induced RAW 264.7 cells. C. officinalis and three-herbs formula promoted wound healing in HUVEC. For intracellular mechanisms, three-herbs formula inhibited the expressions of molecules in STAT1 and STAT3-dependent pathways. In vivo model showed that topical application of three-herbs formula on challenged ear reduced ear swelling and mice scratching frequencies. H&E and toluidine blue staining of the challenged ear tissue demonstrated that three-herbs formula reduced the epidermal thickness and mast cell infiltration, respectively.ConclusionThe three-herbs formula of Cortex Moutan, Herba Menthae and C. officinalis at 1:1:1 (w/w) exhibited anti-inflammatory effect and promotion of cell migration in vitro. It also alleviated ear redness, swelling, epidermal thickness and inflammation of the OXA-induced AD mice. These findings suggest a potential beneficial role of the topical application of the three-herbs formula for treatment of 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.     

DNCB致敏/激发Nc/Nga小鼠特应性皮炎模型的建立

目的研究外用2,4-二硝基氯苯（DNCB）对Nc/Nga小鼠的致敏作用,探索建立特应性皮炎（AD）模型的方法。方法外用1%DNCB7周,间隔为1周,重复刺激并致敏7周大NC/Nga小鼠的双侧耳朵及背部皮肤。结果外用DNCB7周可以引起显著的炎症,并伴有高滴度的IgE和IL-4,利用HE染色进行组织病理分析,提示表皮炎性细胞明显增加。结论外用DNCB重复刺激Nc/Nga小鼠能产生AD样皮炎,可以作为研究AD病因及治疗AD的有效动物模型。     

Platycodon grandiflorum root-derived saponins attenuate atopic dermatitis-like skin lesions via suppression of NF-κB and STAT1 and activation of Nrf2/ARE-mediated heme oxygenase-1

PurposeThe consequences of precipitously rising allergic skin inflammation rates worldwide have accelerated the risk of atopic dermatitis (AD). Natural product-based agents with good efficacy and low risk of side effects offer promising prevention and treatment strategies for inflammation-related diseases. We have already reported that Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) have many pharmacological effects, including anti-inflammatory and anti-allergic effects, but its influence on AD remains unclear. Therefore, we evaluated the inhibitory effect of CKS, mainly platycodin D, on AD-like skin symptoms in mice and the possible mechanisms in cells.MethodsMice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNCB). Four weeks after challenge, mice were treated with oral administration of CKS for 4 weeks. In addition, cells were used to evaluate the effect of CKS, mainly platycodin D, on the TARC expression regulated mechanism.ResultsCKS attenuated DNCB-induced dermatitis severity, serum levels of IgE and TARC, and mRNA expression of TARC, TNF-α, IFN-γ, IL-4, IL-5, and IL-13 in mice. Histopathological examination showed reduced thickness of the epidermis/dermis and dermal infiltration of inflammatory cells and mast cells in the ears. Moreover, CKS and platycodin D inhibited TNF-α/IFN-γ-induced TARC expression through the suppression of NF-κB and STAT1 and induction of Nrf2/ARE-mediated hemeoxygenase-1 (HO-1) expression in cells.ConclusionWe suggest that CKS and platycodin D inhibited the development of AD-like skin symptoms by regulating cytokine mediators and may be an effective alternative therapy for AD-like skin symptoms.     

Study of the topical anti-inflammatory activity of Achillea ageratum on chronic and acute inflammation models

We have produced a chloroform extract from Achillea which includes stigmasterol and sitosterol. By comparing it with the pure compounds an anti-inflammatory effect (with mouse ears) is assumed. The topical anti-inflammatory effect of the chloroform extract from Achillea ageratum (Asteraceae) and of stigmasterol and beta-sitosterol, isolated of this extract has been evaluated, against to 12-0-tetradecanoylphorbol acetate (TPA)-induced mouse ear edema, using simple (acute model) and multiple applications (chronic model) of the phlogistic agent. Myeloperoxydase activity also was studied in the inflamed ears. In the acute model the extract exerted a dose-dependent effect. All the doses assayed (1, 3 and 5 mg/ear) significantly reduced the edema (50%, 66% and 82%, respectively). The isolated sterols stigmasterol and beta-sitosterol (with doses of 0.5 mg/ear) had similar effect as the extract with doses of 1 and 3 mg (59% and 65% respectively). In the chronic model the anti-inflammatory effect generally was a more moderate one. The highest dose of the extract decreased the edema reduction to 26% with the highest dose of the extract applied. With the compounds the effect decreased to 36% with stigmasterol, and 40.6% with beta-sitosterol. Myeloperoxydase activity (MPO) was reduced by the extract and the compounds in the acute model, however, in the chronic edema, the enzyme inhibition was very weak with all treatments even with the standard substance. These results indicate that the chloroform extract of Achillea ageratum and some of the its components stigmasterol and beta-sitosterol are more effective as topical anti-inflammatory agents in acute than in the chronic process and their action is markedly influenced by the inhibition of neutrophil migration into inflamed tissue.     

Effect of nodakenin on atopic dermatitis-like skin lesions

Nodakenin, derived from the roots of Angelica gigas Nakai, is an important natural resource and medicinal material with anti-allergic and anti- inflammatory activities. We have previously shown that nodakenin inhibits IgE/Ag-induced degranulation in mast cells. In this study, we investigated the inhibitory effect of nodakenin on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)- like skin lesions in ICR mice. Scratching behavior, skin severity score, blood IgE level, and skin thickness were improved in DNCB-induced AD-like ICR mice. Our results showed that nodakenin suppressed the increase of AD-like skin lesions in ICR mice. These results suggest that nodakenin may be a potential therapeutic resource for AD as well as an adjunctive agent to control itching associated with AD.     

Suppression of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice by transduced Tat-Annexin protein

We examined that the protective effects of ANX1 on 12-O-tetradecanoylphorbol- 13-acetate (TPA)-induced skin inflammation in animal models using a Tat-ANX1 protein. Topical application of the Tat-ANX1 protein markedly inhibited TPAinduced ear edema and expression levels of cyclooxygenase-2 (COX-2) as well as pro-inflammatory cytokines such as interleukin- 1 beta (IL-1 β), IL-6, and tumor necrosis factor-alpha (TNF-α). Also, application of Tat-ANX1 protein significantly inhibited nuclear translocation of nuclear factor-kappa B (NF-κ B) and phosphorylation of p38 and extracellular signalregulated kinase (ERK) mitogen-activated protein kinase (MAPK) in TPA-treated mice ears. The results indicate that Tat-ANX1 protein inhibits the inflammatory response by blocking NF-κ B and MAPK activation in TPA-induced mice ears. Therefore, the Tat-ANX1 protein may be useful as a therapeutic agent against inflammatory skin diseases.     

Different inflammatory mediators induce inflammation and pain after application of liquid nitrogen to the skin

The application of liquid nitrogen to the skin induces inflammation and pain. However, there is little data on the role of inflammatory mediators in the production of these symptoms. We have developed an experimental model to study some aspects of the inflammatory response and its mediators following the application of cold. We have applied liquid nitrogen jets to subcutaneous air pouches in the dorsal skin of rats to study the kinetics of the migration of inflammatory cells; also to the ear for histopathological analysis and on the paws for edema and pain. Inflammatory mediators were identified by pharmacological means. The results showed that the cellular inflammatory response was characterized by persistent cell migration, mainly of granulocytes. Histopathology of the ears confirmed these findings. Histamine and sympathomimetic mediators were mainly responsible for the resultant swelling. However, the hypernociception that resulted involved other mediators including IL-1 and eicosanoids. These data suggest that interference with the release of inflammatory mediators might reduce the side effects of cryosurgery and prevent hyperalgesia and inflammation at the site of application of cold.     

Different inflammatory mediators induce inflammation and pain after application of liquid nitrogen to the skin

The application of liquid nitrogen to the skin induces inflammation and pain. However, there is little data on the role of inflammatory mediators in the production of these symptoms. We have developed an experimental model to study some aspects of the inflammatory response and its mediators following the application of cold. We have applied liquid nitrogen jets to subcutaneous air pouches in the dorsal skin of rats to study the kinetics of the migration of inflammatory cells; also to the ear for histopathological analysis and on the paws for edema and pain. Inflammatory mediators were identified by pharmacological means. The results showed that the cellular inflammatory response was characterized by persistent cell migration, mainly of granulocytes. Histopathology of the ears confirmed these findings. Histamine and sympathomimetic mediators were mainly responsible for the resultant swelling. However, the hypernociception that resulted involved other mediators including IL-1 and eicosanoids. These data suggest that interference with the release of inflammatory mediators might reduce the side effects of cryosurgery and prevent hyperalgesia and inflammation at the site of application of cold.     

Effect of Pyeongwee-San (KMP6) on 2,4-dinitrofluorobenzene-induced atopic dermatitis-like skin lesions in NC/Nga mice

AimsRecently, some studies reported that digestive tract disease is closely associated with atopic dermatitis (AD). Pyeongwee-San (KMP6) is a Korean medicine, which has come onto the drugstore for the treatment of digestive tract disease. The aim of the present study was to examine whether KMP6 could suppress 2,4-dinitrofluorobenzene (DNFB)-induced AD-like skin lesions in NC/Nga mice.Main methodsMice were sensitized with DNFB by applying to shaved dorsal skin. At that time, the drugs or saline were orally administrated to DNFB-applied mice.Key findingsThe administration of KMP6 or glycyrrhizic acid (GL), a major component of KMP6, inhibited the scratching number in DNFB-induced AD model. The mRNA expressions of interleukin (IL)-4, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and CCR3 were upregulated by DNFB sensitization, but the upregulated mRNA expressions were significantly reduced by the administration of KMP6 or GL. In addition, the levels of IgE, histamine, and IL-4 were significantly reduced by the administration of KMP6 or GL in serum of DNFB-induced AD model. However, the level of IFN-γ in serum was significantly increased by KMP6 or GL. KMP6 or GL also significantly inhibited the numbers of inflammatory cells, mast cells, and protein level of IL-4 in lesions of DNFB-induced AD model. Finally, KMP6 or GL significantly decreased the productions of IL-4, IFN-γ, and TNF-α in anti-CD3 plus anti-CD28 antibody-stimulated splenocytes.SignificanceKMP6 showed anti-atopic potential in this setting; hence we suggest it as a potential prospect for anti-atopic agent besides being just a medicine for the stomach and bowels.     

A combination of Olea europaea leaf extract and Spirodela polyrhiza extract alleviates atopic dermatitis by modulating immune balance and skin barrier function in a 1-chloro-2,4-dinitrobenzene-induced murine model

BackgroundAtopic dermatitis is a chronic inflammatory skin disease in humans. Although Olea europaea leaf extract (OLE) and Spirodela polyrhiza extract (SPE) have been used to protect against skin damage, the effects of their combined administration on atopic dermatitis have yet to studied.PurposeIn this study, we evaluated the potential therapeutic effects of an OLE and SPE combination on the progression of atopic dermatitis and the possible mechanisms underlying these effects in 1-chloro-2,4-dinitrobenzene (DNCB)-treated NC/Nga mice.MethodsAtopic dermatitis was induced by topical application of 0.2% w/v DNCB prepared in an olive oil:acetone solution (1:3), and thereafter OLE, SPE and OLE + SPE were administered orally for 5 weeks. We determined atopic dermatitis symptoms, serum IgE levels, and levels of cytokine- and gene expression in the dorsal skin and splenocytes, and performed histological and immune cell subtype analyses. The expression of skin barrier-related proteins (filaggrin, sirtuin 1, and claudin 1) was also evaluated.ResultsThe OLE + SPE combination significantly ameliorated atopic dermatitis symptoms, including dermatitis scores, and reduced epidermal thickness and infiltration of different inflammatory cells in mice with DNCB-induced atopic dermatitis. It also significantly reduced the number of CD4⁺, CD8⁺, and CD4⁺/CD69⁺ T cells; immunoglobulin E-producing B cells (CD23⁺/B220⁺) in the axillary lymph nodes; CD3⁺ T-cell eosinophils (chemokine–chemokine receptor 3⁺/CD11b⁺) in the skin; and CD3⁺ T cells, immunoglobulin E-producing B cells (CD23⁺/B220⁺), and eosinophils in peripheral blood mononuclear cells. Additionally, the experimental combination lowered levels of serum immunoglobulin E and histamine, as well as Th2-mediated cytokines, and interleukin-4, -5, and -13, whereas it increased the levels of Th1-mediated cytokine interferon-γ in splenocytes. Furthermore, the preparation significantly restored expression of the skin barrier-related proteins filaggrin, sirtuin 1, and claudin 1, and also reduced the expression of the inflammatory cytokine interleukin-6 and chemokine–chemokine receptor 3, as well as the pruritus-related cytokine interleukin-31 and interleukin-31 receptor, in atopic dermatitis skin lesions.ConclusionTaken together, our findings indicate that administration of a combination of OLE and SPE can alleviate atopic dermatitis symptoms by regulating immune balance and skin barrier function and may be an effective therapeutic option for the treatment of atopic dermatitis.     

Fictive locomotion and scratching inhibit dorsal horn neurons receiving thin fiber afferent input

In decerebrate paralyzed cats, we examined the effects of two central motor commands (fictive locomotion and scratching) on the discharge of dorsal horn neurons receiving input from group III and IV tibial nerve afferents. We recorded the impulse activity of 74 dorsal horn neurons, each of which received group III input from the tibial nerve. Electrical stimulation of the mesencephalic locomotor region (MLR), which evoked fictive static contraction or fictive locomotion, inhibited the discharge of 44 of the 64 dorsal horn neurons tested. The mean depth from the dorsal surface of the spinal cord of the 44 neurons whose discharge was inhibited by MLR stimulation was 1.77 +/- 0.04 mm. Fictive scratching, evoked by topical application of bicuculline to the cervical spinal cord and irritation of the ear, inhibited the discharge of 22 of the 29 dorsal horn neurons tested. Fourteen of the twenty-two neurons whose discharge was inhibited by fictive scratching were found to be inhibited by MLR stimulation as well. The mean depth from the dorsal surface of the cord of the 22 neurons whose discharge was inhibited by fictive scratching was 1.77 +/- 0.06 mm. Stimulation of the MLR or the elicitation of fictive scratching had no effect on the activity of 22 dorsal horn neurons receiving input from group III and IV tibial nerve afferents. The mean depth from the dorsal surface of the cord was 1.17 +/- 0.07 mm, a value that was significantly (P < 0.05) less than that for the neurons whose discharge was inhibited by either MLR stimulation or fictive scratching. We conclude that centrally evoked motor commands can inhibit the discharge of dorsal horn neurons receiving thin fiber input from the periphery.     

Effects of a pyroglutamyl pentapeptide isolated from fermented barley extract on atopic dermatitis-like skin lesions in hairless mouse

ABSTRACT

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritic and eczematous skin lesions. The skin of AD patients is generally in a dried condition. Therefore, it is important for AD patients to manage skin moisturization. In this study, we examined the effects of orally administered fermented barley extract P (FBEP), which is prepared from a supernatant of barley shochu distillery by-product, on stratum corneum (SC) hydration and transepidermal water loss (TEWL) in AD-like lesions induced in hairless mice using 2,4,6-trinitrochlorobenzene. Oral administration of FBEP increased SC hydration and decreased TEWL in the dorsal skin of this mouse model. Further fractionation of FBEP showed that a pyroglutamyl pentapeptide, pEQPFP comprising all -L-form amino acids, is responsible for these activities. These results suggested that this pyroglutamyl pentapeptide may serve as a modality for the treatment of AD.