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.     

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.     

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.     

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.     

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.     

The inhibitory effect of naringenin on atopic dermatitis induced by DNFB in NC/Nga mice

Aims

Atopic dermatitis (AD) is a chronic and relapsing inflammatory dermatitis characterized by pruritic and eczematous skin lesions. Here, we investigated the therapeutic effect of the fruit flavonoid naringenin on DNFB induced atopic dermatitis mice model.

Main methods

AD-like skin lesion was induced by repetitive skin contact with DNFB in NC/Nga mice and the effects of the fruit flavonoid naringenin were evaluated on the basis of histopathological findings of skin, ear swelling and cytokine production of CD4⁺T cells.

Key findings

Intraperitoneal injection of naringenin for one week after DNFB challenge significantly lowered ear swelling and improved back skin lesions. In addition, naringenin significantly suppressed production of interferon-gamma (IFN-γ) by activated CD4⁺ T cells and serum IgE level. Furthermore, naringenin reduced DNFB-induced infiltration of eosinophils, mast cells, CD4⁺ T cells, and CD8⁺ T cells in skin lesions.

Significance

Naringenin may suppress the development of AD-like skin lesions in DNFB-treated NC/Nga mice by reducing IFN-γ production of activated CD4⁺ T cells, serum IgE levels and infiltration of immune cells to skin lesion.     

Inhibitory effect of Pterocarpus indicus Willd water extract on IgE/Ag-induced mast cell and atopic dermatitis-like mouse models

Pterocarpus indicus Willd has been widely used as a traditional medicine to treat edema, cancer, and hyperlipidemia, but its antiallergic properties and underlying mechanisms have not yet been studied. The purpose of this study was to evaluate the antiallergic activity of Pterocarpus indicus Willd water extract (PIW) using activated mast cells and an atopic dermatitis (AD)-like mouse model. PIW decreased IgE/Ag-induced mast cell degranulation and the phosphorylation of Syk and downstream signaling molecules such as PLC-γ, Akt, Erk 1/2, JNK compared to stimulated mast cells. In DNCB-induced AD-like mice, PIW reduced IgE level in serum, as well as AD-associated scratching behavior and skin severity score. These results indicate that PIW inhibits the allergic response by reducing mast cell activation and may have clinical potential as an antiallergic agent for disorders such as AD.     

Sex-related differences in SLIGRL-induced pruritus in mice

Aims

Pruritus is a common symptom of skin diseases, and is associated with impaired sleep quality and a considerable reduction in the patient's quality of life. Recently, it was reported that there are sex-specific differences in scratching behavior in chronic pruritus patients. Namely, female chronic pruritus patients scratch more and have significantly more scratch lesions than male patients. However, few animal studies have examined sex-related differences in scratching behavior. Thus, the present work investigated sex-related differences in animal pruritus using pruritogens, which are often used to create experimental animal models of itching.

Main methods

Acute pruritus was induced in ICR mice by a single intradermal injection of histamine, 4-methylhistamine, serotonin, compound 48/80, substance P (SP), or the proteinase-activated receptor-2 (PAR-2)-activating peptide SLIGRL-NH₂. Chronic pruritus was induced by 5 weeks of the repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) to BALB/c mice.

Key findings

Female mice showed significantly higher scratching counts in SLIGRL-NH₂-induced pruritus than male mice. Conversely, there was no obvious sex-related difference in scratching behavior for the other pruritogens examined.

Significance

These results indicate that sex-related differences may exist in the pruritogen-responsive neurons that transmit the itch signal induced by SLIGRL-NH₂, but not by histamine or 5-HT.     

Therapeutic effect of tyndallized Lactobacillus rhamnosus IDCC 3201 on atopic dermatitis mediated by down‐regulation of immunoglobulin E in NC/Nga mice

The therapeutic effect of oral administration of Lactobacillus rhamnosus IDCC 3201 tyndallizate (RHT3201) on atopic dermatitis (AD)‐like skin lesions in NC/Nga mice were investigated. After induction of dermatitis in NC/Nga mice with house‐dust mite extract, each group was fed RHT3201 with 1 × 10⁸, 1 × 10⁹, or 1 × 10¹⁰ cells orally once a day for 8 weeks. Dermatitis scores and frequency of scratching were improved by oral feeding with RHT3201. In contrast to the control group, RHT3201‐fed mice showed significantly down‐regulated mast cell numbers and serum immunoglobulin E (IgE) concentrations had significantly less IL4 in their axillary lymph node cells. The therapeutic effect of RHT3201 was found to be dose‐dependent. These findings indicate that RHT3201 has potential for treating AD.     

BuShenYiQi Granule Inhibits Atopic Dermatitis via Improving Central and Skin Hypothalamic -Pituitary -Adrenal Axis Function

BackgroundDysfunction of central and skin Hypothalamic-Pituitary-Adrenal (HPA) axis play important roles in pathogenesis of atopic dermatitis (AD). Our previous studies showed that several Chinese herbs could improve HPA axis function. In this study, we evaluated the anti-inflammatory effects of BuShenYiQi granule (BSYQ), a Chinese herbs formula, in AD mice and explored the effective mechanism from regulation of HPA axis.MethodsThe ovalbumin (OVA) induced AD mice model were established and treated with BSYQ. We evaluated dermatitis score and histology analysis of dorsal skin lesions, meanwhile, serum corticosterone (CORT), adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH) and inflammatory cytokines were determined by ELISA. The changes of CRH/proopiomelanocortin(POMC) axis elements, corresponding functional receptors and crucial genes of glucocorticosteroidogenesis in the skin were measured by quantitative real-time PCR and western blot, respectively.ResultsThe symptoms and pathological changes in skin of AD mice were significantly improved and several markers of inflammation and allergy descended obviously after BSYQ treatment. We found that AD mice had insufficient central HPA tone, but these conditions were markedly improved after BSYQ treatment. The AD mice also showed a disturbed expression of skin HPA. In lesion skin of AD mice, the mRNA and protein expressions of CRH decreased significantly, on the contrary, POMC and cytochrome P450 side-chain cleavage enzyme (CYP11A1) increased markedly, meanwhile, NR3C1 (mouse GR), CRHR2 and 11-hydroxylase type 1(CYP11B1) were reduced locally. Most of these tested indexes were improved after BSYQ treatment.ConclusionsAD mice displayed the differential expression pattern of central and skin HPA axis and BSYQ treatment significantly alleviated the symptoms of AD mice and presented anti-inflammatory and anti-allergic effects via regulating the expression of central and skin HPA axis.     

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.     

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.     

Development of atopic dermatitis-like skin lesions in STAT6-deficient NC/Nga mice

Atopic dermatitis (AD) is a pruritic inflammatory skin disease characterized by elevation of plasma levels of total IgE, infiltration of mast cells and eosinophils, and the expression of cytokines by Th2 T cells. However, the role of Th2 cells in the pathogenesis of AD is not fully understood. In this study we examined the NC/Nga (NC) mouse model of AD and established STAT6-deficient (SATA6(-/-)) NC mice to investigate the relevance of IL-4-mediated immune responses. Surprisingly, these mice elicited AD-like skin lesions at equivalent frequency and time of onset compared with normal NC littermates. Histological features of the lesion in STAT6(-/-) NC mice fulfilled the criteria for the pathogenesis of AD, although these mice fail to produce IgE and Th2 cytokines. The lymph nodes proximal to the regions of skin that developed lesions exhibited massive enlargement elicited by the accumulation of activated IFN-gamma-secreting T cells. Moreover, caspase I, IL-18, IL-12, and IFN-gamma are found to be highly expressed at the skin lesion, occurring simultaneously with elevation of eotaxin 2 and CCR3 expression. Therefore, the Th2-mediated immune response is not necessary for the development of AD-like skin disease in NC mice. The skin microenvironment that favored IFN-gamma production tightly correlates with the skin disease in NC mice through the infiltration of eosinophils.     

Filaggrin null mutations are associated with altered circulating Tregs in atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex pathogenesis. Although regulatory T cells (Tregs) have previously been studied in AD, their role remains controversial, likely owing to patient heterogeneity. Thus, we recruited adult AD patients and age‐matched healthy controls, and assessed their filaggrin (FLG) genotype, serum IgE level, and eczema area and severity index (EASI). We found increased proportions of all circulating Treg subpopulations in AD patients. Moreover, we show positive correlations between circulating Tregs and serum IgE FLG null mutations limited the expansion of both memory and effector Tregs and enhanced that of recently thymus‐emigrated Tregs. Furthermore, proportions of circulating Th2‐ or Th17‐Tregs but not Th1‐Tregs were increased in AD patients, and accentuated by FLG null mutations, thereby mimicking the immune deviation observed in Th cell populations. Moreover, ICOS⁺ Tregs showed reduced production of interleukin‐10, suggesting impaired immunosuppression in AD. The level of demethylation of FOXP3i1, which reflects the stability of FOXP3 expression, was similar in the blood and skin of AD patients and healthy controls. Overall, these results show that Tregs may participate into AD pathogenesis and that FLG null mutations exert further modifications on specific subpopulations of circulating Tregs.     

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.     

Suppression of skin lesions by transdermal application of CpG-oligodeoxynucleotides in NC/Nga mice, a model of human atopic dermatitis

Atopic dermatitis (AD) is a pruritic inflammatory skin disease characterized by an elevation of the total IgE level in plasma, the infiltration of mast cells and eosinophils, and the expression of cytokines by Th2 cells. NC/Nga mice kept in conventional conditions are known to develop skin lesions resembling human AD. We examined in this study the alterations of immune response in NC/Nga mice kept in conventional conditions, following transdermal application of CpG-oligodeoxynucleotides (ODN), which plays a critical role in immunity via the augmentation of Th1-type and suppression of Th2-type responses. CpG-ODN remarkably changed the immune response from type Th2 to Th1 as determined from cytokine mRNA and Ab levels. The serum IgE level was decreased and the expression of IgG2a was up-regulated. The application of CpG-ODN to the skin also decreased inflammatory infiltration of mast cells, and suppression in the skin lesions was observed. Furthermore, the generation of regulatory T cells, which are considered immune suppressive T cells, was observed in the skin on treatment with CpG-ODN. These results suggested CpG-ODN is effective for immunotherapy in patients with AD, which is characterized by Th2-dominated inflammation.     

Association of cathepsin E deficiency with development of atopic dermatitis

Atopic dermatitis (AD) is a pruritic inflammatory skin diseases associated with a family history of atropy. Here we show that mice lacking the endolysosomal aspartic proteinase cathepsin E spontaneously develop skin lesions similar to those of humans with AD when reared under conventional conditions but not under specific pathogen-free conditions. These mice showed the increase in the ratio of CD4+/CD8+ T cells, the strong polarization of na?ve T cells to T helper 2 cells, and the systemic accumulation of IL-18 and IL-1beta accompanied by a marked increase in IL-4, IL-5, and IgE. The relative rates of degradation of IL-18 and IL-1beta were significantly lower in cathepsin E-deficient mice than wild-type mice. These results strongly suggest that the development of AD in cathepsin E-deficient mice is initiated by systemic accumulation of IL-18 and IL-1beta, mainly due to their reduced turnover rates. In addition, the reduced expression of cathepsin E was also observed in erythrocytes of both humans with AD and the AD mouse model NC/Nga. Cathepsin E deficiency might thus be responsible for the induction of AD in humans and mice.