AD-like Skin Lesions In Mice Research Articles

The JAK/STAT/NF-κB signaling pathway can be regulated by rosemary essential oil, thereby providing a potential treatment for DNCB-induced in mice

ObjectiveThe purpose of this study was to investigate the mechanism through which rosemary essential oil treats atopic dermatitis. MethodsA dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model was established and treated with low (1%), medium (2%), and high (4%) doses of Rosmarinus officinalis essential oil (EORO). Serum levels of interleukin (IL)−6 and tumor necrosis factor-alpha (TNF-α) in each group were determined using enzyme-linked immunosorbent assay (ELISA). Skin tissues were stained with hematoxylin-eosin and toluidine blue. We used network pharmacology and molecular docking techniques to verify the biological activity of essential proteins and their corresponding compounds in the pathway. Gas chromatography-mass spectrometry (GC-MS) was used for metabolomics analysis and multivariate statistical analysis of mouse serum to screen differential metabolites and metabolic pathway analysis. Protein expression of p-JAK1, CD4+ cells, and IL-4 in the skin tissue was detected by immunohistochemistry analysis. Protein levels of STAT3, p-STAT3, P65, and p-P65 in damaged skin tissues were detected using western blotting. ResultThe skin of mice in the model group showed different degrees of erythema, dryness, scratches, epidermal erosion and shedding, and crusting. After treatment, the serum levels of IL-6 and TNF-α in EORO group were significantly decreased, and the expression of p-JAK1,CD4 + cells, IL-4, p-P65 / P65 and p-STAT3 / STAT3 proteins in skin tissues were decreased. ConclusionEORO can effectively improve DNCB-induced AD-like skin lesions in mice by regulating the JAK/STAT/NF-κB signaling pathway, thereby reducing the production of downstream arachidonic acid metabolites, inhibiting skin inflammation, and restoring epidermal barrier function.

Chelidonic acid ameliorates atopic dermatitis symptoms through suppression the inflammatory mediators in in vivo and in vitro

Chelidonic acid (CA), a γ-pyrone compound, exerts various pharmacological functions, including anti-allergic and anti-colitis activities. However, the anti-atopic effect of CA and the mechanisms involved therein are not completely understood. The aim of the present study was to elucidate whether CA modulates atopic dermatitis (AD) in vitro and in vivo. We examined the pharmacological effects of CA on compound 48/80- or histamine-induced scratching behaviors and 2, 4-dinitrochlrobenzene-induced AD-like skin lesions in mice. Additionally, we evaluated the regulatory effects of CA on the expression of tumor necrosis factor -α, interleukin-6, cyclooxygenase -2 and inducible nitric oxide synthase and activation of nuclear factor-kappa B (NF-κB) in vivo and in vitro. The results showed that CA inhibited the symptoms of AD such as itching, eczema, erythema and dryness, and decreased the serum levels of IgE and histamine in mice. The inhibition rates of IgE and histamine levels by CA (2 mg/kg) were approximately 36.21 ± 4.19% and 28.93 ± 6.16%, respectively. Moreover, CA significantly attenuated the expression of inflammatory-related genes and NF-κB activation in AD-like skin lesions and mouse peritoneal macrophages. The maximal inhibition rates of NF-κB activation by CA were approximately 42.05 ± 2.12% (in AD-like skin lesions) and 37.17 ± 6.12% (in LPS-stimulated peritoneal macrophages), respectively. These results suggest that CA may be a useful therapeutic agent for skin inflammatory condition such as AD.

Glycyrrhizic acid suppresses atopic dermatitis-like symptoms by regulating the immune balance.

Glycyrrhiza is one of the most widely used traditional Chinese medicines in China. Its main bioactive ingredient glycyrrhizic acid (GA) has the potential to be used as a treatment for atopic dermatitis (AD) because it has similar actions to steroids, but with relatively few side effects. The objective of this study was to explore the potential mechanisms of GA on AD mice model. Calcipotriol, a vitamin D3 analogue (MC903) was applied topically to establish AD mouse model. Mice were intraperitoneally administrated with 2mg/kg dexamethasone (DEX), 25 or 50 mg/kg GA for 15 days. After mice were executed, skin tissues were collected and detected the expression levels of IL-4, IFN-γ, TNF-α and thymic stromal lymphopoietin (TSLP). The percentages of Th1, Th2, Th17, langerhans cells (LCs) in draining lymph nodes (dLNs) were measured by flow cytometry. Our data demonstrated that GA improved the symptoms of AD by exerting anti-inflammatory and anti-allergic functions in vivo. We found that GA treatment decreased the level of total IgE in serum, suppressed ear swelling, reduced the infiltration of mast cells in skin lesions and decreased expressions of IL-4, IFN-γ, TNF-α and TSLP in skin lesions. Furthermore, our experimental results demonstrated that GA suppressed the Th1/Th2/Th17-immune responses in the dLNs, inhibited the migration of LCs in dLNs. In conclusion, our findings suggested potential therapeutic effects of GA against MC903-induced AD-like skin lesions in mice.

Stem Cells from Human Exfoliated Deciduous Teeth Attenuate Atopic Dermatitis Symptoms in Mice through Modulating Immune Balance and Skin Barrier Function.

Atopic dermatitis (AD) is a chronic skin inflammatory disease associated with immune abnormalities and disrupted skin barrier function. Mesenchymal stem cells (MSCs) have been suggested as an alternative therapeutic option in AD. Stem cells from human exfoliated deciduous teeth (SHEDs) are a unique postnatal stem cell population with high immunomodulatory properties. The aim of this study was to explore the effects of SHEDs on AD in the BALB/c mouse model induced by 2,4-dinitrochlorobenzene (DNCB). SHEDs were administrated intravenously or subcutaneously, and clinical severity, histopathological findings, skin barrier function, and organ indexes were evaluated. Skin tissue cytokine mRNA levels and serum cytokine protein levels were further analysed. SHED administration significantly alleviated AD clinical severity, including dermatitis scores, ear thickness, scratching behaviour, and infiltration of mast cells. In addition, disrupted skin barrier function and enlarged spleens were restored by SHED administration. Further, SHED treatment reduced the levels of IgE, IgG1, and thymic stromal lymphopoietin (TSLP) in the serum and the modulated expression of Th1-, Th2-, and Th17-associated cytokines in skin lesions. In conclusion, SHEDs attenuated AD-like skin lesions in mice by modulating the immune balance and skin barrier function. SHEDs could be a potential new treatment agent for AD.

Therapeutic effects of myricetin on atopic dermatitis in vivo and in vitro

BackgroundMyricetin (Myr) is a flavonoid compound that exist widely in many natural plants. Myr has been proven to have multiple biological functions, including immunomodulatory and anti-inflammatory effects. PurposeIn this study, we investigated the therapeutic effect of Myr on calcipotriol (MC903) induced atopic dermatitis (AD) mouse model and tumor necrosis factor (TNF)-α/interferon (IFN)-γ stimulated human immortal keratinocyte line (HaCaT) in vivo and in vitro. MethodsMC903 was applied topically to the left ears of mice to establish AD mouse model. After the AD model established successfully, the cream base, dexamethasone (DEX) cream or Myr cream were applied on the lesions of mice for 8 days. Through measuring ear thickness and scoring dermatitis severity, we evaluated the therapeutic effect of Myr, the draining lymph nodes (DLNs) and ears of the mice were collected for mechanistic study. In addition, TNF-α and IFN-γ-activated HaCaT cells were used to investigate the underlying mechanism. ResultsOur data demonstrated that Myr alleviated the symptoms of AD by exerting anti-inflammatory and anti-allergic functions in vivo. We found that Myr treatment suppressed ear swelling and IgE level in the serum, reduced the infiltration of mast cells in skin lesions, decreased expressions of thymus and activation regulated chemokine (TARC), IL-4, IFN-γ and thymic stromal lymphopoietin (TSLP) in ear lesions, increased the expressions of filaggrin (FLG). Furthermore, our experimental results demonstrated that Myr down-regulated the mRNA expressions of T-bet and GATA-3 in DLNs. In vitro, Myr treatment decreased MDC and TARC expressions in IFN-γ and TNF-α-induced HaCaT cells by blocking the NF-κB and STAT1 signal pathway. ConclusionThe present study is the first to investigate the anti-atopic effects of Myr. Our findings suggested the therapeutic effects of Myr against MC903-induced AD-like skin lesions in mice. Therefore, Myr may be a potential therapeutic agent for AD.

Efficacy and action mechanisms of a Chinese herbal formula on experimental models of atopic dermatitis

Ethnopharmacological relevanceAtopic dermatitis (AD) is a skin inflammatory disease characterized by erythema, eruption, lichenification and pruritus. Shi Zhen Formula (SZF), an empirical Chinese herbal preparation, has clinical efficacy in relieving the symptoms of AD patients. However, the underlying molecular mechanisms of SZF remained unclear. Aim of the studyWe aimed to investigate the anti-AD effects of SZF and elucidate its underlying molecular mechanisms using in vitro and in vivo models of AD. Materials and methodsHigh-performance liquid chromatography analysis was performed for quality control of SZF extract. The anti-inflammatory effect of SZF was investigated through evaluating the levels of nitric oxide (NO), chemokines and pro-inflammatory cytokines in the lipopolysaccharide (LPS) stimulated RAW264.7 cells. AD-like skin lesions in female BALB/c mice were induced by 2,4-dinitrochlorobenzene (DNCB). SZF (3.15, 6.30 and 9.45 g/kg) and dexamethasone (5 mg/kg) were administered by gavage daily for 15 consecutive days. The body weight, skin thickness, skin dermatitis severity and scratching behaviors were recorded throughout the study. Histological analysis, reverse transcription-quantitative polymerase chain reaction (RT-PCR), western blot (WB) and ELISA analysis were used to illuminate the molecular targets associated with the anti-AD effects of SZF. ResultsSZF markedly decreased the epidermal thickening and infiltration of mast cells in the ears and dorsal skin of the 2,4-dinitrochlorobenzene (DNCB)-treated mice. SZF not only suppressed the levels of immunoglobulin E (IgE), histamine, thymic stromal lymphopoietin (TSLP) and IL-4 in the serum but also suppressed the over-production of IL-4 and IL-6 and gene expressions of IL-4, IL-13, IL-31 and TSLP in the dorsal skin. Moreover, SZF improved epidermal barrier by increasing the protein expressions of filaggrin, involucrin and loricrin and inhibited the activation of NF-κB p65 pathway in the dorsal skin of the DNCB-treated mice. ConclusionSZF alleviates DNCB induced AD-like skin lesions in mice through regulating Th1/Th2 balance, improving epidermal barrier and inhibiting skin inflammation. Our research findings provide scientific footing on the use of this Chinese herbal formula for the treatment of AD.

Poly-γ-Glutamate microneedles as transdermal immunomodulators for ameliorating atopic dermatitis-like skin lesions in Nc/Nga mice

Atopic dermatitis (AD), a common, relapsing, inflammatory disorder of the skin, is associated with T helper type 2 (Th2)-biased immune responses. Despite the efficacy of existing drugs for AD treatment, their safety and side effects cause concern. The present study describes the use of dissolvable poly-γ-glutamate (γ-PGA) microneedles (MNs) with immunomodulatory effects for effectively relieving AD-like symptoms in Nc/Nga mice. γ-PGA MNs can easily penetrate the epidermis and release γ-PGA into the dendritic cell–rich dermis to interact with dendritic cells for modulating immune responses. Transdermal administration of high-molecular-weight (HMW, 1100 kDa) γ-PGA MNs significantly reduced clinical dermatitis scores, epidermal thickness, and mast cell infiltration in mice by downregulating immunoglobulin (Ig)E and IgG1 levels (Th2-associated antibodies) compared with the AD control group. However, low-molecular-weight (200–400 kDa) γ-PGA MNs ameliorated AD-like skin lesions less effectively than HMW γ-PGA MNs, thus indicating that the MW of γ-PGA may affect its immunomodulatory properties. Notably, the mouse skin quickly recovered its barrier function within 4 h after MN application. No weight loss or abnormality was observed in the MN-treated mice during the 8-week treatment period. These results suggest that the γ-PGA MNs represent an innovative, safe, and reliable therapeutic strategy for AD management. Statement of SignificanceThis study is the first to explore the feasibility of using poly-γ-glutamate (γ-PGA) microneedles (MNs) as transdermal immunomodulators for improving atopic dermatitis (AD) symptoms and to evaluate their immunomodulatory effect in mice with spontaneously developed AD. Transdermal administration of γ-PGA MNs enables the γ-PGA to localize in the skin for activation of dermal dendritic cells, thus modulating immune responses. We demonstrate that high-molecular-weight γ-PGA MNs can be retained in the skin for at least 6 days and effectively suppress AD-like skin lesions in mice by reducing infiltration of mast cells and downregulating Th2-associated antibody production (IgE and IgG1). The developed MN device has the potential to replace conventional therapy and to become an innovative treatment strategy for AD.

Conjugated linoleic acid attenuates 2,4-dinitrofluorobenzene-induced atopic dermatitis in mice through dual inhibition of COX-2/5-LOX and TLR4/NF-κB signaling

Conjugated linoleic acid (CLA), commonly found in beef, lamb and dairy products, has been reported to exhibit anti-inflammatory and antipruritus effects and to inhibit the release of chemical mediators such as histamine and eicosanoid in laboratory rodents. The chief objective of the study is to assess the efficacy of CLA on atopic dermatitis (AD) in mice and to explore possible mechanisms with CLA treatments. To develop a new therapy for AD, the anti-AD potential of CLA was investigated by inducing AD-like skin lesions in mice using 2,4-dinitrofluorobenzene. We evaluated dermatitis severity; histopathological changes; serum levels of T helper (Th) cytokines (interferon-γ, interleukin-4); changes in protein expression by western blotting and immunohistochemistry staining for cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), toll like receptor 4 (TLR-4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB) and tumor necrosis factor α (TNF-α); and production of the proinflammatory lipid mediators, such as prostaglandin E2 and leukotriene B4, in the skin lesions. Treatment with CLA ameliorated the development of AD-like clinical symptoms and effectively inhibited epidermal hyperplasia and infiltration of mast cells and CD4+ T cells in the AD mouse skin. Total serum immunoglobulin E levels and the expression levels of Th1/Th2 cytokines and lipid mediators in dorsal skin were dramatically suppressed by CLA. Furthermore, CLA down-regulated the expressions of COX-2, 5-LOX, TLR4, MyD88, NF-κB and TNF-α. Taken together, our findings demonstrate the potential usefulness of CLA as an anti-inflammatory dietary supplement or drug for the prevention and management of AD skin diseases by modulating the COX-2/5-LOX and TLR4/MyD88/NF-κB signaling pathways.

Role of mast cells in Staphylococcus aureus enterotoxin Binduced atopic dermatitis-like skin inflammation in mice

Objective To investigate the role of mast cells in Staphylococcus aureus enterotoxin B (SEB) -induced atopic dermatitis (AD) -like skin inflammation in BALB/c mice. Methods A total of 24 BALB/c mice were randomly and equally divided into 4 groups to be topically treated with ovalbumin (OVA group) , SEB (SEB group) , OVA+ SEB (OVA+ SEB group) and sodium chloride physiological solution (control group) respectively, so as to establish mouse models of epicutaneously induced AD-like skin inflammation. The AD-like skin lesions were evaluated by clinical observation and eczema area and severity index (EASI) . Biopsy specimens were obtained from lesional skin of mice and then subjected to toluidine blue staining and immunohistochemical staining to count the mast cells, observe the morphology and distribution of mast cells, and calculate the percentage of degranulated mast cells. Results After 7-week treatment, the OVA group, SEB group and OVA+ SEB group all showed severer local skin inflammation, higher EASI scores and denser infiltration of inflammatory cells compared with the control group. Moreover, the OVA+ SEB group showed significantly severer local skin inflammation, skin lesions and degree of infiltration of inflammatory cells compared with the OVA group and SEB group (all P < 0.05) . The number of mast cells in the dermis of AD-like skin lesions per high-power field (× 400) was significantly higher in the OVA group (median[quartile range]: 10.625[3.675]) , SEB group (11.000[4.163]) and OVA+ SEB group (13.875[8.813]) than that in the control group (5.925[2.088], all P < 0.05) . The SEB group (71.083% ± 14.519%) and OVA+ SEB group (58.767% ± 16.978%) both showed significantly higher percentage of degranulated mast cells compared with the OVA group (24.050% ± 11.161%, both P < 0.05) and control group (23.617% ± 8.132%, both P < 0.05) . Bivariate correlation analysis showed that the number of mast cells in the skin lesions was positively linearly correlated with the EASI scores (P < 0.05) . Conclusions Epicutaneous application of SEB can induce AD-like skin lesions in mice, and can exacerbate the severity of OVA-induced AD-like skin lesions. Mast cell proliferation, activation/degranulation and tryptase release may participate in the inflammation. Key words: Dermatitis, atopic; Mast cells; Staphylococcus aureus; Enterotoxins; Tryptases; Ovalbumin

Oral administration of freeze-dried powders of honey bee larvae inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice

Abstract Purpose This study was designed to evaluate the suppressive effect of the oral administration of the freeze-dried honey bee larvae powder on atopic dermatitis (AD)-like skin lesions in NC/Nga mice. Methods The effects of freeze-dried honey bee larvae powder on AD-like skin lesions in mice were studied by evaluating the condition of the skin macroscopically and histopathologically, ear swelling degree, serum levels of total IgE, interleukin-4 (IL-4) and interferon-γ (IFN-γ), and level of IL-18 and IL-12 in skin lesions. Results NC/Nga mice fed the freeze-dried honey bee larvae powder-supplemented diet showed a decrease in dermatitis scores of the dorsal skin, ear thickness, skin hypertrophy, inflammatory cell infiltration in the skin, serum total IgE, IL-4, and IFN-γ levels, and IL-18 and IL-12 levels in skin lesions. These results suggest that the freeze-dried powder of honey bee larvae inhibits the development of AD-like skin lesions in NC/Nga mice by suppressing both T-helper (Th) 1 and Th 2 cell responses. Conclusions Our results indicate that oral administration of the freeze-dried honey bee larvae powder could provide an adjunctive therapy for the management of AD.

The Hot-Water Extract of Smilacis Chinae Rhizome Suppresses 2,4-Dinitrochlorobenzene and House Dust Mite-Induced Atopic Dermatitis-Like Skin Lesions in Mice.

Smilacis Chinae Rhizome (SCR) has been used as an oriental folk medicine for various biological activities. However, its effect on atopic dermatitis (AD) remains undetermined to date. We assessed the effect of orally administered hot-water extract of SCR on AD-like skin lesions in mice and its underlying mechanisms. AD-like murine model was prepared by repeated alternate application of house dust mite (Dermatophagoides farinae) extract (DFE) and 2,4-dinitrochlorobenzene (DNCB) for 4 weeks, topically to the ears. Daily oral administration of SCR for 3 and 4 weeks significantly reduced inflammatory ear thickening, with the effect being enhanced at the earlier start and longer period of administration. This effect was accompanied by a significant decrease in both Th2 and Th1 serum antibodies (total IgE, DFE-specific IgE, and IgG2a). Histological analysis showed that SCR markedly decreased the epidermal/dermal ear thickening and the dermal infiltration of inflammatory cells. Furthermore, SCR suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-17, IL-18, TSLP, and IFN-γ genes in the ear tissue. Taken together, our observations demonstrate that chronic oral administration of SCR exerts beneficial effect in mouse AD model, suggesting that SCR has the therapeutic potential as an orally active treatment of AD by modulating both Th1 and Th2 responses.

Danggui buxue tang inhibits 2,4-dinitrochlorobenzene: induced atopic dermatitis in mice.

Danggui Buxue Tang (DBT) is a herbal decoction that has been used in Chinese medicine to enhance qi and blood circulation. Previously, we found that DBT can suppress allergy-related asthma in mice, leading us to hypothesize that DBT might ameliorate allergy disease. In this study, we evaluated whether DBT can attenuate atopic dermatitis (AD) symptoms and have an anti-inflammatory effect on AD-like mice. The dorsal skin of female mice was shaved and sensitized cutaneously (skin smear) with 1-chloro-2,4-dinitrobenzene. Mice were then given various doses of DBT from days 14 to 29 cutaneously. DBT treatment suppressed ear swelling and skin inflammation and decreased mast cell and eosinophil infiltration into skin and ear tissue. DBT also inhibited levels of IgE and Th2-associated cytokine levels in serum. These results demonstrate that cutaneous administration of DBT reduced the development of AD-like skin lesions in mice.

Loss of sirtuin 1 (SIRT1) disrupts skin barrier integrity and sensitizes mice to epicutaneous allergen challenge

Skin barrier integrity requires a highly coordinated molecular system involving the structural protein filaggrin (FLG). Mutational loss of the skin barrier protein FLG predisposes subjects to the development of atopic dermatitis (AD). We sought to determine the role of sirtuin 1 (SIRT1) in skin barrier function, FLG expression, and development of AD. Skin histology of mice with skin-specific SIRT1 deletion and wild-type control animals was examined by using hematoxylin and eosin staining. Protein and mRNA abundance was analyzed by means of immunoblotting, immunohistochemistry, immunofluorescence, and RT-PCR. Serum antibody levels were assessed by means of ELISA. Here we show that FLG is regulated by the protein deacetylase SIRT1 and that SIRT1 is critical for skin barrier integrity. Epidermis-specific SIRT1 ablation causes AD-like skin lesions in mice, and mice with epidermal SIRT1 deletion are sensitive to percutaneous challenge by the protein allergen ovalbumin. In normal human keratinocytes and mouse skin SIRT1 knockdown or genetic deletion downregulates FLG, and regulation of FLG expression by SIRT1 requires the deacetylase activity of SIRT1. SIRT1 also promotes activation of the aryl hydrocarbon receptor, and the aryl hydrocarbon receptor ligand restores FLG expression in SIRT1-inhibited cells. Compared with normal human skin, SIRT1 is downregulated in both AD and non-AD lesions. Our findings demonstrate a critical role of SIRT1 in skin barrier maintenance, open up new opportunities to use SIRT1 as a pharmacologic target, and might facilitate the development of mechanism-based agents for AD prevention and therapy.

Effects of Single and Combined Administration of Fermented Barley Extract and γ-Aminobutyric Acid on the Development of Atopic Dermatitis in NC/Nga Mice

We examined the effects single and combined administration of fermented barley extract P (FBEP), prepared from barley-shochu distillery by-products, and gamma-aminobutyric acid (GABA) on the development of atopic dermatitis (AD)-like skin lesions in NC/Nga mice. Single administration of FBEP and GABA dose-dependently reduced the development of AD-like skin lesions in mice. GABA reduced the development of AD-like skin lesions by suppressing serum immunoglobulin E (IgE) and splenocyte interleukin (IL)-4 production, while FBEP reduced skin lesions without affecting the IgE or cytokine production. However, in mice with induced AD-like skin lesions, combined administration of FBEP and GABA decreased serum IgE levels and splenic cell IL-4 production, and increased splenic cell interferon-gamma production. These results suggest that combined administration of FBEP and GABA alleviated AD-like skin lesions in the NC/Nga mice by adjusting the Th1/Th2 balance to a Th1-predominant immune response.