Pseudoephedrine alleviates atopic dermatitis-like inflammatory responses in vivo and in vitro

Selected traditional Chinese herbal medicines for the treatment of atopic dermatitis - research progress on the effect and mechanism of actions

Atopic dermatitis (AD) is a common chronic, recurrent, inflammatory skin disease characterized by pruritus, lichen-like changes and dry skin. Due to the complex pathogenesis of AD, its mechanism is primarily associated with genetic, skin barrier dysfunction, environmental, and immune factors. AD has been routinely treated with glucocorticoids, antihistamines, local immunomodulators, biological agents, and small molecules; however, the side effects are significant, and the treatment efficacy is limited. In recent years, traditional Chinese medicine (TCM) has gradually been widely used in the treatment of AD. Many studies have shown that TCM mainly regulates inflammatory cytokines, gut microbiota and the immune system. Therefore, it plays a crucial role in the treatment of AD. The treatment of atopic dermatitis using TCM is characterized by targeting multiple pathways and multiple targets, and it demonstrates significant therapeutic effects. This paper reviews the pathogenesis of AD and reports the efficacy of TCM on AD (including TCM prescription, single TCM, treatment of TCM metabolites), which provides a theoretical basis for TCM treatment of AD. TCM has certain therapeutic effects on AD. It can alleviate and treat AD in various ways. We should base our differentiation on syndrome differentiation and treatment differentiation. With the help of modern medicine, the clinical efficacy of TCM in treating AD can be improved.

In-silico exploring pathway and mechanism-based therapeutics for allergic rhinitis: Network pharmacology, molecular docking, ADMET, quantum chemistry and machine learning based QSAR approaches

Allergic rhinitis is a devastating health complication that interrupts the quality of daily life and significantly affects around 40 % of the population worldwide. Despite the availability of various treatment options, many patients continue to struggle with persistent symptoms and side effects, highlighting the need for innovative therapeutic approaches. Therefore, identifying pathway and mechanism-based targeted therapies with more effective and fewer side effects could aid current therapeutics and provide novel therapeutic advantages. This study aimed to identify potential drug candidates for allergic rhinitis treatment by employing in-silico approaches, including network pharmacology, molecular docking, ADMET, similarity, pharmacophore modeling, quantum chemistry, and machine learning-based QSAR modeling. From three traditionally used medicinal plants known as allergic rhinitis curing, Xanthium strumarium, Magnolia liliiflora, and Tylophora indica, 241 compounds were obtained, and their favorable ADMET properties were analyzed. Network pharmacology revealed 203 potential therapeutic targets, with 15 hub targets identified through protein-protein interaction network analysis and most of them play key roles in inflammatory and immune pathways confirmed by KEGG pathway analysis. Molecular docking, similarity testing, and pharmacophore modeling studies identified promising compounds Quercetin, Yinyanghuo E, Uralenin, CID:90643991, CID:42607537, CID:76329670, Heracetin, and Fisetin exhibiting strong binding affinities with key regulatory targets, NFKB1, TRAF6, and key cytokines IL5, and IL6 that directly and indirectly involved in allergic reactions. Quantum chemistry calculations revealed favorable electronic properties and reactivities of these compounds. The machine learning-based QSAR model predicted IC50 < 50 nM for almost all compounds, indicating highly potent inhibitors. Hence, this in-silico study identified some novel promising drug candidates for treating allergic rhinitis by targeting crucial inflammatory and immune pathways, offering improved treatment outcomes and reduced side effects, subject to further experimental validation.

Chinese Herbal Medicine and Their Active Ingredients Involved in the Treatment of Atopic Dermatitis Related Signaling Pathways

Atopic dermatitis (AD) is a common inflammatory dermatitis of the skin and poses therapeutic challenges due to the adverse reactions and high costs associated with available treatments. In Eastern Asian countries, a plethora of herbal remedies is extensively employed for the alleviation of AD. Many of these botanicals are renowned for their formidable anti-inflammatory properties, contributing to AD management. Chinese herbal medicine (CHM) and its active ingredients exhibit both prophylactic and therapeutic promise against AD by modulating inflammatory response, orchestrating immune system functions, and enhancing antioxidant activities. A comprehensive exploration of the underlying mechanisms involved in CHM treatment can enhance the comprehension of AD pathogenesis and facilitate the development of innovative drugs for AD. This study aims to elucidate the signaling pathways and potential targets implicated in CHM-based treatment of AD, providing a systematic theoretical framework for its application in therapy while serving as a valuable reference for developing more effective and safer AD therapeutic agents.

Transdermal delivery of natural products against atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin condition. Natural products have gained traction in AD treatment due to their accessibility, low toxicity, and favorable pharmacological properties. However, their application is primarily constrained by poor solubility, instability, and limited permeability. The transdermal drug delivery system (TDDS) offers potential solutions for transdermal delivery, enhanced penetration, improved efficacy, and reduced toxicity of natural drugs, aligning with the requirements of modern AD treatment. This review examines the application of hydrogels, microneedles (MNs), liposomes, nanoemulsions, and other TDDS-carrying natural products in AD treatment, with a primary focus on their effects on penetration and accumulation in the skin. The aim is to provide valuable insights into the treatment of AD and other dermatological conditions.

Crisaborole combined with vitamin D demonstrates superior therapeutic efficacy over either monotherapy in mice with allergic contact dermatitis

This study evaluated the therapeutic efficacy and underlying mechanisms of crisaborole combined with vitamin D in the treatment of allergic contact dermatitis. While crisaborole, a phosphodiesterase 4 inhibitor, and vitamin D analogs are commonly used in the treatment of atopic dermatitis, their combined therapeutic potential in allergic contact dermatitis (ACD) remains unexplored. Given their anti-inflammatory properties, we hypothesized that the combination of crisaborole and vitamin D could offer superior efficacy in mitigating the symptoms and underlying mechanisms of allergic contact dermatitis. In vitro, HaCaT cells stimulated with tumor necrosis factor-α and interferon-γ were treated with a combination of crisaborole and vitamin D, followed by cytokine expression analysis. In vivo, male C57BL/6 mice were divided into five groups and treated accordingly: blank control, dinitrochlorobenzene-induced model, crisaborole alone, vitamin D alone, and a combination of crisaborole and vitamin D. On day 14, dorsal skin and ear thickness were measured, followed by comprehensive pathological evaluations. In vivo and in vitro experiments showed that the expression levels of inflammatory factors were significantly lower in the DNCB + VD + Cri group than in the DNCB group. Histological analyses revealed that, compared with the DNCB group, the combined treatment group significantly reduced epidermal hyperkeratosis, improved epidermal transdermal water loss, decreased dermatitis scores, and diminished mast cell infiltration. Moreover, it lowered the expression levels of IL-6, IL-4, TNF-α, iNOS, IL-17, CC chemokine ligand 2 (CCL2), and CC chemokine receptor 2 (CCR2). CCL2 recognizes CCR2 and stimulates inflammatory cells, enhancing the inflammatory response. Increased CCL2 expression correlates with heightened inflammation and dendritic cell infiltration in ACD, while downregulation of CCL2 attenuates inflammation. Thus, the combined use of crisaborole and vitamin D demonstrates superior therapeutic efficacy over monotherapy in a mouse model of ACD. The combination of vitamin D and crisaborole significantly reduces inflammation and epidermal hyperkeratosis in a mouse model of allergic contact dermatitis, demonstrating superior therapeutic efficacy compared to either treatment alone. This suggests that the combined therapy could be a promising approach for the prevention and treatment of allergic contact dermatitis.

Small-molecule agents for treating skin diseases

Skin diseases are a class of common and frequently occurring diseases that significantly impact daily lives. Currently, the limited effective therapeutic drugs are far from meeting the clinical needs; most drugs typically only provide symptomatic relief rather than a cure. Developing small-molecule drugs with improved efficacy holds paramount importance for treating skin diseases. This review aimed to systematically introduce the pathogenesis of common skin diseases in daily life, list related drugs applied in the clinic, and summarize the clinical research status of candidate drugs and the latest research progress of candidate compounds in the drug discovery stage. Also, it statistically analyzed the number of publications and global attention trends for the involved skin diseases. This review might provide practical information for researchers engaged in dermatological drugs and further increase research attention to this disease area.

NLRP3 neuroinflammatory intervention of Mahuang-Lianqiao-Chixiaodou decoction for mental disorders in atopic dermatitis mice

ETHNOPHARMACOLOGICAL RELEVANCE

Mahuang-Lianqiao-Chixiaodou decoction (MLCD) is a traditional Chinese medicinal (TCM) formula recorded in the Treatise on Febrile Diseases. It is commonly used for clinical treatment of atopic dermatitis (AD). However, the potential mechanisms of MLCD intervention in AD combined with mental disorders behaviors such as anxiety and depression remain elusive and deserves further investigation.

AIM OF THE STUDY

The study aims to observe the effect of MLCD on anxiety- and depression-like behaviors in AD mice and explore the possible neuroinflammatory mechanism of NOD-like receptor 3 (NLRP3) inflammasome.

MATERIALS AND METHODS

The chemical components of MLCD extracts were identified using UHPLC-MS. The AD mice were induced by 2,4-dinitrofluorobenzene and treated with MLCD or mometasone furoate (MF, as a positive control) for 7 days. The pathological changes in their skin tissue and brain hippocampus were observed by hematoxylin-eosin staining. Elevated plus-maze test (EPM), open field test (OFT), and the suspended tail (TST) were used to measure the anxiety- and depressive-like behaviors in AD mice. Expression of NLRP3 inflammasome-related proteins in brain hippocampus were measured by the quantitative real-time polymerase chain reaction (qPCR) and western blotting (WB).

RESULTS

We found that MLCD contain many active ingredients, including ephedrine, Forsythoside A, phillyrin, glycyrrhizic acid, etc. Both MLCD and MF alleviated skin lesions and promoted positive histopathological changes in the hippocampus of AD mince to varying degrees. MLCD however, could further increase their proportion of open arm entry times (Oentries%) in EPM, residence time in the central area (Ctime) and the proportion of the number of times in the central area (Centries%) in OFT significantly. MLCD also reduces their immobility time in TST considerably. Mechanistically, MLCD downregulated the relative mRNA expression and protein level of NLRP3, Caspase-1, IL-1β, and IL-18 in hippocampal tissue compared to the model group.

CONCLUSIONS

MLCD can alleviate anxiety-like and depression-like behaviors in AD mice by intervening in the gene and protein expression of NLRP3 inflammasome-related factors, thus treating AD.

Comprehensive Review on Phytoconstituents-based Nanomedicine for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is known as a chronic disease characterized by eczematous and pruritus skin lesions. The pathology behind atopic dermatitis etiology is loss of epidermal barrier, which prevents the production of protein filaggrin that can induce T-cell infiltration and inflammation. Treatment of AD is majorly based on limiting skin repair as well as reducing inflammation and itching. There are several remedies available for the treatment of AD, such as Janus kinase and calcineurin inhibitors, topical corticosteroids, and phosphodiesterase-4 inhibitors. The conventional formulations in the market have limited safety and efficacy. Hence, effective treatment of atopic dermatitis requires the development of novel, efficacious, reliable, and specific therapies. Recent research data have revealed that some naturally occurring medicinal plants have potential applications in the management of AD through different mechanisms. The nanotechnology-based therapeutics have gained a lot of attention in the last decade for the improvement in the activity of drugs having low absorption due to poor solubility, thus leading to lesser bioavailability. Therapies based on nanotechnology can be an effective way to overcome these obstacles. Due to their effective propensity to provide better drug diffusion and bioavailability as well as drug targeting potential at the desired site of action, these approaches may have decreased adverse drug effects, better penetration, and enhanced therapeutic efficacy. Hence, this review highlights the potential of phytoconstituents-based novel formulations for the treatment of atopic dermatitis. Furthermore, recent patents on therapeutic approaches to atopic dermatitis have also been briefly described.

Ursolic acid ameliorates DNCB-induced atopic dermatitis-like symptoms in mice by regulating TLR4/NF-κB and Nrf2/HO-1 signaling pathways

BACKGROUND

Ursolic acid (UA) is a triterpenoid compound found in natural plants. It has been reported to have anti-inflammatory, antioxidant, and immunomodulatory properties. However, its role in atopic dermatitis (AD) is unknown. This study aimed to evaluate the therapeutic effect of UA in AD mice and explore the underlying mechanisms.

METHODS

Balb/c mice were treated with 2, 4-dinitrochlorobenzene (DNCB) to induce AD-like lesions. During modeling and medication administration, dermatitis scores and ear thickness were measured. Subsequently, histopathological changes, levels of T helper cytokines, and oxidative stress markers levels were evaluated. Immunohistochemistry staining was used to assess changes in the expression of the nuclear factor of kappa B (NF-κB) and NF erythroid 2-related factor 2 (Nrf2). Furthermore, CCK8 assay, reactive oxygen species (ROS) assay, real-time PCR, and western blotting were employed to evaluate the effects of UA on ROS levels, inflammatory mediator production, and the NF-κB and Nrf2 pathways in TNF-α/IFN-γ-stimulated HaCaT cells.

RESULTS

The results showed that UA significantly reduced dermatitis score and ear thickness, effectively inhibited skin proliferation and mast cell infiltration in AD mice, and decreased the expression level of T helper cytokines. Meanwhile, UA improved oxidative stress in AD mice by regulating lipid peroxidation and increasing the activity of antioxidant enzymes. In addition, UA inhibited ROS accumulation and chemokine secretion in TNF-α/IFN-γ-stimulated HaCaT cells. It might exert anti-dermatitis effects by inhibiting the TLR4/NF-κB pathway and activating the Nrf2/HO-1 pathway.

CONCLUSION

Taken together, our results suggest that UA may have potential therapeutic effects on AD and could be further studied as a promising drug for AD treatment.

In vitro and in vivo exploration of the anti-atopic dermatitis mechanism of action of Tibetan medicine Qi-Sai-Er-Sang-Dang-Song decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Tibetan medicine Qi-Sai-Er-Sang-Dang-Song Decoction(QSD, ཆུ་སེར་སེང་ལྡེང་སུམ་ཐང་།)is a traditional Tibetan medical formulation with demonstrated clinical benefits in atopic dermatitis (AD). However, its potential mechanism and molecular targets remain to be elucidated.

AIM OF THE STUDY

This study aims to explore the activity and mechanism of QSD on AD in multiple dimensions by combining in vitro and in vivo experiments with network pharmacology.

MATERIALS AND METHODS

The AD effect of QSD was investigated by evaluating the levels of nitric oxide (NO) and interleukin-6 (IL-6) in the lipopolysaccharide (LPS) stimulated RAW264.7 cells. AD-like skin lesions in female BALB/c mice were induced by 2,4-dinitrochlorobenzene (DNCB). QSD or dexamethasone (positive control) were gavagely administered daily for 15 consecutive days. The body weight and skin lesion severity were recorded throughout the study. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analysis were used to illuminate the molecular targets associated with the anti-AD effects of QSD. Meanwhile, the ingredients of QSD in the blood were revealed and analyzed by Ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method. Network pharmacology was used to predict the targets and mechanism of active ingredient therapy for AD. In addition, the network pharmacology outcomes were further verified by molecular docking.

RESULT

After treatment with QSD, the levels of NO and IL-6 were decreased in the cell supernatant. Herein, QSD markedly decreased the eosinophil and mast cells infiltration in the dorsal skin of the 2,4-dinitrochlorobenzene. Moreover, QSD reconstructed the epidermal barrier by increasing the content of collagen fibers and changing the arrangement of DNCB-treated mice. QSD not only inhibited the levels of tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12) but also inhibited phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) proteins in the dorsal skin. Four active ingredients were identified through UPLC-Q-TOF/MS, including (-)-epicatechin, kaempferol-7-O-glucoside, cassiaside, and questin. After the network pharmacological analysis, six core targets of QSD closely related to AD were obtained, including TNF-α, IL-6, Caspase-3 (CASP3), Epidermal growth factor (EGFR), Peroxisome proliferator-activated receptor gamma (PPARG), and Neurotrophic Receptor Tyrosine Kinase 1 (NTRK1). Meanwhile, through Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, the Mitogen-activated protein kinase (MAPK) signaling pathway occupies an important position in the QSD treatment of AD. The molecular docking results showed that the six core targets are stable in binding to the four active ingredients as indicated by the molecular docking results.

CONCLUSIONS

The anti-AD effect of QSD might be related to the reconstruction of the epidermal barrier and inhibition of inflammation, which regulated the MAPK pathway. Hence, it provided a promising idea for the study of Tibetan medicine prescriptions for the treatment of AD.

Ablation of Basic Leucine Zipper Transcription Factor ATF-Like Potentiates Estradiol to Induce Atopic Dermatitis

Background

Atopic dermatitis (AD) is an inflammatory and immune skin disorder. Basic leucine zipper transcription factor ATF-like (BATF) plays a key role in regulating the differentiation and functions of lymphocytes. However, the mechanism underlying the transcriptional regulation of BATF on AD is still not well understood.

Methods

BATF knockout (BATF-/-) and C57BL/6(B6) mice were used for the development of spontaneous dermatitis. 17β-Estradiol was injected intraperitoneally to induce AD. The lesioned tail skin of the mice was stained with hematoxylin and eosin to analyze the pathological characteristics. Impaired skin barrier function was assessed by measuring the transepidermal water loss (TEWL). The skin epithelial barrier indicators and cytokine mRNA levels were quantified by real-time quantitative PCR. The total serum immunoglobulin E (IgE) levels were measured by enzyme-linked immunosorbent assay (ELISA). T lymphocytes were analyzed using flow cytometry.

Results

Ablation of BATF led to the spontaneous development of AD only in female mice and not in male mice. BATF deletion led to elevated serum levels of IgE and increased infiltration of eosinophils, neutrophils, and lymphocytes and promoted cytokine production including IL-4, IL-22, IL-1β, IFN-γ, and TNF-α in the lesioned tail skin of the mice. The mRNA expression levels of filaggrin and loricrin significantly decreased, while S100A8 and S100A9 increased in female BATF-/- mice. BATF-deficient female mice were found to increase proliferation and IL-5 production by skin-infiltrating CD4+ T cells which implies Th2 activation. Moreover, AD was successfully induced only in the estradiol-treated BATF-deficient male mice and not in WT male mice. Estradiol enhanced the allergic and immunological responses to dermatitis primarily by triggering Th2-type immune responses via enhanced serum IgE and inflammatory cytokine levels in the male BATF-/- mice.

Conclusion

The study concluded that BATF potentiates estradiol to induce mouse atopic dermatitis via potentiating inflammatory cytokine releases and Th2-type immune responses and may have important clinical implications for patients with AD.

Jiu-Wei-Yong-An Formula suppresses JAK1/STAT3 and MAPK signaling alleviates atopic dermatitis-like skin lesions

ETHNOPHARMACOLOGICAL RELEVANCE

Jiu-Wei-Yong-An (JWYA) formula is a traditional Chinese medicine (TCM) prescription used to treat atopic dermatitis (AD) in the clinic. JWYA is considered to have anti-inflammatory and antipruritic properties. However, the mechanism of JWYA remains unclear.

AIM OF THE STUDY

This study aimed to investigate the effect of JWYA on an experimental mouse AD model.

MATERIALS AND METHODS

Mice were sensitized with 2,4-dinitrochlorobenzene (DNCB) and intragastrically administered with JWYA for 14 days. The therapeutic effect was assessed using a grade four dermatitis score, skin moisture, thickness measurements, and a mouse behavior tests. H&E and toluidine blue staining were used to observe epidermal inflammatory thickening and mast cells in mouse skin lesions. Serum IgE levels and skin TNF-α and IL-4 levels were determined using ELISAs. The TNF-α, IL-1β, IL-4, IL-13, IL-31, IL-33, and IFN-γ mRNA expression levels in skin lesions were detected using qPCR. Network pharmacology analysis based on serum active components was performed to elucidate the mechanism, and the results were verified by Western blotting. Finally, we tested the binding affinity between the active ingredients of JWYA and JAK1 via molecular docking.

RESULTS

JWYA improved the skin lesions of AD mice, relieved itching and reduced skin thickening. Additionally, JWYA decreased the serum IgE level and the levels of TNF-α, IL-1β, IL-4, IL-13, IL-31, IL-33, and IFN-γ in skin. Moreover, JWYA inhibited the activation of JAK1/STAT3 and MAPK (p38, ERK, and JNK) signaling. Molecular docking showed that kaempferol, luteolin, and forsythin have high affinity for JAK1.

CONCLUSIONS

JWYA alleviates AD-like skin lesions and inhibited inflammation and skin itch. The effect of JWYA is attributed to blocking the JAK1/STAT3 and MAPK signaling pathways. We suggest that JWYA may be an alternative therapy for the treatment of AD.

Angelica Yinzi alleviates 1-chloro-2,4-dinitrobenzene-induced atopic dermatitis by inhibiting activation of NLRP3 inflammasome and down-regulating the MAPKs/NF-kB signaling pathway

Background

Atopic dermatitis (AD), characterized by eczema as a chronic pruritic inflammatory skin disease, has become a serious health problem with recurrent clinical episodes. However, current clinical treatments have limited relief and are accompanied by adverse effects. Therefore, there is a necessity to develop new effective drugs for AD treatment. Angelica Yinzi (AYZ) is a classic ancient prescription for nourishing blood, moistening dryness, dispelling wind, and relieving itching. However, its mechanism for alleviating atopic dermatitis remains unknown. Therefore, this study aimed at determining the effects of AYZ and its potential mechanism in alleviating AD-like symptoms.

Methods

In the present study, we used 1-chloro-2,4-dinitrobenzene (DNCB) to establish a mouse model of atopic dermatitis, where DNCB readily penetrates the epidermis to cause inflammation. Histopathological analysis was performed to examine the thickening of dorsal skin and infiltration in the inflammatory and mast cells in C57BL/6 mice. Additionally, the immunoglobulin E (IgE) levels in serum were determined by enzyme-linked immunosorbent assay (ELISA) kits. The IL-1β and TNF-α expression were detected using qRT-PCR. Next, the Western blotting and immunohistochemistry assays were performed to assess the contribution of MAPKs/NF-κB signaling pathways and the NLRP3 inflammasome in AD responses.

Results

Histopathological examination revealed that AYZ reduced the epidermal thickness of AD-like lesioned skin and repressed the infiltration of mast cells into AD-like lesioned skin. AYZ significantly decreased the phosphorylation of p38 MAPK, JNK, ERK and NF-κB and downregulated serum IgE levels and IL-1β and TNF-α mRNA levels. Additionally, the NLRP3, ASC, Caspase-1, and IL-1β expression in dorsal skin were effectively down-regulated following AYZ treatment (p < 0.05 and p < 0.01).

Conclusion

These findings revealed that AYZ effectively suppressed AD-induced skin inflammation by inhibiting the activation of the NLRP3 inflammasome and the MAPKs/NF-kB signaling. Therefore, AYZ is a potential therapeutic agent against AD in the clinical setting.

Different molecular weight hyaluronic acid alleviates inflammation response in DNFB-induced mice atopic dermatitis and LPS-induced RAW 264.7 cells

AIMS

Atopic dermatitis (AD) is an inflammatory chronic disease which severely interferes the life of patients. Hence, there is a great need for new therapies. Hyaluronic acid (HA) is an effective potential inflammation modifier; however, there is limited information about their implementation in inflammation therapies. This study aimed to evaluate the anti-inflammatory activities of HA and the influence of its molecular weight.

MAIN METHODS

Male C57BL/6 J mice were stimulated by 2,4-dinitrofluorobenzene to induce AD-like symptoms and immune response. The skin lesions and histopathological change, as well as levels of inflammatory factors were evaluated. RAW 264.7 mouse macrophages were treated with lipopolysaccharides (LPS) to induce inflammation. NO, IL-6, and TNF-α levels were detected through ELISA kits.

KEY FINDINGS

DNFB challenge induced mice AD symptoms including epidermal thickening, mast cell infiltration, Th2/Th1 immune response, skin lesions IL-4 and IFN-γ, and serum IgE elevation. HA treatment ameliorated such symptoms through the inhibition of PI3K/Akt signaling pathway. LPS induction stimulated the secretion of NO, IL-6, and TNF-α in RAW 264.7 cells, while HA pre-treatment reduced the concentration of the cytokines in cell supernatants.

SIGNIFICANCE

These findings give clear insight into the interaction between HA and inflammatory response, which can help guiding the utilization of HA in the AD therapies.

Euphorbia hirta Leaf Ethanol Extract Suppresses TNF-α/IFN-γ-Induced Inflammatory Response via Down-Regulating JNK or STAT1/3 Pathways in Human Keratinocytes

Skin inflammation may cause allergic diseases such as allergic rhinitis, asthma, and atopic dermatitis. Euphorbia hirta (E. hirta) is a member of the Euphorbiaceae family and is well-known for its anti-asthma effects. E. hirta has traditionally been used to treat respiratory ailments, dysentery, jaundice, and digestive problems. However, its effects on skin inflammation remain unclear. Here, we determined the effects of 70% ethanol extract of E. hirta leaves (ELE) in vitro using human keratinocyte HaCaT cells, which constitute most epidermal skin cells. We determined the inhibitory effects of ELE on the inflammation caused by tumor necrosis factor (TNF)-α/interferon (IFN)-γ in keratinocytes using ELISA, immunoblotting, and qRT-PCR assay. ELE was found to reduce the production and mRNA expression of pro-inflammatory cytokines such as TNF-α or interleukin-6 and the expression of various proteins, including signal transducers, activators of transcription 1/3, and mitogen-activated protein kinase. Expression levels of these proteins were found to be upregulated in the TNF-α/IFN-γ-stimulated condition and downregulated by ELE treatment. These results indicate that ELE protects HaCaT cells against TNF-α/IFN-γ-induced skin inflammation.

Compound traditional Chinese medicine dermatitis ointment ameliorates inflammatory responses and dysregulation of itch-related molecules in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease accompanied with itchy and scaly rash. Compound traditional Chinese medicine dermatitis ointment (CTCMDO) consists of a mixture of extracts from five plants, which had been used in AD treatment due to good anti-inflammatory and anti-allergic effects.

MATERIALS AND METHODS

In this study, high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometer (LC/MS) were performed to analyze the active ingredients of CTCMDO in detail and to establish its HPLC fingerprint. Furthermore, the anti-inflammatory and antipruritic activities of CTCMDO were studied in the treatment of DNCB-induced AD in mice.

RESULTS

A total of 44 compounds including phenylpropionic acid compounds, alkaloid compounds, curcumin compounds and lignans were identified via combined HPLC and LC/MS. A fingerprint with 17 common peaks was established. In AD-like mice, DNCB-induced scratching behavior had been suppressed in the treatment of CTCMDO in a dose-dependent manner. Furthermore, the detailed experimental results indicated that the AD can be effectively improved via inhibiting the production of Th1/2 cytokines in serum, reversing the upregulation of substance P levels of itch-related genes in the skin, and suppressing the phosphorylation of JNK, ERK, and p38 in the skin.

CONCLUSION

This work indicated that CTCMDO can significantly improve AD via attenuating the pathological alterations of Th1/2 cytokines and itch-related mediators, as well as inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB).

Immune-Regulatory and Molecular Effects of Antidepressants on the Inflamed Human Keratinocyte HaCaT Cell Line

Allergic contact dermatitis (ACD) is a T cell-mediated type of skin inflammation resulting from contact hypersensitivity (CHS) to antigens. There is strong comorbidity between ACD and major depression. Keratinocytes release immunomodulatory mediators including pro-inflammatory cytokines and chemokines, which modulate skin inflammation and are crucial cell type for the development of CHS. Our previous studies showed that fluoxetine and desipramine were effective in suppressing CHS in different mouse strains. However, the immune and molecular mechanisms underlying this effect remain to be explored. The aim of the current study was to determine the immune and molecular mechanisms of action of antidepressant drugs engaged in the inhibition of CHS response in the stimulated keratinocyte HaCaT cell line. The results show that LPS, TNF-α/IFN-γ, and DNFB stimulate HaCaT cells to produce large amounts of pro-inflammatory factors including IL-1β, IL-6, CCL2, and CXCL8. HaCaT stimulation was associated with increased expression of ICAM-1, a cell adhesion molecule, and decreased expression of E-cadherin. Imipramine, desipramine, and fluoxetine suppress the production of IL-1β, CCL2, as well as the expression of ICAM-1. LPS and TNF-α/IFN-γ activate p-38 kinase, but antidepressants do not regulate this pathway. LPS decreases E-cadherin protein expression and fluoxetine normalizes these effects. In summary, the antidepressant drugs examined in this study attenuate the stimulated secretion of pro-inflammatory cytokines, chemokines, and modulate adhesion molecule expression by the HaCaT cell line. Therefore, antidepressants may have some clinical efficacy in patients with ACD and patients with comorbid depression and contact allergy.

A comprehensive review of natural products against atopic dermatitis: Flavonoids, alkaloids, terpenes, glycosides and other compounds

Atopic dermatitis (AD) is considered a great challenge for human communities and imposes both physiological and mental burdens on patients. Natural products have widely been used to treat a wide range of diseases, including cancer, gastrointestinal diseases, asthma, neurological disorders, and infections. To seek potential natural products against AD, in the current review, we searched the terms "atopic dermatitis" and "natural product" in Pubmed, Medline, Web of Science，Science Direct, Embase, EBSCO, CINAHL, ACS. The results show that many natural products, especially puerarin, ferulic acid and ginsenosides, cound protect against AD. Meanwhile, we discussed the therapeutic mechanisms and showed that the natural products exert their anti-inflammatory effects by suppressing the quantity and activity of many inflammatory cell types and cytokines, including neutrophils, monocytes, lymphocytes, Langerhans cells, interleukins (ILs, including IL-1α, IL-1β, IL-4), TNF-α, and TSLP, IgE. via inhibition of JAK/STAT, MAPKs and NF-κB signaling pathways, thereby, halting the inflammatory cascade. Future investigations should focus on studies with more reflective of the clinical characteristics and demographics, so as to develop natural products that will be hopefully available for the treatment of human AD disease.