Artesunate attenuates 2, 4-dinitrochlorobenzene-induced atopic dermatitis by down-regulating Th17 cell responses in BALB/c mice

Topical application of Artemisia annua L. essential oil ameliorates 2,4-dintrochlorobenzene-induced atopic dermatitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Volatile oil is widely used in traditional Chinese medicine owing to its unique hydrophobic and lipophilic properties and rapid skin absorption. Artemisia annua L. (A.annua) essential oil (AAEO), a volatile oil extracted from A. annua, exhibits anti-inflammatory properties. However, few studies have investigated its effects on skin inflammation.

AIM OF THE STUDY

To investigate and elucidate the mechanisms of action of AAEO in the treatment of atopic dermatitis (AD).

MATERIALS AND METHODS

Network pharmacology was used to predict the targets and pathways of AAEO for the treatment of AD. The AD mouse model was established by topical application of 2,4-dintrochlorobenzene (DNCB), AAEO, and the positive control drug hydrocortisone butyrate cream (HBC). We evaluated the symptoms of AD, SCORAD scores, histological analysis, and serum IgE and TNF-α levels in mice. Immunofluorescence, western blotting, and qPCR were used to investigate the signaling pathways.

RESULTS

Network pharmacology analysis indicated that AAEO may exert its effects via the MAPK/NF-κB signaling pathway. Animal experiments demonstrated that topical application of AAEO and HBC significantly ameliorated skin lesions, reduced dermatitis score, and decreased spleen weight compared to DNCB treatment. AAEO reduced skin epidermal thickness and mast cell infiltration. DNCB markedly reduced the protein levels of filaggrin (FLG) and loricrin (LOR), whereas AAEO reversed these changes. Notably, the 5% concentration of AAEO demonstrated substantial improvement in skin barrier function. Compared to the DNCB group, the levels of FLG and LOR remained almost unchanged following HBC treatment. DNCB markedly elevated IgE and TNF-α levels, which were reversed by AAEO and HBC treatment. Among the inflammatory cytokines, DNCB increased mRNA expression of TNF-α, IL-1β, and IL-6, however, it reduced IL-10, with AAEO and HBC reversing these changes to various degrees. Additionally, DNCB-induced ERK, JNK, and P38 phosphorylation, associated with the upregulation of phosphorylation of NF-κB, whereas, AAEO and HBC exhibited potent inhibition of the MAPK/NF-κB signaling pathway.

CONCLUSIONS

This study systematically demonstrated the possible therapeutic effects and mechanisms of AAEO in AD via network pharmacological analysis and experimental confirmation. These results revealed that topical application of AAEO can suppress skin inflammation and restore skin barrier function. These findings provide the potential application of AAEO in synthesizing external preparations for both pharmacological and cosmetic industries.

Characterization of Different Inflammatory Skin Conditions in a Mouse Model of DNCB-Induced Atopic Dermatitis

The mouse model of 2,4-dinitrochlorbenzene (DNCB)-induced human-like atopic dermatitis (hlAD) has been widely used to test novel treatment strategies and compounds. However, the study designs and methods are highly diverse, presenting different hlAD disease patterns that occur after sensitization and repeated challenge with DNCB on dorsal skin. In addition, there is a lack of information about the progression of the disease during the experiment and the achieved pheno- and endotypes, especially at the timepoint when therapeutic treatment is initiated. We here examine hlAD in a DNCB-induced BALB/cJRj model at different timepoints: (i) before starting treatment with dexamethasone, representing a standard drug control (day 12) and (ii) at the end of the experiment (day 22). Both timepoints display typical AD-associated characteristics: skin thickening, spongiosis, hyper- and parakeratosis, altered cytokine and gene expression, increased lipid mediator formation, barrier protein and antimicrobial peptide abnormalities, as well as lymphoid organ hypertrophy. Increased mast cell infiltration into the skin and elevated immunoglobulin E plasma concentrations indicate a type I allergy response. The DNCB-treated skin showed an extrinsic moderate sub-acute hlAD lesion at day 12 and an extrinsic mild sub-acute to chronic pheno- and endotype at day 22 with a dominating Th2 response. A dependency of the filaggrin formation and expression in correlation to the disease severity in the DNCB-treated skin was found. In conclusion, our study reveals a detailed classification of a hlAD at two timepoints with different inflammatory skin conditions and pheno- and endotypes, thereby providing a better understanding of the DNCB-induced hlAD model in BALB/cJRj mice.

WLJP-025p, a homogeneous Lonicera japonica polysaccharide, attenuates atopic dermatitis by regulating the MAPK/NFκB/AP-1 axis via Act1

Atopic dermatitis (AD) is usually treated with steroids, but long-term use is not an effective cure because side effects and disease aggravation. Therefore, more effective and safer treatments are needed. Using dexamethasone as the positive control, the mechanism of action of water-extracted homogeneous honeysuckle Lonicera japonica polysaccharide (WLJP-025p) to alleviate AD was studied. Mice were administered 2,4-dinitrochlorobenzene in their bare back and right ear to mimic an AD model. The efficacy of WLJP-025p in AD was assessed by measuring right ear thickness and skin lesion scores, pathological observation (haematoxylin-eosin and toluidine blue staining), and serum IgE and IL-1β concentrations. The expression of relevant genes and proteins in the serum and back skin was detected using RT-qPCR, ELISA, western blotting, and immunofluorescence. Molecular docking and dynamic simulation of WLJP-025p and Act1 were performed. WLJP-025p considerably alleviated skin hyperplasia and pathological abnormalities in AD mice and inhibited the expression of Act1, Nucleus-P65, Nucleus-AP-1, and MAPK-related proteins in skin tissues. WLJP-025p formed a stable conformation with Act1, inhibited splenic Th17 differentiation, IL-17 release, and upregulated the expression of related skin barrier proteins. In conclusion, WLJP-025p affects the inflammation regulation via the MAPK/NFκB/AP-1 axis by binding to Act1, promotes the recovery of epithelial barrier function, and alleviates AD in mice.

Biofunctional Inorganic Layered Double Hydroxide Nanohybrid Enhances Immunotherapeutic Effect on Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a widespread, recurrent, and chronic inflammatory skin condition that imposes a major burden on patients. Conventional treatments, such as corticosteroids, are associated with various side effects, underscoring the need for innovative therapeutic approaches. In this study, the possibility of using indole-3-acetic acid-loaded layered double hydroxides (IAA-LDHs) is evaluated as a novel treatment for AD. IAA is an auxin-class plant hormone with antioxidant and anti-inflammatory effects. Following the synthesis of IAA-LDH nanohybrids, their ability to induce M2-like macrophage polarization in macrophages obtained from mouse bone marrow is assessed. The antioxidant activity of IAA-LDH is quantified by assessing the decrease in intracellular reactive oxygen species levels. The anti-inflammatory and anti-atopic characteristics of IAA-LDH are evaluated in a mouse model of AD by examining the cutaneous tissues, immunological organs, and cells. The findings suggest that IAA-LDH has great therapeutic potential as a candidate for AD treatment based on its in vitro and in vivo modulation of AD immunology, enhancement of macrophage polarization, and antioxidant activity. This inorganic drug delivery technology represents a promising new avenue for the development of safe and effective AD treatments.

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

OBJECTIVE

The purpose of this study was to investigate the mechanism through which rosemary essential oil treats atopic dermatitis.

METHODS

A 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.

RESULT

The 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.

CONCLUSION

EORO 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.

Vitamin D attenuates DNCB-induced atopic dermatitis-like skin lesions by inhibiting immune response and restoring skin barrier function

Atopic dermatitis (AD) is a common chronic inflammatory skin disease causing erythema and itching. The etiology of AD is complex and not yet clear. Vitamin D is a fat-soluble vitamin that promotes skin cell growth and differentiation and regulates immune function. This study aimed to explore the therapeutic effect of calcifediol, the active metabolite of vitamin D, on experimental AD and the possible mechanism of action. We found that the levels of vitamin D binding protein (VDBP) and vitamin D receptor (VDR) in biopsy skin samples from AD patients decreased compared with controls. We used 2,4-dinitrochlorobenzene (DNCB) to induce an AD mouse model on the ear and back of BALB/c mice. A total of five groups were used: the control group, the AD group, the AD + calcifediol group, the AD + dexamethasone group, and the calcifediol alone group. Under calcifediol treatment, mice exhibited reduced spinous layer thickening, reduced inflammatory cell infiltration, downregulated aquaporin 3 (AQP3) expression, and restored the barrier function of the skin. Simultaneous calcifediol treatment decreased STAT3 phosphorylation, inhibited inflammation and chemokine release, decreased AKT1 and mTOR phosphorylation, and suppressed epidermal cell proliferation and abnormal differentiation. In conclusion, our study demonstrated that calcifediol significantly protected mice against DNCB-induced AD. In a mouse model of AD, calcifediol may reduce inflammatory cell infiltration and chemokines by inhibiting the phosphorylation of STAT3 and may restore skin barrier function through the downregulation of AQP3 protein expression and inhibition of cell proliferation.

Establishment and Characterization of Mild Atopic Dermatitis in the DNCB-Induced Mouse Model

In dermatological research, 2,4-dinitrochlorbenzene (DNCB)-induced atopic dermatitis (AD) is a standard model as it displays many disease-associated characteristics of human AD. However, the reproducibility of the model is challenging due to the lack of information regarding the methodology and the description of the phenotype and endotype of the mimicked disease. In this study, a DNCB-induced mouse model was established with a detailed procedure description and classification of the AD human-like skin type. The disease was induced with 1% DNCB in the sensitization phase and repeated applications of 0.3% and 0.5% DNCB in the challenging phase which led to a mild phenotype of AD eczema. Pathophysiological changes of the dorsal skin were measured: thickening of the epidermis and dermis, altered skin barrier proteins, increased TH1 and TH2 cytokine expression, a shift in polyunsaturated fatty acids, increased pro-resolving and inflammatory mediator formation, and dysregulated inflammation-associated gene expression. A link to type I allergy reactions was evaluated by increased mast cell infiltration into the skin accompanied by elevated IgE and histamine levels in plasma. As expected for mild AD, no systemic inflammation was observed. In conclusion, this experimental setup demonstrates many features of a mild human-like extrinsic AD in murine skin.

A homogeneous Lonicera japonica polysaccharide alleviates atopic dermatitis by promoting Nrf2 activation and NLRP3 inflammasome degradation via p62

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunb. is a traditional medicinal herb with a long history owing to its widespread use in Asia for the treatment of several inflammatory diseases including allergic dermatitis; however, its active components and mechanism of action have not been fully elucidated.

AIM OF THE STUDY

In this study, a homogeneous polysaccharide with strong anti-inflammatory effects was extracted from the traditional Chinese medicine Lonicera japonica. The mechanism by which the polysaccharide WLJP-025p regulates p62 to activate Nrf2, promote NLRP3 inflammasome degradation, and improve AD was investigated.

MATERIALS AND METHODS

An AD model was established using DNCB, and saline was used as a control. The WLJP-L and WLJP-H groups were administered 30 and 60 mg/kg WLJP-025p during the model challenge period, respectively. The therapeutic effect of WLJP-025p was evaluated by determining the skin thickness, performing HE and toluidine blue staining, detecting TSLP via IHC, and determining serum IgE and IL-17 levels. Th17 differentiation was detected using flow cytometry. IF and WB were performed to evaluate the expression levels of c-Fos, p-p65, NLRP3 inflammatory bodies, autophagy pathway, ubiquitination, and Nrf2 proteins.

RESULTS

WLJP-025p significantly inhibited DNCB-induced skin hyperplasia and pathological abnormalities and increased TSLP levels in mice. The differentiation of Th17 in the spleen, IL-17 release, p-c-Fos, p-p65 protein expression, and NLRP3 inflammasome activation in the skin tissues were reduced. Furthermore, p62 expression, p62 Ser403 phosphorylation, and ubiquitinated proteins were increased.

CONCLUSIONS

WLJP-025p improved AD in mice by upregulating p62 to activate Nrf2 and promote the ubiquitination and degradation of NLRP3.

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.

Artesunate targets cellular metabolism to regulate the Th17/Treg cell balance

INTRODUCTION

Metabolic reprogramming is one of the important mechanisms of cell differentiation, and different cells have different preferences for energy sources. During the differentiation of naive CD4 + T cells into Th17 and Treg cells, these cells show specific energy metabolism characteristics. Th17 cells depend on enhanced glycolysis, fatty acid synthesis, and glutaminolysis. In contrast, Treg cells are dependent on oxidative phosphorylation, fatty acid oxidation, and amino acid depletion. As a potent antimalarial drug, artesunate has been shown to modulate the Th17/Treg imbalance and regulate cell metabolism.

METHODOLOGY

Relevant literatures on ART, cellular metabolism, glycolysis, lipid metabolism, amino acid metabolism, CD4 + T cells, Th17 cells, and Treg cells published from January 1, 2010 to now were searched in PubMed database.

CONCLUSION

In this review, we will highlight recent advances in which artesunate can restore the Th17/Treg imbalance in disease states by altering T-cell metabolism to influence differentiation and lineage selection. Data from the current study show that few studies have focused on the effect of ART on cellular metabolism. ART can affect the metabolic characteristics of T cells (glycolysis, lipid metabolism, and amino acid metabolism) and interfere with their differentiation lineage, thereby regulating the balance of Th17/Treg and alleviating the symptoms of the disease.

Physalis alkekengi L. var. franchetii combined with hormone therapy for atopic dermatitis

Atopic dermatitis (AD) is a common, chronic, and recurring inflammatory skin disease. Physalis alkekengi L. var. franchetii (Mast) Makino (PAF), a traditional Chinese medicine, is primarily used for the clinical treatment of AD. In this study, a 2,4-dinitrochlorobenzene-induced AD BALB/c mouse model was established, and a comprehensive pharmacological method was used to determine the pharmacological effects and molecular mechanisms of PAF in the treatment of AD. The results indicated that both PAF gel (PAFG) and PAFG+MF (mometasone furoate) attenuated the severity of AD and reduced the infiltration of eosinophils and mast cells in the skin. Serum metabolomics showed that PAFG combined with MF administration exerted a synergistic effect by remodeling metabolic disorders in mice. In addition, PAFG also alleviated the side effects of thymic atrophy and growth inhibition induced by MF. Network pharmacology predicted that the active ingredients of PAF were flavonoids and exerted therapeutic effects through anti-inflammatory effects. Finally, immunohistochemical analysis confirmed that PAFG inhibited the inflammatory response through the ERβ/HIF-1α/VEGF signaling pathway. Our results revealed that PAF can be used as a natural-source drug with good development prospects for the clinical treatment of AD.

Inhibitory Effect of Bisdemethoxycurcumin on DNCB-Induced Atopic Dermatitis in Mice

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Bisdemethoxycurcumin (BDMC) is an ingredient from the rhizome of the traditional Chinese herbal medicine turmeric. BDMC has been reported to have important pharmacological properties, such as anti-inflammatory, antioxidant, antitumor and antiproliferative activities. However, its effect on atopic dermatitis has not been reported. The purpose of our study was to demonstrate the effectiveness of BDMC on TNF-α/IFNγ-stimulated HaCaT cells and on 2,4-dinitrochlorobenzene (DNCB)-induced AD mice. Our studies showed in vitro that BDMC was able to significantly inhibit the mRNA expression of chemokines and cytokines in TNF-α/IFN-γ-stimulated HaCaT cells and alleviate their inflammatory response. Our studies found in vivo that BDMC was able to significantly improve the symptoms of DNCB-induced AD skin lesions, decrease the number of scratches, ear thickness, and spleen index, improve inflammatory cells and mast cell infiltration and decrease skin thickness. Moreover, it was also able to inhibit the mRNA expression levels of chemokines and inflammatory cytokines and the activation of the MAPK and NF-κB signaling pathways. Thus, the results indicated that BDMC can improve atopic dermatitis in mice and that further clinical studies are warranted on its treatment of AD.

Integrated Network Pharmacology Analysis and Serum Metabolomics to Reveal the Anti-malaria Mechanism of Artesunate

Artesunate is a widely used drug in clinical treatment of malaria. The aim of this study was to investigate the therapeutic mechanism of artesunate on malaria using an integrated strategy of network pharmacology and serum metabolomics. The mice models of malaria were established using 2 × 10⁷ red blood cells infected with Plasmodium berghei ANKA injection. Giemsa and hematoxylin-eosin (HE) staining were used to evaluate the efficacy of artesunate on malaria. Next, network pharmacology analysis was applied to identify target genes. Then, a metabolomics strategy has been developed to find the possible significant serum metabolites and metabolic pathways induced by artesunate. Additionally, two parts of the results were integrated to confirm each other. Giemsa and HE staining results showed that artesunate significantly inhibited the proliferation of Plasmodium and reduced liver and spleen inflammation. Based on metabolomics, 18 differential endogenous metabolites were identified as potential biomarkers related to the artesunate for treating malaria. These metabolites were mainly involved in the relevant pathways of biosynthesis of unsaturated fatty acids; aminoacyl-tRNA biosynthesis; valine, leucine, and isoleucine biosynthesis; and phenylalanine, tyrosine, and tryptophan biosynthesis. The results of the network pharmacology analysis showed 125 potential target genes related to the treatment of malaria with artesunate. The functional enrichment was mainly associated with lipid and atherosclerosis; pathways of prostate cancer and proteoglycans in cancer; and PI3K-Akt, apoptosis, NF-κB, Th17 cell, and AGE-RAGE signaling pathways. These findings were partly consistent with the findings of the metabolism. Our results further suggested that artesunate could correct the inflammatory response caused by malaria through Th17 cell and NF-κB pathways. Meanwhile, our work revealed that cholesterol needed by Plasmodium berghei came directly from serum. Cholesterol and palmitic acid may be essential in the growth and reproduction of Plasmodium berghei. In summary, artesunate may have an effect on anti-malarial properties through multiple targets.

Inhibitory effect of α-cubebenoate on atopic dermatitis-like symptoms by regulating Th2/Th1/Th17 balance in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Bakumijiogan (Kampo herbal formulation) and Kangqian decoction (Chinese herbal medicine formulation) have been used for the treatment of atopic dermatitis (AD) like symptoms. Schisandra chinensis Baill (Family: Magnoliaceae) is a component of both formulations. Its extracts showed inhibition of AD.

AIM OF THE STUDY

We aimed to elucidate an active phytochemical from Schisandra chinensis and evaluated its effects on AD-like symptoms.

MATERIALS AND METHODS

We fractionated a component from Schisandra chinensis by chasing inhibitory activity on mast cell degranulation. We identified α-cubebenoate as an active phytochemical and investigated its effects by using an in vivo 1-chloro-2,4-dinitrobenzene (CDNB)-induced AD model in BALB/c mice.

RESULTS

α-Cubebenoate significantly decreased CDNB-induced skin hypertrophy and accumulation of mast cells in the epidermis and dermis. Increases in pro-inflammatory chemokine and cytokine levels in the skin, lymph node size, and immunoglobulin E levels in the serum were significantly ameliorated by α-cubebenoate.

CONCLUSION

α-Cubebenoate regulates dermal immune responses by suppressing the Th2/Th17/Th1 immune balances, resulting in amelioration of AD-like symptoms and suppression of immune response in lymph nodes. Thereby, this study provides evidence for its therapeutic efficacy in the treatment of AD symptoms.

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.

The Complexity of Sesquiterpene Chemistry Dictates Its Pleiotropic Biologic Effects on Inflammation

Sesquiterpenes (SQs) are volatile compounds made by plants, insects, and marine organisms. SQ have a large range of biological properties and are potent inhibitors and modulators of inflammation, targeting specific components of the nuclear factor-kappaB (NF-κB) signaling pathway and nitric oxide (NO) generation. Because SQs can be isolated from over 1600 genera and 2500 species grown worldwide, they are an attractive source of phytochemical therapeutics. The chemical structure and biosynthesis of SQs is complex, and the SQ scaffold represents extraordinary structural variety consisting of both acyclic and cyclic (mono, bi, tri, and tetracyclic) compounds. These structures can be decorated with a diverse range of functional groups and substituents, generating many stereospecific configurations. In this review, the effect of SQs on inflammation will be discussed in the context of their complex chemistry. Because inflammation is a multifactorial process, we focus on specific aspects of inflammation: the inhibition of NF-kB signaling, disruption of NO production and modulation of dendritic cells, mast cells, and monocytes. Although the molecular targets of SQs are varied, we discuss how these pathways may mediate the effects of SQs on inflammation.

Adipose-derived stem cells ameliorate atopic dermatitis by suppressing the IL-17 expression of Th17 cells in an ovalbumin-induced mouse model

Background

Mesenchymal stem cells (MSCs) have therapeutic potential for atopic dermatitis (AD) owing to their immunoregulatory effects. However, the underlying mechanisms associated with the therapeutic efficacy of MSCs on AD are diverse and related to both cell type and delivery method.

Objectives

This study investigated the therapeutic effect and mechanisms of adipose-derived stem cells (ADSCs) on AD using an ovalbumin (OVA)-induced AD mouse model.

Methods

AD mice were subcutaneously injected with mouse ADSCs, cortisone, or PBS, and the therapeutic effects were determined by gross and histological examinations and serum IgE levels. Additionally, qPCR, RNA-sequencing analyses of skin samples and co-culture of ADSCs and Th17 cells were conducted to explore the underlying therapeutic mechanisms.

Results

ADSCs treatment attenuated the AD pathology, decreased the serum IgE levels, and decreased mast cells infiltration in the skin of the model mice. Moreover, tissue levels of IL-4R and Th17-relevant products (IL-17A, CCL20, and MMP12) were suppressed in the ADSC- and cortisone-treated groups. Genomics and bioinformatics analyses demonstrated significant enrichment of inflammation-related pathways in the downregulated genes of the ADSC- and cortisone-treated groups, specifically the IL-17 signaling pathway. Co-culture experiments revealed that ADSCs significantly suppressed the proliferation of Th17 cells and the expression of proinflammatory cytokines (IL-17A and RORγT). Furthermore, expression levels of PD-L1, TGF-β, and PGE2 were significantly upregulated in co-cultured ADSCs relative to those in monocultured ADSCs.

Conclusion

ADSCs ameliorate OVA-induced AD in mice mainly by downregulating IL-17 secretion of Th17 cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02774-7.

Recent Advances in the Therapeutic Efficacy of Artesunate

Artesunate, a semisynthetic artemisinin derivative, is well-known and used as the first-line drug for treating malaria. Apart from treating malaria, artesunate has also been found to have biological activity against a variety of cancers and viruses. It also exhibits antidiabetic, anti-inflammatory, anti-atherosclerosis, immunosuppressive activities, etc. During its administration, artesunate can be loaded in liposomes, alone or in combination with other therapeutic agents. Administration routes include intragastrical, intravenous, oral, and parenteral. The biological activity of artesunate is based on its ability to regulate some biological pathways. This manuscript reports a critical review of the recent advances in the therapeutic efficacy of artesunate.

New Insights into Artesunate as a Pleiotropic Regulator of Innate and Adaptive Immune Cells

Artesunate, one of the derivatives of artemisinin (“qinghaosu” in Chinese), is known as an antimalarial drug with high efficiency and low toxicity. Of interest, emerging evidences suggest that artesunate also possesses an immunomodulatory effect during innate and adaptive immune responses in cell types and context-dependent manner. Although it shows promising application in many diseases, such as inflammatory diseases, hypersensitivity, autoimmune diseases, and cancers, little is known about underlying molecular. In this review, we summarize recent advances of how artesunate regulates innate and adaptive immune cells. In addition, its potential application in immune-related diseases is also highlighted.

Bifidobacterium longum and Galactooligosaccharide Improve Skin Barrier Dysfunction and Atopic Dermatitis-like Skin

Purpose

The beneficial effects of a combination therapy using Bifidobacterium longum and galactooligosaccharide (GOS) for the treatment of atopic dermatitis (AD) have not been elucidated.

Methods

Gene expressions of interleukin (IL)-4 and IL-13 from peripheral blood mononuclear cells and fecal abundance of B. longum from 12-month-old infants were evaluated. Human primary epidermal keratinocytes (HEKs) and hairless mice were treated with B. longum, GOS, B. longum-derived extracellular vesicles (BLEVs), dinitrochlorobenzene (DNCB), or a synbiotic mixture of B. longum and GOS. Expression of epidermal barrier proteins and cytokines as well as serum immunoglobulin E (IgE) levels were analyzed in HEKs and mice. Dermatitis scores, transepidermal water loss (TEWL), epidermal thickness, and fecal B. longum abundance were evaluated in mice.

Results

Fecal abundance of B. longum was negatively correlated with blood IL-13 expression in infants. B. longum or BLEVs increased expression of filaggrin (FLG) and loricrin (LOR) in HEKs. B. longum increased the efficacy of GOS to upregulate FLG and LOR expressions in HEKs. Oral administration of GOS increased fecal abundance of B. longum in mice. Oral administration of B. longum attenuated DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, and deficiency of epidermal barrier proteins. Moreover, the combination of B. longum and GOS showed greater effects to improve DNCB-induced skin inflammation, abnormal TEWL, AD-like skin, serum IgE levels, IL-4 over-expression, and the deficiency of epidermal barrier proteins than the administration of B. longum alone.

Conclusions

B. longum and GOS improve DNCB-induced skin barrier dysfunction and AD-like skin.

Artesunate treatment ameliorates ultraviolet irradiation-driven skin photoaging via increasing β-catenin expression

OBJECTIVE

Artesunate, a semi-synthetic derivative of artemisinin, exerts various pharmacological activities. Nevertheless, the effects of Art on skin photoaging remain unclear. Herein, we investigated whether Art ameliorated ultraviolet-irradiated skin photoaging in HaCaT cells and mice.

METHODS

To construct skin photoaging cellular models, HaCaT cells were irradiated by UV (UVB, 20mJ/cm²) for 5 days. HaCaT cells were pretreated with three concentrations of Art (1, 5 and 20 μg/ml) for 2 h each day. After 5 days, cell senescence, ROS production, SOD levels, p16^INK4a and β-catenin expression, proliferation and apoptosis were detected in HaCaT cells. Effects of Art on normal cells were investigated. After sh-β-catenin transfection or XAV-939 treatment, HaCaT cells were pretreated with 20 μg/ml Art and irradiated by UVB. After 5 days, skin photoaging was then observed. Furthermore, skin photoaging mouse models were established and the effects of Art and β-catenin silencing on skin photoaging were investigated.

RESULTS

Art treatment suppressed cell senescence, intracellular ROS production, p16^INK4a expression and apoptosis and promoted proliferation and SOD and β-catenin expression in UVB irradiated HaCaT cells. But Art had no toxic effects on normal cells. Silencing β-catenin by sh-β-catenin or XAV-939 exacerbated UVB irradiation-mediated cell senescence, apoptosis, and ROS production in HaCaT cells, which was ameliorated by Art treatment. The therapeutic effects of Art on skin photoaging were also confirmed in mouse models.

CONCLUSIONS

These findings suggested that Art treatment alleviated UVB irradiation-driven skin photoaging through enhancing β-catenin expression, which offered novel clues for pharmacological activity of Art.

Gallic Acid Ameliorates Atopic Dermatitis-Like Skin Inflammation Through Immune Regulation in a Mouse Model

Background

Gallic acid (GA) has an anti-inflammatory effect by regulating inflammatory molecules. This study aimed to investigate the effect of GA on atopic dermatitis (AD)-like skin inflammation.

Methods

4-dinitrochlorobenzene (DNCB) was used to induce an AD-like skin inflammation model. The effect of GA on DNCB-induced inflammation was assessed by measuring the thickness and histopathological examination of the ear. Serum IgE and TNF-α levels were detected. The effect of GA on lymph nodes was determined by measuring the weights and mRNA/protein expression levels of TNF-α, IL-4, IFN-γ and IL-17. Ratio of Treg cells and Th17 cells was also analyzed.

Results

It was found that the thickness and pathology of the ear were significantly improved by GA in the DNCB-induced mice. Serum IgE and TNF-α levels were significantly reduced in GA-treated model mice compared to the model group. GA treatment lowered the weight of lymph node and the expression of mRNAs of TNF-α, IL-4, IFN-γ, and IL-17 of lymph node. In the ear, inflammatory factors (IL-4, IL-5, IL-17, or IL-23) showed a significant decrease in GA-treated model mice versus model mice, while the expression levels of IL-10 and TGF-β showed a great increase in GA-treated model mice. ROR-γt showed a decrease in GA-treated model group, along with an increase expression of SOCS3.

Conclusion

GA could ameliorate AD-like skin inflammation possibly through Th17 mediated immune regulation in a DNCB-induced mouse model.

Salvianolic Acid A Suppresses DNCB-Induced Atopic Dermatitis-Like Symptoms in BALB/c Mice

Prevalence of atopic dermatitis (AD), a chronic, pruritic, and relapsing inflammatory skin disorder, is growing. Because available therapeutics is limited, immune regulators from natural resources could be helpful for treating AD symptoms. The root of Salvia miltiorrhiza Bunge (Lamiaceae) has been studied for the treatment of inflammatory diseases, including dermatologic disorders in Korea. This study examined the effect of salvianolic acid A on AD-like symptoms. Sensitization on the dorsal skin and repeated application on the ears with 2,4-dinitrochlorobenzene (DNCB) were performed in BALB/c mice to induce AD-like skin lesions. After induction of atopic dermatitis, salvianolic acid A (5 and 10 mg/kg) or dexamethasone (10 mg/kg) were administrated via intraperitoneal injection for 3 weeks. Salvianolic acid A suppressed DNCB-induced AD-like symptoms like ear skin hypertrophy and decreased mast cell infiltration into skin lesions. Salvianolic acid A not only reduced DNCB-induced increase of serum IgE but also lowered levels of the Th2 cytokines (IL-4 and IL-13), Th1 cytokine (interferon-γ), and Th17 cytokine (IL-17A). Furthermore, salvianolic acid A blocked DNCB-induced lymph node enlargement. In summary, these results suggest that salvianolic acid A might have a therapeutic potential for the treatment of AD.

Immunoregulation by Artemisinin and Its Derivatives: A New Role for Old Antimalarial Drugs

Artemisinin and its derivatives (ARTs) are known as conventional antimalarial drugs with clinical safety and efficacy. Youyou Tu was awarded a Nobel Prize in Physiology and Medicine due to her discovery of artemisinin and its therapeutic effects on malaria. Apart from antimalarial effects, mounting evidence has demonstrated that ARTs exert therapeutic effects on inflammation and autoimmune disorders because of their anti-inflammatory and immunoregulatory properties. In this aspect, tremendous progress has been made during the past five to seven years. Therefore, the present review summarizes recent studies that have explored the anti-inflammatory and immunomodulatory effects of ARTs on autoimmune diseases and transplant rejection. In this review, we also discuss the cellular and molecular mechanisms underlying the immunomodulatory effects of ARTs. Recent preclinical studies will help lay the groundwork for clinical trials using ARTs to treat various immune-based disorders, especially autoimmune diseases.

The immunosuppressive activity of artemisinin-type drugs towards inflammatory and autoimmune diseases

The sesquiterpene lactone artemisinin from Artemisia annua L. is well established for malaria therapy, but its bioactivity spectrum is much broader. In this review, we give a comprehensive and timely overview of the literature regarding the immunosuppressive activity of artemisinin-type compounds toward inflammatory and autoimmune diseases. Numerous receptor-coupled signaling pathways are inhibited by artemisinins, including the receptors for interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), β3-integrin, or RANKL, toll-like receptors and growth factor receptors. Among the receptor-coupled signal transducers are extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), AKT serine/threonine kinase (AKT), mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase (ERK) kinase (MEK), phospholipase C γ1 (PLCγ), and others. All these receptors and signal transduction molecules are known to contribute to the inhibition of the transcription factor nuclear factor κ B (NF-κB). Artemisinins may inhibit NF-κB by silencing these upstream pathways and/or by direct binding to NF-κB. Numerous NF-κB-regulated downstream genes are downregulated by artemisinin and its derivatives, for example, cytokines, chemokines, and immune receptors, which regulate immune cell differentiation, apoptosis genes, proliferation-regulating genes, signal transducers, and genes involved in antioxidant stress response. In addition to the prominent role of NF-κB, other transcription factors are also inhibited by artemisinins (mammalian target of rapamycin [mTOR], activating protein 1 [AP1]/FBJ murine osteosarcoma viral oncogene homologue [FOS]/JUN oncogenic transcription factor [JUN]), hypoxia-induced factor 1α (HIF-1α), nuclear factor of activated T cells c1 (NF-ATC1), Signal transducers and activators of transcription (STAT), NF E2-related factor-2 (NRF-2), retinoic-acid-receptor-related orphan nuclear receptor γ (ROR-γt), and forkhead box P-3 (FOXP-3). Many in vivo experiments in disease-relevant animal models demonstrate therapeutic efficacy of artemisinin-type drugs against rheumatic diseases (rheumatoid arthritis, osteoarthritis, lupus erythematosus, arthrosis, and gout), lung diseases (asthma, acute lung injury, and pulmonary fibrosis), neurological diseases (autoimmune encephalitis, Alzheimer's disease, and myasthenia gravis), skin diseases (dermatitis, rosacea, and psoriasis), inflammatory bowel disease, and other inflammatory and autoimmune diseases. Randomized clinical trials should be conducted in the future to translate the plethora of preclinical results into clinical practice.

Mouse models of atopic dermatitis: a critical reappraisal

Mouse models for atopic dermatitis (AD) are an indispensable preclinical research tool for testing new candidate AD therapeutics and for interrogating AD pathobiology in vivo. In this Viewpoint, we delineate why, unfortunately, none of the currently available so-called "AD" mouse models satisfactorily reflect the clinical complexity of human AD, but imitate more "allergic" or "irriant" contact dermatitis conditions. This limits the predictive value of AD models for clinical outcomes of new tested candidate AD therapeutics and the instructiveness of mouse models for human AD pathophysiology research. Here, we propose to initiate a rational debate on the minimal criteria that a mouse model should meet in order to be considered relevant for human AD. We suggest that valid AD models should at least meet the following criteria: (a) an AD-like epidermal barrier defect with reduced filaggrin expression along with hyperproliferation, hyperplasia; (b) increased epidermal expression of thymic stromal lymphopoietin (TSLP), periostin and/or chemokines such as TARC (CCL17); (c) a characteristic dermal immune cell infiltrate with overexpression of some key cytokines such as IL-4, IL-13, IL-31 and IL-33; (d) distinctive "neurodermatitis" features (sensory skin hyperinnervation, defective beta-adrenergic signalling, neurogenic skin inflammation and triggering or aggravation of AD-like skin lesions by perceived stress); and (e) response of experimentally induced skin lesions to standard AD therapy. Finally, we delineate why humanized AD mouse models (human skin xenotransplants on SCID mice) offer a particularly promising preclinical research alternative to the currently available "AD" mouse models.

Meta-analysis of transcriptome datasets: An alternative method to study IL-6 regulation in coronavirus disease 2019

In coronavirus disease 2019 (COVID-19) patients, interleukin (IL)-6 is one of the leading factors causing death through cytokine release syndrome. Hence, identification of IL-6 downstream from clinical patients’ transcriptome is very valid for analyses of its mechanism. However, clinical study is conditional and time consuming to collect optional size of samples, as patients have the clinical heterogeneity. A possible solution is to deeply mine the relative existing data. Several transcriptome-based studies on other diseases or treatments have revealed different genes to be regulated by IL-6. Through our meta-analysis of these transcriptome datasets, 352 genes were suggested to be regulated by IL-6 in different biological conditions, some of which were related to virus infection and cardiovascular disease. Among them, 232 genes were not identified by current transcriptome studies from clinical research. ICAM1 and PFKFB3 were the most significantly upregulated genes in our meta-analysis and could be employed as biomarkers in patients with severe COVID-19. In general, a meta-analysis of transcriptome datasets could be an alternative way to analyze the immune response and complications of patients suffering from severe COVID-19 and other emergency diseases.

[Dihydroartemisinin alleviates atopic dermatitis in mice by inhibiting mast cell infiltration]

OBJECTIVE

To observe the therapeutic effect of different doses of dihydroartemisinin (DHA) on atopic dermatitis (AD) in mice and explore the mechanism.

METHODS

Forty-two C57BL/6 mice were randomly divided into 7 groups (n=6), including a blank control group, a 2, 4-dinitrochlorobenzene (DNCB)-induced AD model group, a solvent-treated group, 3 DHA treatment groups treated with 25, 75, and 125 mg/kg DHA, and a dexamethasone treatment group. The counts of skin scratches were recorded and the lesion scores were evaluated on a daily basis. After 7 consecutive days of treatment, skin tissues were sampled from the lesions on the back and ear of the mice for pathological examination with HE staining, Masson staining and toluidine blue staining.

RESULTS

Treatment with 25, 75, and 125 mg/kg DHA and dexamethasone all alleviated AD symptoms of mice, reduced the severity scores of skin lesions, and ameliorated pathological changes of the skin tissue. DHA at 125 mg/kg produced the most obvious therapeutic effect and significantly alleviated mast cell infiltration in the lesions as compared with the other treatment groups (P < 0.05).

CONCLUSIONS

DHA is effective for the treatment of AD in mice with an optimal dose of 125 mg/kg. The therapeutic effect of DHA is achieved probably through regulation of local immunity by inhibiting mast cell infiltration in the lesions.

Sika deer (Cervus nippon) velvet antler ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like clinical signs in a rodent model

Context Deer velvet is a rarely used component in traditional Chinese medicine and has beneficial effects against several diseases. As a substance that covers the bone and cartilage of immature antlers, deer velvet is a natural cytokine ‘storeroom’ that is rich in protein and proteoglycans. Recently, proteoglycans have been shown to have beneficial effects against inflammation. Aims To determine whether antler extract possesses therapeutic effects in a mouse model of atopic dermatitis (AD) and to explore the underlying mechanisms of action. Methods BALB/c mice were randomly divided into the following groups: control, AD, and AD + antler groups. We established an in vivo AD model by repeatedly exposing the ears of mice to Dermatophagoides farinae extract (house dust-mite extract) and 2,4-dinitrochlorobenzene once per week for 4 weeks. On the day after induction, ear thickness was measured. Antler extract (100 mg/kg) was administered orally once a day for 26 days. After 4 weeks of treatment with antler extract, the epidermal and dermal ear thickness, mast-cell infiltration, spleen weight, and lymph-node weight were measured. In addition, the mRNA levels of several pathogenic cytokines in the ears were measured. The concentrations of IL-4, IL-5, IL-10, IL-31 and IL-17 mRNA in the skin lesions of each group were measured by quantitative polymerase chain reaction. Key results Epidermal and dermal ear thickness, mast-cell infiltration, lymph-node weight, and gene expression levels of pathogenic cytokines in ear tissue were diminished following oral administration of antler extract, unlike in the control group. Conclusions The results of the present study strongly suggest that antler extract exhibits therapeutic activity against atopic dermatitis via regulation of inflammatory response. Implications Further exploration of the mechanisms of action of antler extract will be important for clinical application.