Polyozellin alleviates atopic dermatitis-like inflammatory and pruritic responses in activated keratinocytes and mast cells

PL-ReliefTMplus Alleviates Atopic Dermatitis and Regulates Inflammatory Responses via Inhibiting NF-κB Signaling Pathway

BACKGROUND

Atopic dermatitis (AD) has various detrimental effects on individuals with limited drug cure rates which necessitate the development of new treatment methods. PL-ReliefTMplus (PLR) is composed of SupraOlive, Crocus Sativus extracts and Citrus reticulata extracts. The effect of PLR on AD remains to be explored.

METHODS

2,4-dinitrofluorobenzene-induced AD model mice were involved and the histopathology of the skin lesions was observed along with the levels of inflammatory chemokines levels were measured. To further validate the molecular mechanism of PLR, RNA-seq was performed in HaCaT cells. Western blotting and immunofluorescence were performed to investigate NF-κB signaling pathways response in AD.

RESULTS

Due to PLR treatment, the thickening of the epidermis and dermis was inhibited and the number of eosinophils, mast cells, and CD4+ T cells in the skin lesion was decreased. In addition, the levels of inflammatory cytokines were decreased in dorsal skin tissues and LPS-stimulated HaCat cells. Furthermore, KEGG pathway analysis suggested that most identified downstream biological functions were associated with inflammatory response. PLR inhibited NF-κB signaling in AD mice and HaCaT cells.

CONCLUSIONS

These results indicate that PLR is a potent therapeutic agent for attenuating symptoms of AD.

Effect of Ampelopsis brevipedunculata (Maxim.) Trautv extract on a model of atopic dermatitis in HaCaT cells and mice

Ampelopsis brevipedunculata (Maxim.) Trautv. has been used for a long time as a folk remedy. According to studies, it possesses anti-inflammatory, antioxidant, and antibacterial properties. However, its effects on atopic dermatitis (AD) are poorly studied. Thus, we investigated the therapeutic effect of A. brevipedunculata (Maxim.) Trautv. extract (ABE-M) on 2,4-dinitrochlorobenzene (DNCB)-induced AD. For in vitro analysis, keratinocytes cell lines (HaCaT cells) were used. To evaluate the gene and protein expression levels of cytokines and chemokines, TNF-α/IFN-γ-stimulated HaCaT cells were treated with ABE-M. The cells and the supernatant were collected, then gene and protein levels were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay analysis. For in vivo analysis, BALB/c mice (6 weeks) were randomly separated into five groups (n = 5). The mice were applied DNCB and phosphate-buffered saline, dexamethasone (DX) or ABE-M (50, 100, and 200 mg/kg) was orally administrated for 28 days. At the end, ear tissues and blood were collected for histological analysis and evaluation of cytokines and chemokines. In keratinocytes, ABE-M inhibited the protein and mRNA levels of chemokines, and cytokines exposed by TNF-α/IFN-γ. Similarly, the expression of chemokines was suppressed by ABE-M in AD animal model induced by DNCB and the level of pro-inflammatory cytokines was decreased in a dose-dependent manner. Our research indicates that ABE-M could be a candidate material that can be used to improve skin immunity enhancement, health, and beauty.

Matrine regulates Th1/Th2 inflammatory responses by inhibiting the Hsp90/NF-κB signaling axis to alleviate atopic dermatitis

Atopic dermatitis (AD) is a common inflammatory skin disease. Matrine is the main component of the traditional Chinese medicine Sophora flavescens, and it poses good therapeutic effects on inflammatory diseases. This study aimed to explore the pharmacological effects of matrine on AD and its underlying mechanism. An AD mouse model and inflamed human epidermal keratinocyte cells (HaCaT) cells were established. Histopathological aspects were examined using hematoxylin and eosin staining, toluidine blue staining, and immunohistochemistry. The mRNA and protein expressions were assessed using quantitative real-time polymerase chain reaction and Western blot, respectively. The secretions of cytokines and chemokines were examined by enzyme-linked immunosorbent assay. Flow cytometry was carried out to analyze the proportions of T-helper (Th) 1 and Th2 cells. Herein, our results displayed that matrine diminished AD symptoms and decreased heat shock protein 90 (Hsp90) expression. Matrine decreased the Th2 cytokine levels in the ear tissues and serum, and it also significantly repressed inflammatory cytokines (thymus activation regulated chemokine and interleukin-6) secretions by repressing the Hsp90/NF-κB signaling axis in inflamed HaCaT cells. Furthermore, matrine inhibited Th2 differentiation of CD4⁺ T cells when co-cultured with inflamed HaCaT cells. Matrine can regulate the Th1/Th2 inflammatory response by inhibiting the Hsp90/NF-κB signaling axis to alleviate AD. Therefore, it may be a candidate for AD treatment.

Inhibition of Mast Cell Degranulation in Atopic Dermatitis by Celastrol through Suppressing MRGPRX2

Background

Atopic dermatitis is a common dermatological disease, and mast cell degranulation is believed to be related with the progression of atopic dermatitis. Mas-related G protein-coupled receptor-X2 (MRGPRX2), and calcium release-activated calcium channel protein 1-2 (ORAI-1, ORAI-2) are involved in mast cell degranulation. Celastrol is an active monomer of Tripterygium wilfordii, and it presents an antiatopic role.

Methods

2,4-Dinitrofluorobenzene (DNFB) and compound 48/80 (C 48/80) were used to establish a slow and acute scratching animal model, respectively. Hematoxylin-eosin and toluidine blue staining was used to investigate tissue injury. Inflammatory factor concentration was measured with ELISA. The expression of MRGPRX2, ORAI-1, and ORAI-2 was detected with immunohistochemistry (IHC) staining. Gene expression profiling and microRNA array were performed to investigate gene differential expression.

Results

Celastrol greatly inhibited atopic dermatitis-related tissues injury, mast cell production, histamine release, scratching level, inflammatory factor expression, and activation of MRGPRX2/ORAI axis in the DNFB-induced atopic dermatitis model. The influence of Celastrol on atopic dermatitis was remarkably reversed by overexpression of MRGPRX2.

Conclusion

We found that the improvements of atopic dermatitis caused by Celastrol were reversed by treatment with MRGPRX2^OE, indicating that Celastrol might affect atopic dermatitis through MRGPRX2. This study might provide a novel thought for the prevention and treatment of atopic dermatitis by regulating MRGPRX2.

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

BACKGROUND

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.

AIMS

The objective of this study was to explore the potential mechanisms of GA on AD mice model.

METHODS

Calcipotriol, a vitamin D3 analogue (MC903) was applied topically to establish AD mouse model. Mice were intraperitoneally administrated with 2 mg/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.

RESULTS

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.

CONCLUSIONS

In conclusion, our findings suggested potential therapeutic effects of GA against MC903-induced AD-like skin lesions in mice.

Terminalia chebula Retz. extract ameliorates the symptoms of atopic dermatitis by regulating anti-inflammatory factors in vivo and suppressing STAT1/3 and NF-ĸB signaling in vitro

BACKGROUND

Terminalia chebula (TC) is a traditional medicinal plant used for treating various diseases in humans. However, pharmacological mechanisms underlying the effects of TC in atopic treatment remain unelucidated.

HYPOTHESIS/PURPOSE

We investigated the therapeutic effects of TC extract in a mouse model of atopic dermatitis (AD) in vivo and the anti-inflammatory mechanism in vitro.

STUDY DESIGN/METHODS

For the in vivo study, AD was induced by Dermatophagoides farinae extract (Dfe) in NC/Nga mice. After 14 days of oral administration, the effects of TC concentrations of 30, 100, and 300 mg/kg were analyzed by assessing morphological changes visually; measuring serum levels of inflammatory chemokines/cytokines, IgE, histamine, MDC, TARC, RANTES, and TSLP using ELISA kits; and counting infiltrated mast cells. For in vitro analyses, we used IFNγ/TNF-α-stimulated human keratinocyte cell lines to study the mechanism of action. The production of chemokines/cytokines in the IFNγ/TNF-α-stimulated HaCaT cells was measured using ELISA and a bead array kit. The signaling pathways were analyzed by western blotting and the expression of the transcriptional factors using RT-PCR and luciferase assay.

RESULTS

Administration of TC significantly alleviated AD-like symptoms in vivo and decreased the ear thickness, dermatitis score, keratinization, and mast cell infiltration. It also resulted in decreased serum levels of IgE, histamine, and inflammation-related mediators MDC, TARC, RANTES, and TSLP compared with those in the Dfe treatment group. Moreover, TC downregulated the expression of the inflammatory chemokines RANTES and MDC in IFNγ/TNF-α-stimulated HaCaT cells. TC inhibited phosphorylated STAT1/3 and NK-κB subunits and nuclear translocation of NF-κB. It also suppressed the transcription of IFNγ, IL-6, IL-8 and MCP-1 in the IFNγ/TNF-α-stimulated HaCaT cells. TC and its constituents, chebulic acid, gallic acid, corlagin, chebulanin, chbulagic acid, ellagic acid, and chebulinic acid, strongly inhibited the nuclear translocation of NF-κB, STAT1, and STAT3 and decreased the expression of inflammatory cytokines at the mRNA level.

CONCLUSIONS

Overall, TC extract alleviated AD-like symptoms by regulating anti-inflammatory factors in vivo and suppressing STAT1/3 and NF-κB signaling in vitro. In addition, our results show the in vivo effect of partial improvements in AD, as well as the in vitro effect on inflammatory factors by the constituents of TC. This finding provides that TC extract and its components could be potential therapeutic drugs for AD.

Inhibitory effect of Isatis tinctoria L. water extract on DNCB-induced atopic dermatitis in BALB/c mice and HaCaT cells

BACKGROUND

Isatis tinctoria L (PLG) is a medicinal herb from the roots of Isatis indigotica Fort (Family Cruciferae). Previous studies have shown that PLG has anti-inflammatory and therapeutic effects against conditions such as acute and chronic hepatitis, various respiratory inflammations, and cancer. The purpose of this study was to define the pharmacological effects of PLG on inflammatory reactions and skin hyperkeratosis, which are the main symptoms of atopic dermatitis (AD), in vivo and in vitro.

METHODS

For the AD in vivo experiment, 2,4-dinitrochlorobenzene (DNCB) induction and oral administration of PLG were performed on male BALB/c mice for four weeks. For in vitro experiments, keratinocytes were activated using TNF-α/IFN-γ in cultured human keratinocyte (HaCaT) cells. PLG inhibited inflammatory chemokine production and blocked the nuclear translocation of NF-κB p65 in activated keratinocytes.

RESULTS

As a result of oral administration of PLG, dermis and epidermis thickening, as well as eosinophil and mast cell infiltration, were attenuated in AD skin lesions. In addition, the levels of immunoglobulin E (IgE), pro-inflammatory cytokines, and the MAPK/NF-κB signaling pathway were decreased in serum and dorsal skin tissues. Furthermore, PLG inhibited inflammatory chemokine production and blocked the nuclear translocation of NF-κB p65 in activated keratinocytes. In addition, epigoitrin and adenosine, the standard compounds of PLG, were identified as candidate AD compounds.

CONCLUSIONS

These results indicate that PLG is a potent therapeutic agent for attenuating symptoms of AD.

Inhibitory Effects of Euscaphic Acid in the Atopic Dermatitis Model by Reducing Skin Inflammation and Intense Pruritus

Atopic dermatitis (AD) is a complex and multifactorial skin disease characterized by skin inflammation and intense pruritus. There are many commercially available treatments such as topical corticosteroids and immunosuppressants to treat of AD, but their effectiveness is limited, and frequent use of these treatments can cause serious side effects. Therefore, the development of new therapeutic agents is necessary for the treatment of AD. Hence, an alternative agent that was derived from natural products that are effective and safe for AD treatment was investigated using experimental models. The biological activity of euscaphic acid has anti-inflammatory, anticoagulant, and antioxidant effects. Despite the various biomedical properties of euscaphic acid, its therapeutic effects on AD have not been well studied. In this study, we investigated the effects of euscaphic acid on skin inflammation and pruritus in AD mouse model. The effects of euscaphic acid were investigated in activated human epidermal keratinocytes and leukemia T lymphoblast cell lines, and Dermatophagoides farina extract and 2,4-dinitrochlorobenzene-induced AD mouse model. Euscaphic acid ameliorated AD properties, such as the expression of inflammatory cytokines and activation of transcription factors. In addition, euscaphic acid reduced critical factors for pruritus such as immunoglobulin E hyperproduction, mast cell invasion, and interleukin-33 expression. Taken together, euscaphic acid could be a potent therapeutic agent for the treatment of AD.

Gomisin M2 alleviates psoriasis‑like skin inflammation by inhibiting inflammatory signaling pathways

Psoriasis, a chronic inflammatory skin disease, is characterized by the excessive proliferation and impaired differentiation of epidermal keratinocytes and is accompanied by the increased infiltration of inflammatory cells. The condition requires long‑term treatment and has no definitive cure. Hence, supplements and therapeutic agents have been intensely investigated. Gomisin M2 (GM2), a lignan extracted from Schisandra chinensis (Turcz). Baill. (Schisandraceae; S. chinensis), has demonstrated diverse pharmacological properties, including anticancer, anti‑inflammatory and antiallergic effects. Based on these findings, the present study examined the effects of GM2 on an imiquimod (IMQ)‑induced psoriasis mouse model and on keratinocytes stimulated by tumor necrosis factor (TNF)‑α and interferon‑γ. IMQ was topically applied to the back skin of mice for 7 consecutive days, and the mice were orally administered CD. These results showed that the oral administration of GM2 suppressed the symptoms of psoriasis, as evidenced by reductions in skin thickness, psoriasis area severity index scores for psoriasis lesions, transepidermal water loss and myeloperoxidase (MPO)‑associated cell infiltration. Furthermore, GM2 reduced the pathologically increased levels of immunoglobulin G2a, MPO and TNF‑α in the serum and T helper (Th)1 and Th17 cell populations in the spleen. GM2 decreased the gene expression of inflammatory‑related cytokines and chemokines and inhibited the expression of signal transducer and activator of transcription 1 and nuclear factor‑κB in the activated keratinocytes. These results suggested that GM2 from S. chinensis is a potential therapeutic candidate to alleviate psoriasis‑like skin inflammation.

Bioactive Phytochemical Constituents of Wild Edible Mushrooms from Southeast Asia

Mushrooms have a long history of uses for their medicinal and nutritional properties. They have been consumed by people for thousands of years. Edible mushrooms are collected in the wild or cultivated worldwide. Recently, mushroom extracts and their secondary metabolites have acquired considerable attention due to their biological effects, which include antioxidant, antimicrobial, anti-cancer, anti-inflammatory, anti-obesity, and immunomodulatory activities. Thus, in addition to phytochemists, nutritionists and consumers are now deeply interested in the phytochemical constituents of mushrooms, which provide beneficial effects to humans in terms of health promotion and reduction of disease-related risks. In recent years, scientific reports on the nutritional, phytochemical and pharmacological properties of mushroom have been overwhelming. However, the bioactive compounds and biological properties of wild edible mushrooms growing in Southeast Asian countries have been rarely described. In this review, the bioactive compounds isolated from 25 selected wild edible mushrooms growing in Southeast Asia have been reviewed, together with their biological activities. Phytoconstituents with antioxidant and antimicrobial activities have been highlighted. Several evidences indicate that mushrooms are good sources for natural antioxidants and antimicrobial agents.