A novel chrysin derivative produced by gamma irradiation attenuates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in Balb/c mice

CM1, a Chrysin Derivative, Protects from Endotoxin-Induced Lethal Shock by Regulating the Excessive Activation of Inflammatory Responses

Sepsis, a leading cause of death worldwide, is a harmful inflammatory condition that is primarily caused by an endotoxin released by Gram-negative bacteria. Effective targeted therapeutic strategies for sepsis are lacking. In this study, using an in vitro and in vivo mouse model, we demonstrated that CM1, a derivative of the natural polyphenol chrysin, exerts an anti-inflammatory effect by inducing the expression of the ubiquitin-editing protein TNFAIP3 and the NAD-dependent deacetylase sirtuin 1 (SIRT1). Interestingly, CM1 attenuated the Toll-like receptor 4 (TLR4)-induced production of inflammatory cytokines by inhibiting the extracellular-signal-regulated kinase (ERK)/MAPK and nuclear factor kappa B (NF-κB) signalling pathways. In addition, CM1 induced the expression of TNFAIP3 and SIRT1 on TLR4-stimulated primary macrophages; however, the anti-inflammatory effect of CM1 was abolished by the siRNA-mediated silencing of TNFAPI3 or by the genetic or pharmacologic inhibition of SIRT1. Importantly, intravenous administration of CM1 resulted in decreased susceptibility to endotoxin-induced sepsis, thereby attenuating the production of pro-inflammatory cytokines and neutrophil infiltration into the lung compared to control mice. Collectively, these findings demonstrate that CM1 has therapeutic potential for diverse inflammatory diseases, including sepsis.

Living symbiotic bacteria-involved skin dressing to combat indigenous pathogens for microbiome-based biotherapy toward atopic dermatitis

Many skin diseases, such as atopic dermatitis (AD), are featured with the dysbiosis of skin microbiota. The clinically recommended options for AD treatments suffer from poor outcomes and high side-effects, leading to severe quality-of-life impairment. To deal with this long-term challenge, we develop a living bacterial formulation (Hy@Rm) that integrates skin symbiotic bacteria of Roseomonas mucosa with poly(vinyl pyrrolidone), poly(vinyl alcohol) and sodium alginate into a skin dressing by virtue of the Ca²⁺-mediated cross-linking and the freezing-thawing (F-T) cycle method. Hy@Rm dressing creates a favorable condition to not only serve as extrinsic culture harbors but also as nutrient suppliers to support R. mucosa survival in the harsh microenvironment of AD sites to defeat S. aureus, which predominantly colonizes AD skins as an indigenous pathogen, mainly through the secretion of sphingolipids metabolites by R. mucosa like a therapeutics bio-factory. Meanwhile, this elaborately designed skin dressing could accelerate wound healing, normalize aberrant skin characters, recover skin barrier functions, alleviate AD-associated immune/inflammation responses, functioning like a combinational therapy. This study offers a promising means for the topical bacteria transplant to realize effective microbe biotherapy toward the skin diseases feature with microbe milieu disorders, including but not limited to AD disease.

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Symbiotic bacteria were employed to defeat pathogenic bacteria in the diseased skins to treat atopic dermatitis (AD).

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A living symbiotic bacteria-involved skin dressing was designed to serve as extrinsic culture harbors and nutrient suppliers to support R. mucosa survival in the harsh microenvironment to defeat S. aureus, which predominantly colonizes AD skins.

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This study offered a promising means for the topical bacteria transplant to realize effective microbiome-based biotherapy toward the skin diseases feature with microbe milieu disorders.

Anti-allergic function of the cell wall (DeinoWall) from Deinococcus radiodurans

Deinococcus radiodurans is an extremophile, well known to be extremely resistant to external stresses due to its unique physiological system and structure of cellular components. Although the proportion of D. radiodurans has been reported to be negatively correlated with atopic dermatitis, the exact function of D. radiodurans in allergic diseases and its precise mechanisms have not been studied. In the present study, we hypothesize that D. radiodurans or its cellular constituents play a critical role in the skin to prevent allergic inflammatory responses by modulating immunity. Heat-killed D. radiodurans inhibited the production of Th2 cytokines, such as IL-4 and IL-5, induced by ovalbumin (OVA) stimulation in splenocytes from OVA-sensitized mice. Among the cellular constituents of D. radiodurans, such as cell wall (DeinoWall), cell membrane (DeinoMem), and exopolysaccharide (DeinoPol), only DeinoWall inhibited the production of Th2 cytokines and 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD), a Th2-predominant allergic disease in mice. Moreover, serum IgE levels and infiltration of mast cells into skin lesions, the markers of Th2 response induced by DNCB application, were significantly inhibited by treatment with DeinoWall. Remarkably, DeinoWall induced the maturation of bone marrow-derived dendritic cells (BMDCs) that promote Th1-biased immunity, which might balance Th1/Th2 and regulate allergic inflammatory responses. Collectively, these results suggest that DeinoWall acts as a major cellular constituent in the negative regulation of allergic inflammatory responses by D. radiodurans and might be a viable candidate for the treatment of allergic diseases.

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.

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.

Bis-(3-amino-2-pyridine) diselenide improves psychiatric disorders -atopic dermatitis comorbidity by regulating inflammatory and oxidative status in mice

Suppressive effect of bis (3-amino-2-pyridine) diselenide (BAPD) on psychiatric disorders - atopic dermatitis (AD) comorbidity in mice was investigated. To sensitize the animals, 2,4-dinitrochlorobenzene (DNCB) was applied to their dorsal skin on days 1-3. Mice were challenged with DNCB on their ears and dorsal skin on days 14, 17, 20, 23, 26, and 29. BAPD and Dexamethasone were administered to the animals, from days 14-29, and skin severity scores and behavioral tests were determined. Oxidative stress and inflammatory parameters were evaluated on the dorsal skin of mice. Na⁺, K⁺-ATPase activity and corticosterone levels were determined in hippocampus/cerebral cortex and plasma of mice, respectively. BAPD improved cutaneous damage, scratching behavior, inflammatory and oxidative stress markers. BAPD showed anxiolytic- and antidepressant-like effects and restored Na⁺, K⁺-ATPase activity and corticosterone levels. The present study was performed using female mice due the susceptibility for this disease. But, the evaluation of AD model in male mice would help to verify whether the male gender has the same predisposition to present this pathology. Our data demonstrated the suppressive effect of BAPD on psychiatric disorders - AD comorbidity by regulating inflammatory and oxidative status in mice.

Chrysin: Perspectives on Contemporary Status and Future Possibilities as Pro-Health Agent

Chrysin belongs to the group of natural polyphenols. It can be found, among others, in honey, propolis and fruits and has a wide range of biological activities, including the prevention of oxidative stress, inflammation, neurodegeneration and carcinogenesis. Being a part of the human diet, chrysin is considered to be a promising compound to be used in the prevention of many diseases, including cancers, diabetes and neurodegenerative diseases such as Alzheimer's or Parkinson's. Nevertheless, due to the low solubility of chrysin in water and under physiological conditions, its bioavailability is low. For this reason, attempts at its functionalization have been undertaken, aiming to increase its absorption and thus augment its in vivo therapeutic efficacy. The aim of this review is to summarize the most recent research on chrysin, including its sources, metabolism, pro-health effects and the effects of its functionalization on biological activity and pharmacological efficacy, evaluated both in vitro and in vivo.

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.

HMOC, a chrysin derivative, induces tolerogenic properties in lipopolysaccharide-stimulated dendritic cells

Although we previously identified a new hydroxymethoxyl chrysin derivative (HMOC) using ionizing radiation, the anti-inflammatory mechanism of HMOC in dendritic cells remains unclear. In this study, we investigate the effects of HMOC on phenotypic and functional changes in activated bone marrow-derived dendritic cells (BMDCs). In lipopolysaccharide (LPS)-stimulated BMDCs, HMOC treatment inhibited pro-inflammatory cytokines (TNF-α, IL-12p70, and IL-1β), surface molecules (CD80, CD86, MHC-I, and MHC-II), and antigen-presentation to MHC-I and II without a decrease in IL-10. Furthermore, HMOC increased indoleamine 2,3-dioxygenase-1 (IDO1) activity via activation of JNK and p38 signaling in the presence of LPS. Interestingly, LPS-stimulated DCs treated with HMOC inhibited the proliferation and activation of CD4+ and CD8+ T cells, as well as differentiation of CD4+ T cells into Th1-, Th2- and Th17 cells. In addition, LPS-stimulated DCs treated with HMOC induced an increase in CD4+CD25+Foxp3+ regulatory T cells (Tregs). Collectively, our results suggest that HMOC confers tolerogenic properties in BMDCs, which are responsible for inducing Th cell differentiation to Tregs. Our findings provide a better understanding of the anti-inflammatory mechanism of HMOC in DCs and may contribute to development of a valuable therapeutic candidate for atopic dermatitis.

Chrysin Inhibits TNFα-Induced TSLP Expression through Downregulation of EGR1 Expression in Keratinocytes

Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine that acts as a critical mediator in the pathogenesis of atopic dermatitis (AD). Various therapeutic agents that prevent TSLP function can efficiently relieve the clinical symptoms of AD. However, the downregulation of TSLP expression by therapeutic agents remains poorly understood. In this study, we investigated the mode of action of chrysin in TSLP suppression in an AD-like inflammatory environment. We observed that the transcription factor early growth response (EGR1) contributed to the tumor necrosis factor alpha (TNFα)-induced transcription of TSLP. Chrysin attenuated TNFα-induced TSLP expression by downregulating EGR1 expression in HaCaT keratinocytes. We also showed that the oral administration of chrysin improved AD-like skin lesions in the ear and neck of BALB/c mice challenged with 2,4-dinitrochlorobenzene. We also showed that chrysin suppressed the expression of EGR1 and TSLP by inhibiting the extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) 1/2 mitogen-activated protein kinase pathways. Collectively, the findings of this study suggest that chrysin improves AD-like skin lesions, at least in part, through the downregulation of the ERK1/2 or JNK1/2-EGR1-TSLP signaling axis in keratinocytes.

Microneedle-assisted genome editing: A transdermal strategy of targeting NLRP3 by CRISPR-Cas9 for synergistic therapy of inflammatory skin disorders

We report a dissolvable microneedle (MN) patch that can mediate transdermal codelivery of CRISPR-Cas9-based genome-editing agents and glucocorticoids for the effective treatment of inflammatory skin disorders (ISDs). The MN is loaded with polymer-encapsulated Cas9 ribonucleoprotein (RNP) targeting NLRP3 and dexamethasone (Dex)-containing polymeric nanoparticles. Upon insertion into the skin, the MN can be dissolved quickly to release two types of nanoformulations, which are subsequently internalized by keratinocytes and surrounding immune cells to exert their therapeutic effects in the inflammatory subcutaneous layers. Thus, the MN-enabled transdermal codelivery of Cas9 RNP nanocomplexes and Dex nanoparticles result in the disruption of subcutaneous intracellular NLRP3 inflammasomes, which is demonstrated to be critical to alleviate skin inflammations and contributes to glucocorticoid therapy in mouse models of ISDs, including psoriasis and atopic dermatitis. Our study offers innovative insights into the rational design of transdermal delivery systems and defines an effective therapeutic option for the treatment of ISDs.

A novel chrysin thiazole derivative polarizes macrophages to an M1 phenotype via targeting TLR4

Tumor-associated macrophages (TAMs) are an important cause of tumorigenesis and tumor development. M2 macrophages can promote tumor growth while M1 macrophages kill tumor cells, therefore, polarizing macrophages to achieve a functional M1 phenotype could effectively play its anti-tumor role. In the current study, we synthesized a novel chrysin derivative which is termed as ChR-TD. And we found ChR-TD might be a ligand of TLR4 that polarized the TAMs towards M1 phenotype and played its anti-tumor role. Further study indicated that ChR-TD reprogrammed the macrophages into an M1 phenotype via TLR4 activation. Moreover, ChR-TD activated TLR4/NF-κB signaling pathway and promoted the NF-κB/p65 translocated into the nuclear, leading to the activation of NF-κB and proinflammatory cytokines release. In addition, type I interferon signaling was also activated by ChR-TD, leading to the expressions of IFN-α and IFN-β and its targeted genes NOS2, MCP-1 and IP-10 were significantly increased in macrophages. Importantly, these effects were disturbed in TLR4^-/- macrophages, which are constructed by using CRISPR/Cas9 system. And the molecule docking simulation further indicated that ChR-TD could bind to TLR4 and might be a ligand of TLR4. Hence, these findings suggested that ChR-TD might be a ligand of TLR4 and can be used as a potential lead compound for tumors treatment.

Inhibitory Effects of a Novel Chrysin-Derivative, CPD 6, on Acute and Chronic Skin Inflammation

The skin is an important physiological barrier against external stimuli, such as ultraviolet radiation (UV), xenobiotics, and bacteria. Dermal inflammatory reactions are associated with various skin disorders, including chemical-induced irritation and atopic dermatitis. Modulation of skin inflammatory response is a therapeutic strategy for skin diseases. Here, we synthesized chrysin-derivatives and identified the most potent derivative of Compound 6 (CPD 6). We evaluated its anti-inflammatory effects in vitro cells of macrophages and keratinocytes, and in vivo dermatitis mouse models. In murine macrophages stimulated by lipopolysaccharide (LPS), CPD 6 significantly attenuated the release of inflammatory mediators such as nitric oxide (NO) (IC₅₀ for NO inhibition: 3.613 μM) and other cytokines. In cultured human keratinocytes, CPD 6 significantly attenuated the release of inflammatory cytokines induced by the combination of IFN-γ and TNF-α, UV irradiation, or chemical irritant stimulation. CPD 6 inhibited NFκB and JAK2/STAT1 signaling pathways, and activated Nrf2/HO-1 signaling. In vivo relevancy of anti-inflammatory effects of CPD 6 was observed in acute and chronic skin inflammation models in mice. CPD 6 showed significant anti-inflammatory properties both in vitro cells and in vivo dermatitis animal models, mediated by the inhibition of the NFκB and JAK2-STAT1 pathways and activation of Nrf2/HO-1 signaling. We propose that the novel chrysin-derivative CPD 6 may be a potential therapeutic agent for skin inflammation.