Oral Administration of Sargassum horneri Improves the HDM/DNCB-Induced Atopic Dermatitis in NC/Nga Mice

The beneficial effects of ethanolic extract of Sargassum serratifolium in DNCB-induced mouse model of atopic dermatitis

Atopic dermatitis is a chronic complex inflammatory skin disorder that requires sustainable treatment methods due to the limited efficacy of conventional therapies. Sargassum serratifolium, an algal species with diverse bioactive substances, is investigated in this study for its potential benefits as a therapeutic agent for atopic dermatitis. RNA sequencing of LPS-stimulated macrophages treated with ethanolic extract of Sargassum serratifolium (ESS) revealed its ability to inhibit a broad range of inflammation-related signaling, which was proven in RAW 264.7 and HaCaT cells. In DNCB-induced BALB/c or HR-1 mice, ESS treatment improved symptoms of atopic dermatitis within the skin, along with histological improvements such as reduced epidermal thickness and infiltration of mast cells. ESS showed a tendency to improve serum IgE levels and inflammation-related cytokine changes, while also improving the mRNA expression levels of Chi3l3, Ccr1, and Fcεr1a genes in the skin. Additionally, ESS compounds (sargachromanol (SCM), sargaquinoic acid (SQA), and sargahydroquinoic acid (SHQA)) mitigated inflammatory responses in LPS-treated RAW264.7 macrophages. In summary, ESS has an anti-inflammatory effect and improves atopic dermatitis, ESS may be applied as a therapeutics for atopic dermatitis.

The Beneficial Roles of Sargassum spp. in Skin Disorders

As the body's largest organ, the skin is located at the internal and external environment interface, serving as a line of defense against various harmful stressors. Recently, marine-derived physiologically active ingredients have attracted considerable attention in the cosmeceutical industry due to their beneficial effects on skin health. Sargassum, a genus of brown macroalgae, has traditionally been consumed as food and medicine in several countries and is rich in bioactive compounds such as meroterpenoids, sulfated polysaccharides, fucoidan, fucoxanthin, flavonoids, and terpenoids. Sargassum spp. have various beneficial effects on skin disorders. They help with atopic dermatitis by improving skin barrier protection and reducing inflammation. Several species show potential in treating acne by inhibiting bacterial growth and reducing inflammation. Some species, such as Sargassum horneri, demonstrate antiallergic effects by modulating mast cell activity. Certain Sargassum species exhibit anticancer activity by inhibiting tumor growth and promoting apoptosis, and some species help with wound healing by promoting angiogenesis and reducing oxidative stress. Overall, Sargassum spp. demonstrate potential for treating and managing various skin conditions. Therefore, the bioactive compounds of Sargassum spp. may be natural ingredients with a wide range of functional properties for preventing and treating skin disorders. The present review focused on the various biological effects of Sargassum extracts and derived compounds on skin disorders.

Crisaborole loaded nanoemulgel for the mitigation of atopic dermatitis in mice model

OBJECTIVE

The present work aims to formulate nanoemulgel of crisaborole (CB) and evaluate its effectiveness against 2,4-Di-nitrochlorobenzene induced (DNCB) atopic dermatitis (AD) in mice.

SIGNIFICANCE

AD is a chronic inflammation of the skin affecting the quality of life. CB is a topical PDE4 inhibitor marketed as a 2% ointment. It, however, possesses poor aqueous solubility. An o/w nanoemulsion shall exhibit an enhanced therapeutic effect owing to the increased solubility of CB and an augmented skin penetration. The addition of a gelling agent to form a nanoemulgel further provides ease of application to the patients.

METHODS

Nanoemulsion was prepared by aqueous titration method using caproyl PGMC, cremophore EL and propylene glycol as the oil, surfactant, and cosurfactant respectively. The formulations were characterized by their size, zeta potential and polydispersity index (PDI). 1% Carbopol 934 was used as the gelling agent to formulate nanoemulgel comprising of optimized nanoemulsion (NE 9). Ex vivo skin permeation of the CB nanoemulgel was compared with the CB ointment. Its therapeutic effect was evaluated in Balb/c mice.

RESULTS

NE 9 comprised of 7.49% oil, 37.45% Smix (1:3) and water 55.06%. Its particle size, PDI and zeta potential were 15.45 ± 5.265 nm, 0.098 and -17.9 ± 8.00 mV respectively. The nanoemulgel exhibited a 3-fold higher permeation flux as compared to the ointment. In vivo studies demonstrated that the nanoemulgel provided better therapeutic effect than the ointment.

CONCLUSION

We can thereby conclude that nanoemulgel formulation can be a successful drug delivery strategy for enhancing the therapeutic effect of CB.

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.

Immune-Enhancing Effect of Sargassum horneri on Cyclophosphamide-Induced Immunosuppression in BALB/c Mice and Primary Cultured Splenocytes

Sargassum horneri (SH) is a seaweed that has several features that benefit health. In this study, we investigated the immune-enhancing effect of SH, focusing on the role of spleen-mediated immune functions. Chromatographic analysis of SH identified six types of monosaccharide contents, including mannose, rhamnose glucose, galactose xylose and fucose. SH increased cell proliferation of primary cultured naïve splenocytes treated with or without cyclophosphamide (CPA), an immunosuppression agent. SH also reversed the CPA-induced decrease in Th1 cytokines. In vivo investigation revealed that SH administration can increase the tissue weight of major immune organs, such as the spleen and thymus. A similar effect was observed in CPA-injected immunosuppressed BALB/c mice. SH treatment increased the weight of the spleen and thymus, blood immune cell count and Th1 cytokine expression. Additionally, the YAC-1-targeting activities of natural killer cells, which are important in innate immunity, were upregulated upon SH treatment. Overall, our study demonstrates the immune-enhancing effect of SH, suggesting its potential as a medicinal or therapeutic agent for pathologic conditions involving immunosuppression.

Sargassum horneri extract containing polyphenol alleviates DNCB-induced atopic dermatitis in NC/Nga mice through restoring skin barrier function

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin barrier dysfunction. Sargassum horneri (S. horneri) is a brown alga that has been widely used in traditional medicine of eastern Asian countries. Recent studies proved that a brown alga S. horneri has anti-inflammatory activity. In this study, we investigated the effect of S. horneri ethanol extract (SHE) against AD in 2,4-dinitrobenzene (DNCB) induced AD in NC/Nga mice. We observed that SHE treatment decreased the epidermal thickness and epidermal hyperplasia that had been worsened through DNCB application. Moreover, SHE significantly inhibited the proliferation of mast cells and decreased the expression of IL-13 on CD4⁺ cells prompted by elevated thymic stromal lymphopoietin (TSLP) expression in DNCB-induced AD in mice. We also demonstrated that SHE directly inhibited the expression of keratinocyte-produced TSLP known to exacerbate skin barrier impairment. Especially, the decrease of filaggrin, an integral component of proper skin barrier function through a function in aggregating keratin filaments, observed in DNCB-induced AD mice was significantly improved when treated with SHE. More importantly, we proved that SHE was able to decrease the serum levels of IgG₁ and IgG₂ₐ, two crucial factors of AD, indicating the protective effect of SHE. Taken together, our findings suggest that SHE may protect NC/Nga mice against DNCB-induced AD via promoting skin barrier function.

Potential Beneficial Effects of Sargassum spp. in Skin Aging

Seaweeds are receiving much attention as a rich source of bioactive compounds with cosmeceutical potential. Recent studies have revealed that Sargassum spp., a genus of brown algae in the family Sargassaceae, has multiple functions in preventing and improving skin aging. Sargassum spp. contains many bioactive compounds, such as fucoidan, fucoxanthin, terpenoids, flavonoids, and meroterpenoids. These Sargassum spp. extracts and derivative compounds have excellent potential for skincare, as they exhibit skin health-promoting properties, including antioxidants, anti-inflammation, whitening, skin barrier repair, and moisturizing. Therefore, searching for bioactive compounds in marine resources such as Sargassum spp. could be an attractive approach to preventing and improving skin aging. The current review focused on the various biological abilities of Sargassum extracts or derived compounds for anti-skin aging.

Deacetylasperulosidic Acid Ameliorates Pruritus, Immune Imbalance, and Skin Barrier Dysfunction in 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis NC/Nga Mice

The prevalence of atopic dermatitis (AD), a disease characterized by severe pruritus, immune imbalance, and skin barrier dysfunction, is rapidly increasing worldwide. Deacetylasperulosidic acid (DAA) has anti-atopic activity in the three main cell types associated with AD: keratinocytes, mast cells, and eosinophils. Our study investigated the anti-atopic activity of DAA in 2,4-dinitrochlorobenzene-induced NC/Nga mice. DAA alleviated the symptoms of AD, including infiltration of inflammatory cells (mast cells and eosinophils), epidermal thickness, ear thickness, and scratching behavior. Furthermore, DAA reduced serum IgE, histamine, and IgG1/IgG2a ratio and modulated the levels of AD-related cytokines and chemokines, namely interleukin (IL)-1β, IL-4, IL-6, IL-9, IL-10, IL-12, tumor necrosis factor-α, interferon-γ, thymic stromal lymphopoietin, thymus and activation-regulated chemokine, macrophage-derived chemokine, and regulated on activation the normal T cell expressed and secreted in the serum. DAA restored immune balance by regulating gene expression and secretion of Th1-, Th2-, Th9-, Th17-, and Th22-mediated inflammatory factors in the dorsal skin and splenocytes and restored skin barrier function by increasing the expression of the pro-filaggrin gene and barrier-related proteins filaggrin, involucrin, and loricrin. These results suggest DAA as a potential therapeutic agent that can alleviate the symptoms of AD by reducing pruritus, modulating immune imbalance, and restoring skin barrier function.

Sargachromenol Purified from Sargassum horneri Inhibits Inflammatory Responses via Activation of Nrf2/HO-1 Signaling in LPS-Stimulated Macrophages

In this study, we isolated sargachromenol (SC) from Sargassum horneri and evaluated its anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. SC did not show cytotoxicity at all concentrations and effectively increased the cell viability by reducing the nitric oxide (NO) and intracellular reactive oxygen species (ROS) production in LPS-stimulated RAW 264.7 macrophages. In addition, SC decreased the mRNA expression levels of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and inflammatory mediators (iNOS and COX-2). Moreover, SC suppressed the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) and mitogen-activated protein kinase (MAPK) signaling, whereas activated the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling in LPS-stimulated RAW 264.7 macrophages. Interestingly, the anti-inflammatory effect of SC was abolished by the inhibition of HO-1 in LPS-stimulated RAW 264.7 macrophages. According to the results, this study suggests that the antioxidant capacity of SC leads to its anti-inflammatory effect and it potentially may be utilized in the nutraceutical and pharmaceutical sectors.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

Sargassum horneri (Turner) C. Agardh ethanol extract attenuates fine dust-induced inflammatory responses and impaired skin barrier functions in HaCaT keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Sargassum horneri (Turner) C. Agardh is well known in East Asia as an edible brown alga rich in bioactive compounds. It has an ethnopharmacological significance in traditional Chinese medicine to treat inflammatory disorders varying from edema, furuncles, dysuria to cardiovascular diseases.

AIM OF THE STUDY

Surge of fine dust (FD), in densely populated areas, have been reported to cause adverse health conditions ranging from respiratory diseases to inflammatory skin disorders. The current study investigates the protective effects of an ethanol extract from S. horneri (SHE) on FD-induced inflammatory responses and impaired skin hydration in HaCaT keratinocytes.

MATERIALS AND METHODS

Intracellular reactive oxygen species (ROS) generation was evaluated with the 2',7'-Dichlorofluorescin diacetate (DCFH-DA) stain. Anti-inflammatory properties of SHE in FD-stimulated HaCaT keratinocytes were investigated for the suppression of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) pathways and downregulation of pro-inflammatory cytokines. As a means of studying FD-induced skin barrier disruption and the effects of SHE on stratum corneum hydration-controlling factors, tight junction regulatory mediators, and hyaluronic acid (HA) production were evaluated using keratinocytes.

RESULTS

SHE suppressed the intracellular ROS production, simultaneously improving cell viability in FD-stimulated keratinocytes. Also, SHE upregulated anti-inflammatory cytokine interleukin (IL)-4 while downregulating inflammatory cytokines IL-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α; epidermal and epithelial cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP); thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and regulated upon activation, normally T-expressed, and presumably secreted expression and suppressed (RANTES) chemokine, MAPK and NF-κB mediators in a dose-dependent manner. Furthermore, SHE ameliorated filaggrin, involucrin, lymphoepithelial Kazal-type-related inhibitor (LEKTI), signifying its beneficial effects on deteriorated skin hydration caused by FD-induced inflammation. SHE further exhibited its skin protective effects regulating the tight junction proteins; Occludin, zonula occludens (ZO)-1, claudin-1, claudin-4, claudin-7, and claudin-23 while increasing the production of HA minimizing skin damage.

CONCLUSIONS

Anti-inflammatory effects of, SHE against FD-induced keratinocyte inflammation is attributable to the suppression of upstream MAPK and NF-κB mediators. SHE indicated potential anti-inflammatory properties attenuating deteriorated skin barrier function in HaCaT keratinocytes. The effects are attributable to the polyphenols and other antioxidant compounds in SHE. Further studies could envisage the use of SHE for developing rejuvenating cosmetics.

UVB protective effects of Sargassum horneri through the regulation of Nrf2 mediated antioxidant mechanism

The present study aimed to evaluate the protective effect of a methanol extract of Sargassum horneri (SHM), which contains 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one (HTT) and apo-9'-fucoxanthinone, against ultraviolet B (UVB)-induced cellular damage in human keratinocytes and its underlying mechanism. SHM significantly improved cell viability of UVB-exposed human keratinocytes by reducing the generation of intracellular reactive oxygen species (ROS). Moreover, SHM inhibited UVB exposure-induced apoptosis by reducing the formation of apoptotic bodies and the populations of the sub-G1 hypodiploid cells and the early apoptotic cells by modulating the expression of the anti- and pro-apoptotic molecules, Bcl-2 and Bax, respectively. Furthermore, SHM inhibited NF-κB p65 activation by inducing the activation of Nrf2/HO-1 signaling. The cytoprotective and antiapoptotic activities of SHM are abolished by the inhibition of HO-1 signaling. In further study, SHM restored the skin dryness and skin barrier disruption in UVB-exposed human keratinocytes. Based to these results, our study suggests that SHM protects the cells against UVB-induced cellular damages through the Nrf2/HO-1/NF-κB p65 signaling pathway and may be potentially useful for the prevention of UVB-induced skin damage.

Sargassum horneri as a Functional Food Ameliorated IgE/BSA-Induced Mast Cell Activation and Passive Cutaneous Anaphylaxis in Mice

Sargassum horneri (S. horneri), an edible brown alga, has been proposed as a functional food with an improvement effect on abnormal skin immune responses. The present study investigates the anti-allergic effect of an ethanol extract from S. horneri (SHE) on immunoglobulin E (IgE)/bovine serum albumin (BSA)-mediated activation in bone marrow-derived cultured-mast cells (BMCMCs) and passive cutaneous anaphylaxis (PCA) reaction in mice. SHE markedly and dose-dependently suppressed the degranulation of BMCMCs by reducing the β-hexosaminidase and histamine release without cytotoxicity. In addition, SHE significantly decreased the FcεRI expression on the surface of BMCMCs and its IgE binding. Moreover, SHE reduced the mRNA expression and the production of allergic cytokines; interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-10, IL-13; interferon (IFN)-γ and/or tumor necrosis factor (TNF)-α; and a chemokine, thymus and activation-regulated chemokine (TARC), by suppressing the activation of Src-family kinases and nuclear factor (NF)-κB signaling. In further study, the application of SHE reduced the PCA reaction in an IgE/BSA-induced type I allergic mice model. Taken together, we suggest that SHE has an anti-allergic effect in type I allergic responses.