Anti-inflammatory activity of compounds isolated from Astragalus sinicus L. in cytokine-induced keratinocytes and skin

Formononetin attenuates psoriasiform inflammation by regulating interferon signaling pathway

BACKGROUND

Psoriasis is a long-lasting, inflammatory, continuous illness caused through T cells and characterized mainly by abnormal growth and division of keratinocytes. Currently, corticosteroids are the preferred option. However, prolonged use of traditional topical medication can lead to adverse reactions and relapse, presenting a significant therapeutic obstacle. Improved alternative treatment options are urgently required. Formononetin (FMN) is a representative component of isoflavones in Huangqi (HQ) [Astragalus membranaceus (Fisch.) Bge.]. It possesses properties that reduce inflammation, combat oxidation, inhibit tumor growth, and mimic estrogen. Although FMN has been shown to ameliorate skin barrier devastation via regulating keratinocyte apoptosis and proliferation, there are no reports of its effectiveness in treating psoriasis.

OBJECTIVE

Through transcriptomics clues and experimental investigation, we aimed to elucidate the fundamental mechanisms underlying FMN's action on psoriasis.

MATERIALS AND METHODS

Cell viability was examined using CCK8 assay in this study. The results of analysis of differentially expressed genes (DEGs) between FMN-treated HaCaT cells and normal HaCaT cells using RNA-sequencing (RNA-seq) were presented on volcano plots and heatmap. Enrichment analysis was conducted on DEGs using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO), and results were validated through RT-qPCR verification. After 12 days of FMN treatment in psoriasis mouse model, we gauged the PASI score and epidermis thickness. A variety of techniques were used to assess FMN's effectiveness on inhibiting inflammation and proliferation related to psoriasis, including RT-qPCR, HE staining, western blot, and immunohistochemistry (IHC).

RESULTS

The findings indicated that FMN could suppress the growth of HaCaT cells using CCK8 assay (with IC50 = 40.64 uM) and 20 uM FMN could reduce the level of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) to the greatest extent. FMN-treated HaCaT cells exhibited 985 up-regulated and 855 down-regulated DEGs compared to normal HaCaT cells. GO analysis revealed that DEGs were linked to interferon (IFN) signaling pathway. Furthermore, FMN improved pathological features, which encompassed decreased erythema, scale, and thickness scores of skin lesions in psoriasis mouse model. In vivo experiments confirmed that FMN down-regulated expression of IFN-α, IFN-β, IFN-γ, decreased secretion of TNF-α and IL-17 inflammatory factors, inhibited expression of IFN-related chemokines included Cxcl9, Cxcl10, Cxcl11 and Cxcr3 and reduced expression of transcription factors p-STAT1, p-STAT3 and IFN regulatory factor 1 (IRF1) in the imiquimod (IMQ) group.

CONCLUSIONS

In summary, these results suggested that FMN played an anti-inflammatory and anti-proliferative role in alleviating psoriasis by inhibiting IFN signaling pathway, and FMN could be used as a potential therapeutic agent.

Human NCF190H Variant Promotes IL-23/IL-17-Dependent Mannan-Induced Psoriasis and Psoriatic Arthritis

Recently, a major single nucleotide variant on the NCF1 gene, leading to an amino acid replacement from arginine to histidine at position 90 (NCF1^R90H), associated with low production of reactive oxygen species (ROS), was found to be causative for several autoimmune diseases. Psoriasis in the skin (PsO) and psoriatic arthritis (PsA) were induced with mannan by intraperitoneal injection or epicutaneous application, evaluated by visual and histology scoring. Immunostaining was used to identify macrophages, NCF1, and keratinocytes. The population of immune cells was quantified by flow cytometry, gene expression was analyzed by RT-qPCR, and the JAK/STAT signaling pathway was investigated by immunohistochemical staining and western blot. We found that the low ROS responder NCF1^90H variant promotes PsO and PsA (the MIP model). The NCF1^90H-expressing mice had hyperactivated macrophages, expanded keratinocytes, and dramatically increased numbers of γδT17 cells with upregulated IL-17A, IL-23, and TNF-α. In addition, the JAK1/STAT3 signaling pathway was also upregulated in cells in the psoriatic skin tissues of Ncf1^90H mice. To summarize, a defined SNP (NCF1-339, also named NCF1^90H) was found to activate the IL-23/IL-17 axis and JAK-STAT signaling pathways, leading to hyperactivation of macrophages and keratinocytes and causing mouse psoriasis and psoriatic arthritis.

Kaempferol modulates IFN-γ induced JAK-STAT signaling pathway and ameliorates imiquimod-induced psoriasis-like skin lesions

Immune-mediated inflammation contributes to the development of psoriasis. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects including recurrent infections. Kaempferol (KP), a natural flavonol, present in various plants is proposed to be useful for the treatment of psoriasis patients. Nevertheless, an explicit understanding of KP induced mechanisms is a prerequisite for its use in clinics. Therefore, we investigated the therapeutic effects and potential mode of action of KP using IFN-γ induced HaCaT cells and imiquimod-induced psoriasis-like skin lesions in mice. In this study, we found KP reduced intracellular ROS production, inhibited rhIFN-γ-induced IFN-γR1 expression, and up-regulated SOCS1 levels in HaCaT cells. In addition, KP inhibited rhIFN-γ-induced phosphorylation of JAK-STAT signaling molecules in HaCaT cells. Most importantly, KP alleviated imiquimod-induced psoriasis-like skin lesions in mice, histopathology and proportion of DCs in the skin. Besides, it reduced the population of γδT17 cells in the lymph nodes of the psoriatic mice and also decreased the gene expression of many proinflammatory cytokines, including interleukin IL-23, IL-17A, TNF-α, IL-6, and IL-1β in addition to down-regulation of the proinflammatory JAK-STAT signaling pathway. Thus, KP modulated IFN-γ induced JAK-STAT signaling pathway by inducing IFN-γR1 expression and up-regulating SOCS1 expression. In addition, KP also ameliorated imiquimod-induced psoriasis by reducing the dendritic cell numbers, and γδT17 cell population, along with down- modulation of the JAK-STAT pathway.

Advances in the modulation of ROS and transdermal administration for anti-psoriatic nanotherapies

Reactive oxygen species (ROS) at supraphysiological concentration have a determinate role in contributing to immuno-metabolic disorders in the epithelial immune microenvironment (EIME) of psoriatic lesions. With an exclusive focus on the gene-oxidative stress environment interaction in the EIME, a comprehensive strategy based on ROS-regulating nanomedicines is greatly anticipated to become the mainstay of anti-psoriasis treatment. This potential therapeutic modality could inhibit the acceleration of psoriasis via remodeling the redox equilibrium and reshaping the EIME. Herein, we present a marked overview of the current progress in the pathomechanisms of psoriasis, with particular concerns on the potential pathogenic role of ROS, which significantly dysregulates redox metabolism of keratinocytes (KCs) and skin-resident or -infiltrating cells. Meanwhile, the emergence of versatile nanomaterial-guided evolution for transdermal drug delivery has been attractive for the percutaneous administration of antipsoriatic therapies in recent years. We emphasize the underlying molecular mechanism of ROS-based nanoreactors for improved therapeutic outcomes against psoriasis and summarize up-to-date progress relating to the advantages and limitations of nanotherapeutic application for transdermal administration, as well as update an insight into potential future directions for nanotherapies in ROS-related skin diseases.

Signaling pathways and targets of natural products in psoriasis treatment

Aim: Psoriasis is a common chronic inflammatory skin disorder, which has adverse effects on patients’ quality of life. Natural products exhibit significant therapeutic capacities with small side effects and might be preferable alternative treatments for patients with psoriasis. This study summarizes the signaling pathways with the potential targets of natural products and their efficacy for psoriasis treatment. Methods: The literature for this article was acquired from PubMed and Web of Science, from January 2010 to December 2020. The keywords for searching included “psoriasis” and “natural product”, “herbal medicine”, “herbal therapy”, “medicinal plant”, “medicinal herb” or “pharmaceutical plant”. Results: Herbal extracts, natural compounds, and herbal prescriptions could regulate the signaling pathways to alleviate psoriasis symptoms, such as T helper 17 (Th17) differentiation, Janus kinase (JAK)/signal transducer and activator of transcription (STAT), nuclear factor-kappa B (NF-κB), mitogen‑activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), and other signaling pathways, which are involved in the inflammatory response and keratinocyte hyperproliferation. The anti-psoriatic effect of natural products in clinical trials was summarized. Conclusions: Natural products exerted the anti-psoriatic effect by targeting multiple signaling pathways, providing evidence for the investigation of novel drugs. Further experimental research should be performed to screen and characterize the therapeutic targets of natural products for application in psoriasis treatment.

Simultaneous Determination and Pharmacokinetic Study of Six Components in Beagle Dog Plasma by UPLC-MS/MS after Oral Administration of Astragalus Membranaceus Aqueous Extract

Astragalus Membranaceus (AM) is widely applied in Chinese herbal compound formulas for treating various kinds of diseases. However, relative pharmacokinetics (PK) data on AM in non-rodents is still lacking. Here, an UPLC-MS/MS method for determining six main compounds of AM was developed. The chromatographic separation was carried out by a Waters Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 μm) with gradient elution of water - formic acid (99.98:0.02, v/v), and acetonitrile - formic acid (99.98:0.02, v/v) at a flow rate of 0.3 mL/min within 11 min. Analyses of all compounds were conducted in multiple reaction monitoring (MRM) mode with a positive/negative (P/N) ion-switching mode of electrospray ionization (ESI) source in a single run. The analytical method was validated in terms of specificity, linearity, accuracy, precision, stability, etc. The method showed excellent linearity (r > 0.999) over certain concentration ranges. The intra-day and inter-day precisions were evaluated, and the RSD values were less than 12.4%. Furthermore, the validated method was successfully applied to determine the six components in plasma after oral administration of AM aqueous extract to beagle dogs and obtained pharmacokinetic parameters. Together, this study provides a reference for medication in the clinical practice of AM.

Short Overview of Some Assays for the Measurement of Antioxidant Activity of Natural Products and Their Relevance in Dermatology

Impaired systemic redox homeostasis is implicated in the onset and development of various diseases, including skin diseases. Therefore, continuous search for natural products with antioxidant bioactivities applicable in biomedicine is attractive topic of general interest. Research efforts aiming to validate antioxidant potentials of natural products has led to the development of several assays based on various test principles. Hence, understanding the advantages and limitations of various assays is important for selection of assays useful to study antioxidant and related bioactivities of natural products of biomedical interest. This review paper gives a short overview on some chemical and cellular bioassays used to estimate the antioxidant activity of chosen natural products together with a brief overview on the use of natural products with antioxidant activities as adjuvant medicinal remedies in dermatology.

An integrated strategy for the identification and screening of anti-allergy components from natural products based on calcium fluctuations and cell extraction coupled with HPLC-Q-TOF-MS

Allergic diseases are a significant public health problem worldwide. Traditional Chinese medicines (TCMs) with reported anti-allergy effects may be important sources for the development of new anti-allergy drugs. Thus, establishing an analytical method that can simultaneously identify and screen anti-allergic compounds in TCMs is important. The increased concentrations of intracellular calcium ions resulting in mast cell degranulation releasing active mediators play a key role in allergic diseases, which can be used as a potential index to identify anti-allergic herbs and compounds. In this study, we provide a new strategy that was applied to screening natural anti-allergic compounds based on fluorescence calcium ion (Ca²⁺) fluctuation integrated with cell extract and high-performance liquid chromatography-mass spectrometry (HPLC-MS). A low-cost, convenient fluorescence detection Ca²⁺ signaling method was established and successfully applied to identify three herbs. Then, the method was integrated with biospecific cell fishing and HPLC-MS to screen potential active components that have the effect of stabilizing the cell membrane of rat basophilic leukemia granulocytes (RBL-2H3). Seven components, namely, albiflorin and paeoniflorin from Radix Paeoniae Alba, ononin and formononetin from Radix Astragali, cimifugin, 4'-O-β-D-glucosyl-5-O-methylvisamminol, and prim-O-glucosylcimifugin from Radix Saposhnikoviae were fished. These seven compounds have the effect of inhibiting cell Ca²⁺ influx. 4'-O-β-D-Glucosyl-5-O-methylvisamminol, prim-O-glucosylcimifugin, paeoniflorin, ononin, and formononetin significantly inhibit the release of β-hexosaminidase, which is equivalent to the positive drug. In conclusion, the integrated strategy of fluorescence detection calcium ion kinetic method binding with biospecific cell fishing was an effective mode to identify and screen natural anti-allergic compounds.

Astragalus species: Insights on its chemical composition toward pharmacological applications

Astragalus L. is widely distributed throughout the temperate regions of Europe, Asia, and North America. The genus is widely used in folk medicine and in dietary supplements, as well as in cosmetics, teas, coffee, vegetable gums, and as forage for animals. The major phytoconstituents of Astragalus species with beneficial properties are saponins, flavonoids, and polysaccharides. Astragalus extracts and their isolated components exhibited promising in vitro and in vivo biological activities, including antiaging, antiinfective, cytoprotective, antiinflammatory, antioxidant, antitumor, antidiabesity, and immune-enhancing properties. Considering their proven therapeutic potential, the aim of this work is to give a comprehensive summary of the Astragalus spp. and their active components, in an attempt to provide new insight for further clinical development of these xenobiotics. This is the first review that briefly describes their ethnopharmacology, composition, biological, and toxicological properties.

Formononetin attenuates atopic dermatitis by upregulating A20 expression via activation of G protein-coupled estrogen receptor

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a complex skin disease with highly heterogeneous inflammation, which ranks among the largest component of the nonfatal diseases worldwide. The medications currently used to treat AD primarily include antihistamines, vitamin D and anti-inflammatory drugs, etc. But, the usage of these drugs is usually accompanied by various side-effects. Formononetin (FMN), a natural active ingredient of Astragalus membranaceus (Fisch.) Bunge, decreases the AD relapse rate, reduces recurring severity incidence and resists the inflammation in the initial stage of AD. However, the underlying mechanism of FMN on repressing the development of AD is still unknown.

AIM OF THE STUDY

To investigate the potential mechanism of FMN on relieving the initial responses of AD and elucidate its possible therapeutic targets in vivo and in vitro.

MATERIALS AND METHODS

A fluorescein isothiocyanate (FITC)-induced mouse model of the initial stage of AD was established in vivo. Human keratinocytes (HaCaT) cells were co-stimulated with tumor necrosis factor alpha (TNF-α) and polyinosinic-polycytidylic acid (Poly(I:C)) in vitro. The production of thymic stromal lymphopoietin (TSLP) and immunoglobulin E (IgE) were detected by enzyme-linked immunosorbnent assay (ELISA). The protein expression was measured through immunohistochemistry and western blotting. The mRNA expression was examined by real-time quantitative polymerase chain reaction (RT-qPCR). The impact of TNF-α-induced protein 3 (TNFAIP3/A20) was reflected using its small interfering RNA (siRNA). The role of G protein-coupled estrogen receptor (GPER) was explored using its agonist (G1), antagonist (G15) or siRNA (siGPER) in vitro.

RESULTS

We found that FMN upregulated the expression of A20 protein and mRNA in the initial stage of AD model, especially in the epithelial region of ear tissue, and inhibited the production of TSLP simultaneously. Consistently, FMN significantly upregulated A20 protein and its mRNA expression while reduced TSLP protein and its mRNA expression in vitro, and this effect could be antagonized by A20 siRNA (siA20). Moreover, compared with PPT (ERα agonist) and DPN (ERβ agonist), G1 could significantly increase the expression of A20. In addition, compared with MPP (ERα antagonist) and PHTPP (ERβ antagonist), G15 could markedly reduce the expression of A20. Furthermore, the effects of FMN on A20 were interfered by siGPER and G15 in vitro and in vivo.

CONCLUSIONS

These results demonstrated that FMN attenuated AD by upregulating A20 expression via activation of GPER. This new strategy might have effective therapeutic potential for AD and other inflammatory disorders.

Sophoricoside from Sophora japonica ameliorates allergic asthma by preventing mast cell activation and CD4+ T cell differentiation in ovalbumin-induced mice

Asthma is a chronic inflammatory lung disorder with continuously increasing prevalence worldwide. Novel strategies are needed to prevent or improve asthma. The aim of this study was to investigate the effects of sophoricoside from Sophora japonica on allergic asthma. The mature seeds of S. japonica contain a large amount of sophoricoside. Sophoricoside reduced allergic and asthmatic symptoms by suppressing airway inflammation and antibody-antigen reaction in mouse models. In particular, sophoricoside suppressed immune cell recruitment into the airway lumens of the lungs and production of pro-inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) of ovalbumin (OVA)-induced mice. It also decreased the amounts of histamine and arachidonic acid metabolites released in OVA-induced mice and antibody-antigen stimulated mast cells. In addition, sophoricoside decreased differentiation of naïve CD4+ T cells into T helper type 1 (Th1), Th2, and Th17 cells. Overall, we demonstrated that sophoricoside improved allergic asthma by suppressing mast cell activation and CD4+ T cell differentiation.

Alginic Acid from Padina boryana Abate Particulate Matter-Induced Inflammatory Responses in Keratinocytes and Dermal Fibroblasts

Particulate matter (PM) is a significant participant in air pollution and is hence an inducer of serious health issues. This study aimed to evaluate the dust protective effects of alginate from Padina boryana (PBA) via inflammatory-associated pathways to develop anti-fine dust skincare products. In between the external and internal environments, the skin is considered to be more than a physical barrier. It was observed that PM stimulates inflammation in the skin via activating NF-κB and MAPK pathways. The potential of PBA to inhibit the studied pathways were evident. The metal ion content of PM was considerably reduced by PBA and thus attributed to its chelation ability. Current research demonstrated the potential of P. boryana alginates to be implemented as a protective barrier against inflammation imposed with heavy metal and bacterial-derived endotoxin bound to the surface of the PM. Concisely, the results suggest that the bioactive components derived from the brown algae Padina boryana increased the cellular resistance to PM-stimulated inflammation-driven skin damage.

Identification of candidate medicinal herbs for skincare via data mining of the classic Donguibogam text on Korean medicine

Background

Korean cosmetics are widely exported throughout Asia. Cosmetics exploiting traditional Korean medicine lead this trend; thus, the traditional medicinal literature has been invaluable in terms of cosmetic development. We sought candidate medicinal herbs for skincare.

Methods

We used data mining to investigate associations between medicinal herbs and skin-related keywords (SRKs) in a classical text. We selected 26 SRKs used in the Donguibogam text; these referred to 626 medicinal herbs. Using a term frequency-inverse document frequency approach, we extracted data on herbal characteristics by assessing the co-occurrence frequencies of 52 medicinal herbs and the 26 SRKs.

Results

We extracted the characteristics of the 52 herbs, each of which exhibited a distinct skin-related action profile. For example Ginseng Radix was associated at a high-level with tonification and anti-aging, but Rehmanniae Radix exhibited a stronger association with anti-aging. Of the 52 herbs, 46 had been subjected to at least one modern study on skincare-related efficacy.

Conclusions

We made a comprehensive list of candidate medicinal herbs for skincare via data mining a classical medical text. This enhances our understanding of such herbs and will help with discovering new candidate herbs.

The anti-TH17 polarization effect of Indigo naturalis and tryptanthrin by differentially inhibiting cytokine expression

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese herbal medicine Qing-Dai (also known as Indigo naturalis) extracted from indigo-bearing plants including Baphicacanthus cusia (Ness) Bremek was previously reported to exhibit anti-psoriatic effects in topical treatment. TH17 was later established as a key player in the pathogenesis of psoriasis. We investigated the anti-TH17 effect of Indigo naturalis and its active compounds. The aim of this study is to evaluate the toxicity of Indigo naturalis (IN) and its derivatives on five cell types involved in psoriasis, and to study the anti-inflammatory mechanism for the toxicity.

MATERIALS AND METHODS

Following the fingerprint and quantity analysis of indirubin, indigo, and tryptanthrin in IN extract, we used MTS kits to measure the anti-proliferative effect of IN and three active compounds on five different cell types identified in psoriatic lesions. Quantitative RT-PCR analysis was used to measure the expression of various genes identified in the activated keratinocytes and TH17 polarized gene expression in RORγt-expressing T cells.

RESULTS

We showed that IN differentially inhibited the proliferation of keratinocytes and endothelial cells but not monocytes, fibroblasts nor Jurkat T cells. Among three active compounds identified in IN, tryptanthrin was the most potent compound to reduce their proliferation. In addition to differentially reducing IL6 and IL8 expression, both IN and tryptanthrin also potently decreased the expression of anti-microbial S100A9 peptide, CCL20 chemokine, IL1B and TNFA cytokines, independent of NF-κB-p65-activation. Their attenuating effect was also detected on the expression of signature cytokines or chemokines induced during RORγT-induced TH17 polarization.

CONCLUSIONS

We were the first to confirm a direct anti-TH17 effect of both IN herbal extract and tryptanthrin.

Role of PGE-2 and Other Inflammatory Mediators in Skin Aging and Their Inhibition by Topical Natural Anti-Inflammatories

Human skin aging is due to two types of aging processes, “intrinsic” (chronological) aging and “extrinsic” (external factor mediated) aging. While inflammatory events, triggered mainly by sun exposure, but also by pollutants, smoking and stress, are the principle cause of rapid extrinsic aging, inflammation also plays a key role in intrinsic aging. Inflammatory events in the skin lead to a reduction in collagen gene activity but an increase in activity of the genes for matrix metalloproteinases. Inflammation also alters proliferation rates of cells in all skin layers, causes thinning of the epidermis, a flattening of the dermo-epidermal junction, an increase in irregular pigment production, and, finally, an increased incidence of skin cancer. While a large number of inflammatory mediators, including IL-1, TNF-alpha and PGE-2, are responsible for many of these damaging effects, this review will focus primarily on the role of PGE-2 in aging. Levels of this hormone-like mediator increase quickly when skin is exposed to ultraviolet radiation (UVR), causing changes in genes needed for normal skin structure and function. Further, PGE-2 levels in the skin gradually increase with age, regardless of whether or not the skin is protected from UVR, and this smoldering inflammation causes continuous damage to the dermal matrix. Finally, and perhaps most importantly, PGE-2 is strongly linked to skin cancer. This review will focus on: (1) the role of inflammation, and particularly the role of PGE-2, in accelerating skin aging, and (2) current research on natural compounds that inhibit PGE-2 production and how these can be developed into topical products to retard or even reverse the aging process, and to prevent skin cancer.

Anti-inflammatory potential of alginic acid from Sargassum horneri against urban aerosol-induced inflammatory responses in keratinocytes and macrophages

The airborne particulate pollutants originating in the deserts of Mongolia and China which becomes contaminated with industrial effluents and traffic emissions while moving with the wind currents towards East Asia has recently become a serious environmental and health issue in the region. They cause asthma, collateral lung tissue damage, oxidative stress, allergic reactions, and inflammation. The current study was undertaken to evaluate the protective effects of alginate extracted from the invasive alga Sargassum horneri (SHA) against fine dust collected from Beijing, China (Chinese fine dust; CFD). It was found that CFD induces inflammation in HaCaT keratinocytes and inhibits macrophage activation. All of the particulate matter (PM) comprising CFD was < PM13 majority being < PM2.5 which is defined for mineral elements and polycyclic aromatic hydrocarbons. SHA attenuated PGE2 levels in CFD-induced HaCaT keratinocytes. The IC50 for SHA was 36.63 ± 4.11 µg mL-l. SHA also reduced the levels of COX-2, IL-6, and TNF-α, and inhibited certain key molecular mediators of the NF-κB and MAPK pathways in keratinocytes. SHA substantially reduced the levels of CFD-derived metal ions like Pb2+ and Ca2+ in keratinocytes attributable to its metal ion chelating properties. CFD-induced HaCaT keratinocyte culture media increased inflammatory responses in RAW 264.7 macrophages. These cells presented with increased levels of NO, iNOS, COX-2, PGE2, and pro-inflammatory cytokines. It was found that the aforementioned effects could be reversed in RAW 264.7 macrophages when keratinocytes were treated with SHA. Therefore, SHA could be used against fine dust-induced inflammation in keratinocytes.

Calycosin alleviates allergic contact dermatitis by repairing epithelial tight junctions via down-regulating HIF-1α

Calycosin, a bioactive component derived from Astragali Radix (AR; Huang Qi), has been shown to have an effect of anti‐allergic dermatitis with unknown mechanism. This study aims to investigate the mechanism of calycosin related to tight junctions (TJs) and HIF‐1α both in FITC‐induced mice allergic contact dermatitis and in IL‐1β stimulated HaCaT keratinocytes. Th2 cytokines (IL‐4, IL‐5 and IL‐13) were detected by ELISA. The epithelial TJ proteins (occludin, CLDN1 and ZO‐1), initiative key cytokines (TSLP and IL‐33) and HIF‐1α were assessed by Western blot, real‐time PCR, immunohistochemistry or immunofluorescence. Herein, we have demonstrated that allergic inflammation and the Th2 cytokines in ACD mice were reduced significantly by calycosin treatment. Meanwhile, calycosin obviously decreased the expression of HIF‐1α and repaired TJs both in vivo and in vitro. In HaCaT keratinocytes, we noted that IL‐1β induced the deterioration of TJs, as well as the increased levels of TSLP and IL‐33, which could be reversed by silencing HIF‐1α. In addition, administration of 2‐methoxyestradiolin (2‐ME), a HIF‐1α inhibitor,significantly repaired the TJs and alleviated the allergic inflammation in vivo. Furthermore, TJs were destroyed by DMOG or by overexpressing HIF‐1α in HaCaT keratinocytes, and simultaneously, calycosin down‐regulated the expression of HIF‐1α and repaired the TJs in this process. These results revealed that calycosin may act as a potential anti‐allergy and barrier‐repair agent via regulating HIF‐1α in AD and suggested that HIF‐1α and TJs might be possible therapy targets for allergic dermatitis.

Rhododendrin inhibits toll-like receptor-7-mediated psoriasis-like skin inflammation in mice

Many active compounds present in Rhododendron brachycarpum have been used in traditional Oriental medicine for the treatment of various skin diseases. However, the precise mechanism of action of the compounds isolated from R. brachycarpum and their relevance as therapeutics for the treatment of psoriasis remain elusive. In this study, we report that rhododendrin isolated from R. brachycarpum strongly inhibits imiquimod (IMQ)-induced psoriasis-like skin inflammation in mice. We showed that topical treatment with rhododendrin reduces IMQ-induced skin hyperplasia, inflammatory mononuclear cell infiltration and the expression of pro-inflammatory mediators in mouse skin. In addition, we found that rhododendrin inhibits the activation of the TLR-7/NF-κB and mitogen-activated protein kinase pathways in both IMQ-induced psoriasis-like skin inflammation in mice and in normal human epidermal keratinocytes treated with IMQ. These results suggest that rhododendrin has an anti-inflammatory effect and can be used as a therapeutic to fight against psoriasis and other inflammatory skin diseases.

Astragalus polysaccharide protects human cardiac microvascular endothelial cells from hypoxia/reoxygenation injury: The role of PI3K/AKT, Bax/Bcl-2 and caspase-3

In the present study, the mechanisms associated with the Astragalus polysaccharide (APS)-mediated protection of human cardiac microvascular endothelial cells (HCMEC) against hypoxia/reoxygenation (HR) injury were investigated. Pretreatment of HCMECs with APS at various concentrations was performed prior to Na2S2O4-induced HR injury. Subsequently, cell viability and apoptosis were measured by MTT and Hoechst assays, respectively. The viability of HCMECs was reduced by Na2S2O4 and apoptosis was enhanced; however, cell viability was observed to be increased by APS via inhibition of apoptosis. Additionally, intracellular reactive oxygen species (ROS), Ca2+, nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), B‑cell lymphoma‑2 (Bcl‑2), Bcl‑2 associated X protein (Bax) and caspase‑3 were measured using detection kits or western blot analysis. In HCMECs with HR injury, the levels of ROS and Ca2+, MDA and Bax expression levels, and the activity of caspase‑3 were elevated. By contrast, the level of NO, the protein expression levels of SOD, Bcl‑2 and PI3K, and the phosphorylation of AKT were decreased. However, compared with the HR group, the effects of HR injury were significantly reduced by APS, with APS providing a protective effect on HCMECs, particularly at higher doses. The current study concluded that APS protects HCMECs from Na2S2O4‑induced HR injury by reducing the levels of ROS, Ca2+, MDA and Bax, inhibiting the activity of caspase‑3, and enhancing the levels of NO, SOD, Bcl‑2, PI3K and phosphorylated AKT. These results may provide an insight into the clinical application of APS and novel therapeutic strategies for HR injury.

Alleviation of collagen-induced arthritis by the benzoxathiole derivative BOT-4-one in mice: Implication of the Th1- and Th17-cell-mediated immune responses

Autoimmune rheumatoid arthritis is characterized by chronic inflammation and hyperplasia in the synovial joints. Although the cause of rheumatoid arthritis is largely unknown, substantial evidence has supported the importance of immune cells and inflammatory cytokines in the initiation and progression of this disease. Herein, we demonstrated that the benzoxathiole derivative 2-cyclohexylimino-6-methyl-6,7-dihydro-5H-benzo[1,3]oxathiol-4-one (BOT-4-one) alleviated type II collagen-induced arthritis in a mouse model. The levels of pro-inflammatory cytokines are elevated in both human patients with rheumatoid arthritis and mice with collagen-induced arthritis. BOT-4-one treatment reduced the levels of pro-inflammatory cytokines in mice and endotoxin-stimulated macrophages. BOT-4-one treatment suppressed the polarization of Th1- and Th17-cell subsets by inhibiting the expression and production of their lineage-specific master transcription factors and cytokines, as well as activation of signal transducer and activator of transcription proteins. In addition, BOT-4-one inhibited mitogen-activated protein kinase and NF-kappaB signaling as well as the transcriptional activities and DNA-binding of transcription factors, including activator protein-1, cAMP response element-binding protein and NF-kappaB. Our results suggest that BOT-4-one may have therapeutic potential for the treatment of chronic inflammation associated with autoimmune rheumatoid arthritis.

Mori folium inhibits interleukin-1β-induced expression of matrix metalloproteinases and inflammatory mediators by suppressing the activation of NF-κB and p38 MAPK in SW1353 human chondrocytes

The pro-inflammatory cytokine interleukin-1β (IL-1β) is known to play a crucial role in the pathogenesis of osteoarthritis (OA) by stimulating several mediators that contribute to cartilage degradation. Mori folium, the leaves of Morus alba L., has long been used in traditional medicine to treat diabetes, protect the liver, and lower blood pressure; however, the role of Mori folium in OA is not yet fully understood. Therefore, in the present study, we investigated whether Mori folium water extract (MF) inhibited the catabolic effects of IL-1β in vitro, and also whether it inhibited the matrix metalloproteinases (MMPs), inducible nitric oxide (NO) synthase (iNOS) and cyclooxygenase-2 (COX-2) through the attenuation of nuclear factor-κB (NF-κB) and mitogen activated protein kinase (MAPK) pathways in SW1353 human chondrocytes. MMP proteins in culture medium were determined using a cytokine‑specific enzyme-linked immunosorbent assay (ELISA). The production of NO and prostaglandin E2 (PGE2) were evaluated using Griess reagent and ELISA. Subsequently, the mRNA and protein levels of MMPs, iNOS, COX-2, NF-κB and MAPKs were examined by RT-qPCR and/or western blot analysis. The results indicate that MF significantly reduced the IL-1β‑induced release of MMP-1 and -13 in SW1353 cells, which was associated with the inhibition of MMP-1 and -13 mRNA and protein expression in a concentration‑dependent manner at concentrations with no cytotoxicity. MF also attenuated the IL-1β-induced production of NO and PGE2, and reduced iNOS and COX-2 expression. Furthermore, we noted that MF markedly suppressed the IL-1β‑induced nuclear translocation of NF-κB, which correlated with the inhibitory effects of MF on inhibitor-κB (IκB) degradation, and the phosphorylation of p38 MAPK was selectively restored by MF upon IL-1β stimulation. These results indicate that MF inhibited the production and expression of MMP-1 and -13 and inflammatory mediators, at least in part, through suppressing the activation of either NF-κB or p38 MAPK in IL-1β-treated SW1353 chondrocytes. Therefore, the novel findings of the present study suggest that MF is a potential therapeutic choice for chondroprotection against the collagen matrix breakdown in the cartilage of diseased tissues, such as those found in patients with arthritic disorders.

Anti-inflammatory effects of Hwang-Heuk-San, a traditional Korean herbal formulation, on lipopolysaccharide-stimulated murine macrophages

BACKGROUND

Hwang-Heuk-San (HHS), a Korean traditional herbal formula comprising four medicinal herbs, has been used to treat patients with inflammation syndromes and digestive tract cancer for hundreds of years; however, its anti-inflammatory potential is poorly understood. The aim of the present study was to investigate the anti-inflammatory effects of HHS using a lipopolysaccharide (LPS)-activated RAW 264.7 macrophage model.

METHODS

The inhibitory effects of HHS on LPS-induced nitric oxide (NO), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) production were examined using Griess reagent and enzyme-linked immunosorbent assay (ELISA) detection kits. The effects of HHS on the expression of inducible NO synthase (iNOS), IL-1β and TNF-α, their upstream signal proteins, including nuclear factor κB (NF-κB), mitogen-activated protein kinases (MAPKs), and activator protein (AP-1), were also investigated.

RESULTS

A noncytotoxic concentration of HHS significantly reduced the production of NO, IL-1β and TNF-α in LPS-stimulated RAW 264.7 cells, which was correlated with reduced expression of iNOS, IL-1β and TNF-α at the mRNA and protein levels. HHS efficiently blocked the phosphorylation of MAPKs, especially that of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) but not that of the p38 MAPK. The reduced production of inflammatory molecules by HHS was followed by decreased activity of NF-κB and AP-1.

CONCLUSIONS

These results suggest that HHS may offer therapeutic potential for treating inflammatory diseases accompanied by macrophage activation.

Nrf2-mediated HO-1 induction contributes to antioxidant capacity of a Schisandrae Fructus ethanol extract in C2C12 myoblasts

This study was designed to confirm the protective effect of Schisandrae Fructus, which are the dried fruits of Schisandra chinensis (Turcz.) Baill, against oxidative stress-induced cellular damage and to elucidate the underlying mechanisms in C2C12 myoblasts. Preincubating C2C12 cells with a Schisandrae Fructus ethanol extract (SFEE) significantly attenuated hydrogen peroxide (H₂O₂)-induced inhibition of growth and induced scavenging activity against intracellular reactive oxygen species (ROS) induced by H₂O₂. SFEE also inhibited comet tail formation and phospho-histone γH2A.X expression, suggesting that it prevents H₂O₂-induced cellular DNA damage. Furthermore, treating C2C12 cells with SFEE significantly induced heme oxygenase-1 (HO-1) and phosphorylation of nuclear factor-erythroid 2 related factor 2 (Nrf2). However, zinc protoporphyrin IX, a potent inhibitor of HO-1 activity, significantly reversed the protective effects of SFEE against H₂O₂-induced growth inhibition and ROS generation in C2C12 cells. Additional experiments revealed that the potential of the SFEE to induce HO-1 expression and protect against H₂O₂-mediated cellular damage was abrogated by transient transfection with Nrf2-specific small interfering RNA, suggesting that the SFEE protected C2C12 cells against oxidative stress-induced injury through the Nrf2/HO-1 pathway.

Schisandrae Fructus Inhibits IL-1β-Induced Matrix Metalloproteinases and Inflammatory Mediators Production in SW1353 Human Chondrocytes by Suppressing NF-κB and MAPK Activation

Proinflammatory cytokine interleukin-1 beta (IL-1β) plays a crucial role in the pathogenesis of osteoarthritis (OA) by stimulating several mediators that contribute to cartilage degradation. Schisandrae Fructus (SF), the dried fruit of Schisandra chinensis (Turcz.) Baill. (Magnoliaceae), is widely used in traditional medicine for the treatment of a number of chronic inflammatory diseases. This study investigated the antiosteoarthritis properties of an ethanol extract of SF on IL-1β-stimulated SW1353 chondrocytes. SF attenuated IL-1β-induced expression and activity of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 and also reduced the elevated levels of cyclooxygenase-2 and inducible nitric oxide synthase associated with the inhibition of prostaglandin E2 and nitric oxide production in IL-1β-stimulated SW1353 chondrocytes. In addition, SF markedly suppressed the nuclear translocation of nuclear factor-kappa B (NF-κB) by blocking inhibitor κB-alpha degradation and inhibited the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). These results indicate that the inhibitory effect of SF on IL-1β-stimulated expression of MMPs and inflammatory mediators production in SW1353 cells were associated with the suppression of the NF-κB and JNK/p38 MAPK signaling pathways. The results from this study indicate that SF may have therapeutic potential for the treatment of OA due to its anti-inflammatory and chondroprotective features.

Effects of treatment with Astragalus Membranaceus on function of rat leydig cells

BACKGROUND

Astragalus membranaceus (AM) is a Chinese traditional herb which has been reported to have broad positive effects on many diseases, including hepatitis, heart disease, diabetes and skin disease. AM can promote cell proliferation, increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and inhibit apoptosis by regulating the transcription of proto-oncogenes controlling cell death. While AM is included in some commercially available "testosterone boosting supplements", studies directly testing ability of AM to modulate testosterone production are lacking. In the present study, we examined the effects of AM on Leydig cell function in vitro.

METHODS

Rat Leydig cells were purified and treated with AM at different concentrations (0 μg/mL, 10 μg/mL, 20 μg/mL, 50 μg/mL, 100 μg/mL and 150 μg/mL) and cell counting-8 (CCK-8) assay, Enzyme-linked immunosorbent assay, quantitative real time PCR and analysis of activities of SOD and GPx were done respectively.

RESULTS

Treatment with 100 μg/mL (P<0.05) and 150 μg/mL AM (P<0.01) significantly increased Leydig cell numbers. Treatment with AM (20 μg/mL, 50 μg/mL and 100 μg/mL) significantly increased testosterone production (P<0.01). In addition, increased Leydig cell SOD and GPx activities were observed in response to 20 μg/mL and 50 μg/mL AM treatment (P<0.01). Furthermore, expression of Bax mRNA was significantly decreased (P<0.01), and the ratio of Bcl-2/Bax mRNA was significantly increased in response to 20 μg/mL AM in the culture medium (P<0.05).

CONCLUSIONS

Results supported a beneficial effect of AM on multiple aspects of rat Leydig cell function in vitro including testosterone production.

The Cytoprotective Effect of Petalonia binghamiae Methanol Extract against Oxidative Stress in C2C12 Myoblasts: Mediation by Upregulation of Heme Oxygenase-1 and Nuclear Factor-Erythroid 2 Related Factor 2

This study was designed to examine the protective effects of the marine brown algae Petalonia binghamiae against oxidative stress-induced cellular damage and to elucidate the underlying mechanisms. P. binghamiae methanol extract (PBME) prevented hydrogen peroxide (H2O2)-induced growth inhibition and exhibited scavenging activity against intracellular reactive oxygen species (ROS) induced by H2O2 in mouse-derived C2C12 myoblasts. PBME also significantly attenuated H2O2-induced comet tail formation in a comet assay, histone γH2A.X phosphorylation, and annexin V-positive cells, suggesting that PBME prevented H2O2-induced cellular DNA damage and apoptotic cell death. Furthermore, PBME increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2 related factor 2 (Nrf2). However, zinc protoporphyrin IX, a HO-1 competitive inhibitor, significantly abolished the protective effects of PBME on H2O2-induced ROS generation, growth inhibition, and apoptosis. Collectively, these results demonstrate that PBME augments the antioxidant defense capacity through activation of the Nrf2/HO-1 pathway.

Anti-Inflammatory Effects of 3-(4'-Hydroxyl-3',5'-Dimethoxyphenyl)Propionic Acid, an Active Component of Korean Cabbage Kimchi, in Lipopolysaccharide-Stimulated BV2 Microglia

We investigated the protective ability of 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid (HDMPPA), an active principle in Korean cabbage kimchi, against the production of proinflammatory mediators and cytokines, and the mechanisms involved in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. HDMPPA significantly suppressed the production of nitric oxide (NO) and prostaglandin E2, along with the expression of inducible NO synthase and cyclooxygenase-2 in LPS-stimulated BV2 cells, at concentrations with no cytotoxicity. HDMPPA also attenuated the LPS-induced expression and secretion of proinflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β. Furthermore, HDMPPA inhibited LPS-induced nuclear factor-κB (NF-κB) activation, which was associated with the abrogation of IκB-α degradation and phosphorylation, and subsequent decreases in NF-κB p65 levels. Moreover, the phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt, a downstream molecule of phosphatidylinositol-3-kinase (PI3K), in LPS-stimulated BV2 cells was suppressed markedly by HDMPPA. This effect was associated with a significant reduction in the formation of intracellular reactive oxygen species. The findings in this study suggest that HDMPPA may exert anti-inflammatory responses by suppressing LPS-induced expression of proinflammatory mediators and cytokines through blockage of NF-κB, MAPKs, and PI3K/Akt signaling pathways and oxidative stress in microglia.

Essential oils purified from Schisandrae semen inhibits tumor necrosis factor-α-induced matrix metalloproteinase-9 activation and migration of human aortic smooth muscle cells

BACKGROUND

The migration of vascular smooth muscle cells from the tunica media to the subendothelial region may be a key event in the development of atherosclerosis after arterial injury. In this study, we investigated the potential mechanisms underlying the anti-atherosclerotic effects of Schisandrae Semen essential oil (SSeo) in human aortic smooth muscle cells (HASMCs).

METHODS

Metalloproteinase-2/9 (MMP-2/9) activity was evaluated by gelatin zymography and gelatinase activity assay kit. The possible mechanisms underlying SSeo-mediated reduction of by tumor necrosis factor (TNF)-α-induced cell invasion and inhibition of secreted and cytosolic MMP-9 production in HASMCs were investigated.

RESULTS

Our results indicate that SSeo treatment has an inhibitory effect on activation as well as expression of MMP-9 induced by TNF-α in HASMCs in a dose-dependent manner without significant cytotoxicity. SSeo attenuated nuclear translocation of TNF-α-mediated nuclear factor-kappa B (NF-κB) and blocked degradation of the NF-κB inhibitor proteins as well as the production of reactive oxygen species. SSeo also reduced TNF-α-induced production of pro-inflammatory mediators such as nitric oxide and prostaglandin E2 and inhibited inducible nitric oxide synthase and cyclooxygenase-2 expression in HASMCs. Furthermore, the Matrigel migration assay showed that SSeo effectively reduced TNF-α-induced HASMC migration compared with that in the control group.

CONCLUSIONS

Taken together, these results suggest that SSeo treatment suppresses TNF-α-induced HASMC migration by selectively inhibiting MMP-9 expression, which was associated with suppression of the NF-κB signaling pathway. Taken together, these results suggest that SSeo has putative potential anti-atherosclerotic activity.

Astragalus membranaceus inhibits peritoneal fibrosis via monocyte chemoattractant protein (MCP)-1 and the transforming growth factor-β1 (TGF-β1) pathway in rats submitted to peritoneal dialysis

Inflammation and transforming growth factor-β1 (TGF-β1) contribute to the development of peritoneal fibrosis (PF), which is associated with peritoneal dialysis (PD). Astragalus membranaceus (Astragalus) has anti-inflammatory and anti-fibrotic effects in many diseases. The goal of this study was to determine the anti-fibrotic effects of Astragalus on the PF response to PD. A rat model of PD was induced using standard PD fluid, and PF was verified by HE and Masson’s staining, as well as through the expression of fibroblast surface protein (FSP) and collagen III. The expression levels of monocyte chemoattractant protein (MCP)-1, F4/80 (macrophage/monocyte marker in rat), TGF-β1 and the downstream proteins phospho-SMAD 2/3 in dialyzed peritoneal tissue treated with or without Astragalus was evaluated using immunohistochemistry analysis. Overall correlations between MCP-1 and TGF-β1 staining were analyzed using both the Spearman and Pearson methods. The results showed that Astragalus could inhibit the recruitment and activation of monocytes/macrophages, thereby reducing the production of TGF-β1 in the dialyzed peritoneal membrane. PF was also significantly decreased following treatment with Astragalus. MCP-1 expression had a strong positive correlation with TGF-β1 sensitivity, suggesting that the anti-fibrotic function of Astragalus was mediated by MCP-1 and the TGF-β1 pathway. Our results indicate that Astragalus could be a useful agent against PD-induced PF.

Effect of enteral administration of α-linolenic acid and linoleic acid against methotrexate induced intestinal toxicity in albino rats

The present study was conducted to show the effect of α-linolenic acid (18 : 3, ω-3) and linoleic acid (18 : 2, ω-6) on experimental intestinal toxicity induced by methotrexate.