The Leaves of Broussonetia kazinoki Siebold Inhibit Atopic Dermatitis-Like Response on Mite Allergen-Treated Nc/Nga Mice

The Genus Broussonetia: An Updated Review of Phytochemistry, Pharmacology and Applications

The Broussonetia genus (Moraceae), recognized for its value in many Chinese traditional herbs, mainly includes Broussonetia papyrifera (L.) L’Hér. ex Vent. (BP), Broussonetia kazinoki Siebold (BK), and Broussonetia luzonica (Blanco) Bureau (BL). Hitherto, researchers have found 338 compounds isolated from BP, BK, and BL, which included flavonoids, polyphenols, phenylpropanoids, alkaloids, terpenoids, steroids, and others. Moreover, its active compounds and extracts have exhibited a variety of pharmacological effects such as antitumor, antioxidant, anti-inflammatory, antidiabetic, anti-obesity, antibacterial, and antiviral properties, and its use against skin wrinkles. In this review, the phytochemistry and pharmacology of Broussonetia are updated systematically, after its applications are first summarized. In addition, this review also discusses the limitations of investigations and the potential direction of Broussonetia. This review can help to further understand the phytochemistry, pharmacology, and other applications of Broussonetia, which paves the way for future research.

Management of Atopic Dermatitis Via Oral and Topical Administration of Herbs in Murine Model: A Systematic Review

Over the past few decades, complementary and alternative medicine (CAM) using herbs, or their active constituents have garnered substantial attention in the management of a chronic and relapsing inflammatory skin disorder called atopic dermatitis (AD), particularly in attenuating disease recurrence and maintaining long-term remission. In Eastern Asian countries including China, Korea and Taiwan, herbal medicine available in both topical and oral preparation plays a significant role in treating skin diseases like AD as they possibly confer high anti-inflammatory properties and immunomodulatory functions. Conventional murine models of AD have been employed in drug discovery to provide scientific evidence for conclusive and specific pharmacological effects elicited by the use of traditional herbs and their active constituents. Coupled with the goal to develop safe and effective novel therapeutic agents for AD, this systematic review consists of a summary of 103 articles on both orally and topically administered herbs and their active constituents in the murine model, whereby articles were screened and selected via a specialized framework known as PICO (Population, Intervention, Comparator and Outcome). The objectives of this review paper were to identify the efficacy of oral and topical administered herbs along with their active constituents in alleviating AD and the underlying mechanism of actions, as well as the animal models and choice of inducer agents used in these studies. The main outcome on the efficacy of the majority of the herbs and their active constituents illustrated suppression of Th2 response as well as improvements in the severity of AD lesions, suppression of Immunoglobulin E (IgE) concentration and mast cell infiltration. The majority of these studies used BALB/c mice followed by NC/Nga mice (commonly used gender–male; commonly used age group – 6–8 weeks). The most used agent in inducing AD was 2, 4-Dinitrochlorobenzene (DNCB), and the average induction period for both oral and topical administered herbs and their active constituents in AD experiments lasted between 3 and 4 weeks. In light of these findings, this review paper could potentially assist researchers in exploring the potential candidate herbs and their active constituents using murine model for the amelioration of AD.

Broussonin A- and B-mediated inhibition of angiogenesis by blockade of VEGFR-2 signalling pathways and integrin β1 expression

In the present study, we demonstrate the regulatory effects and mechanism of broussonin A and B, diphenylpropane derivatives isolated from Broussonetia kazinoki, on vascular endothelial growth factor‐A (VEGF‐A)–stimulated endothelial cell responses in vitro and microvessel sprouting ex vivo. Treatment with broussonin A or B suppressed VEGF‐A‐stimulated endothelial cell proliferation by regulating the expression of cell cycle–related proteins and the phosphorylation status of retinoblastoma protein. In addition, treatment with broussonin A or B abrogated VEGF‐A‐stimulated angiogenic responses including endothelial cell migration, invasion, tube formation and microvessel formation from rat aortic rings. These anti‐angiogenic activities of broussonin A and B were mediated through inactivation of VEGF‐A‐stimulated downstream signalling pathways, localization of vascular endothelial‐cadherin at cell‐cell contacts, and down‐regulation of integrin β1 and integrin‐liked kinase. Furthermore, treatment with broussonin A or B inhibited proliferation and invasion of non–small cell lung cancer and ovarian cancer cells. Taken together, our findings suggest the pharmacological potential of broussonin A and B in the regulation of angiogenesis, cancer cell growth and progression.

Oleanolic Acid Alleviates Atopic Dermatitis-like Responses In Vivo and In Vitro

Oleanolic acid (OA) is a pentacyclic triterpenoid, abundantly found in plants of the Oleaceae family, and is well known for its beneficial pharmacological activities. Previously, we reported the inhibitory effect of OA on mast cell-mediated allergic inflammation. In this study, we investigated the effects of OA on atopic dermatitis (AD)-like skin lesions and its underlying mechanism of action. We evaluated the inhibitory effect of OA on AD-like responses and the possible mechanisms using a 1-chloro-2,4-dinitrochlorobenzene (DNCB)-induced AD animal model and tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated HaCaT keratinocytes. We found that OA has anti-atopic effects, including histological alterations, on DNCB-induced AD-like lesions in mice. Moreover, it suppressed the expression of Th2 type cytokines and chemokines in the AD mouse model and TNF-α/IFN-γ-induced HaCaT keratinocytes by blocking the activation of serine-threonine kinase Akt, nuclear factor-κB, and the signal transducer and activator of transcription 1. The results demonstrate that OA inhibits AD-like symptoms and regulates the inflammatory mediators; therefore, it may be used as an effective and attractive therapeutic agent for allergic disorders, such as AD. Moreover, the findings of this study provide novel insights into the potential pharmacological targets of OA for treating AD.

Atopic dermatitis: new insight into the etiology, pathogenesis, diagnosis and novel treatment strategies

Atopic dermatitis (AD) is the long-lasting chronic inflammatory skin condition associated with cutaneous hyper-reactivity and triggered by environmental factors. The attributes of AD include dry skin, pruritus, lichenification and frequent eczematous abrasions. This has a strong heritable aspect and typically occurs with asthma and allergic rhinitis. The complex pathological mechanism behind AD etiology is epidermal barrier destruction resulting in the lack of filaggrin protein that can induce inflammation and T-cell infiltration. T-helper 2 cell-mediated pathways also bear the responsibility of damage to the epidermal barrier. Certain causative factors for AD include microbial imbalance of skin microbiota, immunoglobulin-E-induced sensitization and neuro-inflammation. Numerous beneficial topical and oral treatments have been available to patients and there are even more drugs in the pipeline for the treatment of AD. Topical moisturizers, corticosteroids, anti-inflammatory agents such as calcineurin inhibitors, phototherapy, cAMP-specific 3, 5 half-cyclic phosphodiesterase 4 inhibitors and systemic immunosuppressants are widely available for AD treatments. Different positions and pathways inside the immune system including JAK-STAT, phosphodiesterase 4, aryl hydrocarbon receptor and T-helper 2 cytokines are targeted by above-mentioned drug treatments. Instead of the severe side effects of topical steroids and oral antihistamines, herbal plants and their derived phytoconstituents are commonly used for the treatment of AD. A clear understanding of AD's cellular and molecular pathogenesis through substantial advancement in genetics, skin immunology and psychological factors resulted in advancement of AD management. Therefore, the review highlights the recent advancements in the understanding of clinical features, etiology, pathogenesis, treatment and management and non-adherence to AD treatment.

Prevention of Oxidative Stress-Induced Pancreatic Beta Cell Damage by Broussonetia Kazinoki Siebold Fruit Extract Via the ERK-Nox4 Pathway

Pancreatic beta cells are vulnerable to oxidative stress, which causes beta cell death and dysfunction in diabetes mellitus. Broussonetia kazinoki Siebold (BK) is a widely used herbal medicine, but its potential effects against beta cell death-induced diabetes have not been studied. Therefore, we investigated the protective effect of an ethanolic extract of BK fruit (BKFE) against streptozotocin (STZ)-induced toxicity in pancreatic beta cells. Intraperitoneal injection of STZ in mice induced hyperglycemia; however, oral administration of BKFE significantly decreased the blood glucose level as well as HbA1c levels. BKFE treatment improved glucose tolerance and increased body weight in diabetic mice. Moreover, BKFE treatment resulted in increased serum insulin levels and insulin expression in the pancreas as well as decreased 4-hydroxynonenal levels induced by oxidative stress. Treatment with STZ decreased cell viability of mouse insulinoma cells (MIN6), which was blocked by BKFE pretreatment. BKFE significantly inhibited apoptotic cells and decreased the expression levels of cleaved-caspase-3 and cleaved-poly (ADP-ribose) polymerase (PARP) induced by STZ treatment. Production of reactive oxygen species in STZ-treated MIN6 cells was also significantly decreased by treatment with BKFE. Erk phosphorylation and Nox4 levels increased in STZ-treated MIN6 cells and the pancreas of mice injected with STZ and this increase was inhibited by treatment with BKFE. Inhibition of Erk phosphorylation by treatment with the PD98059 inhibitor or siRNA Erk also blocked the expression of Nox4 induced by STZ treatment. In conclusion, BKFE inhibits Erk phosphorylation, which in turn prevents STZ-induced oxidative stress and beta cell apoptosis. These results suggested that BKFE can be used to prevent or treat beta cell damage in diabetes.

The formulae and biologically active ingredients of Chinese herbal medicines for the treatment of atopic dermatitis

Atopic dermatitis (AD) is a common relapsing inflammatory skin disease characterized by severe pruritus that seriously affects the quality of patients' life. There is an increasingly large amount of research demonstrating that traditional Chinese medicine (TCM) including herbal formulae and bioactive ingredients exerts pharmacological effects on atopic dermatitis. It has been a long history of TCM being used to treat atopic dermatitis, especially in preventing disease recurrence, maintaining long-term remission, and reducing disease burden. Nowadays, both of TCM monomer preparations and traditional formulae are still widely used. This review focuses on TCM as well as its bioactive ingredients for the treatment of AD, from the perspectives of animal model construction, pharmacodynamic mechanisms and clinical studies of formulae. To be more specific, the regulation and molecular mechanisms of the herbal formulae and bioactive ingredients of TCM are investigated, and the latest clinical research on TCM formulae is discussed. Furthermore, it provides a summary of the strengths and utilities of TCM, and will be useful for doctors who use Chinese medicine for treatment or researchers who select candidates for clinical treatments or further high-quality clinical studies.

Anti-Allergic and Anti-Inflammatory Effects of Undecane on Mast Cells and Keratinocytes

The critical roles of keratinocytes and resident mast cells in skin allergy and inflammation have been highlighted in many studies. Cyclic adenosine monophosphate (cAMP), the intracellular second messenger, has also recently emerged as a target molecule in the immune reaction underlying inflammatory skin conditions. Here, we investigated whether undecane, a naturally occurring plant compound, has anti-allergic and anti-inflammatory activities on sensitized rat basophilic leukemia (RBL-2H3) mast cells and HaCaT keratinocytes and we further explored the potential involvement of the cAMP as a molecular target for undecane. We confirmed that undecane increased intracellular cAMP levels in mast cells and keratinocytes. In sensitized mast cells, undecane inhibited degranulation and the secretion of histamine and tumor necrosis factor α (TNF-α). In addition, in sensitized keratinocytes, undecane reversed the increased levels of p38 phosphorylation, nuclear factor kappaB (NF-κB) transcriptional activity and target cytokine/chemokine genes, including thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and interleukin-8 (IL-8). These results suggest that undecane may be useful for the prevention or treatment of skin inflammatory disorders, such as atopic dermatitis, and other allergic diseases.

Antioxidant evaluation-guided chemical profiling and structure-activity analysis of leaf extracts from five trees in Broussonetia and Morus (Moraceae)

Morus and Broussonetia trees are widely used as food and/or feed. Among 23 phenolics identified from leaves of five Moraceae species using UPLC–QTOF–MS/MS, 15 were screened using DPPH/ABTS-guided HPLCs, including seven weak (flavonoids with one hydroxyl on B-ring) and eight strong (four caffeoylquinic acids and four flavonoids, each with a double hydroxyl on B-ring) antioxidants. We then determined the activity and synergistic effects of individual antioxidants and a mixture of the eight strongest antioxidants using DPPH-guided HPLC. Our findings revealed that (1) flavonoid glucuronide may have a more negative effect on antioxidant activity than glucoside, and (2) other compounds in the mixture may exert a negative synergistic effect on antioxidant activity of the four flavonoids with B-ring double hydroxyls but not the four caffeoylquinic acids. In conclusion, the eight phenolics with the strongest antioxidant ability reliably represented the bioactivity of the five extracts examined in this study. Moreover, the Morus alba hybrid had more phenolic biosynthesis machinery than its cross-parent M. alba, whereas the Broussonetia papyrifera hybrid had significantly less phenolic machinery than B. papyrifera. This difference is probably the main reason for livestock preference for the hybrid of B. papyrifera over B. papyrifera in feed.

Protective Effects of Broussonetia kazinoki Siebold Fruit Extract against Palmitate-Induced Lipotoxicity in Mesangial Cells

Diabetic nephropathy is one of the most serious complications of diabetes. Lipotoxicity in glomerular mesangial cells is associated with the progression of diabetic nephropathy. Paper mulberry, Broussonetia kazinoki Siebold (BK), has been used in oriental medicine for human health problems. However, to date, the beneficial effect of BK fruit has not been studied. In this study, we investigated the protective effect of an ethanolic extract of BK fruit (BKFE) against palmitate- (PA-) induced toxicity in mesangial cells. BKFE significantly increased the viability of PA-treated SV40 MES13 cells. BKFE significantly inhibited PA-induced apoptosis and decreased the expression of apoptotic genes, cleaved caspase-3, and cleaved PARP. Moreover, BKFE inhibited the expression of endoplasmic reticulum (ER) stress-related genes, such as BiP, phosphorylated eIF2α, cleaved ATF6, and spliced XBP-1, in PA-treated SV40 MES13 cells. BKFE decreased PA-induced ROS production. In addition, BKFE activated the transcription factor Nrf2 and increased the expression of antioxidant enzymes. However, knockdown of Nrf2 using siRNA suppressed this BKFE-induced increase in antioxidant enzyme expression. Furthermore, the protective effect of BKFE on PA-induced apoptosis was significantly reduced by Nrf2 knockdown. In conclusion, BKFE induced the expression of antioxidant enzymes via activation of Nrf2 and protected against PA-induced lipotoxicity in mesangial cells.

Forsythia suspensa Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

Forsythia suspensa (F. suspensa) is a traditional medicine for treatment of inflammation. In this study, we evaluated the therapeutic effects of an ethanol extract from F. suspensa fruits on atopic dermatitis both in vivo and in vitro. We investigated the inhibitory effects of F. suspensa extract on the development of atopic dermatitis-like skin lesions in an NC/Nga mouse model exposed to Dermatophagoides farinae crude extract. Topical application of F. suspensa extract to the mice attenuated the atopic dermatitis symptoms, including increased dermatitis severity score, ear thickness, infiltration of inflammatory cells in the skin lesions, serum levels of IgE, TNF-α, and histamine, and expression of chemokines, cytokines, and adhesion molecules in ear tissue. In addition, F. suspensa extract inhibited the production of chemokines in TNF-α/IFN-γ-activated human keratinocytes. High-performance liquid chromatography analysis of FSE revealed the presence of four chemical constituents (forsythiaside, phillyrin, pinoresinol, and phylligenin). These compounds inhibited the production of chemokines in TNF-α/IFN-γ-activated human keratinocytes. These results suggest that the F. suspensa might be a useful candidate for treating allergic skin inflammatory disorders.

Kazinol-E is a specific inhibitor of ERK that suppresses the enrichment of a breast cancer stem-like cell population

Growing evidence shows that cancer stem-like cells (CSLCs) contribute to breast cancer recurrence and to its resistance to conventional therapies. The extracellular signal-regulated kinase (ERK) signaling pathway is a major determinant in the control of diverse cellular processes, including the maintenance of CSLCs. In this study, we found that Kazinol-E, an antioxidant flavan from Broussonetia kazinoki, decreased the CSLC population of a breast cancer cell line, MCF7. The CSLC population, characterized by CD44 high/CD24 low expression or by high Aldehyde dehydrogenase 1 activity, was decreased by a concentration of Kazinol-E that did not affect the growth of bulk-cultured MCF7 cells. Kazinol-E did not decrease EGF-induced ERK phosphorylation in CSLCs, but did block the phosphorylation of an ERK substrate, p90RSK2, at Thr359/Ser363. We further demonstrated that EGF-induced ERK activity was blocked by Kazinol-E in a wild-type K-Ras-expressing non-small cell lung cancer cell line H226B. An in vitro kinase assay with purified ERK1 and p90RSK2 as its substrate demonstrated a direct inhibition of ERK activity by Kazinol E. Additionally, a the molecular docking study provided putative binding modes of Kazinol-E into the ATP binding pocket of ERK1 Collectively, these results suggest that Kazinol-E is a direct inhibitor of ERK1, and more studies are warranted to develop this reagent for therapeutic breast CSLC targeting.

Combined Skin Moisturization of Liposomal Serine Incorporated in Hydrogels Prepared with Carbopol ETD 2020, Rhesperse RM 100 and Hyaluronic Acid

We investigated the combined moisturizing effect of liposomal serine and a cosmeceutical base selected in this study. Serine is a major amino acid consisting of natural moisturizing factors and keratin, and the hydroxyl group of serine can actively interact with water molecules. Therefore, we hypothesized that serine efficiently delivered to the stratum corneum (SC) of the skin would enhance the moisturizing capability of the skin. We prepared four different cosmeceutical bases (hydrogel, oil-in-water (O/W) essence, O/W cream, and water-in-oil (W/O) cream); their moisturizing abilities were then assessed using a Corneometer®. The hydrogel was selected as the optimum base for skin moisturization based on the area under the moisture content change-time curves (AUMCC) values used as a parameter for the water hold capacity of the skin. Liposomal serine prepared by a reverse-phase evaporation method was then incorporated in the hydrogel. The liposomal serine-incorporated hydrogel (serine level=1%) showed an approximately 1.62~1.77 times greater moisturizing effect on the skin than those of hydrogel, hydrogel with serine (1%), and hydrogel with blank liposome. However, the AUMCC values were not dependent on the level of serine in liposomal serine-loaded hydrogels. Together, the delivery of serine to the SC of the skin is a promising strategy for moisturizing the skin. This study is expected to be an important step in developing highly effective moisturizing cosmeceutical products.