Salvia plebeia suppresses atopic dermatitis-like skin lesions

Efficacy of Topical Palmitoylethanolamide (Levagen+) for the Management of Eczema Symptoms: A Double-Blind, Comparator-Controlled, Randomized Clinical Trial

INTRODUCTION

Eczema is a debilitating skin disorder clinically characterised by the development of itchy, dry, rough, and scaling skin caused by a series of rudimentary clinical phenotypes.

METHODS

This double-blind, randomised, comparator-controlled trial evaluated the effectiveness of topical application of a novel palmitoylethanolamide formulation (Levagen+) compared with a standard moisturiser (comparator) to reduce eczema severity and improve patient outcomes. Seventy-two participants aged over 18 years old with atopic eczema (symptoms including redness, dry skin, scaling, and/or itchiness) on their hands or arm were recruited. Participants were randomly allocated to one of two treatment groups (Levagen + or comparator). Treatment was applied to the affected area twice daily for 4 weeks. Outcome measures included Self-Assessed Eczema Area Severity Index (SA-EASI) scoring and Patient-Oriented Eczema Measure (POEM) from baseline to week 4.

RESULTS

Levagen+ was effective at alleviating symptom severity of eczema over 4 weeks. Levagen+ significantly reduced redness, dryness, and total POEM score compared to a comparator cream.

CONCLUSION

Levagen+ can significantly reduce eczema symptom severity compared to a comparator product, supporting its use as a potential treatment for eczema.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT05003453.

The decoy oligodeoxynucleotide against HIF-1α and STAT5 ameliorates atopic dermatitis-like mouse model

Atopic dermatitis (AD) is a common inflammatory skin disease caused by an immune disorder. Mast cells are known to be activated and granulated to maintain an allergic reaction, including rhinitis, asthma, and AD. Although hypoxia-inducible factor-1 alpha (HIF-1α) and signal transducer and activator of transcription 5 (STAT5) play crucial roles in mast cell survival and granulation, their effects need to be clarified in allergic disorders. Thus, we designed decoy oligodeoxynucleotide (ODN) synthetic DNA, without open ends, containing complementary sequences for HIF-1α and STAT5 to suppress the transcriptional activities of HIF-1α and STAT5. In this study, we demonstrated the effects of HIF-1α/STAT5 ODN using AD-like in vivo and in vitro models. The HIF-1α/STAT5 decoy ODN significantly alleviated cutaneous symptoms similar to AD, including morphology changes, immune cell infiltration, skin barrier dysfunction, and inflammatory response. In the AD model, it also inhibited mast cell infiltration and degranulation in skin tissue. These results suggest that the HIF-1α/STAT5 decoy ODN ameliorates the AD-like disorder and immunoglobulin E (IgE)-induced mast cell activation by disrupting HIF-1α/STAT5 signaling pathways. Taken together, these findings suggest the possibility of HIF-1α/STAT5 as therapeutic targets and their decoy ODN as a potential therapeutic tool for AD.

A comprehensive review on pharmacological, toxicity, and pharmacokinetic properties of phillygenin: Current landscape and future perspectives

Forsythiae Fructus is a traditional Chinese medicine frequently in clinics. It is extensive in the treatment of various inflammation-related diseases and is renowned as 'the holy medicine of sores'. Phillygenin (C21H24O6, PHI) is a component of lignan that has been extracted from Forsythiae Fructus and exhibits notable biological activity. Modern pharmacological studies have confirmed that PHI demonstrates significant activities in the treatment of various diseases, including inflammatory diseases, liver diseases, cancer, bacterial infection and virus infection. Therefore, this review comprehensively summarizes the pharmacological effects of PHI up to June 2023 by searching PubMed, Web of Science, Science Direct, CNKI, and SciFinder databases. According to the data, PHI shows remarkable anti-inflammatory, antioxidant, hepatoprotective, antitumour, antibacterial, antiviral, immunoregulatory, analgesic, antihypertensive and vasodilatory activities. More importantly, NF-κB, MAPK, PI3K/AKT, P2X7R/NLRP3, Nrf2-ARE, JAK/STAT, Ca2+-calcineurin-TFEB, TGF-β/Smads, Notch1 and AMPK/ERK/NF-κB signaling pathways are considered as important molecular targets for PHI to exert these pharmacological activities. Studies of its toxicity and pharmacokinetic properties have shown that PHI has very low toxicity, incomplete absorption in vivo and low oral bioavailability. In addition, the physico-chemical properties, new formulations, derivatives and existing challenges and prospects of PHI are also reviewed and discussed in this paper, aiming to provide direction and rationale for the further development and clinical application of PHI.

Protective effect of Salvia plebeia R. Br ethanol extract on UVB-induced skin photoaging in vitro and in vivo

BACKGROUND

UV exposure is one of the primary factors responsible for photoaging, causing the increase in matrix metalloproteinases (MMPs) and the reduction in collagen. Salvia plebeia R. Br (SP), as an herbaceous plant, contains abundant flavonoids and possesses excellent anti-inflammatory and antioxidant activities. This study aimed to investigate the photoprotective effects of SP on UVB-induced photodamage in immortalized human keratinocytes (HaCaTs) and Kunming mice, as well as its main active components such as homoplantaginin (HP).

METHODS

CCK-8 was applied to detect the cell viability in UVB-irradiated or non-irradiated HaCaTs. Commercial kits were used to evaluate the levels of ROS, MDA, SA-β-Gal, MMP-1, and IL-6. The expression of MAPK and TGF-β/Smad pathways was detected by western blot. HE and Masson's trichrome staining were performed to examine the epidermis thickness and collagen degradation of Kunming mice.

RESULTS

Our results found that SP and HP notably decreased UVB-induced ROS, MDA, and SA-β-Gal production, and inhibited MMP-1 and IL-6 secretion by inhibiting the MAPK signaling pathway. In addition, SP and HP significantly promoted type I procollagen synthesis by activation of TGF-β/Smad pathway. Consistently, the in vivo experiments also indicated that SP and HP had a photoprotective effect, which significantly reversed UVB-induced epidermis thickness and collagen degradation.

CONCLUSION

This study demonstrated that SP effectively could protect skin from UVB-induced photoaging, while HP acted as the active substance in SP. All these findings provided a new strategy for skin photoaging treatment.

Myricetin treatment has ameliorative effects in DNFB-induced atopic dermatitis mice under high-fat conditions

Atopic dermatitis (AD) is a chronic, inflammatory cutaneous disorder. Obesity is associated with increased prevalence and severity of AD for reasons that remain poorly understood. Myricetin, a dietary flavonoid found in fruits and vegetables, is known to have anti-inflammatory effects, but its role in AD is unclear. Thus, we investigated the effects of obesity on exacerbation AD lesions and evaluated the effects of myricetin on obese AD. Mice were fed normal diet (ND) or high-fat diet, and then 2,4-dinitrofluorobenzene was used to induce AD-like lesions. We found that obesity exacerbated AD lesions, and myricetin topical administration ameliorated symptoms and skin lesions of obsess AD mice, such as dermatitis scores, scratching behavior, epidermal thickness, and mast cell infiltration. In addition, myricetin reduced the levels of immunoglobulin E and histamine, inhibited the infiltration of CD4+T cells, and modulated the expression of Th1, Th2, Th17, and Th22 cytokines and pro-inflammatory factors (CCL17, CCL22, IL-1β, and TGF-β). Moreover, myricetin restored impaired barrier function by reducing transepidermal water loss, increasing lamellar body secretion, as well as upregulating the mRNA and protein expression of filaggrin. Western blot results showed that significantly increased levels of phosphorylated IκB and NF-κB p65 was observed in the obese AD mice compared with the AD mice fed ND, whereas the myricetin could downregulated the phosphorylations of IκB and NF-κB, and inhibited mRNA expression of iNOS and COX2. Taken together, our results suggest that myricetin treatment exhibits potentially protective effects against the obeseassociated AD by inhibiting inflammatory response and restoring skin barrier function.

Unveiling the Chemical Composition and Biological Properties of Salvia cacaliifolia Benth. Essential Oil

Salvia is widely recognized for its therapeutic potential. However, the biological relevance of some species remains unknown, namely Salvia cacaliifolia Benth. Therefore, the aim of this study is to unveil the chemical composition and relevant properties to its essential oil (EO). The EO was characterized by GC and GC-MS and its antifungal effect was evaluated according to the CLSI guidelines on dermatophytes and yeasts. The anti-inflammatory potential was assessed on lipopolysaccharide-stimulated macrophages, by assessing the production of nitric oxide (NO) and the effect on the protein levels of two key pro-inflammatory enzymes, iNOS and COX-2 by western blot analysis. Wound healing capacity was determined using the scratch wound healing assay, and the anti-aging potential was assessed by evaluating the senescence marker β-galactosidase. The EO was mainly characterized by γ-curcumene, β-bisabolene, bicyclogermacrene and curzerenone. It is effective in inhibiting the growth of dermatophytes and C. neoformans. The EO significantly decreased iNOS and COX-2 protein levels and concomitantly reduced NO release. Additionally, it demonstrated anti-senescence potential and promoted wound healing. Overall, this study highlights relevant pharmacological properties of the EO of Salvia cacaliifolia, which should be further explored envisaging the development of sustainable, innovative, and environmentally friendly skin products.

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.

Sarsasapogenin and fluticasone combination improves DNFB induced atopic dermatitis lesions in BALB/c mice

OBJECTIVE

Atopic dermatitis (AD) is a pruritic, chronic, relapsing inflammatory skin disease. The research aims to study the effects of Sarsasapogenin and its combination with Fluticasone in 2, 4-Dinitrofluorobenzene (DNFB) induced atopic dermatitis in BALB/c mice.

MATERIAL AND METHODS

Thirty male Balb/c mice were divided into 5 groups: (i) Normal control (NC), (ii) Disease control (DNFB), (iii) Sarsasapogenin (SG) (50 µg/mice), (iv) Fluticasone (FC) (50 µg/mice), (v) Sarsasapogenin + Fluticasone (SG + FC) combination (25 µg/mice). Dermatitis was induced by repeated application of DNFB in Balb/c mice. On topical application of SG, FC, and SG + FC combination on the ear and skin lesions, body weight, ear weight, ear thickness, erythema score, spleen weight, cytokines, immunoglobulin E (IgE) levels, nitric oxide (NO) level, hematological parameters, and oxidative stress markers were evaluated. Histological analysis of the ear tissue was also done.

RESULTS

The results stated that SG and SG + FC treatment to mice considerably decrease the ear weight, ear thickness, spleen weight, serum IgE, cytokines, NO levels, and restoration of antioxidant stress markers with elevation in the hematological parameters. The observations were further confirmed by histopathological analysis of ear tissue.

CONCLUSION

These data specify that SG has been demonstrated as a probable therapy for the treatment of allergic skin diseases in combination with FC by decreasing its dose from 50 to 25 µg/mice to avoid the chronic side effects of FC. Hence, it can be concluded that SG and SG + FC combination significantly improved the AD-like symptoms in the DNFB sensitized mice through mitigating the production of proinflammatory mediators and restoration of oxidative stress markers.

Lycopus lucidus Turcz ameliorates DNCB‑induced atopic dermatitis in BALB/c mice

Atopic dermatitis (AD) is a chronic inflammatory allergic skin disease, characterized by pruritic and eczematous skin lesions. Lycopus lucidus Turcz (LLT) is a perennial herb that has been reported to have various biological properties, including effects on blood circulation, as well as anti-inflammatory, antioxidant, anti-vascular inflammation and wound-healing effects. However, whether LLT improves dermatitis and the underlying mechanisms has yet to be determined. The aim of the present study was to determine whether LLT can improve 2,4-dinitrochlorobenzene (DNCB)-induced dermatitis and to verify the inhibitory effect of LLT on the expression of chemokines and pro-inflammatory cytokines in the HaCaT immortalized keratinocyte cell line. In addition, the anti-inflammatory function of LLT in RAW264.7 mouse macrophages was investigated. In the DNCB-induced AD mouse model, LLT inhibited infiltration by mast cells, eosinophils and CD8⁺ cells in the dorsal skin tissue of AD mice, and suppressed the expression of IgE and IL-6 in serum. In addition, LLT inhibited the phosphorylation of ERK and JNK, as well as NF-κB in skin tissue. In the HaCaT cell model induced by TNF-α/IFN-γ, LLT inhibited the expression of thymus and activation-regulated chemokine, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein-1, TNF-α and IL-1β, whilst inhibiting the phosphorylation of NF-κB. In addition, in the lipopolysaccharide-induced RAW 264.7 cell inflammation model, LLT inhibited the expression of TNF-α and IFN-γ, the nuclear translocation of NF-κB and the phosphorylation of ERK and JNK. These results suggested that LLT may be a promising candidate for the treatment of inflammatory dermatitis.

Nepetoidin B from Salvia plebeia R. Br. Inhibits Inflammation by Modulating the NF-κB and Nrf2/HO-1 Signaling Pathways in Macrophage Cells

Salvia plebeia has been used to treat a variety of inflammatory diseases, as well as colds and bronchitis. Macrophages have antioxidant defense mechanisms to cope with the intracellular reactive oxygen species (ROS) produced as part of the immune response. The nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase (HO)-1 pathway in inflamed macrophages is an appealing target due to its protective effect against ROS-induced cell damage. In this study, nepetoidin B (NeB) was first isolated from S. plebeia and identified by nuclear magnetic resonance spectroscopy. NeB reduced pro-inflammatory mediators (nitric oxide and prostaglandin E₂) and cytokines (tumor necrosis factor-α, interleukin (IL)-6, and IL-1β) in LPS-activated RAW 264.7 cells by inhibiting the NF-κB signaling pathway. In the NeB-treated group, catalase and superoxide dismutase levels were significantly higher, and ROS expression decreased. By activating Nrf2 signaling, NeB enhanced HO-1 expression. Furthermore, when the cells were pretreated with tin protoporphyrin (an HO-1 inhibitor), the anti-inflammatory effects of NeB were reduced. Therefore, NeB may activate the Nrf2/ HO-1 pathway. These results reveal the NeB isolated from S. plebeia exerts anti-inflammatory effects by modulating NF-κB signaling and activating the Nrf2/HO-1 pathway in LPS-stimulated RAW 264.7 cells.

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.

Eupatilin: a natural pharmacologically active flavone compound with its wide range applications

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a pharmacologically active flavone which has been isolated from a variety of medicinal plants. Eupatilin is known to possess various pharmacological properties such as anti-cancer, anti-oxidant, and anti-inflammatory. It is speculated that eupatilin could be subjected to structural optimization for the synthesis of derivative analogs to reinforce its efficacy, to minimize toxicity, and to optimize absorption profiles, which will ultimately lead towards potent drug candidates. Although, reported data acclaim multiple pharmacological activities of eupatilin but further experimentations on its molecular mechanism of action are yet mandatory to elucidate full spectrum of its pharmacological activities.

Salvia plebeia R. Br. : an overview about its traditional uses, chemical constituents, pharmacology and modern applications

Salvia plebeia R. Br. (SP), has been widely used in traditional Chinese medicine (TCM). It contains a number of chemical components and reported to possess a variety of pharmacological activities. SP is distributed in many countries such as China, Korea, Japan, Afghanistan and India. SP was first described in Compendium of Materia Medica in the Ming dynasty. The aim of this review is to compile all the information reported in the literature on SP. This review covers traditional uses, including 16 TCM classics and 21 traditional prescriptions; a total of 93 compounds from SP have been reported, including flavonoids, monoterpenoids, sesquiterpenoids, diterpenoids, triterpenes, phenolic acids etc; biological actives such as antioxidant, antimicrobial, hypoglycaemic, anti-inflammatory, analgesic, sedative, antiasthmatic, antiviral, antitumour, hepatoprotective effects etc. In addition, this paper also compiled the quality control studies and clinical applications. The future prospects and the existing problems of SP were also discussed. Overall, we believe this review will be a comprehensive record of SP for researchers to refer for carrying out for further research.

Gardenia jasminoides extract without crocin improved atopic dermatitis-like skin lesions via suppression of Th2-related cytokines in Dfe-induced NC/Nga mice

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a pruritic, chronic, relapsing inflammatory skin disease. Gardenia jasminoides extract (GJE) has been used as a traditional remedy for the treatment of various inflammatory diseases, including AD. The specific effects of the extract components, which include crocin, geniposidic acid, and gardenoside, on inflammatory responses in AD are not entirely clear.

AIM OF THE STUDY

We determined the effects of G. jasminoides extract with crocin removed (GJE-C) on AD-like skin lesions in Dermatophagoies farina crude extract (Dfe)-treated NC/Nga mice, a well-known AD mouse model.

MATERIALS AND METHODS

To prepare the mice, 150 μl of 4% sodium dodecyl sulfate (SDS) was applied to the shaved dorsal skin or ear of NC/Nga mice 1 h before application of 100 mg Dfe. After 7 d, GJE-C was applied every day for 14 d. We performed behavior, histological, ELISA, assays to evaluate chemokines, cytokines, and skin barrier proteins in skin or serum samples from treated and untreated NC/Nga mice.

RESULTS

Topical application of GJE-C improved the severity scores of the AD-like skin lesions, frequency of scratching, and ear swelling in Dfe-treated NC/Nga mice similar to the complete GJE. In addition, GJE-C also reduced serum IgE and chemokine levels as well as the inflammatory response. Topical application of GJE-C also resulted in decreased infiltration of inflammatory cells, such as mast cells, via reduction of Th2 inflammatory mediators, including interleukin (IL)-4, IL-5, and IL-13, pro-inflammatory cytokines, and chemokines, and increased skin barrier protein expression in Dfe-treated NC/Nga mice. The GJE components geniposidic acid and gardenoside inhibited the production of atopic-related chemokines in HaCaT cells, but inclusion of crocin dampened this inhibition of chemokine production.

CONCLUSIONS

Together, these findings indicate that GJE-C may improve AD-like lesions by inhibiting the Th2 inflammatory response and expression of chemokines while increasing the expression of skin barrier proteins. These data provide experimental evidence that GJE-C may harbor therapeutic potential for AD.

Subacute Oral Toxicity and Bacterial Mutagenicity Study of a Mixture of Korean Red Ginseng (Panax ginseng C.A. Meyer) and Salvia plebeia R. Br. Extracts

As various populations are rapidly becoming an aging society worldwide and interest in health issues has increased, demand for functional foods including herbal products has increased markedly to maintain a healthy state which has led to safety issues about their intake as an inevitable result. The objective of this study was to identify the safety profile of a Korean red ginseng and Salvia plebeia R. Br. extract mixture (KGC-03-PS) which is a valuable ingredient that can be used as a functional food. In the present study, the subacute oral toxicity and bacterial reverse mutagenicity of KGC-03-PS were evaluated. Sprague Dawley rats were administered KGC-03-PS orally for 28 days by gavage. Daily KGC-03-PS dose concentrations were 0, 500, 1,000, or 2,000 mg/kg body weight (bw) per day. Bacterial reverse mutation test with KGC-03-PS dose levels ranging from 312.5 to 5,000 μg/plate was carried out by OECD test guideline No. 471. Five bacterial strains (Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2) were tested in the presence or absence of metabolic activation by plate incorporation method. There were no toxicological effects related with test substance in the clinical evaluation of subacute oral toxicity test including clinical signs, body weight, and food consumption. Moreover, no toxicological changes related to KGC-03-PS were observed in the hematological and serum biochemical characteristics as well as in the pathological examinations, which included organ weight measurements and in the gross- or histopathological findings. KGC-03-PS did not induce an increase in the number of revertant colonies in all bacterial strains of the bacterial reverse mutation test. The no-observed-adverse-effect level of KGC-03-PS is greater than 2,000 mg/kg bw/day, and KGC-03-PS did not induce genotoxicity related to bacterial reverse mutations under the conditions used in this study.

Lamiaceae: An Insight on Their Anti-Allergic Potential and Its Mechanisms of Action

The prevalence of allergic diseases such as asthma, allergic rhinitis, food allergy and atopic dermatitis has increased dramatically in recent decades. Conventional therapies for allergy can induce undesirable effects and hence patients tend to seek alternative therapies like natural compounds. Considering the fact above, there is an urgency to discover potential medicinal plants as future candidates in the development of novel anti-allergic therapeutic agents. The Lamiaceae family, or mint family, is a diverse plant family which encompasses more than 7,000 species and with a cosmopolitan distribution. A number of species from this family has been widely employed as ethnomedicine against allergic inflammatory skin diseases and allergic asthma in traditional practices. Phytochemical analysis of the Lamiaceae family has reported the presence of flavonoids, flavones, flavanones, flavonoid glycosides, monoterpenes, diterpenes, triterpenoids, essential oil and fatty acids. Numerous investigations have highlighted the anti-allergic activities of Lamiaceae species with their active principles and crude extracts. Henceforth, this review has the ultimate aim of compiling the up-to-date (2018) findings of published scientific information about the anti-allergic activities of Lamiaceae species. In addition, the botanical features, medicinal uses, chemical constituents and toxicological studies of Lamiaceae species were also documented. The method employed for data collection in this review was mainly the exploration of the PubMed, Ovid and Scopus databases. Additional research studies were obtained from the reference lists of retrieved articles. This comprehensive summarization serves as a useful resource for a better understanding of Lamiaceae species. The anti-allergic mechanisms related to Lamiaceae species are also reviewed extensively which aids in future exploration of the anti-allergic potential of Lamiaceae species.

Inhibitory Effects of Helianthus tuberosus Ethanol Extract on Dermatophagoides farina body-induced Atopic Dermatitis Mouse Model and Human Keratinocytes

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by complex symptoms. To treat AD without adverse effects, alternative therapeutic agents are required. The tubers of Helianthus tuberosus L. (Jerusalem artichoke) have been used in folk remedies for diabetes and rheumatism. However, its effect on AD development remains unknown. Therefore, this study examined the inhibitory effect of H. tuberosus (HT) on AD skin symptoms using an NC/Nga mouse model and HaCaT keratinocytes. The effect of HT and associated molecular mechanisms were evaluated in Dermatophagoides farina body (Dfb)-induced AD mice and tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated HaCaT keratinocytes by ELISA, western blot, and histological analysis. Topical HT administration attenuated AD skin symptoms in Dfb-induced AD mice, with a significant reduction in the dermatitis score and production of inflammatory mediators. HT also decreased epidermal thickness and mast cell infiltration. Moreover, HT restored filaggrin expression and inhibited adhesion molecules in the mice. These effects were confirmed in vitro. Furthermore, HT suppressed the activation of NF-κB, Akt, and mitogen-activated protein kinase (MAPK) signaling pathways induced by TNF-α/IFN-γ. These results suggest that HT is a potential therapeutic agent or supplement for skin allergic inflammatory diseases such as AD.

Anti-inflammatory Activity of Eudesmane-Type Sesquiterpenoids from Salvia plebeia

Nine new sesquiterpenoid lactones and 11 known analogues were isolated from the aerial parts of Salvia plebeia R.Br. Their structures were elucidated via HRESIMS and NMR data, and their absolute configurations were defined via electronic circular dichroism data, X-ray crystallographic analysis, and the modified Mosher's ester method. Compounds 1-20 were investigated for their ability to inhibit LPS-stimulated nitric oxide production in murine macrophage cells. Of the isolates, epi-eudebeiolide C (20) showed the highest inhibitory effect (IC₅₀ of 17.9 μM). mRNA and protein expression of inducible nitric oxide synthase (iNOS), but not that of cyclooxygenase-2 (COX-2), was dose-dependently decreased by 20 in LPS-activated RAW 264.7 cells. Based on a mechanistic study involving the nuclear factor-κB (NF-κB) signaling pathway, the anti-inflammatory effect of 20 was attributed to NF-κB activation blockade via inhibition of NF-κB (IκB) phosphorylation. Therefore, 20 might be a potential candidate for relieving inflammatory diseases.

Anti‑inflammatory effect of Amomum xanthioides in a mouse atopic dermatitis model

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disorder. The present study investigated the effects of Amomum xanthioides extract (AXE) on AD‑like skin inflammation using a Dermatophagoides farinae extract (DFE) and 2,4‑dinitrochlorobenzene (DNCB)‑induced mouse AD model. Hematoxylin and eosin staining results demonstrated that repeated DFE/DNCB exposure markedly increased the thickening of the dermis and epidermis, in addition to the infiltration of eosinophils and mast cells. However, oral administration of AXE reduced these histopathological alterations in a dose‑dependent manner. Elevated serum histamine, total and DFE‑specific immunoglobulin E (IgE), and IgG2a were also decreased by treatment with AXE. In addition, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) results demonstrated that the mRNA expression of tumor necrosis factor (TNF)‑α, interferon (IFN)‑γ, interleukin (IL)‑4, IL‑13, IL‑31 and IL‑17A was reduced in ear skin following AXE administration in AD mice. Fluorescence‑activated cell sorting demonstrated that the population of CD4+/IL‑4+, CD4+/IFN‑γ+ and CD4+/IL‑17A+ cells in draining lymph nodes was also significantly decreased in AXE‑treated mice compared with AD mice without AXE treatment. Furthermore, keratinocytes that were stimulated with TNF‑α and IFN‑γ exhibited increased gene expression of pro‑inflammatory cytokines and chemokines, including TNF‑α, IL‑1β, IL‑6, IL‑8, C‑C motif chemokine ligand (CCL)17 and CCL22, as determined by RT‑qPCR. However, upregulation of these genes was reduced by AXE pretreatment. Based on these results, we hypothesize that AXE may be useful in the treatment of allergic skin inflammation, particularly AD.

Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br

This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5-7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R² > 0.9999) within the test ranges (0.005-0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1-104.8% and 97.2-107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

Inhibitory effect of Salvia plebeia leaf extract on ultraviolet-induced photoaging-associated ion channels and enzymes

In traditional Korean/Asian medicine, Salvia plebeia R.Br. (S. plebeia) leaves are used to treat inflammatory diseases, including dermatitis, cough, asthma and toothache. Recently, S. plebeia leaves have been applied in skin care, as they promote skin lightening and elasticity. Therefore, the present study investigated the anti-aging effects of S. plebeia leaf methanolic extract and its fractions (dichloromethane, ethylacetate and n-butanol). The results of a whole-cell patch clamp analysis indicated that the methanolic extract mediated ultraviolet (UV)-induced photoaging-associated ion channels, transient receptor potential vanilloid 1 (TRPV1) and calcium release-activated calcium channel protein 1 (ORAI1) channel activity in HEK293T cells overexpressing TRPV1 or ORAI1 and STIM1. Electrophysiological analysis revealed that the butanol fraction inhibited capsaicin-induced TRPV1 (84±8% at -60 mV/86±1% at 100 mV at 100 µg/ml) and ORAI1 (87±2% at -120 mV at 100 µg/ml) currents. Furthermore, the dichloromethane and hexane fractions inhibited tyrosinase activity by 32.4±0.69 and 22.6±0.96% at 330 µg/ml, respectively. Furthermore, the ethylacetate and butanol fractions inhibited elastase activity by 65.2±1.30 and 31.7±1.23% at 330 µg/ml, respectively. Tyrosinase and elastase, which are UV-induced photoaging-associated enzymes, regulate skin pigmentation and wrinkle formation, respectively. The results of the present study indicated that S. plebeia leaves may be a novel treatment for UV-induced photoaging.

2-Hydroxy-3-methoxybenzoic acid attenuates mast cell-mediated allergic reaction in mice via modulation of the FcεRI signaling pathway

Mast cells are important effector cells in immunoglobulin (Ig) E-mediated allergic reactions such as asthma, atopic dermatitis and rhinitis. Vanillic acid, a natural product, has shown anti-oxidant and anti-inflammatory activities. In the present study, we investigated the anti-allergic inflammatory effects of ortho-vanillic acid (2-hydroxy-3-methoxybenzoic acid, o-VA) that was a derivative of vanillic acid isolated from Amomum xanthioides. In mouse anaphylaxis models, oral administration of o-VA (2, 10, 50 mg/kg) dose-dependently attenuated ovalbumin-induced active systemic anaphylaxis and IgE-mediated cutaneous allergic reactions such as hypothermia, histamine release, IgE production and vasodilation; administration of o-VA also suppressed the mast cell degranulator compound 48/80-induced anaphylaxis. In cultured mast cell line RBL-2H3 and isolated rat peritoneal mast cells in vitro, pretreatment with o-VA (1-100 μmol/L) dose-dependently inhibited DNP-HSA-induced degranulation of mast cells by decreasing the intracellular free calcium level, and suppressed the expression of pro-inflammatory cytokines TNF-α and IL-4. Pretreatment of RBL-2H3 cells with o-VA suppressed DNP-HSA-induced phosphorylation of Lyn, Syk, Akt, and the nuclear translocation of nuclear factor-κB. In conclusion, o-VA suppresses the mast cell-mediated allergic inflammatory response by blocking the signaling pathways downstream of high affinity IgE receptor (FcεRI) on the surface of mast 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.

Salvia plebeia R.Br. inhibits signal transduction of IL-6 and prevents ovariectomy-induced bone loss by suppressing osteoclastogenesis

The interleukin-6 (IL-6) family of cytokines plays a key role in the pathogenesis of rheumatoid arthritis and osteoporosis through the regulation of bone formation and resorption. In this study, it was observed that ethanol extract of Salvia plebeia R.Br. (S.P-EE) inhibited IL-6-induced signaling cascade including phosphorylation of JAK2/STAT3 and ERK. Subsequently, it was examined whether S.P-EE treatment could recover bone loss in ovariectomized (OVX) mice. Indeed, S.P-EE exhibited both preventive and therapeutic effect on OVX-induced bone loss in trabecular microarchitecture along with significant increase in bone mineral density and content. To understand the mechanism of action of S.P-EE in bone metabolism, the effect of S.P-EE on osteoclast differentiation and activity was investigated. S.P-EE significantly inhibited RANKL-induced osteoclast differentiation by suppressing phosphorylation of MAPK and Akt, and expression of NFATc1 and osteoclast marker genes. S.P-EE also inhibited bone-resorbing activity of osteoclasts. Furthermore, isolation and identification of the active compounds which are responsible for the inhibitory effect of S.P-EE on osteoclast differentiation was carried out. Six major flavonoids and plebeiolide A-C were isolated and examined their effects on osteoclast differentiation. Luteolin and hispidulin, and plebeiolide A and C, not B exhibited potent inhibitory activity on RANKL-induced osteoclast formation.

The Immunoregulatory Effects of Traditional Chinese Medicine on Treatment of Asthma or Asthmatic Inflammation

Asthma is a chronic respiratory symptoms with variable airflow limitation and airway hyperresponsiveness (AHR), and causes high economic burden. Traditional Chinese medicine (TCM) has a long-lasting history of using herbal medicine in the treatment of various respiratory diseases including asthma. In the last several decades, an increasing number of herbs have been shown to be effective in the treatment of asthma in clinical trials or asthmatic inflammation in animal models. Literature about the effects of TCM on the immune system were searched in electronic databases such as PubMed, Google Scholar and Scopus from 2000 to 2014. 'TCM' and 'asthma' were used as keywords for the searches. Over 400 literatures were searched and the literatures about the immune system were selected and reviewed. We only reviewed literatures published in English. Accumulating evidence suggests that TCM can directly inhibit the activation and migration of inflammatory cells, regulate the balance of Th1/Th2 responses, and suppress allergic hyperreactivity through inducing regulatory T cells or attenuating the function of dendritic cells (DCs). These studies provided useful information to facilitate the use of TCM to treat asthma. This review was conducted to classify the findings based on their possible mechanisms of action reported.

Tyrosol Suppresses Allergic Inflammation by Inhibiting the Activation of Phosphoinositide 3-Kinase in Mast Cells

Allergic diseases such as atopic dermatitis, rhinitis, asthma, and anaphylaxis are attractive research areas. Tyrosol (2-(4-hydroxyphenyl)ethanol) is a polyphenolic compound with diverse biological activities. In this study, we investigated whether tyrosol has anti-allergic inflammatory effects. Ovalbumin-induced active systemic anaphylaxis and immunoglobulin E-mediated passive cutaneous anaphylaxis models were used for the immediate-type allergic responses. Oral administration of tyrosol reduced the allergic symptoms of hypothermia and pigmentation in both animal models. Mast cells that secrete allergic mediators are key regulators on allergic inflammation. Tyrosol dose-dependently decreased mast cell degranulation and expression of inflammatory cytokines. Intracellular calcium levels and activation of inhibitor of κB kinase (IKK) regulate cytokine expression and degranulation. Tyrosol blocked calcium influx and phosphorylation of the IKK complex. To define the molecular target for tyrosol, various signaling proteins involved in mast cell activation such as Lyn, Syk, phosphoinositide 3-kinase (PI3K), and Akt were examined. Our results showed that PI3K could be a molecular target for tyrosol in mast cells. Taken together, these findings indicated that tyrosol has anti-allergic inflammatory effects by inhibiting the degranulation of mast cells and expression of inflammatory cytokines; these effects are mediated via PI3K. Therefore, we expect tyrosol become a potential therapeutic candidate for allergic inflammatory disorders.

Inhibitory effect of 1,2,4,5-tetramethoxybenzene on mast cell-mediated allergic inflammation through suppression of IκB kinase complex

As the importance of allergic disorders such as atopic dermatitis and allergic asthma, research on potential drug candidates becomes more necessary. Mast cells play an important role as initiators of allergic responses through the release of histamine; therefore, they should be the target of pharmaceutical development for the management of allergic inflammation. In our previous study, anti-allergic effect of extracts of Amomum xanthioides was demonstrated. To further investigate improved candidates, 1,2,4,5-tetramethoxybenzene (TMB) was isolated from methanol extracts of A. xanthioides. TMB dose-dependently attenuated the degranulation of mast cells without cytotoxicity by inhibiting calcium influx. TMB decreased the expression of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-4 at both the transcriptional and translational levels. Increased expression of these cytokines was caused by translocation of nuclear factor-κB into the nucleus, and it was hindered by suppressing activation of IκB kinase complex. To confirm the effect of TMB in vivo, the ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and IgE-mediated passive cutaneous anaphylaxis (PCA) models were used. In the ASA model, hypothermia was decreased by oral administration of TMB, which attenuated serum histamine, OVA-specific IgE, and IL-4 levels. Increased pigmentation of Evans blue was reduced by TMB in a dose-dependent manner in the PCA model. Our results suggest that TMB is a possible therapeutic candidate for allergic inflammatory diseases that acts through the inhibition of mast cell degranulation and expression of pro-inflammatory cytokines.