Apigenin Inhibits IL-31 Cytokine in Human Mast Cell and Mouse Skin Tissues

Analgesic and anti-inflammatory effects of galangin: a potential pathway to inhibit transient receptor potential vanilloid 1 receptor activation

Background

Galangin, commonly employed in traditional Chinese medicine for its diverse medicinal properties, exhibits potential in treating inflammatory pain. Nevertheless, its mechanism of action remains unclear.

Methods

Mice were randomly divided into 4 groups for 7 days: a normal control group, a galangin-treated (25 and 50 mg/kg), and a positive control celecoxib (20 mg/kg). Analgesic and anti-inflammatory effects were evaluated using a hot plate test, acetic acid-induced writhing test, acetic acid-induced vascular permeability test, formalininduced paw licking test, and carrageenan-induced paw swelling test. The interplay between galangin, transient receptor potential vanilloid 1 (TRPV1), NF-κB, COX-2, and TNF-α proteins was evaluated via molecular docking. COX- 2, PGE2, IL-1β, IL-6, and TNF-α levels in serum were measured using ELISA after capsaicin administration (200 nmol/L). TRPV1 expression in the dorsal root ganglion was analyzed by Western blot. The quantities of substance P (SP) and calcitonin gene-related peptide (CGRP) were assessed using qPCR.

Results

Galangin reduced hot plate-induced licking latency, acetic acid-induced contortions, carrageenantriggered foot inflammation, and capillary permeability in mice. It exhibited favorable affinity towards TRPV1, NF- κB, COX-2, and TNF-α, resulting in decreased levels of COX-2, PGE2, IL-1β, IL-6, and TNF-α in serum following capsaicin stimulation. Galangin effectively suppressed the upregulation of TRPV1 protein and associated receptor neuropeptides CGRP and SP mRNA, while concurrently inhibiting the expression of NF-κB, TNF-α, COX-2, and PGE2 mRNA.

Conclusions

Galangin exerts its anti-inflammatory pain effects by inhibiting TRPV1 activation and regulating COX-2, NF-κB/TNF-α expression, providing evidence for the use of galangin in the management of inflammatory pain.

Mast cell-sensory neuron crosstalk in allergic diseases

Mast cells (MCs) are tissue-resident immune cells, well-positioned at the host-environment interface for detecting external antigens and playing a critical role in mobilizing innate and adaptive immune responses. Sensory neurons are afferent neurons innervating most areas of the body but especially in the periphery, where they sense external and internal signals and relay information to the brain. The significance of MC-sensory neuron communication is now increasingly becoming recognized, especially because both cell types are in close physical proximity at the host-environment interface and around major organs of the body and produce specific mediators that can activate each other. In this review, we explore the roles of MC-sensory neuron crosstalk in allergic diseases, shedding light on how activated MCs trigger sensory neurons to initiate signaling in pruritus, shock, and potentially abdominal pain in allergy, and how activated sensory neurons regulate MCs in homeostasis and atopic dermatitis associated with contact hypersensitivity and type 2 inflammation. Throughout the review, we also discuss how these 2 sentinel cell types signal each other, potentially resulting in a positive feedback loop that can sustain inflammation. Unraveling the mysteries of MC-sensory neuron crosstalk is likely to unveil their critical roles in various disease conditions and enable the development of new therapeutic approaches to combat these maladies.

Apigenin accelerates wound healing in diabetic mice by promoting macrophage M2-type polarization via increasing miR-21 expression

The alteration of inflammatory phenotype by macrophage polarization plays an important role in diabetic wound repair. Apigenin has been reported to be anti-inflammatory and promote tissue repair; however, whether it regulates macrophage polarization to participate in diabetic wound repair remains to be investigated. We found that apigenin promoted miR-21 expression in LPS-stimulated RAW264.7 cells, inhibited cellular M1-type factor TNF-α and IL-1β secretion and increased M2-type factor IL-10 and TGF-β secretion, and accelerated macrophage conversion from M1 type to M2 type, whereas this protective effect of apigenin was counteracted by a miR-21 inhibitor. Moreover, we established a macrophage-HUVECs cell in vitro co-culture system and found that apigenin accelerated the migration, proliferation, and VEGF secretion of HUVECs by promoting macrophage miR-21 expression. Further, mechanistic studies revealed that this was mediated by the TLR4/Myd88/NF-κB axis. In in vivo study, diabetic mice had significantly delayed wound healing compared to non-diabetic mice, accelerated wound healing in apigenin-treated diabetic mice, and decreased M1-type macrophages and increased M2-type macrophages in wound tissues.

In Vitro Safety and Efficacy Evaluation of a Juniperus communis Callus Culture Extract and Matricaria recutita Processing Waste Extract Combination as a Cosmetic Ingredient

For skin health promotion and cosmetic applications, combinations of plant cell extracts are extensively utilized. As most natural ingredient suppliers offer crude extracts from individual plants or specific isolated compounds, the potential interactions between them are assessed in the development phase of cosmetic products. The industry seeks extract combinations that have undergone optimization and scrutiny for their bioactivities. This study presents a combination of two sustainably produced botanical ingredients and outlines their chemical composition, in vitro safety, and bioactivity for skin health enhancement. The amalgamation comprises the extract of Matricaria recutita processing waste and the extract from Juniperus communis callus culture. Chemical analysis revealed distinct compounds within the extracts, and their combination led to a broader array of potentially synergistic compounds. In vitro assessments on skin cells demonstrated that the combination possesses robust antioxidant properties and the ability to stimulate keratinocyte proliferation, along with regulating collagen type I and matrix metalloproteinase 1 (MMP-1) production by dermal fibroblasts. The identified traits of this combination render it an appealing cosmetic component. To the best of our knowledge, this represents the first case when the extracts derived from medicinal plant processing waste and biotechnological plant cell cultivation processes have been combined and evaluated for their bioactivity.

Apigenin attenuates visceral hypersensitivity in water avoidance stress rats by modulating the microbiota-gut-brain axis and inhibiting mast cell activation

Visceral hypersensitivity (VH) and gut microbiota dysbiosis significantly contribute to the occurrence and development of irritable bowel syndrome (IBS), exacerbated by stress. Apigenin, a natural flavonoid derived from plants, possesses a range of beneficial properties. However, additional research is necessary to investigate its potential in alleviating symptoms of IBS and elucidating its underlying mechanisms of action. Our study confirms that apigenin effectively reverses mast cell and microglial activation, regulates the composition and abundance of the gut microbiota, improves intestinal barrier function in rats induced with water-avoidance stress, and mitigates VH and colonic hypermotility. Furthermore, in vitro studies suggest a potential role of dysbiotic gut microbiota in activating mast cells at the cellular level. Notably, apigenin inhibits mast cell degranulation through the toll-like receptor 4 (TLR4) / myeloid differentiation primary response gene 88 (MyD88) / nuclear factor-kappa B (NF-κB) pathway. In conclusion, this study discusses the potential therapeutic effects of apigenin in alleviating VH and modulating the gut-brain axis in water-avoidance stress rats, providing a novel or alternative treatment approach for IBS.

Exploring the Potential of Supercritical Fluid Extraction of Matricaria chamomilla White Ray Florets as a Source of Bioactive (Cosmetic) Ingredients

Aromatic and medicinal plants are a great source of useful bioactive compounds for use in cosmetics, drugs, and dietary supplements. This study investigated the potential of using supercritical fluid extracts obtained from Matricaria chamomilla white ray florets, a kind of industrial herbal byproduct, as a source of bioactive cosmetic ingredients. Response surface methodology to optimize the supercritical fluid extraction process by analyzing the impact of pressure and temperature on yield and the main bioactive compound groups were used. High-throughput 96-well plate spectrophotometric methods were used to analyze the extracts for total phenols, flavonoids, tannins, and sugars, as well as their antioxidant capacity. Gas chromatography and liquid chromatography-mass spectrometry was used to determine the phytochemical composition of the extracts. The extracts were also analyzed for antimicrobial activity, cytotoxicity, phototoxicity, and melanin content. Statistical analysis was performed to establish correlations between the extracts and develop models to predict the targeted phytochemical recovery and chemical and biological activities. The results show that the extracts contained a diverse range of phytochemical classes and had cytotoxic, proliferation-reducing, and antimicrobial activities, making them potentially useful in cosmetic formulations. This study provides valuable insights for further research on the uses and mechanisms of action of these extracts.

Therapeutic effects and mechanisms of Ku-Gan formula on atopic dermatitis: A pilot clinical study and modular pharmacology analysis with animal validation

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a persistent, recurrent inflammatory skin disorder with a rapid upward trend worldwide. The first-line treatment for AD consists of topical medicines such as topical corticosteroids (TCSs). However, long-term use of conventional topical medicine results in side effects and recurrence, presenting therapeutic challenges for the management of AD. Ku-Gan formula (KG) has been extensively used to treat skin diseases since the Song dynasty. In particular, topical administration of the KG alleviates the cutaneous symptoms of AD and reduces recurrence rates with a good safety profile; however, the mechanisms of the KG's action remain unknown.

AIM OF THE STUDY

The current study aimed to evaluate the efficacy and safety of KG in AD patients and to investigate the molecular mechanisms that underlie the efficacy of KG in the treatment of AD.

MATERIALS AND METHODS

A single-arm prospective pilot study with historical controls was conducted. This study evaluated 11 patients with mild to moderate AD, who underwent topical KG treatment. The primary outcome was the change in local eczema area and severity index (EASI) scores. The secondary outcomes included the recurrence rate and safety. The recurrence rate were compared to those of a matched historical control group. Secondly, modular pharmacology analysis was used to elucidate the therapeutic mechanism of KG in AD treatment by identifying the hub genes and kernel pathways. Moreover, we evaluated treatment effects and verified modular pharmacology-based findings using the calcipotriol (MC903)-induced mouse model and bioinformatics analysis.

RESULTS

Our clinical pilot study demonstrated that the KG wet wrapping could effectively ameliorate skin lesions in AD patients with a significant drop from 4.18 to 1.63 in local EASI. Compared to the historical controls, KG had a reduced recurrence rate (36%) and a longer median time to relapse (>12 weeks). Modular pharmacology analysis identified the hub genes including IL6, IL1B, VEGFA, STAT3, JUN, TIMP1 and ARG1, and kernel pathway including IL-17 signaling pathway of KG. Pharmacodynamic results suggested that KG ameliorated skin symptoms and demonstrated no less efficacy than halcinonide (HC) in MC903-induced AD-like mice. In addition, KG regulated the mRNA expression of hub genes as well as the related genes involved in IL-17 signaling pathway including Il25, Il17a,Traf3ip2, and Traf6, in skin lesions of AD-like mice.

CONCLUSION

These results showed that KG is a safe and effective topical treatment for AD with low recurrence. In addition, our study identified potential molecular pathways and therapeutic candidate targets of the KG formula, providing evidence for its clinical applicability in AD.

Epicutaneous Sensitization and Food Allergy: Preventive Strategies Targeting Skin Barrier Repair-Facts and Challenges

Food allergy represents a growing public health and socio-economic problem with an increasing prevalence over the last two decades. Despite its substantial impact on the quality of life, current treatment options for food allergy are limited to strict allergen avoidance and emergency management, creating an urgent need for effective preventive strategies. Advances in the understanding of the food allergy pathogenesis allow to develop more precise approaches targeting specific pathophysiological pathways. Recently, the skin has become an important target for food allergy prevention strategies, as it has been hypothesized that allergen exposure through the impaired skin barrier might induce an immune response resulting in subsequent development of food allergy. This review aims to discuss current evidence supporting this complex interplay between the skin barrier dysfunction and food allergy by highlighting the crucial role of epicutaneous sensitization in the causality pathway leading to food allergen sensitization and progression to clinical food allergy. We also summarize recently studied prophylactic and therapeutic interventions targeting the skin barrier repair as an emerging food allergy prevention strategy and discuss current evidence controversies and future challenges. Further studies are needed before these promising strategies can be routinely implemented as prevention advice for the general population.

Apigenin: A Therapeutic Agent for Treatment of Skin Inflammatory Diseases and Cancer

The skin is the main barrier between the body and the environment, protecting it from external oxidative stress induced by ultraviolet rays. It also prevents the entrance of infectious agents such as viruses, external antigens, allergens, and bacteria into our bodies. An overreaction to these agents causes severe skin diseases, including atopic dermatitis, pruritus, psoriasis, skin cancer, and vitiligo. Members of the flavonoid family include apigenin, quercetin, luteolin, and kaempferol. Of these, apigenin has been used as a dietary supplement due to its various biological activities and has been shown to reduce skin inflammation by downregulating various inflammatory markers and molecular targets. In this review, we deal with current knowledge about inflammatory reactions in the skin and the molecular mechanisms by which apigenin reduces skin inflammation.

Apigenin and its dermatological applications: A comprehensive review

Apigenin is one of the abundant flavonoids in fruits and vegetables of human diet with several demonstrated health benefits. The aim of the present study is to provide an overview of the current evidence regarding the effect of apigenin on different dermatological complications. Electronic databases including PubMed, Scopus, and Web of Science were searched to retrieve all papers assessing the dermatological effects of apigenin. Preclinical studies support beneficial effects of apigenin on UV-induced skin damage, vitiligo, dermatitis, wounds, skin aging, and some types of skin cancer. The compound mostly acts via inhibition of inflammation through suppression of pro-inflammatory cytokines and intracellular inflammatory mediators, as well as antioxidant properties such as improvement of endogenous antioxidant defense mechanisms. There are also some studies for the design and development of novel drug delivery systems for apigenin to improve its oral and topical bioavailability. Nevertheless, no clinical study has evaluated apigenin as a natural supplement for skin conditions. Considering the benefits of apigenin in preclinical models of dermatological disorders, as well as the acceptable safety of this compound, apigenin may be a future candidate to be used in dermatological disorders. Future clinical studies are needed to further confirm the safety and efficacy of apigenin in skin care products.

Cytokines and chemokines modulation of itch

Itch (pruritus) is a common cutaneous symptom widely associated with many skin complaints, and chronic itch can be a severe clinical problem. The onset and perpetuation of itch are linked to cytokines, such as interleukin (IL)-31, IL-4, IL-13, IL-33, thymic stromal lymphopoietin, and tumor necrosis factor-alpha, and chemokines, such as chemokine (C-C motif) ligand 2 and C-X-C motif chemokine ligand 10. This review highlights research that has attempted to determine the attributes of various cytokines and chemokines concerning the development and modulation of itch. Through such research, clinical approaches targeting cytokines and/or chemokines may arise, which may further the development of itch therapeutics.

New Treatments for Atopic Dermatitis Targeting Skin Barrier Repair via the Regulation of FLG Expression

Atopic dermatitis (AD) is one of the most common chronic, inflammatory skin disorders with a complex etiology and a broad spectrum of clinical phenotypes. Despite its high prevalence and effect on the quality of life, safe and effective systemic therapies approved for long-term management of AD are limited. A better understanding of the pathogenesis of atopic dermatitis in recent years has contributed to the development of new therapeutic approaches that target specific pathophysiological pathways. Skin barrier dysfunction and immunological abnormalities are critical in the pathogenesis of AD. Recently, the importance of the downregulation of epidermal differentiation complex (EDC) molecules caused by external and internal stimuli has been extensively emphasized. The purpose of this review is to discuss the innovations in the therapy of atopic dermatitis, including biologics, small molecule therapies, and other drugs by highlighting regulatory mechanisms of skin barrier-related molecules, such as filaggrin (FLG) as a crucial pathway implicated in AD pathogenesis.

The Anticancer Potential of Apigenin Via Immunoregulation

Apigenin is an edible flavonoid widely distributed in natural plants, including most vegetables and fruits. Previous studies have revealed that apigenin possesses multiple biological functions by demonstrating antiinflammatory, anti-oxidative, anti-bacterial, anti-viral, anti-tumor and cardiovascular protective effects. Furthermore, recent progressions have disclosed a novel perspective of the anti-cancer roles of apigenin through its immunoregulatory functions. With the rapid progression of the groundbreaking strategies being developed for cancer immunotherapy, its immunoregulatory roles are being recognized as intriguing features of the multifaceted apigenin. However, the current understanding of this emerging role of apigenin still remains limited. Therefore, in the present review, recent advances on the immunoregulatory properties of apigenin in various diseases with a special focus on neoplasm, are summarized. Clinical strategies of cancer immunotherapy are briefly introduced and findings on apigenin linked to immunoregulatory roles in immunotherapy-associated aspects are brought together. The bioactivity, bioavailability, toxicity and potential of apigenin, to be considered as a therapeutic agent in anti-tumor immunotherapy, is discussed. Disclosed molecular mechanisms underlying the immunoregulatory roles of apigenin in cancer immunotherapy are also summarized. Based on findings from the literature, apigenin has the potential to serve as a prospective adjuvant for anti-cancer immunotherapy and warrants further investigations.

Valorization of Gleditsia triacanthos Invasive Plant Cellulose Microfibers and Phenolic Compounds for Obtaining Multi-Functional Wound Dressings with Antimicrobial and Antioxidant Properties

Gleditsia triacanthos is an aggressive invasive species in Eastern Europe, producing a significant number of pods that could represent an inexhaustible resource of raw material for various applications. The aim of this study was to extract cellulose from the Gleditsia triacanthos pods, characterize it by spectrophotometric and UHPLC-DAD-ESI/MS analysis, and use it to fabricate a wound dressing that is multi-functionalized with phenolic compounds extracted from the leaves of the same species. The obtained cellulose microfibers (CM) were functionalized, lyophilized, and characterized by ATR-FTIR and SEM. The water absorption and retention capacity as well as the controlled release of phenolic compounds with antioxidant properties evaluated in temporal dynamics were also determined. The antimicrobial activity against reference and clinical multi-drug-resistant Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae, Candida albicans, and Candida parapsilosis strains occurred immediately after the contact with the tested materials and was maintained for 24 h for all tested microbial strains. In conclusion, the multi-functionalized cellulose microfibers (MFCM) obtained from the reproductive organs of an invasive species can represent a promising alternative for the development of functional wound dressings with antioxidant and antimicrobial activity, as well as being a scalable example for designing cost-effective, circular bio-economy approaches to combat the accelerated spread of invasive species.

Importance of food in the control of inflammation in atopic dermatitis

Patients that suffer from inflammatory diseases need to pay special attention to nutrition. For this reason, it is very important to change the approach of both health professionals and food industry specialists. There must be a close collaboration, starting from research, the development phase of foods for special nutrition states. Our primary objective was to identify foods or potential dietary ingredients, which efficacy in the treatment of atopic dermatitis had been scientifically demonstrated in vitro, in vivo and clinically. Furthemore, our perspective is presented regarding the research and development of foods for special nutritional states in atopic dermatitis. The PubMed database was analyzed for the period 2018-2020, as well as the European Legislation regarding the appropriate requirements for the composition and knowledge applicable to foods destined for use in special medical purposes. The search criteria were 'chronic dermatitis', 'atopic dermatitis', 'psoriasis', 'alternative treatments', 'natural treatments', 'complementary treatments', 'treatments for chronic dermatitis'. We also looked for undesirable effects or side effects of the foods included in the research in order to treat atopic dermatitis. The results showed that prebiotics, probiotics and certain plant extracts had a high efficacy in controlling inflammation in atopic dermatitis. The food development research for special nutrition states (atopic dermatitis) involves a multidisciplinary team. We started with the establishment of the general objective and continued with the consultation of the PubMed, EMBASE and other databases, and with the in vitro, preclinical and/or clinical determination of the efficacy of new developed foods, that must be protected with patents. The development of foods for special nutrition states represents a solution for improving the quality of life of atopic dermatitis patients.

Comparative Study on the Biological Effects of Sodium Citrate-Based and Apigenin-Based Synthesized Silver Nanoparticles

The apigenin is a bioactive flavonoid mostly found in fruits and vegetables that possess various biological activities. The current study was performed to compare the biological potentials of sodium citrate-based (SC-SNPs) and apigenin-based (AP-SNPs) synthesized silver nanoparticles under the in vitro and in vivo conditions. The synthesized silver nanoparticles were physically and chemically characterized. The anticancer, pro-apoptotic, and their anti-bacterial activities were determined. Further, the mice trial was conducted to determine the possible toxic effects of the synthesized silver nanoparticles. The result of particle size analysis revealed the nanometer sizes of the SC-SNPs and AP-SNPs were about 95.5 and 93.94 nm, respectively. Both nanoparticles indicated pseudo-spherical shape, homogenous dispersion with an appropriate good degree of stability. However, the anticancer potential, pro-apoptotic effects and antibacterial activity of AP-SNPs were higher than that of SC-SNPs. Moreover, the mice trial indicated that AP-SNPs improved the liver function through modulation of liver enzymes, lipid peroxidation, and increase in the expression of antioxidant enzymes (SOD and GPx) as compared to the mice received AP-SNPs during 30 day experiment. Consequently the synthesis of silver nanoparticles using apigenin as reducing bioactive compound may result in production of silver nanoparticles with enhanced anticancer, antibacterial and antioxidant activities.

Apigenin Attenuates the Allergic Reactions by Competitively Binding to ER With Estradiol

Apigenin (API) is a natural phytoestrogen with properties including anti-inflammatory and other abilities. This study aims to 1) systematically validate that excessive estrogen exacerbates allergic reactions; 2) explore the anti-allergic effects and mechanisms of API. We conduct a survey of college students, indicating that of the 505 effective results, 70 individuals were self-reported allergic and 74.1% of them were women, which proved the gender difference in allergic reactions. BALB/c mice are grouped into the negative control group (N-Ctrl), the OVA-sensitized group (P-Ctrl), the estrogenized OVA-sensitized group (E2), and three treatment groups administrating different dose of API (E2 + API/L/M/H). In vivo data indicated that API treatment significantly inhibited the enhancement of estradiol on clinical symptoms. Moreover, we found that high doses of API inhibited Th2 type humoral response and mast cell degranulation levels in vivo and in vitro. Additionally, medium, and high doses of API significantly reduced the potentiation of estradiol on ER expression, attenuated the transmission of estrogen/ER signaling, thereby inhibiting the phosphorylation of ERK1/2 and JNK1/2/3 in the MAPK. Besides, we found that API competitively bound to ER with estradiol, and showed a weak selectivity to ERβ. Overall, we identified API can be beneficial in allergic disease.