Topical apigenin alleviates cutaneous inflammation in murine models

Apigenin: A Bioflavonoid with a Promising Role in Disease Prevention and Treatment

Apigenin is a powerful flavone compound found in numerous fruits and vegetables, and it offers numerous health-promoting benefits. Many studies have evidenced that this compound has a potential role as an anti-inflammatory and antioxidant compound, making it a promising candidate for reducing the risk of pathogenesis. It has also been found to positively affect various systems in the body, such as the respiratory, digestive, immune, and reproductive systems. Apigenin is effective in treating liver, lung, heart, kidney, neurological diseases, diabetes, and maintaining good oral and skin health. Multiple studies have reported that this compound is capable of suppressing various types of cancer through the induction of apoptosis and cell-cycle arrest, suppressing cell migration and invasion, reduction of inflammation, and inhibiting angiogenesis. When used in combination with other drugs, apigenin increases their efficacy, reduces the risk of side effects, and improves the response to chemotherapy. This review broadly analyzes apigenin's potential in disease management by modulating various biological activities. In addition, this review also described apigenin's interaction with other compounds or drugs and the potential role of nanoformulation in different pathogeneses. Further extensive research is needed to explore the mechanism of action, safety, and efficacy of this compound in disease prevention and treatment.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

Narrative Review of Drug-Associated Nail Toxicities in Oncologic Patients

INTRODUCTION

Nail toxicity represents one of the most common cutaneous adverse effects of both classic chemotherapeutic agents and new oncologic drugs, including targeted treatments and immunotherapy.

OBJECTIVES

We aimed to provide a comprehensive literature review of nail toxicities derived from conventional chemotherapeutic agents, targeted therapies (EGFR inhibitors, multikinase inhibitors, BRAF and MEK inhibitors) and immune checkpoint inhibitors (ICIs), including clinical presentation, implicated drugs and approaches for prevention and management.

METHODS

Retrieved literature from PubMed registry database was reviewed to include all articles published up to May 2021 relevant to the clinical presentation, diagnosis, incidence, prevention, and treatment of oncologic treatment-induced nail toxicity. The internet was searched for relevant studies.

RESULTS

A wide spectrum of nail toxicities is associated with both, conventional and newer anticancer agents. The frequency of nail involvement, especially with immunotherapy and new targeted agents remains unknown and patients with different cancer types receiving different regimens may develop the same nail disorder, whereas patients with the same type of cancer under the same chemotherapeutic treatment may develop different types of nail alterations. The underlying mechanisms of the varying individual susceptibility and the diverse nail responses to various anticancer treatments need further investigation.

CONCLUSION

Early recognition and treatment of nail toxicities can minimize their impact, allowing better adherence to conventional and newer oncologic treatments. Dermatologists, oncologists and other implicated physicians should be aware of these burdensome adverse effects in order to guide management and prevent impairment of patients' quality of life.

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.

Keratinocytes: An Enigmatic Factor in Atopic Dermatitis

Atopic dermatitis (AD), characterized by rashes, itching, and pruritus, is a chronic inflammatory condition of the skin with a marked infiltration of inflammatory cells into the lesion. It usually commences in early childhood and coexists with other atopic diseases such as allergic rhinitis, bronchial asthma, allergic conjunctivitis, etc. With a prevalence rate of 1–20% in adults and children worldwide, AD is gradually becoming a major health concern. Immunological aspects have been frequently focused on in the pathogenesis of AD, including the role of the epidermal barrier and the consequent abnormal cytokine expressions. Disrupted epidermal barriers, as well as allergic triggers (food allergy), contact allergens, irritants, microbes, aggravating factors, and ultraviolet light directly initiate the inflammatory response by inducing epidermal keratinocytes, resulting in the abnormal release of various pro-inflammatory mediators, inflammatory cytokines, and chemokines from keratinocytes. In addition, abnormal proteinases, gene mutations, or single nucleotide polymorphisms (SNP) affecting the function of the epidermal barrier can also contribute towards disease pathophysiology. Apart from this, imbalances in cholinergic or adrenergic responses in the epidermis or the role played by immune cells in the epidermis such as Langerhans cells or antigen-presenting cells can also aggravate pathophysiology. The dearth of specific biomarkers for proper diagnosis and the lack of a permanent cure for AD necessitate investigation in this area. In this context, the widespread role played by keratinocytes in the pathogenesis of AD will be reviewed in this article to facilitate the opening up of new avenues of treatment for AD.

Optimizing emollient therapy for skin barrier repair in atopic dermatitis

OBJECTIVE

We compared the principal characteristics of over-the-counter moisturizers with physiological lipid-based barrier repair therapy (BRT).

DATA SOURCES

An extended literature reported that moisturizers are considered standard ancillary therapy for anti-inflammatory skin disorders such as atopic dermatitis (AD). Additional studies have found that physiological lipid-based BRT can comprise effective, stand-alone therapy for pediatric AD.

RESULTS

Not all moisturizers are beneficial-some negatively impact skin function, and in doing so, they risk inducing or exacerbating inflammation in patients with AD. The frequent self-reported occurrences of sensitive skin in patients with AD could reflect the potential toxicity of such formulations. A still unanswered question is whether improper formulations could also prove to be counterproductive in other types of sensitive skin, such as rosacea. In contrast, we found how physiological lipid-based BRT (when comprised of the 3 key stratum corneum lipids in sufficient quantities and at an appropriate molar ratio) can correct the barrier abnormality, thereby reducing inflammation in AD and possibly in other inflammatory dermatoses, such as adult eczemas and possibly even psoriasis.

CONCLUSION

We provide guidelines for the appropriate dispensation of moisturizers and physiological lipid-based, BRT for the treatment of AD. Both over-the-counter (Atopalm) and prescription (EpiCeram) products are available in the United States with these characteristics.

Promising Natural Products in New Drug Design, Development, and Therapy for Skin Disorders: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

The skin is the largest organ in the human body, composed of the epidermis and the dermis. It provides protection and acts as a barrier against external menaces like allergens, chemicals, systemic toxicity, and infectious organisms. Skin disorders like cancer, dermatitis, psoriasis, wounds, skin aging, acne, and skin infection occur frequently and can impact human life. According to a growing body of evidence, several studies have reported that natural products have the potential for treating skin disorders. Building on this information, this review provides brief information about the action of the most important in vitro and in vivo research on the use of ten selected natural products in inflammatory, neoplastic, and infectious skin disorders and their mechanisms that have been reported to date. The related studies and articles were searched from several databases, including PubMed, Google, Google Scholar, and ScienceDirect. Ten natural products that have been reported widely on skin disorders were reviewed in this study, with most showing anti-inflammatory, antioxidant, anti-microbial, and anti-cancer effects as the main therapeutic actions. Overall, most of the natural products reported in this review can reduce and suppress inflammatory markers, like tumor necrosis factor-alpha (TNF-α), scavenge reactive oxygen species (ROS), induce cancer cell death through apoptosis, and prevent bacteria, fungal, and virus infections indicating their potentials. This review also highlighted the challenges and opportunities of natural products in transdermal/topical delivery systems and their safety considerations for skin disorders. Our findings indicated that natural products might be a low-cost, well-tolerated, and safe treatment for skin diseases. However, a larger number of clinical trials are required to validate these findings. Natural products in combination with modern drugs, as well as the development of novel delivery mechanisms, represent a very promising area for future drug discovery of these natural leads against skin disorders.

Phytochemical Screening of Himatanthus sucuuba (Spruce) Woodson (Apocynaceae) Latex, In Vitro Cytotoxicity and Incision Wound Repair in Mice

Himatanthus sucuuba, also known as "Bellaco caspi", is a medicinal plant whose latex, stem bark, and leaves possess phenolic acids, lupeol, β-dihydro-plumbericinic acid, plumericin, and plumeride, among other components. Some of these have been linked to such biological activities as antiulcer, anti-inflammatory, and wound healing. The aim of this study was to determine the phytochemical compounds of H. sucuuba latex, as well as its in vitro cytotoxicity and wound healing effect in mice. Latex was collected in the province of Iquitos, Peru. Phytochemical analysis was carried out with UPLC-ESI-MS/MS. The cytotoxicity was evaluated on two colon tumor cell lines (SW480 and SW620) and non-malignant cells (human keratinocytes, HaCaT, and Chinese hamster ovary, CHO-K1). The mice were distributed into two groups, as follows: Group I-control (n = 10; without treatment); II-(n = 10) H. sucuuba latex; wounds were induced with a scalpel in the dorsal-cervical area and treatments were applied topically twice a day on the incision for 10 days. Molecular docking was carried out on the glycogen synthase kinase 3β protein. Twenty-four chemical compounds were determined, mainly flavonoid-type compounds. Latex did not have a cytotoxic effect on tumor cells with IC₅₀ values of more than 500 µg/mL. The latex had a regenerative effect on wounds in mice. Acacetin-7-O-neohesperidoside had the best docking score of -9.9 kcal/mol. In conclusion, H. sucuuba latex had a wound healing effect in mice, as confirmed by histological study. However, a non-cytotoxic effect was observed on colon tumor cells SW480 and SW620.

The Active Compounds and Therapeutic Mechanisms of Pentaherbs Formula for Oral and Topical Treatment of Atopic Dermatitis Based on Network Pharmacology

To examine the molecular targets and therapeutic mechanism of a clinically proven Chinese medicinal pentaherbs formula (PHF) in atopic dermatitis (AD), we analyzed the active compounds and core targets, performed network and molecular docking analysis, and investigated interacting pathways. Information on compounds in PHF was obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and target prediction was performed using the Drugbank database. AD-related genes were gathered using the GeneCards and Online Mendelian Inheritance in Man (OMIM) databases. Network analysis was performed by Cytoscape software and protein-protein interaction was analyzed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources were applied for the enrichment analysis of the potential biological process and pathways associated with the intersection targets between PHF and AD. Autodock software was used to perform protein compound docking analysis. We identified 43 active compounds in PHF associated with 117 targets, and 57 active compounds associated with 107 targets that form the main pathways linked to oral and topical treatment of AD, respectively. Among them, quercetin, luteolin, and kaempferol are key chemicals targeting the core genes involved in the oral use of PHF against AD, while apigenin, ursolic acid, and rosmarinic acid could be used in topical treatment of PHF against AD. The compound–target–disease network constructed in the current study reveals close interactions between multiple components and multiple targets. Enrichment analysis further supports the biological processes and signaling pathways identified, indicating the involvement of IL-17 and tumor necrosis factor signaling pathways in the action of PHF on AD. Our data demonstrated the main compounds and potential pharmacological mechanisms of oral and topical application of PHF in AD.

Assessment of non-invasive techniques and herbal-based products on dermatological physiology and intercellular lipid properties

Skin is the largest external organ of the human body. It acts as a barrier to protect the human body from environmental pollution, mechanical stress, and excessive water loss. The defensive function resides primarily on top of the epidermis layer commonly known as stratum corneum (SC). Human SC consists of three major lipids, namely ceramide, free fatty acid, and cholesterol that comprise approximately 50%, 25%, and 25% of the total lipid mass, respectively. The optimal composition of SC lipids is the vital epidermal barrier function of the skin. On the other hand, skin barrier serves to limit passive water loss from the body, reduces chemical absorption from the environment, and prevents microbial infection. In contrast, epidermal lipids are important to maintain the cell structure, growth and differentiation, cohesion and desquamation as well as formation of a permeability barrier. Multiple non-invasive in vivo approaches were implemented on a regular basis to monitor skin physiological and intercellular lipid properties. The measurement of different parameters such as transepidermal water loss (TEWL), hydration level, skin elasticity, collagen intensity, melanin content, sebum, pH, and tape stripping is essential to evaluate the epidermal barrier function. Novel non-invasive techniques such as tape stripping, ultrasound imaging, and laser confocal microscopy offer higher possibility of accurate and detailed characterisation of skin barrier. To date, these techniques have also been widely used to determine the effects of herbal plants in dermatology. Herbal plants have been traditionally used for ages to treat a variety of skin diseases, as reported by the World Health Organisation (WHO). Their availability, lower cost, and minimal or no side effects have created awareness among society, thus increase the demand for natural sources as the remedy to treat various skin diseases. This paper reviews several non-invasive techniques and evaluations of herbal-based product in dermatology.

Metformin ameliorates animal models of dermatitis

Metformin, a potent AMPK activator is the most commonly used drug for diabetes. According to recent reports, metformin lowers the risk of diabetic complications and inflammatory diseases. We found the expression levels of AMPK subunits including PRKAA1, PRKAA2, PRKAB1 and PRKAB2 are decreased in skin biopsies of dermatitis patients from multiple datasets. Interestingly, metformin treatment ameliorates dermatitis symptom in animal model of dermatitis using O-tetradecanoylphorbol-13-acetate (TPA). Especially, the levels of epidermis and dermis thickness were decreased by metformin. We found NFκB activity as well as of gene expression associated with collagen synthesis are attenuated by metformin treatment. These results suggest that metformin treatment alleviates animal model of dermatitis.

Phytomedicines containing Matricaria species for the treatment of skin diseases: A biotechnological approach

Skin diseases have a notable impact on the life of the affected and in their health conditions. In order to allow a more effective and economical treatment for such disorders, new therapeutic approaches have been continuously investigated. Due to its high therapeutic and phytochemical potential, Matricaria species emerges as a pleasant alternative, since it is an important source of bioactive secondary metabolites suitable for the treatment of varied skin diseases. Therefore, this review aimed to catalog inventions that have used Matricaria species as the active component for skin disease treatment in order to assess the status of the technological development of the fitomedicines. For this, a search of patents was performed in four specialized patent database, which have reported the discovery of pharmaceutical bioproducts that used Matricaria species in its composition for skin treatment. Therefore, it is possible to notice that the pharmaceutical industry has driven efforts and investment to produce medicines for the dermatopathies, using species of this genus as an active principle. Besides, a trend of growth has been identified for the last years, which is accompanied by the continuous publication of scientific articles on the subject. It is known that a long journey is traversed between the scientific findings and their applications in the pharmaceutical market, creating the perspective that new Matricaria-based medicines may reach the pharmaceutical market in the coming years.

Prophylactic management for taxane-induced nail toxicity: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis was performed to assess the efficacy of cryotherapy and nail solution (NS) use in preventing nail toxicity (NT) induced by taxane-based chemotherapy.

METHODS

PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov registry databases were searched for relevant studies published up to December 2018. The primary outcome was taxane-induced NT. Secondary outcomes were skin toxicity (ST), time to toxicity and patient comfort.

RESULTS

We reviewed three randomised control trials and six prospective studies with 708 patients. For meta-analysis, taxane-induced NT grading was compared. NT and ST were significantly lower in the cryotherapy patients than in the controls (grade 1 NT: risk ratio [RR] = 0.51, 95% confidence interval [CI] = 0.30-0.89; grade 2-3 NT: RR = 0.36, 95% CI = 0.11-1.12; total NT: RR = 0.49; 95% CI = 0.30-0.79; ST: RR = 0.46, 95% CI = 0.33-0.64). The NS-treated patients exhibited significantly lower NT than the controls.

CONCLUSIONS

Nail solution-treated or cryotherapy patients exhibited lower NT incidence and severity associated with taxane-based chemotherapy than the controls. For patients who can afford and comply with NS use or cryotherapy, these measures represent effective prophylactic management for taxane-induced NT and improve their quality of life and functional statuses. Further studies are needed to establish the routine usage protocols, long-term efficacy and safety for these interventions.

Network Pharmacology-Based Investigation of Protective Mechanism of Aster tataricus on Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a common clinical condition that badly influences people's health. Recent studies indicated that Aster tataricus (RA) had potential effects on ALI, but the effective components and their mechanism is not clear. In this study, we found that the Fraction-75 eluted from RA extract could significantly protect the lipopolysaccharide (LPS)-induced ALI in mice, including alleviating the severity of lung pathology, attenuating the pulmonary edema, and reducing the release of inflammatory cells. Further ingredient analyses demonstrated that there were mainly 16 components in it, among which 10 components were collected according to their relative peak area and oral bioavailability. Next, the components-disease targets network suggested that the candidate components had extensive associations with 49 known therapeutic targets of ALI, among which 31 targets could be regulated by more than one component. Herein, GO functional and pathway analysis revealed that the common targets were associated with four biological processes, including the inflammatory response to stimulus, cellular process, chemokine biosynthetic process and immune system process. Furthermore, the ELISA validation indicated that the candidate components in RA extract may protect the LPS-induced ALI mainly through inhibiting the release of inflammatory cytokines and promoting the repair of vascular endothelial.

Efficacy of a repair cream containing Rhealba oat plantlets extract l-ALA-l-GLU dipeptide, and hyaluronic acid in wound healing following dermatological acts: a meta-analysis of >2,000 patients in eight countries corroborated by a dermatopediatric clinical case

Background

The frequency of dermatological acts is increasing. These procedures often cause injuries and traumatic alterations in specific skin layers, slowing down wound healing.

Patients and methods

An open observational study lasting 1 month was conducted on 2,363 patients who had undergone various dermatological procedures. This study was conducted in eight European countries and an Asian country during which the tolerance and efficacy of a cosmetic cream based on Rhealba oat plantlets’ extract, l-ALA–l-GLU dipeptide, and hyaluronic acid were assessed on patients’ wounds.

Results

Efficacy was observed 5′ after the first application, which leads to an immediate relief, confirmed by the overall efficacy judged by the doctors as good or very good in 96.8% of the cases. In Germany, the efficacy of the same cream was assessed on children suffering from first- or second-degree burns. In this dermatopediatric case, the aim was to support the regeneration process and prevent scarring by using a topical cream rather than a silicon bandage or corticosteroids. A positive effect on skin regeneration and prevention of scaring could already be observed after 4 weeks of application without any undesired complication.

Conclusion

This clinical focus complements the previous meta-analysis by demonstrating that the tested cream containing Rhealba oat plantlets’ extracts, l-ALA–l-GLU dipeptide, and hyaluronic acid could also be used with a great efficacy in children after thermal burns to prevent scaring.

Pediococcus pentosaceus-Fermented Cordyceps militaris Inhibits Inflammatory Reactions and Alleviates Contact Dermatitis

Cordyceps militaris is a medicinal mushroom used to treat immune-related diseases in East Asia. We investigated the anti-inflammatory effect of the extract of C. militaris grown on germinated Rhynchosia nulubilis (GRC) fermented with Pediococcus pentosaceus ON89A isolated from onion (GRC-ON89A) in vivo as well as in vitro. The anti-inflammatory effect of GRC-ON89A was investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The total polyphenol content (TPC) and total flavonoid content (TFC) in the GRC-ON89A ethanol extract were significantly increased compared to that in GRC. GRC-ON89A hexane fraction (GRC-ON89A-Hex) inhibited the release of nitric oxide (NO) compared to that of the LPS-treated control without cytotoxicity in LPS-stimulated RAW 264.7 macrophages. GRC-ON89A-Hex decreased the inducible NO synthase (iNOS), cyclooxygenase 2 (COX2), and tumor necrosis factor (TNF)-α mRNA expression in LPS-stimulated RAW 264.7 macrophages. In addition, pre-treatment with GRC-ON89A-Hex significantly inhibited LPS-stimulated phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB. To induce allergic contact dermatitis (ACD), 1-fluoro-2, 4-dinitrofluorobenzene (DNFB) was applied to the surface of the right ears of C57BL/6N mice. GRC-ON89A reduced the ear swelling and thickness in DNFB-induced ACD mice. This study demonstrates the potential usefulness of GRC-ON89A as an anti-inflammatory dietary supplement or drug.

Antiskin Inflammatory Activity of Black Ginger (Kaempferia parviflora) through Antioxidative Activity

Kaempferia parviflora (Krachaidum (KD)) is a traditional herbal medicine and has properties that are beneficial for human health. In the current study, we sought to investigate the anti-inflammatory properties of KD extract (KPE). In mouse skin tissue, UV light representing solar wavelengths (sUV) increased COX-2 expression, while treatment with KPE reduced this effect. The anti-inflammatory activity of KPE was confirmed in in vitro models. MAPK signaling pathways were activated by sUV irradiation, and this was also repressed in the presence of KPE treatment. It is assumed that the anti-inflammatory activity of KPE is caused by the antioxidative effect. Furthermore, we confirmed the critical role of oxidative stress in sUV-induced COX-2 expression. We analyzed the polyphenol composition of KPE. Of the polyphenols identified, gallic acid, apigenin, and tangeretin were identified as the major polyphenols (at 9.31 ± 1.27, 2.37 ± 0.14, and 2.15 ± 0.19 μg/mg dry weight, resp.). Collectively, these findings show that in the presence of sUV irradiation, KD has anti-inflammatory properties and antioxidative effects in the skin.

Herbal Medicines Prevent the Development of Atopic Dermatitis by Multiple Mechanisms

Atopic dermatitis (AD) is among the most common skin disorders in humans. Although a variety of regimens are available for the treatment of AD, preventive approaches are limited. Recent studies have demonstrated that certain naturally-occurring herbal medicines are effective in preventing the development of AD via divergent mechanisms, such as inhibiting cytokine and chemokine expression, IgE production, inflammatory cell infiltration, histamine release, and/or enhancement of epidermal permeability barrier function. Yet, they exhibit few adverse effects. Since herbal medicines are widely available, inexpensive and generally safe, they could represent an ideal approach for preventing the development of AD, in both highly developed and developing countries.

Validation of a RP-HPLC-DAD Method for Chamomile (Matricaria recutita) Preparations and Assessment of the Marker, Apigenin-7-glucoside, Safety and Anti-Inflammatory Effect

Chamomile is a medicinal plant, which presents several biological effects, especially the anti-inflammatory effect. One of the compounds related to this effect is apigenin, a flavonoid that is mostly found in its glycosylated form, apigenin-7-glucoside (APG), in natural sources. However, the affectivity and safety of this glycoside have not been well explored for topical application. In this context, the aim of this work was to develop and validate a reversed-phase high-performance liquid chromatography (RP-HPLC-DAD) method to quantify APG in chamomile preparations. Additionally, the safety and the anti-inflammatory potential of this flavonoid were verified. The RP-HPLC-DAD method was developed and validated with linearity at 24.0-36.0 μg/mL range (r = 0.9994). Intra- and interday precision (RSD) were 0.27-2.66% and accuracy was 98.27-101.21%. The validated method was applied in the analysis of chamomile flower heads, glycolic extract, and Kamillen cream, supporting the method application in the quality control of chamomile preparations. Furthermore, the APG safety was assessed by MTT cytotoxicity assay and mutagenic protocols and the anti-inflammatory activity was confirmed by a diminished TNF-α production showed by mice macrophages treated with APG following LPS treatment.

Apigenin attenuates acute myocardial infarction of rats via the inhibitions of matrix metalloprotease-9 and inflammatory reactions

Acute myocardial infarction (AMI) is the myocardial necrosis caused by coronary artery acute and persistent ischemia and hypoxia. Matrix metalloprotease-9 (MMP-9) plays an important role in a series of process of occurrence and development of AMI. Inflammatory reaction plays the key role in all kinds of damage factors in AMI. Apigenin (API) has effectively restrained the activity of MMP-9, anti-inflammatory and hepatic fat oxidizing properties. API significantly improved AMI of rats through inhibiting MMP-9 and inflammatory reactions in a few recent studies. Our investigation detected the infarct size of AMI rats, casein kinase (CK), the MB isoenzyme of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) activities in AMI rats were also analyzed with commercial kits. Additionally, Nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) levels of whole bloods of AMI rats were also detected using commercial kits. Next, MMP-9 protein of cardiac in AMI rats was measured with gelatin zymography assays. Finally, caspase-3 and caspase-9 activities in AMI rats were analyzed with commercial kits. In the present study, our work indicated API might significantly reduce the infarction size of AMI rat. It was shown that the treatment of API could decrease the expression of MMP-9 level and reduce the activities of NF-κB, TNF-α, IL-1β and IL-6 in AMI rats. Next, API treatment could reduce caspase-3 and caspase-9 activities and decrease cellular apoptosis of AMI rats. Our findings concluded that API ameliorates acute myocardial infarction of rats via inhibiting MMP-9 and inflammatory reactions.

Intestinal anti-inflammatory activity of apigenin K in two rat colitis models induced by trinitrobenzenesulfonic acid and dextran sulphate sodium

Flavonoids are polyphenolic compounds that are widespread in nature, and consumed as part of the human diet in significant amounts. The aim of the present study was to test the intestinal anti-inflammatory activity of apigenin K, a soluble form of apigenin, in two models of rat colitis, namely the trinitrobenzenesulfonic acid (TNBS) model and the dextran sulphate sodium (DSS) model. Apigenin K (1, 3 and 10 mg/kg; by the oral route; n 4-6 per group) was administered as a pre-treatment to rats with TNBS and DSS colitis, and colonic status was checked by macroscopic and biochemical examination. Apigenin K pre-treatment resulted in the amelioration of morphological signs and biochemical markers in the TNBS model. The results demonstrated a reduction in the inflamed area, as well as lower values of score and colonic weight:length ratio compared with the TNBS group. Myeloperoxidase (MPO) activity was reduced by 30 % (P< 0·05). Moreover, apigenin K pre-treatment ameliorated morphological signs and biochemical markers in the DSS model. Thus, macroscopic damage was significantly reduced and the colonic weight:length ratio was lowered by approximately 10 %, while colonic MPO and alkaline phosphatase activities were decreased by 35 and 21 %, respectively (P< 0·05). Apigenin K pre-treatment also tended to normalise the expression of a number of colonic inflammatory markers (e.g. TNF-α, transforming growth factor-β, IL-6, intercellular adhesion molecule 1 or chemokine (C-C motif) ligand 2). In conclusion, apigenin K is found to have anti-inflammatory effects in two preclinical models of inflammatory bowel disease.

Novel apigenin based small molecule that targets snake venom metalloproteases

The classical antivenom therapy has appreciably reduced snakebite mortality rate and thus is the only savior drug available. Unfortunately, it considerably fails to shield the viper bite complications like hemorrhage, local tissue degradation and necrosis responsible for severe morbidity. Moreover, the therapy is also tagged with limitations including anaphylaxis, serum sickness and poor availability. Over the last decade, snake venom metalloproteases (SVMPs) are reported to be the primary component responsible for hemorrhage and tissue degradation at bitten site. Thus, antivenom inability to offset viper venom-induced local toxicity has been a basis for an insistent search for SVMP inhibitors. Here we report the inhibitory effect of compound 5d, an apigenin based molecule against SVMPs both in silico and in vivo. Several apigenin analogues are synthesized using multicomponent Ugi reactions. Among them, compound 5d effectively abrogated Echis carinatus (EC) venom-induced local hemorrhage, tissue necrosis and myotoxicity in a dose dependant fashion. The histopathological study further conferred effective inhibition of basement membrane degradation, and accumulation of inflammatory leucocytes at the site of EC venom inoculation. The compound also protected EC venom-induced fibrin and fibrinogen degradation. The molecular docking of compound 5d and bothropasin demonstrated the direct interaction of hydroxyl group of compound with Glu146 present in hydrophobic pocket of active site and does not chelate Zn²⁺. Hence, it is concluded that compound 5d could be a potent agent in viper bite management.

Topical hesperidin prevents glucocorticoid-induced abnormalities in epidermal barrier function in murine skin

Systemic and topical glucocorticoids (GC) can cause significant adverse effects not only on the dermis, but also on epidermal structure and function. In epidermis, a striking GC-induced alteration in permeability barrier function occurs that can be attributed to an inhibition of epidermal mitogenesis, differentiation and lipid production. As prior studies in normal hairless mice demonstrated that topical applications of a flavonoid ingredient found in citrus, hesperidin, improve epidermal barrier function by stimulating epidermal proliferation and differentiation, we assessed here whether its topical applications could prevent GC-induced changes in epidermal function in murine skin and the basis for such effects. When hairless mice were co-treated topically with GC and 2% hesperidin twice-daily for 9 days, hesperidin co-applications prevented the expected GC-induced impairments of epidermal permeability barrier homoeostasis and stratum corneum (SC) acidification. These preventive effects could be attributed to a significant increase in filaggrin expression, enhanced epidermal β-glucocerebrosidase activity and accelerated lamellar bilayer maturation, the last two likely attributable to a hesperidin-induced reduction in stratum corneum pH. Furthermore, co-applications of hesperidin with GC largely prevented the expected GC-induced inhibition of epidermal proliferation. Finally, topical hesperidin increased epidermal glutathione reductase mRNA expression, which could counteract multiple functional negative effects of GC on epidermis. Together, these results show that topical hesperidin prevents GC-induced epidermal side effects by divergent mechanisms.

Exploration of the wound healing potential of Helichrysum graveolens (Bieb.) Sweet: isolation of apigenin as an active component

ETHNOPHARMACOLOGICAL RELEVANCE

In Turkish traditional medicine, the flowers of Helichrysum graveolens (Bieb.) Sweet (Asteraceae) have been used for the treatment of jaundice, for wound-healing and as a diuretic.

AIM OF THE STUDY

In order to find scientific evidence for the traditional utilization of this plant in wound-healing, the effect of the plant extract was investigated by using in vivo and in vitro experimental models. Then through bioassay-guided fractionation procedures active wound-healing component(s) was isolated and its possible role in the wound-healing process was also determined.

MATERIAL AND METHODS

The linear incision and the circular excision wound models were applied in order to evaluate in vivo wound-healing potential of Helichrysum graveolens. Anti-inflammatory and antioxidant activities, which are known to involve in wound-healing process, were also assessed by the Whittle method and the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging assay, respectively. The total phenolic content of the crude extract and solvent fractions was estimated to find correlation between the phenolic content and the antioxidant activity. Combined application of the chromatographic separation techniques on sephadex and silica gel columns, and bioassay techniques have yielded the active wound-healing principle of Helichrysum graveolens. Moreover, in vitro inhibitory effect of active principle on hyaluronidase, collagenase and elastase enzymes were investigated to explore the activity pathways.

RESULTS

The 85% methanol (MeOH) extract of Helichrysum graveolens flowers displayed significant wound-healing, anti-inflammatory and antioxidant activities. Then the crude extract was partitioned by successive solvent extractions, in increasing polarity, to give five solvent fractions. Among the solvent fractions, the ethyl acetate (EtOAc) fraction exerted the highest activity. The EtOAc fraction was further subjected to chromatographic separations to yield active constituent and its structure was elucidated to be apigenin by spectrometric methods. Further in vivo and in vitro assays revealed that apigenin was one of the components responsible for the wound-healing effect of the plant remedy and also found to possess significant anti-inflammatory, antioxidant, anti-hyaluronidase and anti-collagenase activities.

CONCLUSION

Present study supported the traditional use of Helichrysum graveolens flowers for wound-healing and through bioassay-guided fractionation procedures from the crude extract apigenin was isolated as one of the active components.