Oxidative Stress and Atopic Dermatitis

Clinical application of hempseed or flaxseed oil-based lyotropic liquid crystals: Evaluation of their impact on skin barrier function

The principal function of skin is to form an effective barrier between the human body and its environment. Impaired barrier function represents a precondition for the development of skin diseases such as atopic dermatitis (AD), which is the most common inflammatory skin disease characterized by skin barrier dysfunction. AD significantly affects patients' quality of life, thus, there is a growing interest in the development of novel delivery systems that would improve therapeutic outcomes. Herein, eight novel lyotropic liquid crystals (LCCs) were investigated for the first time in a double-blind, interventional, before-after, single-group trial with healthy adult subjects and a twice-daily application regimen. LCCs consisted of constituents with skin regenerative properties and exhibited lamellar micro-structure, especially suitable for dermal application. The short- and long-term effects of LCCs on TEWL, SC hydration, erythema index, melanin index, and tolerability were determined and compared with baseline. LCCs with the highest oil content and lecithin/Tween 80 mixture stood out by providing a remarkable 2-fold reduction in TEWL values and showing the most distinctive decrease in skin erythema levels in both the short- and long-term exposure. Therefore, they exhibit great potential for clinical use as novel delivery systems for AD treatment, capable of repairing skin barrier function.

Phytochemical Composition, Anti-Inflammatory Property, and Anti-Atopic Effect of Chaetomorpha linum Extract

Utilizing plant-based resources, particularly their by-products, aligns with sustainability principles and circular bioeconomy, contributing to environmental preservation. The therapeutic potential of plant extracts is garnering increasing interest, and this study aimed to demonstrate promising outcomes from an extract obtained from an underutilized plant waste. Chaetomorpha linum, an invasive macroalga found in the Orbetello Lagoon, thrives in eutrophic conditions, forming persistent mats covering approximately 400 hectares since 2005. The biomass of C. linum undergoes mechanical harvesting and is treated as waste, requiring significant human efforts and economic resources-A critical concern for municipalities. Despite posing challenges to local ecosystems, the study identified C. linum as a natural source of bioactive metabolites. Phytochemical characterization revealed lipids, amino acids, and other compounds with potential anti-inflammatory activity in C. linum extract. In vitro assays with LPS-stimulated RAW 264.7 and TNF-α/IFN-γ-stimulated HaCaT cells showed the extract inhibited reactive oxygen species (ROS), nitric oxide (NO), and prostaglandin E2 (PGE2) productions, and reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions via NF-κB nuclear translocation, in RAW 264.7 cells. It also reduced chemokines (TARC/CCL17, RANTES/CCL5, MCP-1/CCL2, and IL-8) and the cytokine IL-1β production in HaCaT cells, suggesting potential as a therapeutic candidate for chronic diseases like atopic dermatitis. Finally, in silico studies indicated palmitic acid as a significant contributor to the observed effect. This research not only uncovered the untapped potential of C. linum but also laid the foundation for its integration into the circular bioeconomy, promoting sustainable practices, and innovative applications across various industries.

An Overview on Atopic Dermatitis, Oxidative Stress, and Psychological Stress: Possible Role of Nutraceuticals as an Additional Therapeutic Strategy

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a considerable impact on patients' quality of life. Its etiology is multifactorial and, among the predisposing factors, a role is played by oxidative stress. Pollution, recurrent infections, and psychological stress contribute to oxidative stress, amplifying the production of proinflammatory cytokines and worsening barrier damage. There are various oxidative stress mechanisms involved in the pathogenesis of AD. Moreover, AD often appears to be associated with psychological disorders such as alexithymia, depression, and anxiety due to severe itching and related insomnia, as well as social distress and isolation. The increasing incidence of AD requires the evaluation of additional therapeutic approaches in order to reduce the psychological burden of this condition. Our review aims to evaluate the role of some nutraceuticals in AD treatment and its related psychological comorbidities. The combination of some natural compounds (flavonoids, alkaloids, terpenes, isothiocyanates) with traditional AD treatments might be useful in improving the effectiveness of therapy, by reducing chronic inflammation and preventing flare-ups, and in promoting corticosteroid sparing. In addition, some of these nutraceuticals also appear to have a role in the treatment of psychological disorders, although the underlying oxidative stress mechanisms are different from those already known for AD.

Superoxide Dismutase-Mimetic Polyphenol-Based Carbon Dots for Multimodal Bioimaging and Treatment of Atopic Dermatitis

Polyphenols have been investigated for their potential to mitigate inflammation in the context of atopic dermatitis (AD). In this study, epigallocatechin-3-gallate (EGCG)-based carbon dots (EGCG@CDs) were developed to enhance transdermal penetration, reduce inflammation, recapitulate superoxide dismutase (SOD) activity, and provide antimicrobial effects for AD treatment. The water-soluble EGCG@CDs in a few nanometers size exhibit a negative zeta potential, making them suitable for effective transdermal penetration. The fluorescence properties, including an upconversion effect, make EGCG@CDs suitable imaging probes for both in vitro and in vivo applications. By mimicking the SOD enzyme, EGCG@CDs scavenge reactive oxygen species (ROS) and actively produce hydrogen peroxide through a highly catalytic capability toward the oxygen reduction reaction, resulting in the inhibition of bacterial growth. The enhanced antioxidant properties, high charge mobility, and various functional groups of EGCG@CDs prove effective in reducing intracellular ROS in an in vitro AD model. In the mouse AD model, EGCG@CDs incorporated into a hydrogel actively penetrated the epidermal layer, leading to ROS scavenging, reduced mast cell activation, and histological recovery of skin barriers. This research represents the versatile potential of EGCG@CDs in addressing AD and advancing tissue engineering.

Biomarkers for phenotype-endotype relationship in atopic dermatitis: a critical review

Atopic dermatitis (AD) is the most common form of chronic skin inflammation with diverse clinical variants. Historically, various AD phenotypes have been grouped together without considering their heterogeneity. This approach has resulted in a lack of phenotype- and endotype-adapted therapeutic strategies. Comprehensive insights into AD pathogenesis have enabled precise medicinal approach for AD. These efforts aimed to redefine the endophenotype of AD and develop various biomarkers for diverse purposes. Among these endeavours, efforts are underway to elucidate the mechanisms (and related biomarkers) that lead to the emergence and progression of atopic diseases originating from AD (e.g., atopic march). This review focuses on diverse AD phenotypes and calls for a definition of endophenotypes. While awaiting scientific validation, these biomarkers ensure predicting disease onset and trajectory and tailoring therapeutic strategies for the future.

Dual-Site Biomimetic Cu/Zn-MOF for Atopic Dermatitis Catalytic Therapy via Suppressing FcγR-Mediated Phagocytosis

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease that carries a significant global economic burden. Elevated levels of reactive oxygen species (ROS) have been recognized as contributing to AD exacerbation, making them a potential therapeutic target for AD treatment. Here, we introduce a dual-site biomimetic copper/zinc metal-organic framework (Cu/Zn-MOF) featuring four types of enzyme-like activities for AD treatment via suppressing the Fcγ receptor (FcγR)-mediated phagocytosis signal by mimicking the bimetallic sites of natural copper-zinc superoxide dismutase (CuZn-SOD). Interestingly, the neighboring Cu and Zn sites in both Cu/Zn-MOF and CuZn-SOD are at similar distances of ∼5.98 and ∼6.3 Å from each other, respectively, and additionally, both Cu and Zn sites are coordinated to nitrogen atoms in both structures, and the coordinating ligands to Cu and Zn are both imidazole rings. Cu/Zn-MOF exhibits remarkable SOD-like activity as well as its glutathione peroxidase (GPx)-, thiol peroxidase (TPx)-, and ascorbate peroxidase (APx)-like activities to continuously consume ROS and mitigate oxidative stress in keratinocytes. Animal experiments show that Cu/Zn-MOF outperforms halcinonide solution (a potent steroid medication) in terms of preventing mechanical injuries, reducing cutaneous water loss, and inhibiting inflammatory responses while presenting favorable biosafety. Mechanistically, Cu/Zn-MOF functions through an FcγR-mediated phagocytosis signal pathway, decreasing the continuous accumulation of ROS in AD and ultimately suppressing disease progression. These findings will provide an effective paradigm for AD therapy and contribute to the development of two-site bionics (TSB).

Dupilumab therapy reduces urinary biopyrrin levels in atopic patients: a new possible biomarker of oxidative status in atopic dermatitis

BACKGROUND

Accumulating evidence suggests that oxidative stress is involved in the inflammatory process of atopic dermatitis (AD). Biopyrrins are the end products of the oxidative reaction of bilirubin with reactive oxygen species. The aim of our study was to explore the correlation between urinary biopyrrin levels and AD severity as well as to assess the possible modification of them in AD patients during biologic therapy with human monoclonal antibody dupilumab.

METHODS

For this purpose, 25 adult patients with moderate-severe AD who were candidates for dupilumab therapy independently from the study, and 15 healthy control subjects, matched by sex and age, were enrolled. Morning urine samples were collected from all study participants. For AD patients, a collection was planned before starting therapy with dupilumab (WO), after 8, 16, 52 weeks (W8, W16, W52, respectively), and two years (Y2) of treatment. The analysis of urinary levels of biopyrrins was performed by ELISA assay.

RESULTS

Our results demonstrated that urinary biopyrrin levels were significantly augmented in AD patients, and interestingly they correlated with disease severity. Furthermore, dupilumab therapy decreased levels of urinary biopyrrins in AD patients after eight and 16 weeks, maintaining the result after 52 weeks as well as after two years of treatment. The correlation analysis showed a statistically significant positive correlation between the urinary concentration of biopyrrins and EASI Index, circulating total IgE as well as plasma C reactive protein levels.

CONCLUSIONS

Dupilumab therapy was able to ameliorate oxidative state in AD patients.

Antioxidant, Antibacterial Properties of Novel Peptide CP by Enzymatic Hydrolysis of Chromis notata By-Products and Its Efficacy on Atopic Dermatitis

This study investigated the antioxidant, antimicrobial, and anti-atopic dermatitis (AD) effects of a novel peptide (CP) derived from a Chromis notata by-product hydrolysate. Alcalase, Flavourzyme, Neutrase, and Protamex enzymes were used to hydrolyze the C. notata by-product protein, and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity was measured. Alcalase hydrolysate exhibited the highest ABTS radical-scavenging activity, leading to the selection of Alcalase for further purification. The CHAO-1-I fraction, with the highest ABTS activity, was isolated and further purified, resulting in the identification of the peptide CP with the amino acid sequence Ala-Gln-Val-Met-Lys-Leu-Pro-His-Arg-Met-Gln-His-Ser-Gln-Ser. CP demonstrated antimicrobial activity against Staphylococcus aureus, inhibiting its growth. In a 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin model in mice, CP significantly alleviated skin lesions, reduced epidermal and dermal thickness, and inhibited mast cell infiltration. Moreover, CP suppressed the elevated levels of interleukin-6 (IL-6) in the plasma of DNCB-induced mice. These findings highlight the potential of CP as a therapeutic agent for AD and suggest a novel application of this C. notata by-product in the fish processing industry.

Boesenbergia rotunda and Its Pinostrobin for Atopic Dermatitis: Dual 5-Lipoxygenase and Cyclooxygenase-2 Inhibitor and Its Mechanistic Study through Steady-State Kinetics and Molecular Modeling

Human 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) are potential targets for suppressing pruritic skin inflammation in atopic dermatitis (AD). In addition, Staphylococcus aureus colonization and oxidative stress worsen AD skin conditions. We aimed to investigate anti-inflammatory activity, using 5-LOX and COX-2 inhibitions, and the anti-staphylococcal, and antioxidant potentials of several medicinal plants bio-prospected from traditional medicine related to AD pathogenesis. Essential oils and hexane fractions were prepared and analyzed using gas chromatography-mass spectrometry. Boesenbergia rotunda hexane extract displayed anti-Staphylococcus aureus (MIC = 10 µg/mL) and antioxidant activities (IC50 = 557.97 and 2651.67 µg/mL against DPPH and NO radicals, respectively). A major flavonoid, pinostrobin, was further nonchromatographically isolated. Pinostrobin was shown to be a potent 5-LOX inhibitor (IC50 = 0.499 µM) compared to nordihydroguaiaretic acid (NDGA; IC50 = 5.020 µM) and betamethasone dipropionate (BD; IC50 = 2.077 µM) as the first-line of AD treatment. Additionally, pinostrobin inhibited COX-2 (IC50 = 285.67 µM), which was as effective as diclofenac sodium (IC50 = 290.35 µM) and BD (IC50 = 240.09 µM). This kinetic study and molecular modeling showed the mixed-type inhibition of NDGA and pinostrobin against 5-LOX. This study suggests that B. rotunda and its bioactive pinostrobin have promising properties for AD therapy.

Benefits of topical natural ingredients in epidermal permeability barrier

Because of the crucial role of epidermal permeability barrier in regulation of cutaneous and extracutaneous functions, great efforts have been made to identify and develop the regimens that can improve epidermal permeability barrier function. Studies have demonstrated that oral administration of natural ingredients can improve epidermal permeability barrier in various skin conditions, including inflammatory dermatoses and UV-irradiation. Moreover, topical applications of some natural ingredients can also accelerate the repair of epidermal permeability barrier after acute barrier disruption and lower transepidermal water loss in the intact skin. Natural ingredient-induced improvements in epidermal permeability barrier function can be attributable to upregulation of keratinocyte differentiation, lipid production, antioxidant, hyaluronic acid production, expression of aquaporin 3 and sodium-hydrogen exchanger 1. In this review, we summarize the benefits of topical natural ingredients in epidermal permeability barrier in normal skin with or without acute barrier disruption and the underlying mechanisms.

Antioxidant defense of children and adolescents with atopic dermatitis: Association with disease severity

BACKGROUND

Atopic dermatitis (AD) is a relapsing, chronic cutaneous inflammatory disease with onset, in general, in early childhood. Chronic skin inflammation is associated with overproduction of reactive oxygen species (ROS) such as superoxide and hydrogen peroxide. Oxidative stress, an imbalance between the production of free radicals and antioxidant defense, results in tissue inflammation due to the upregulation of genes that encode inflammatory cytokines. This condition plays an important role in the pathogenesis of AD.

OBJECTIVE

To compare the antioxidant defense in children and adolescents with AD with that of healthy individuals and to verify the association of antioxidant defense with disease severity and nutritional status.

METHODS

Cross-sectional study that evaluated 48 children and adolescents with AD and 25 controls for nutritional assessment (body mass index z score [BMIZ] and height for age z score [HAZ]) and levels of vitamins A, C, E, and D, zinc (Zn), copper (Cu), antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx]), high-sensitivity C-reactive protein (CRP) and interleukin 33 (IL-33).

RESULTS

There was no significant difference in the comparison between AD and control groups for serum levels of vitamins (A, D, C, and E), copper, and antioxidant enzymes. Serum zinc levels were higher in the AD group (β = 24.20; 95% CI 13.95-34.91; P < 0.001) even after adjusting the BMIZ, HAZ, gender, IL-33, and CRP. Children and adolescents with moderate or severe AD compared to mild AD (SCORAD - 36.7±17.4 vs 11.8 ± 3.9; P < 0.001) had lower values of the vitamin E/total lipid ratio (3.68 [0.29;12.63] vs 5.92 [3.27;17.37]; P = 0.013).

CONCLUSION

Children and adolescents with AD had higher concentrations OF elevated levels of zinc compared to controls, a fact not observed for other biomarkers of antioxidant defense. AD in moderate or severe forms presented lower concentrations of vitamin E, a potent antioxidant fat soluble.

Tapinarof validates the aryl hydrocarbon receptor as a therapeutic target: A clinical review

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that has wide-ranging roles, including regulation of inflammation and homeostasis. AhR is not a cell surface receptor; rather, it exists in a cytoplasmic complex that responds to a wide variety of structurally dissimilar endogenous, microbial, and environmental ligands. The ubiquitous expression of AhR, its ability to be activated by a wide range of ligands, and its capacity to act as a master regulator for gene expression and homeostasis make it a promising new therapeutic target. Clinical trials of tapinarof cream have now validated AhR agonism as a therapeutic approach that can deliver significant efficacy for treating inflammatory skin diseases, including psoriasis and atopic dermatitis. Tapinarof 1% cream is a first-in-class, nonsteroidal, topical, AhR agonist with a pharmacokinetic profile that results in localized exposure at sites of disease, avoiding systemic safety concerns, drug interactions, or off-target effects. Psoriasis and atopic dermatitis both involve epidermal inflammation, cellular immune responses, dysregulation of skin barrier protein expression, and oxidative stress. On the basis of the clinical effectiveness of tapinarof cream for treating inflammatory skin diseases, we review how targeting AhR may offer a significant opportunity in other conditions that share key aspects of pathogenesis, including asthma, inflammatory bowel disease, eosinophilic esophagitis, ophthalmic, and nervous system diseases.

Biofunctional Inorganic Layered Double Hydroxide Nanohybrid Enhances Immunotherapeutic Effect on Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a widespread, recurrent, and chronic inflammatory skin condition that imposes a major burden on patients. Conventional treatments, such as corticosteroids, are associated with various side effects, underscoring the need for innovative therapeutic approaches. In this study, the possibility of using indole-3-acetic acid-loaded layered double hydroxides (IAA-LDHs) is evaluated as a novel treatment for AD. IAA is an auxin-class plant hormone with antioxidant and anti-inflammatory effects. Following the synthesis of IAA-LDH nanohybrids, their ability to induce M2-like macrophage polarization in macrophages obtained from mouse bone marrow is assessed. The antioxidant activity of IAA-LDH is quantified by assessing the decrease in intracellular reactive oxygen species levels. The anti-inflammatory and anti-atopic characteristics of IAA-LDH are evaluated in a mouse model of AD by examining the cutaneous tissues, immunological organs, and cells. The findings suggest that IAA-LDH has great therapeutic potential as a candidate for AD treatment based on its in vitro and in vivo modulation of AD immunology, enhancement of macrophage polarization, and antioxidant activity. This inorganic drug delivery technology represents a promising new avenue for the development of safe and effective AD treatments.

Neutrophils in Inflammatory Diseases: Unraveling the Impact of Their Derived Molecules and Heterogeneity

Inflammatory diseases involve numerous disorders and medical conditions defined by an insufficient level of self-tolerance. These diseases evolve over the course of a multi-step process through which environmental variables play a crucial role in the emergence of aberrant innate and adaptive immunological responses. According to experimental data accumulated over the past decade, neutrophils play a significant role as effector cells in innate immunity. However, neutrophils are also involved in the progression of numerous diseases through participation in the onset and maintenance of immune-mediated dysregulation by releasing neutrophil-derived molecules and forming neutrophil extracellular traps, ultimately causing destruction of tissues. Additionally, neutrophils have a wide variety of functional heterogeneity with adverse effects on inflammatory diseases. However, the complicated role of neutrophil biology and its heterogeneity in inflammatory diseases remains unclear. Moreover, neutrophils are considered an intriguing target of interventional therapies due to their multifaceted role in a number of diseases. Several approaches have been developed to therapeutically target neutrophils, involving strategies to improve neutrophil function, with various compounds and inhibitors currently undergoing clinical trials, although challenges and contradictions in the field persist. This review outlines the current literature on roles of neutrophils, neutrophil-derived molecules, and neutrophil heterogeneity in the pathogenesis of autoimmune and inflammatory diseases with potential future therapeutic strategies.

Oxidative Stress in Atopic Dermatitis and Possible Biomarkers: Present and Future

Oxidative stress is important in the pathogenesis of atopic dermatitis (AD); it can damage keratinocytes, increase dermal inflammation, and reduce skin barrier function, the hallmarks of atopic dermatitis pathogenesis. Measuring oxidative stress is possible by identifying peripheral markers, which could have a predictive value of disease severity, disease progression and response to therapy, with a potentially significant impact on patient management. Our review explored this fascinating field of research, focusing on old and new possible biomarkers that may represent an effective tool to investigate the inflammatory-oxidative axis in AD, adding clinically important information to patient care.

Shotgun metagenomic sequencing on skin microbiome indicates dysbiosis exists prior to the onset of atopic dermatitis

BACKGROUND

While the microbiome is increasingly seen as a targetable contributor to atopic dermatitis (AD), questions remain as to whether the dysbiosis is secondary to diseased skin or if it predates symptom onset. Previous work has evaluated how the skin microbiome changes with age and established the influence of factors like delivery mode and breastfeeding on global microbiome diversity. However, these studies were unable to identify taxa which predict subsequent AD.

METHODS

Skin swab samples were collected from the first week of life for 72 children in the neonatal intensive care unit (NICU) at a single site hospital. Participants were followed for 3 years to determine their health status. We applied shotgun metagenomic sequencing to assess the microbiome differences between 31 children who went on to develop AD and 41 controls.

RESULTS

We identified that subsequent development of AD was associated with differential abundance of several bacterial and fungal taxa as well as several metabolic pathways, each of which have been previously associated with active AD.

CONCLUSIONS

Our work provides evidence of reproducibility for the previously reported dysbiotic signatures predating AD onset while also expanding prior findings through the first use of metagenomic assessment prior to AD onset. While extrapolation of our findings beyond the pre-term, NICU cohort is limited, our findings add to the evidence that the dysbiosis associated with AD pre-dates disease onset rather than reflect a secondary consequence of skin inflammation.

Excessive Production of Hydrogen Peroxide in Mitochondria Contributes to Atopic Dermatitis

Atopic dermatitis (AD) is a complex disease characterized by chronic recurring eczema and pruritus. In addition, patients with AD display increased cutaneous and systemic levels of oxidative damage markers, whose source remains elusive. In this study, we investigated oxidative and mitochondrial stress in AD epidermis. The levels of superoxide dismutase 2 and hydrogen peroxide are augmented in the mitochondria of flaky tail (ft/ft) mouse keratinocytes, which is associated with the inhibition of the glutathione system and catalase. Furthermore, reduced levels of glutathione peroxidase 4 are associated with accumulation of malondialdehyde, 4-hydroxy-2-nonenal, and oxidized phosphatidylcholines in ft/ft epidermis. Cytochrome c is markedly increased in ft/ft epidermis, hence showing mitochondrial stress. Topical application of MitoQ, which is a mitochondrial-targeting antioxidant, to ft/ft mouse skin reduced damage to macromolecules and inflammation and restored epidermal homeostasis. Absence of alteration in the expression of superoxide dismutase 2, catalase, and glutathione peroxidase 4 and limited lipid peroxidation as well as oxidized phosphatidylcholines in the epidermis of Flg-/- mice suggest that FLG deficiency marginally contributes to oxidative stress in ft/ft epidermis. Increased superoxide dismutase 2, lipid peroxidation, and cytochrome c in the epidermis of patients with AD, associated with reduced antioxidant response in primary AD keratinocytes, corroborate mitochondrial dysfunction and lack of cellular adjustment to oxidative stress in AD epidermis.

Angelica Yinzi Alleviates Pruritus-Related Atopic Dermatitis through Skin Repair, Antioxidation, and Balancing Peripheral μ- and κ-opioid Receptors

Background

Angelica Yinzi (AYZ) is a Chinese traditional herbal formula reported to attenuate itches and inflammation caused by atopic dermatitis (AD). However, the underlying mechanism of AYZ in the attenuation of itchiness and inflammation remains unknown.

Objective

This study investigated the mechanism of AYZ in reducing itchiness in mice with 1-chloro-2,4-dinitrobenzene- (DNCB-)-induced atopic dermatitis.

Methods

Hematoxylin and eosin (H&E) and toluidine blue staining were used to evaluate pathological changes in skin tissue, while an enzyme-linked immunosorbent assay (ELISA) was used to assess the cytokine levels in the skin. After that, qRT-PCR was performed to determine the mRNA levels of cytokines in the skin. Immunofluorescence and western blotting analysis were further used to assess µ-opioid receptor (MOR) expression and immunohistochemistry to assess the p-ERK, p-AKT, and κ-opioid receptor (KOR).

Results

The AYZ treatment alleviated the AD clinical symptoms, including decreasing the scratching frequency, the ear thickness, and the infiltration of mast cells, lymphocytes, inflammatory cells, and mononuclear cells. In addition, AYZ inhibited the expression of interleukin (IL)-13, thymic stromal lymphopoietin (TSLP), and reduced neuraminidase (NA), corticotropin-releasing factor (CRF), and reactive oxygen species (ROS) expression. Markers involved in itches, such as p-ERK and p-AKT, were significantly downregulated following AYZ treatment. Besides, AYZ significantly increased MOR expression and downregulated KOR in the epidermis and spinal cord.

Conclusion

Our findings imply that AYZ ameliorates pruritus-related AD through skin repair, antioxidation, and balancing peripheral MOR and KOR. The findings in this study lay a theoretical foundation for the control mechanism of peripheral itch.

Sodium thiosulfate ameliorates atopic dermatitis via inhibiting the activation of NLRP3 inflammasome

Atopic dermatitis (AD) is a common disease with a considerable impact on the patient's quality of life and limited treatment options. Sodium thiosulfate (STS) is a traditional medicine used in the rescue of cyanide poisoning, and some pruritus dermatosis. However, the exact efficacy and mechanism of its application on AD are not clear. In this work, comparing to other traditional therapy, STS was found to effectively improve the severity of skin lesions and the quality of life in AD patients with a dose-dependent manner. Mechanically, STS downregulated the expression of IL-4, IL-13, IgE in the serum of AD patients, as well as reduce the concentration of eosinophils. Furthermore, in the AD-like mice model triggered by ovalbumin (OVA) and calcitriol, STS was found to reduce the epidermal thickness, scratching times, and the infiltration of dermal inflammatory cells in AD mice, as well as the reactive oxygen species (ROS) production and the expression levels of inflammatory cytokines in the skin tissue. In HacaT cells, STS inhibited the accumulation of ROS and activation of NLRP3 inflammasome and its downstream IL-1β expression. Therefore, this study revealed that STS plays an important therapeutic role in AD, and the mechanism may be that STS inhibits the activation of NLRP3 inflammasome and the subsequent release of inflammatory cytokines. Thus, the role of STS in treating AD was clarified and the possible molecular mechanism was revealed.

Antioxidant and Anti-Glycation Potential of H2 Receptor Antagonists-In Vitro Studies and a Systematic Literature Review

Background: Histamine H2 receptor antagonists are a group of drugs that inhibit gastric juice secretion in gastrointestinal diseases. However, there is evidence to suggest that H2 blockers have a broader spectrum of activity. The antioxidant properties of H2 blockers have not been fully elucidated, and their anti-glycation potential has not been studied to date. Therefore, this is the first study to compare the antioxidant and antiglycation potentials of the most popular H2 antagonists (ranitidine, cimetidine, and famotidine) on protein glycoxidation in vitro. Methods: Bovine serum albumin (BSA) was glycated using sugars (glucose, fructose, galactose, and ribose) as well as aldehydes (glyoxal and methylglyoxal). Results: In the analyzed group of drugs, ranitidine was the only H2 blocker that significantly inhibited BSA glycation in all tested models. The contents of protein carbonyls, protein glycoxidation products (↓dityrosine, ↓N-formylkynurenine), and early (↓Amadori products) and late-stage (↓AGEs) protein glycation products decreased in samples of glycated BSA with the addition of ranitidine relative to BSA with the addition of the glycating agents. The anti-glycation potential of ranitidine was comparable to those of aminoguanidine and Trolox. In the molecular docking analysis, ranitidine was characterized by the lowest binding energy for BSA sites and could compete with protein amino groups for the addition of carbonyl groups. H2 blockers also scavenge free radicals. The strongest antioxidant properties are found in ranitidine, which additionally has the ability to bind transition metal ions. The systematic literature review also revealed that the anti-glycation effects of ranitidine could be attributed to its antioxidant properties. Conclusions: Ranitidine showed anti-glycation and antioxidant properties. Further research is needed, particularly in patients with diseases that promote protein glycation.

Kaempferol therapy improved MC903 induced-atopic dermatitis in a mouse by suppressing TSLP, oxidative stress, and type 2 inflammation

BACKGROUND

Atopic dermatitis is a common skin disease caused by genetic susceptibility, environmental factors, immune response, and skin barrier dysfunction. Kaempferol is a natural flavonoid widely found in tea, vegetables, and fruits and has been reported to have excellent anti-inflammation activity. However, the therapeutic effect of kaempferol on atopic dermatitis is unclear.

OBJECTIVE

This study aimed to elucidate the effect of kaempferol on skin inflammation in atopic dermatitis.

METHODS

The suppressive effect of kaempferol administration on skin inflammation was examined using MC903-induced atopic dermatitis-like skin inflammation mouse model. Quantification of skin dermatitis and transepidermal water loss was performed. A histopathological study was performed to examine thymic stromal lymphopoietin expression, cornified envelope proteins such as filaggrin, loricrin, and involucrin, and the numbers of infiltrating inflammatory cells, including lymphocytes, macrophages, and mast cells in the dermatitis area. The expressions of IL-4 and IL-13 were investigated by qPCR and flow cytometry analysis using skin tissues. The expression of HO-1 was investigated by western blot and qPCR.

RESULTS

Kaempferol therapy significantly suppressed MC903-induced dermatitis, TEWL, TSLP, and HO-1 expression, and infiltration of inflammatory cells. Kaempferol therapy improved the decreased expressions of filaggrin, loricrin, and involucrin in MC903-induced dermatitis skin site. The expressions of IL-4, and IL-13 were partially decreased in kaempferol-treated mice.

CONCLUSION

Kaempferol might improve MC903-induced dermatitis via suppression of type 2 inflammation and improvement of barrier dysfunction by inhibition of TSLP expression and oxidative stress. Kaempferol might have the potential to be a new treatment for atopic dermatitis.

Malondialdehyde as a Potential Oxidative Stress Marker for Allergy-Oriented Diseases: An Update

Malondialdehyde (MDA) is a compound that is derived from the peroxidation of polyunsaturated fatty acids. It has been used as a biomarker to measure oxidative stress in various biological samples in patients who are affected by a wide range of diseases. The aim of our work is to provide an updated overview of the role of MDA as a marker of oxidative stress in allergy-related diseases. We considered studies involving both paediatric and adult patients affected by rhinitis, asthma, urticaria and atopic dermatitis. The measurement of MDA was performed on different types of samples. The reported data highlight the role of serum MDA in inflammatory airway diseases. According to the literature review, the oxidative stress status in asthmatic patients, assessed via MDA determination, appears to worsen in the presence of other allergic airway diseases and in relation to the disease severity. This suggests that MDA can be a suitable marker for monitoring the disease status. However, there are several limitations in the considered studies due to the different samples used and the lack of phenotyping and description of the clinical period of patients examined. In cutaneous allergic diseases, the role of MDA is controversial because of the smallness of the studies and the heterogeneity of the samples and patients.

SALIVARY MELATONIN VALUES SIGNIFICANTLY CORRELATE WITH REDUCED QUALITY OF LIFE IN CHRONIC SPONTANEOUS URTICARIA PATIENTS: A PILOT STUDY

Chronic spontaneous urticaria (CSU) is a dermatological disorder accompanied by itching that greatly affects the quality of life and quality of sleep. Therefore, it is assumed that CSU patients consequently experience reduced melatonin secretion and lower values of serum or salivary melatonin. This pilot study included 20 patients with CSU (chronic urticaria of unknown etiology that lasts for more than 6 weeks) and 10 healthy controls. All subjects were examined by a dermatovenereologist-allergist, as well as an oral pathologist, to exclude oral pathological conditions. Salivary melatonin levels were determined by ELISA and all subjects completed a standardized Dermatology Life Quality Index questionnaire and Pittsburgh Sleep Quality Index on the same day they gave a saliva sample for analysis. According to our results, 86% of CSU patients had decreased values of salivary melatonin, and lower salivary melatonin values significantly correlated with a reduced quality of life in CSU patients. This study was the first to analyze melatonin in CSU patients, also suggesting a possible new therapeutic option for the treatment of CSU.

Evidence-Based Utility of Adjunct Antioxidant Supplementation for the Prevention and Treatment of Dermatologic Diseases: A Comprehensive Systematic Review

Skin conditions are a significant cause of fatal and nonfatal disease burdens globally, ranging from mild irritations to debilitating diseases. Oxidative stress, which is an imbalance between reactive oxygen species and the cells' ability to repair damage, is implicated in various skin diseases. Antioxidants have been studied for their potential benefits in dermatologic health, but the evidence is limited and conflicting. Herein, we conducted a systematic review of controlled trials, meta-analyses, and Cochrane review articles to evaluate the current evidence on the utility of antioxidant supplementation for adjunct prevention and treatment of skin disease and to provide a comprehensive assessment of their role in promoting dermatologic health. The Cochrane Library, PubMed, EMBASE, and Epistemonikos databases were queried. Eligibility criteria included (1) primary focus on nanoparticle utility for skin cancer; (2) includes measurable outcomes data with robust comparators; (3) includes a number of human subjects or cell-line types, where applicable; (4) English language; and (5) archived as full-text journal articles. A total of 55 articles met the eligibility criteria for the present review. Qualitative analysis revealed that topical and oral antioxidant supplementation has demonstrated preliminary efficacy in reducing sunburns, depigmentation, and photoaging. Dietary exogenous antioxidants (namely vitamins A, C, and E) have shown chemopreventive effects against skin cancer. Antioxidant supplementation has also shown efficacy in treating non-cancer dermatoses, including rosacea, psoriasis, atopic dermatitis, and acne vulgaris. While further studies are needed to validate these findings on a larger scale, antioxidant supplementation holds promise for improving skin health and preventing skin diseases.

Beneficial Effects of Two Hydrogen Sulfide (H2S)-Releasing Derivatives of Dexamethasone with Antioxidant Activity on Atopic Dermatitis in Mice

Hydrogen sulfide (H₂S) is particularly produced in the skin, where it participates in the regulation of inflammation, pruritus, cytoprotection, scarring, and angiogenesis. In this study, we compared the effects of dexamethasone (Dex) with two H₂S-releasing Dex derivatives in a murine model of atopic dermatitis (AD) induced by topical application of 2,4-dinitrochlorobenzene (DNCB). After sensitization with DNCB, the animals were topically treated for five consecutive days with either the H₂S-releasing compounds 4-hydroxy-thiobenzamide (TBZ) and 5-(p-hydroxyphenyl)-1,2-dithione-3-thione (ADT-OH), Dex, or the derivatives Dex-TBZ or Dex-ADT. Topical treatment with equimolar doses of either Dex, Dex-TBZ, or Dex-ADT resulted in similar reductions in dermatitis score, scratching behavior, edema, eosinophilia, splenomegaly, and histological changes. In contrast with Dex, the H₂S-releasing derivatives prevented IL-4 elevation and oxidative modification of skin proteins. On an equimolar dose basis, Dex-TBZ, but not Dex-ADT, promoted the elevation of endogenous H₂S production and GPx activity. Neither Dex-TBZ nor Dex-ADT decreased GR activity or caused hyperglycemia, as observed with Dex treatment. We conclude that the presence of H₂S-releasing moieties in the Dex structure does not interfere with the anti-inflammatory effects of this corticosteroid and adds beneficial therapeutical actions to the parent compound.

Markers of Oxidative Stress in Patients with Acne: A Literature Review

Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit. Its pathogenesis is multifactorial and involves the overlap between four main processes: alteration of the keratinization, increased sebum production, colonization with Cutibacterium acnes, and inflammation. The role of oxidative stress (OS) has been intensively studied in inflammatory skin conditions such as psoriasis, vitiligo, or atopic dermatitis. However, the involvement of OS in the pathogenesis of acne is less known. The evidence accumulated over the last decade suggests that in the case of acne patients, there is an imbalance between oxidants and antioxidants. In this review, we analyzed studies that evaluated markers of OS in patients with acne, published in the last ten years, with the aim of providing new insights into the pathogenesis of acne.

Efficacy of the Radical Scavenger, Tempol, to Reduce Inflammation and Oxidative Stress in a Murine Model of Atopic Dermatitis

Atopic dermatitis (AD) is the most common chronically relapsing inflammatory skin disease, predominantly common in children; it is characterized by an eczematous pattern generally referable to skin dryness and itchy papules that become excoriated and lichenified in the more advanced stages of the disease. Although the pathophysiology of AD is not completely understood, numerous studies have demonstrated the complex interaction between genetic, immunological, and environmental factors, which acts to disrupt skin barrier function. Free radicals play a key role by directly damaging skin structure, inducing inflammation and weakening of the skin barrier. Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) is a membrane-permeable radical scavenger, known to be a stable nitroxide, which exhibits excellent antioxidant effects in several human disorders, such as osteoarthritis and inflammatory bowel diseases. Considering the few existing studies on dermatological pathologies, this study aimed to evaluate tempol, in a cream formulation, in a murine model of AD. Dermatitis was induced in mice via dorsal skin application of 0.5% Oxazolone, three times a week for two weeks. After induction, mice were treated with tempol-based cream for another two weeks at three different doses of 0.5%, 1% and 2%. Our results demonstrated the ability of tempol, at the highest percentages, to counteract AD by reducing the histological damage, decreasing mast cell infiltration, and improving the skin barrier properties, by restoring the tight junction (TJs) and filaggrin. Moreover, tempol, at 1% and 2%, was able to modulate inflammation by reducing the nuclear factor kappa-light-chain-enhancer of the activated B cell (NF-κB) pathway, as well as tumor necrosis factor (TNF)-α and interleukin (IL)-1β expression. Topical treatment also attenuated oxidative stress by modulating nuclear factor erythroid 2-related factor 2 (Nrf2), manganese superoxide dismutase (MnSOD), and heme oxygenase I (HO-1) expression levels. The obtained results demonstrate the numerous advantages provided by the topical administration of a tempol-based cream formulation, in reducing inflammation and oxidative stress through modulation of the NF-κB/Nrf2 signaling pathways. Therefore, tempol could represent an alternative anti-atopic approach to treating AD, thereby improving skin barrier function.

Competition between skin antimicrobial peptides and commensal bacteria in type 2 inflammation enables survival of S. aureus

During inflammation, the skin deploys antimicrobial peptides (AMPs) yet during allergic inflammation it becomes more susceptible to Staphylococcus aureus. To understand this contradiction, single-cell sequencing of Il4ra^-/- mice combined with skin microbiome analysis reveals that lower production of AMPs from interleukin-4 receptor α (IL-4Rα) activation selectively inhibits survival of antibiotic-producing strains of coagulase-negative Staphylococcus (CoNS). Diminished AMPs under conditions of T helper type 2 (Th2) inflammation enable expansion of CoNS strains without antibiotic activity and increase Staphylococcus aureus (S. aureus), recapitulating the microbiome on humans with atopic dermatitis. This response is rescued in Camp^-/- mice or after topical steroids, since further inhibition of AMPs enables survival of antibiotic-producing CoNS strains. In conditions of Th17 inflammation, a higher expression of host AMPs is sufficient to directly inhibit S. aureus survival. These results show that antimicrobials produced by the host and commensal bacteria each act to control S. aureus on the skin.

The skin is no barrier to mixtures: Air pollutant mixtures and reported psoriasis or eczema in the Personalized Environment and Genes Study (PEGS)

BACKGROUND

Autoimmune (AI) diseases appear to be a product of genetic predisposition and environmental triggers. Disruption of the skin barrier causes exacerbation of psoriasis/eczema. Oxidative stress is a mechanistic pathway for pathogenesis of the disease and is also a primary mechanism for the detrimental effects of air pollution.

METHODS

We evaluated the association between autoimmune skin diseases (psoriasis or eczema) and air pollutant mixtures in 9060 subjects from the Personalized Environment and Genes Study (PEGS) cohort. Pollutant exposure data on six criteria air pollutants are publicly available from the Center for Air, Climate, and Energy Solutions and the Atmospheric Composition Analysis Group. For increased spatial resolution, we included spatially cumulative exposure to volatile organic compounds from sites in the United States Environmental Protection Agency Toxic Release Inventory and the density of major roads within a 5 km radius of a participant's address from the United States Geological Survey. We applied logistic regression with quantile g-computation, adjusting for age, sex, diagnosis with an autoimmune disease in family or self, and smoking history to evaluate the relationship between self-reported diagnosis of an AI skin condition and air pollution mixtures.

RESULTS

Only one air pollution variable, sulfate, was significant individually (OR = 1.06, p = 3.99E-2); however, the conditional odds ratio for the combined mixture components of PM2.5 (black carbon, sulfate, sea salt, and soil), CO, SO2, benzene, toluene, and ethylbenzene is 1.10 (p-value = 5.4E-3).

SIGNIFICANCE

While the etiology of autoimmune skin disorders is not clear, this study provides evidence that air pollutants are associated with an increased prevalence of these disorders. The results provide further evidence of potential health impacts of air pollution exposures on life-altering diseases.

SIGNIFICANCE AND IMPACT STATEMENT

The impact of air pollution on non-pulmonary and cardiovascular diseases is understudied and under-reported. We find that air pollution significantly increased the odds of psoriasis or eczema in our cohort and the magnitude is comparable to the risk associated with smoking exposure. Autoimmune diseases like psoriasis and eczema are likely impacted by air pollution, particularly complex mixtures and our study underscores the importance of quantifying air pollution-associated risks in autoimmune disease.

Hydrogel dressing integrating FAK inhibition and ROS scavenging for mechano-chemical treatment of atopic dermatitis

Atopic dermatitis (AD) is a chronic skin disease caused by skin immune dyshomeostasis and accompanied by severe pruritus. Although oxidative stress and mechanical scratching can aggravate AD inflammation, treatment targeting scratching is often overlooked, and the efficiency of mechano-chemically synergistic therapy remains unclear. Here, we find that enhanced phosphorylation of focal adhesion kinase (FAK) is associated with scratch-exacerbated AD. We then develop a multifunctional hydrogel dressing that integrates oxidative stress modulation with FAK inhibition to synergistically treat AD. We show that the adhesive, self-healing and antimicrobial hydrogel is suitable for the unique scratching and bacterial environment of AD skin. We demonstrate that it can scavenge intracellular reactive oxygen species and reduce mechanically induced intercellular junction deficiency and inflammation. Furthermore, in mouse AD models with controlled scratching, we find that the hydrogel alleviates AD symptoms, rebuilds the skin barrier, and inhibits inflammation. These results suggest that the hydrogel integrating reactive oxygen species scavenging and FAK inhibition could serve as a promising skin dressing for synergistic AD treatment.

miRNAs' Cross-Involvement in Skin Allergies: A New Horizon for the Pathogenesis, Diagnosis and Therapy of Atopic Dermatitis, Allergic Contact Dermatitis and Chronic Spontaneous Urticaria

Skin inflammation is a common underlying feature of atopic dermatitis, allergic contact dermatitis and chronic spontaneous urticaria. The pathogenetic mechanisms have not been fully elucidated. The purpose of this study was to examine whether miRNA, by regulating inflammatory mechanisms through the modulation of innate and adaptive immune responses, could play a major role in the pathogenesis of these skin conditions. We conducted a narrative review using the Pubmed and Embase scientific databases and search engines to find the most relevant miRNAs related to the pathophysiology, severity and prognosis of skin conditions. The studies show that miRNAs are involved in the pathogenesis and regulation of atopic dermatitis and can reveal an atopic predisposition or indicate disease severity. In chronic spontaneous urticaria, different miRNAs which are over-expressed during urticaria exacerbations not only play a role in the possible response to therapy or remission, but also serve as a marker of chronic autoimmune urticaria and indicate associations with other autoimmune diseases. In allergic contact dermatitis, miRNAs are upregulated in inflammatory lesions and expressed during the sensitization phase of allergic response. Several miRNAs have been identified as potential biomarkers of these chronic skin conditions, but they are also possible therapeutic targets.

Chitosan-based drug delivery systems for skin atopic dermatitis: recent advancements and patent trends

Atopic dermatitis (AD) is a complex, relapsing inflammatory skin disease with a considerable social and economic burden globally. AD is primarily characterized by its chronic pattern and it can have important modifications in the quality of life of the patients and caretakers. One of the fastest-growing topics in translational medicine today is the exploration of new or repurposed functional biomaterials into drug delivery therapeutic applications. This area has gained a considerable amount of research which produced many innovative drug delivery systems for inflammatory skin diseases like AD. Chitosan, a polysaccharide, has attracted attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine, and has been considered a promising candidate for AD treatment due to its antimicrobial, antioxidative, and inflammatory response modulation properties. The current pharmacological treatment for AD involves prescribing topical corticosteroid and calcineurin inhibitors. However, the adverse reactions associated with the long-term usage of these drugs such as itching, burning, or stinging sensation are also well documented. Innovative formulation strategies, including the use of micro- and nanoparticulate systems, biopolymer hydrogel composites, nanofibers, and textile fabrication are being extensively researched with an aim to produce a safe and effective delivery system for AD treatment with minimal side effects. This review outlines the recent development of various chitosan-based drug delivery systems for the treatment of AD published in the past 10 years (2012-2022). These chitosan-based delivery systems include hydrogels, films, micro-, and nanoparticulate systems as well as chitosan textile. The global patent trends on chitosan-based formulations for the AD are also discussed.

Malassezia restricta-mediated Lipoperoxidation: A Novel Trigger in Dandruff

Dandruff is a common scalp disorder with multiple microbial and host-related factors contributing to its aetiology, including alterations in scalp sebum. Despite existing evidence that the yeast Malassezia restricta plays a key role in the onset of dandruff, the interplay of these factors is poorly understood. Recently, squalene monohydroperoxide and malondialdehyde were established as biomarkers of dandruff-afflicted scalp, highlighting the role of sebum lipoperoxidation in the triggering and maintenance of dandruff, although its mechanism of action is unknown. The current study provides evidence that M. restricta mediates sebum peroxidation, leading to production of squalene monohydroperoxide and malondialdehyde. Furthermore, in vitro data show that these lipoperoxidation products act on epidermal cells and alter the skin barrier. These results support the role of Malassezia restricta-induced lipoperoxides as triggers of dandruff, which suggests that blocking their production could be a novel anti-dandruff treatment approach.

Hyaluronic Acid Hydrogel Containing Resveratrol-Loaded Chitosan Nanoparticles as an Adjuvant in Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a common disease-causing skin inflammation, redness, and irritation, which can eventually result in infection that drastically impacts patient quality of life. Resveratrol (Res) is a natural phytochemical famed for its excellent anti-inflammatory and antioxidant activities. However, it is poorly bioavailable. Thus, a drug delivery system is needed to enhance in vivo bioactivity. Herein, we report the preparation of hyaluronic acid (HA) hydrogels containing resveratrol-loaded chitosan (CS) nanoparticles, their physicochemical analysis, and their potential therapeutic effects in the treatment of AD. Positively charged CS nanoparticles prepared by tripolyphosphate (TPP) gelation showed sizes ranging from 120 to around 500 nm and Res encapsulation efficiency as high as 80%. Embedding the nanoparticles in HA retarded their hydrolytic degradation and also slowed resveratrol release. Resveratrol released from nanoparticle-loaded hydrogel counteracted the oxidative damage induced by ROS generation in TNF-α/INF-γ-treated human keratinocytes (HaCaT) used as an AD in vitro model. Moreover, pre-treatment with Res@gel reduced secretion and gene expression of proinflammatory cytokines in HaCaT cells. The physicochemical analysis and in vitro assay confirmed that the formulated hydrogel could be considered an efficient and sustained resveratrol delivery vector in AD treatment.

Induction of autophagy improves skin and hair conditions in dogs with underlying diseases

Background

Autophagy was reported to play a crucial role in maintaining general and skin health.

Methods

The study used a synthesized autophagy inducer (AI) (Aquatide™ cospharm Inc.; Daejeon, Korea), for evaluating the effects of autophagy on skin and hair in dogs. Twenty-two dogs with poor skin and hair which were diagnosed with canine atopic dermatitis (CAD) or pituitary-dependent hyperadrenocorticism (PDH) were included. Clinical scores using Canine Atopic Dermatitis Extent and Severity Index-04 (CADESI-04), Pruritus Visual Analog Scale (PVAS) and skin barrier function using measurement of transepidermal water loss (TEWL) were evaluated and canine keratinocytes were also used in vitro investigation of pro-inflammatory cytokines after AI treatment.

Results

In the AI group, clinical scores and skin barrier function were improved at week 8 significantly compared to in the other groups. In particular, the AI significantly improved the hair surface damage at 8 weeks compared to the baseline. In vitro, the AI reduced pro-inflammatory cytokines by activating the 78-kDa glucose-regulated protein (GRP78).

Conclusion

AI improve skin barrier function and hair damage and reduce pro-inflammatory cytokines by inhibiting reactive oxygen species (ROS) production in dogs.

A Proteome-Centric View of Ageing, including that of the Skin and Age-Related Diseases: Considerations of a Common Cause and Common Preventative and Curative Interventions

The proteome comprises all proteins of a cell or organism. To carry their catalytic and structure-related functions, proteins must be correctly folded into their unique native three-dimensional structures. Common oxidative protein damage affects their functionality by impairing their catalytic and interactive specificities. Oxidative damage occurs preferentially to misfolded proteins and fixes the misfolded state. This review provides an overview of the mechanism and consequences of oxidative proteome damage - specifically irreversible protein carbonylation - in relation to ageing, including that of the skin as well as to age-related degeneration and diseases (ARDD) and their mitigation. A literature review of published manuscripts, available from PubMed, focusing on proteome, proteostasis, proteotoxicity, protein carbonylation, related inflammatory diseases, ARDD and the impact of the damaged proteome on ageing. During ageing, proteome damage, especially protein carbonylation, correlates with biological age. Carbonylated proteins form aggregates which can be considered as markers and accelerators of ageing and are common markers of most ARDD. Protein carbonylation leads to general ageing of the organism and organs including the skin and potentially to diseases including Alzheimer and Parkinson disease, diabetes, psoriasis, and skin cancer. Current research is promising and may open new therapeutic approaches and perspectives by targeting proteome protection as an age and ARDD management strategy.

Alopecia Areata: A Review of the Role of Oxidative Stress, Possible Biomarkers, and Potential Novel Therapeutic Approaches

Alopecia areata (AA) is a dermatological condition characterized by non-scarring hair loss. Exact etiopathogenesis of AA is still unknown although it is known that several factors contribute to the collapse of the hair-follicle (HF)-immune-privileged (IP) site. Oxidative stress (OS) plays an important role in skin diseases. The aim of this review was to clarify the role of OS in AA pathogenesis and diagnosis, and to discuss potential treatment options. Oxidative-stress markers are altered in serum and skin samples of patients with AA, confirming a general pro-oxidative status in patients with AA. OS induces MHC class I chain-related A (MICA) expression in HF keratinocytes that activates the receptor NKG2D, expressed in NK cells and CD8+ T cytotoxic cells leading to destabilization of the HF immune-privileged site through the production of IFN-γ that stimulates JAK1 and JAK2 pathways. OS also activates the KEAP1-NRF2 pathway, an antioxidant system that contributes to skin homeostasis. In addition, a decrease of ATG5 and LC3B in the hair matrix and an increase in p62 levels indicates a reduction of intrafollicular autophagy during the evolution of AA. Potential biomarkers of OS in AA could be: malondialdehyde (MDA), advanced glycation end-products (AGEs), and ischemic-modified albumin (IMA). JAK inhibitors are the new frontier in treatment of AA and the use of nutraceuticals that modulate the OS balance, in combination with standard treatments, represent promising therapeutic tools.

Extract of Wheatgrass and Aronia Mixture Ameliorates Atopic Dermatitis-Related Symptoms by Suppressing Inflammatory Response and Oxidative Stress In Vitro and In Vivo

Atopic dermatitis is regulated by the production of pro-inflammatory cytokines and chemokines via the nuclear factor kappa B or mitogen-activated protein kinase signaling pathways, as well as, the release of oxidative stress-related factors via the NF-E2 p45-related factor 2 signaling pathway. Both wheatgrass (Triticum aestivum L., TA) and aronia (Aronia melanocarpa, AR) are known for their anti-inflammatory and antioxidant properties, however, the anti-inflammatory and antioxidant effects of TA and AR (TAAR) mixture extract have not been elucidated in an atopic dermatitis model. In this study, we assessed the inhibitory effects and underlying molecular mechanism of TAAR extract against lipopolysaccharide-induced inflammation and tumor necrosis factor-α/interferon-γ-induced inflammation and oxidative stress in vitro. We also investigated the alleviating effect of TAAR extract on DNCB-induced atopic dermatitis-like skin lesions in mice in vivo. We found that TAAR extract treatment inhibited inflammatory mediators in both RAW 264.7 cells and HaCaT cells, and increased the expression of oxidative stress defense enzymes in HaCaT cells. Furthermore, treatment of the DNCB-induced mouse model with TAAR extract ameliorated the overall symptoms of atopic dermatitis. Therefore, TAAR extract as a novel natural therapeutic agent may be used for the treatment of atopic dermatitis.

Oxidative Stress and Phototherapy in Atopic Dermatitis: Mechanisms, Role, and Future Perspectives

Atopic dermatitis is a chronic inflammatory skin disease in which the overproduction of reactive oxygen species plays a pivotal role in the pathogenesis and persistence of inflammatory lesions. Phototherapy represents one of the most used therapeutic options, with benefits in the clinical picture. Studies have demonstrated the immunomodulatory effect of phototherapy and its role in reducing molecule hallmarks of oxidative stress. In this review, we report the data present in literature dealing with the main signaling molecular pathways involved in oxidative stress after phototherapy to target atopic dermatitis-affected cells. Since oxidative stress plays a pivotal role in the pathogenesis of atopic dermatitis and its flare-up, new research lines could be opened to study new drugs that act on this mechanism, perhaps in concert with phototherapy.

Circulating redox status in sheep naturally infected with Trichophyton verrucosum

Trichophyton verrucosum is a zoophilic dermatophyte that causes skin inflammation. The present study aimed to evaluate the redox status in the blood of sheep clinically infected with T. verrucosum. According to clinical and mycological investigations, 48 juvenile male Balady sheep were selected in their natural habitat and divided into four groups depending on the lesion size: mild (MID), moderate (MOD), severe (SEV) T. verrucosum infection, and healthy control groups. Compared to the controls, plasma superoxide anion increased (P < 0.05) in both MOD and SEV but total peroxides (TPx) gradually increased (P < 0.05) in MID followed by MOD and SEV. Superoxide dismutase and total antioxidant capacity (TAC) were higher (P < 0.05) in MID and lower (P < 0.05) in MOD and SEV than in controls, but SEV showed lower TAC than MOD. Malondialdehyde (MDA, a lipid peroxide marker) increased (P < 0.05) in SEV than in controls, but protein carbonyl (PC, a protein peroxidation marker) was augmented (P < 0.05) as lesions progressed from mild to severe. The oxidative stress index (TPx/TAC ratio) progressively increased (P < 0.05) in MOD and SEV. The correlation of PC was positive with TPx and negative with TAC (P < 0.01). In conclusion, sheep infection with T. verrucosum is characterized by increased TPx and decreased TAC in plasma depending on the lesion area. The redox status is shifted towards the oxidizing state, particularly in MOD and SEV cases. This results in a condition of OS, which may contribute to the pathogenesis of the disease.

Ameliorative effects of epigallocatechin-3-gallate nanoparticles on 2,4-dinitrochlorobenzene induced atopic dermatitis: A potential mechanism of inflammation-related necroptosis

Atopic dermatitis (AD) is a common autoimmune and chronic inflammatory cutaneous disease with a relapsing-remitting course. Necroptosis is a regulated necrotic cell death mediated by receptor-interacting protein 1 (RIP1), receptor-interacting protein 3 (RIP3), and mixed lineage kinase domain-like pseudokinase (MLKL), which is activated by tumor necrosis factor-α (TNF-α). However, the mechanism and the role of necroptosis have not been delineated in AD progression. (-)-Epigallocatechin-3-gallate (EGCG), the main biological activity of tea catechin, is well known for its beneficial effects in the treatment of skin diseases. Here, PEG-PLGA-EGCG nanoparticles (EGCG-NPs) were formulated to investigate the bioavailability of EGCG to rescue cellular injury following the inhibition of necroptosis after AD. 2,4-dinitrochlorobenzene (DNCB) was used to establish AD mouse models. As expected, topically applied EGCG-NPs elicited a significant amelioration of AD symptoms in skin lesions, including reductions in the ear and skin thickness, dermatitis score, and scratching behavior, which was accompanied by redox homeostasis restored early in the experiment. In addition, EGCG-NPs significantly decreased the expression of inflammatory cytokines like TNF-α, interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-6 (IL-6), and interleukin-17A (IL-17A) in a time-dependent manner than those of in AD group. As a result, the overexpression of RIP1, RIP3, and MLKL in the entire epidermis layers was dramatically blocked by EGCG-NPs, as well as the expression ofphosphorylated p38 (p-p38), extracellular signal-regulated kinase 1 (ERK1), and extracellular signal-regulated kinase 2 (ERK2). These findings promote that EGCG-NPs formulation represents a promising drug-delivery strategy for the treatment of AD by maintaining the balance of Th1/Th2 inflammation response and targeting necroptosis.

Cassia alata, Coriandrum sativum, Curcuma longa and Azadirachta indica: Food Ingredients as Complementary and Alternative Therapies for Atopic Dermatitis-A Comprehensive Review

Traditional medicine is critical in disease treatment and management. Herbs are gaining popularity for disease management and treatment. Therefore, they can be utilised as complementary and alternative treatment (CAT) ingredients. Atopic dermatitis (AD) is one of the common non-communicable diseases. It is characterised by chronic inflammatory skin disease with intense pruritus and eczematous lesions. AD is associated with oxidative stress, microbial infection, and upregulation of inflammatory cytokines. Both children and adults could be affected by this skin disorder. The prevalence of AD is increasing along with the country’s level of development. This review revisited the literature on four medicinal herbs widely used as complementary medicine to manage AD. These therapeutic herbs are commonly eaten as food and used as spices in Asian cuisine. The four food herbs reviewed are Cassia alata, Coriandrum sativum, Curcuma longa Linn, and Azadirachta indica. Their traditional uses and phytochemical content will be covered. Four relevant pharmacological and biological activities of the plants crucial in AD management have been reviewed and discussed, including anti-inflammatory, anti-microbial, antioxidant, and wound recovery.

The Role of Oxidative Stress in Atopic Dermatitis and Chronic Urticaria

Atopic dermatitis (AD) and chronic urticaria (CU) are common skin diseases with an increasing prevalence and pathogenesis that are not fully understood. Emerging evidence suggests that oxidative stress plays a role in AD and CU. The aim of the single-center cross-sectional study was to compare markers of oxidative stress in 21 patients with AD, and 19 CU patients. The products of protein oxidation, total antioxidant capacity (TAC), and markers of lipid peroxidation were estimated in the serum. AD patients had a higher level of advanced protein oxidation products and a lower level of thiol groups than healthy participants. However, CU patients had statistically higher levels of AOPP and 3-nitrotyrosine than healthy subjects. The level of thiol groups and serum TAC decreased significantly in patients with CU. There was no difference in serum concentration of lipid peroxidation products, Amadori products, ratio of reduced to oxidized glutathione, and ability of albumin to binding cobalt between AD or CU patients compared to healthy subjects. We found a moderate positive significant correlation between AOPP and age in patients with AD. In patients with CU, TAC was negatively correlated with age. These results may shed light on the etiopathogenesis of AD or CU, and confirm an oxidative burden in these patients. Furthermore, our study could be useful in developing new therapeutic methods that include using antioxidants in dermatological diseases.

7-O-Methylluteolin Suppresses the 2,4-Dinitrochlorobenzene-Induced Nrf2/HO-1 Pathway and Atopic Dermatitis-like Lesions

7-O-methylluteolin (7-ML) is a flavonoid isolated from the aerial parts of Wikstroemia ganpi (W. ganpi). We describe the anti–atopic dermatitis (AD) effects of 7-ML in tert-butyl hydroperoxide (tBHP)-induced HepG2 cells and 2,4-dinitrochlorobenzene (DNCB)-induced SKH-1 hairless mice. Results demonstrated that 7-ML dose-dependently inhibited the activation of Nrf2 (nuclear factor-erythroid 2-related factor 2) in tBHP-induced HepG2 cells. 7-ML applied topically to our DNCB-induced mouse model upregulated the antioxidant protein expression (phosphorylated Nrf2 (pNrf2), Nrf2, and heme oxygenase-1 (HO-1)) in skin tissues, improved epidermal thickness, and reduced mast cell infiltration into the skin. In addition, 7-ML reduced the serum levels of immunoglobulin E (IgE) and interleukin-4 (IL-4) and improved skin barrier functions. These results suggest that 7-ML should be considered a novel antioxidant and anti-AD agent.

Eco-Sustainable Silk Fibroin/Pomegranate Peel Extract Film as an Innovative Green Material for Skin Repair

Skin disorders are widespread around the world, affecting people of all ages, and oxidative stress represents one of the main causes of alteration in the normal physiological parameters of skin cells. In this work, we combined a natural protein, fibroin, with antioxidant compounds extracted in water from pomegranate waste. We demonstrate the effective and facile fabrication of bioactive and eco-sustainable films of potential interest for skin repair. The blended films are visually transparent (around 90%); flexible; stable in physiological conditions and in the presence of trypsin for 12 days; able to release the bioactive compounds in a controlled manner; based on Fickian diffusion; and biocompatible towards the main skin cells, keratinocytes and fibroblasts. Furthermore, reactive oxygen species (ROS) production tests demonstrated the high capacity of our films to reduce the oxidative stress induced in cells, which is responsible for various skin diseases.

Dual Nanostructured Lipid Carriers/Hydrogel System for Delivery of Curcumin for Topical Skin Applications

This work focuses on the development and evaluation of a dual nanostructured lipid carrier (NLC)/Carbopol®-based hydrogel system as a potential transporter for the topical delivery of curcumin to the skin. Two populations of different sized negatively charged NLCs (P1, 70–90 nm and P2, 300–350 nm) were prepared and characterized by means of dynamic light scattering. NLCs presented an ovoid platelet shape confirmed by transmission electron microscopy techniques. Curcumin NLC entrapment efficiency and release profiles were assessed by HPLC (high pressure liquid chromatography) and spectrophotometric methods. Preservation and enhancement of curcumin (CUR) antioxidant activity in NLCs (up to 7-fold) was established and cell viability assays on fibroblasts and keratinocytes indicated that CUR-NLCs are non-cytotoxic for concentrations up to 10 μM and exhibited a moderate anti-migration/proliferation effect (20% gap reduction). CUR-NLCs were then embedded in a Carbopol®-based hydrogel without disturbing the mechanical properties of the gel. Penetration studies on Franz diffusion cells over 24 h in CUR-NLCs and CUR-NLCs/gels demonstrated an accumulation of CUR in Strat-M® membranes of 22% and 5%, respectively. All presented data support the use of this new dual CUR-NLC/hydrogel system as a promising candidate for adjuvant treatment in topical dermal applications.

Skin Care Product Rich in Antioxidants and Anti-Inflammatory Natural Compounds Reduces Itching and Inflammation in the Skin of Atopic Dermatitis Patients

The atopic dermatitis (AD) complex pathogenesis mechanism reveals marked changes of certain signaling factors as well as some morphological alterations in the epidermis. Reduced resilience against environmental factors and oxidative stress often makes the treatment with corticosteroids or tacrolismus ointments indispensable. In view of the correlation between oxidative stress and AD pathological factors, antioxidants can be incorporated into AD management strategies. This study investigates a curly kale, apple and green tea-containing natural extract rich in antioxidants for its effects on signaling inflammatory molecules and skin barrier enhancement in human epidermal keratinocytes- (NHEKs) based cell assays. Furthermore, the skin penetration on porcine ears was measured ex vivo using Raman micro spectroscopy. Finally, in a double-blind half-side, placebo-controlled clinical study, the effects of a formulation containing this extract were analyzed for the influence of lesion severity, epidermal barrier function, and pruritus in mild to moderately AD patients. Summarizing our results: The extract reduces expression of inflammatory cytokines in keratinocytes and increases barrier-related molecules. The verum formulation with a very high antioxidant capacity used in AD patients with mild to moderate lesions reduces itching, local SCORAD, and improves barrier function and the hydration of skin lesions.