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In this scientific work, a novel and green method for selective lipophilization of EVOO's bioactive phenolic alcohols (PAs), namely, tyrosol, hydroxytyrosol, and its metabolite homovanillyl alcohol as fatty acid esters, is elucidated. The PAs have been employed as hydrogen bond donors in the formation of natural deep eutectic solvents (NADES) with choline chloride (ChCl). The fast and cheap esterification method by in situ formation of choline chloride-based deep eutectic solvents promotes the derivatization of PAs with various fatty acids as acylating agents in the absence of organic solvents and catalysts. Furthermore, given the growing interest in the application of NADES formed by bioactive molecules in the pharmacological and cosmetic fields, we analyzed the activity of antioxidant enzymes, superoxide dismutase, and glutathione S-transferase of three chemical formulations obtained after the formation of PA-oleate in the H 2 O 2 -treated HaCat human keratinocytes cell line, assessing also their toxicity via the MTT assay.

Liposomal drug delivery systems are successfully used in various fields of medicine for external and systemic applications. Marine organisms contain biologically active substances that have a unique structure and exhibit a wide range of biological activities. Polysaccharide of red seaweed (carrageenan (CRG)), and water-insoluble sea urchin pigment (echinochrome (Ech)) interact with each other and form a stable complex. We included the CRG/Ech complex in liposomes for better permeability into cells. In our research, tetramethylrhodamine isothiocyanate TRITC-labeled CRG was synthesized to study the interaction of the complex encapsulated in liposomes with human epidermal keratinocytes (HaCaTs) widely used to expose the skin to a variety of substances. Using confocal microscopy, we found that liposomes were able to penetrate HaCaT cells with maximum efficiency within 24 h, and pre-incubation of keratinocytes with liposomes resulted in the delivery of the CRG/Ech complex into the cytoplasm. We investigated the anti-inflammatory effects of liposomes, including the lysosomal regulation, increased intracellular ROS levels, and increased NO synthesis in lipopolysaccharide (LPS)- or Escherichia coli ( E. coli )-induced inflamed skin cells. Liposomes containing the CRG/Ech complex significantly reduced lysosomal activity by 26% in LPS-treated keratinocytes and decreased ROS levels in cells by 23% after LPS exposure. It was found that liposomes with the complex improved the migration of HaCaT keratinocytes incubated with high-dose LPS by 47%. The results of the work, taking into account the good permeability of liposomes into keratinocytes, as well as the anti-inflammatory effect on cells treated with LPS or E. coli , show the prospects of using liposomes containing the CRG/Ech complex as an anti-inflammatory agent in the fight against skin infections.

Psoriasis is a chronic, relapsing, inflammatory skin disease that is caused by the immune system. Amygdalin possesses immune-modulating and anti-inflammatory effects. To explore the possible effects of amygdalin on psoriasis and its pathogenesis of action, we examined the effects of amygdalin on imiquimod-induced psoriasis, tape-stripping-induced skin barrier disruption, and investigated the potential mechanism of action in vitro. The fact that amygdalin could reduce the thickness of the epidermis and inflammatory cell infiltration in two animal models inhibited the production of IL-1β, IL-6, and TNF-a, and the expression of filaggrin, involucrin, and keratin10 was increased. Also, in IL-17 A and TNF-α induced HaCaT, amygdalin inhibits the expression of IL-6, IL-1β, and TNF-a, promoting the expression of skin barrier recovery-related proteins flaggrin, involucrin, and keratin10. Combined in vivo and in vitro experiments suggest that amygdalin modulates inflammation and the skin barrier in psoriasis. The same study also conducted a preliminary mechanistic exploration and found that amygdalin inhibited the phosphorylation of the p38MAPK signaling pathway. In conclusion, Amygdalin can alleviate psoriasis lesions and improve skin barrier impairment, and the research provides an experimental basis for its future development as a drug candidate for psoriasis therapy., Competing Interests: Declarations. Ethics statement: This animal experiment was reviewed and approved by the Animal Care and Use Committee of Guangzhou University of Traditional Chinese Medicine (2020038) and followed the ARRIVE guidelines. Competing interests: The authors declare no competing interests. Conflict of interest: The author declares no conflict of interest with this article., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Allicin is a sulfide extracted from garlic bulbs responsible for various physiological and pathophysiological effects, including antioxidant, antibacterial, and anti-parasite activities. However, its efficacy and mechanism of protecting UVB-induced photodamage have not been studied. The research explores Allicin's protective roles and underlying mechanisms in UVB-induced photodamage of keratinocytes. UVB was employed to generate photodamage in the HaCaT cell line. DCFH-DA fluorescent and Biochemical analyses were carried out to evaluate reactive oxygen species (ROS) and oxidative stress on UVB-induced photodamage to HaCaT cells. RT-qPCR and western blot were performed to measure mRNA and protein expression. Allicin pretreatment (10 and 25 µM) improved cell proliferation and reduced apoptotic rates in UVB-induced HaCaT cells. Allicin (10 and 25 µM) inhibited tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) expressions (all, P < 0.001). Allicin reduced the intracellular ROS level and attenuated oxidative stress, with reduced malondialdehyde (MDA) level while increasing the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSh-Px) (all, P < 0.001) in UVB-induced HaCaT cells. Allicin pretreatment inhibited autophagy and reduced the protein expression of Beclin-1 while increasing the p62 protein expression (all, P < 0.001). We also observed that Allicin pretreatment reduced the NLRP3-related protein, such as Caspase-1 (P < 0.001) and increased the protein expressions of the PI3K/Akt pathway molecules, such as PI3K and Akt (all, P < 0.001). Our research data demonstrated that Allicin might inhibit UVB-induced photodamage of keratinocytes via inhibiting NLRP3 inflammasomes and activating the PI3K/Akt pathway., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. The authors report no conflict of interest. Ethical approval Ethical approval is not required for this study in accordance with local or national guidelines., (© 2024. The Author(s).)

Advanced glycation end products (AGEs) have adverse effects on the development of diabetic complications. Berberine (BBR), a natural alkaloid, has demonstrated its ability to promote the delayed healing of skin wounds. However, the impact of BBR on AGEs-induced ferroptosis in skin cells and the underlying molecular mechanisms remains unexplored. This study investigated the involvement of ferroptosis in AGEs-induced keratinocyte death, and the impact of BBR on ferroptosis in a db/db mouse model with long-term hyperglycemia was elucidated. A remarkable reduction in cell viability was observed along with increased malondialdehyde (MDA) production in AGEs-induced HaCaT cells. Intracellular reactive oxygen species (ROS) and iron levels were elevated in cells exposed to AGEs. Meanwhile, the protein expression of glutathione peroxidase 4 (GPX4) and ferritin light chain (FTL) was significantly decreased in AGEs-treated cells. However, pretreatment with BBR markedly protected cell viability and inhibited MDA levels, attenuating the intracellular ROS and iron levels and increased expression of GPX4 and FTL in vitro . Significantly diminished antiferroptotic effects of BBR on AGEs-treated keratinocytes were observed upon the knockdown of the nuclear factor E2-related factor 2 ( NRF2 ) gene. In vivo , GPX4, FTL, and FTH expression in the epidermis of diabetic mice was significantly reduced, accompanied by enhanced lipid peroxidation. Treatment with BBR effectively rescued lipid peroxidation accumulation and upregulated GPX4, FTL, FTH, and NRF2 levels in diabetic skin. Collectively, the findings indicate that ferroptosis may play a significant role in AGEs-induced keratinocyte death. BBR protects diabetic keratinocytes against ferroptosis, partly by activating NRF2., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Jiang, Lao, Ran and Zhu.)

Background: To enhance the accuracy of allergen detection in cosmetic compounds, we developed a co-culture system that combines HaCaT keratinocytes (transfected with a luciferase plasmid driven by the AKR1C2 promoter) and THP-1 cells for machine learning applications., Methods: Following chemical exposure, cell cytotoxicity was assessed using CCK-8 to determine appropriate stimulation concentrations. RNA-Seq was subsequently employed to analyze THP-1 cells, followed by differential expression gene (DEG) analysis and weighted gene co-expression net-work analysis (WGCNA). Using two data preprocessing methods and three feature extraction techniques, we constructed and validated models with eight machine learning algorithms., Results: Our results demonstrated the effectiveness of this integrated approach. The best performing models were random forest (RF) and voom-based diagonal quadratic discriminant analysis (voomDQDA), both achieving 100% accuracy. Support vector machine (SVM) and voom based nearest shrunken centroids (voomNSC) showed excellent performance with 96.7% test accuracy, followed by voom-based diagonal linear discriminant analysis (voomDLDA) at 95.2%. Nearest shrunken centroids (NSC), Poisson linear discriminant analysis (PLDA) and negative binomial linear discriminant analysis (NBLDA) achieved 90.5% and 90.2% accuracy, respectively. K-nearest neighbors (KNN) showed the lowest accuracy at 85.7%., Conclusion: This study highlights the potential of integrating co-culture systems, RNA-Seq, and machine learning to develop more accurate and comprehensive in vitro methods for skin sensitization testing. Our findings contribute to the advancement of cosmetic safety assessments, potentially reducing the reliance on animal testing., Competing Interests: The authors declare that they have no competing interests. The authors are all employed by Pigeon Manufacturing (Shanghai) Co., Ltd., (© 2024 Qiao et al.)

Agrimonia eupatoria L. (AE) has a rich tradition of use in wound healing improvement across various cultures worldwide. In previous studies, we revealed that Agrimonia eupatoria L. water extract (AE) possesses a rich polyphenolic composition, displaying remarkable antioxidant properties. Our investigations also demonstrated that lipophosphonoxin (LPPO) exhibited antibacterial efficacy in vitro while preserving the proliferation and differentiation of fibroblasts and keratinocytes. Building upon our prior findings, in this study, we intended to examine whether a combination of AE and LPPO could enhance skin wound healing while retaining antibacterial attributes. The antibacterial activity of AE/LPPO against Staphylococcus aureus was evaluated, alongside its effects on fibroblast-to-myofibroblast transition, the formation of extracellular matrix (ECM), and endothelial cells and keratinocyte proliferation/phenotype. We also investigated AE/LPPO's impact on TGF- β 1 and VEGF-A signaling in keratinocytes/fibroblasts and endothelial cells, respectively. Additionally, wound healing progression in rats was examined through macroscopic observation and histological analysis. Our results indicate that AE/LPPO promotes myofibroblast-like phenotypic changes and augments ECM deposition. Clinically relevant, the AE/LPPO did not disrupt TGF- β 1 and VEGF-A signaling and accelerated wound closure in rats. Notably, while AE and LPPO individually exhibited antibacterial activity, their combination did not lead to synergism, rather decreasing antibacterial activity, warranting further examination. These findings underscore substantial wound healing improvement facilitated by AE/LPPO, requiring further exploration in animal models closer to human physiology.

Inflammatory skin disease is characterized by a pathologic interplay between skin cells and immunocytes and can result in disfiguring cutaneous lesions and systemic inflammation. Immunosuppression is commonly used to target the inflammatory component; however, these drugs are often expensive and associated with side effects. To identify previously unidentified targets, we carried out a nonbiased informatics screen to identify drug compounds with an inverse transcriptional signature to keratinocyte inflammatory signals. Using psoriasis, a prototypic inflammatory skin disease, as a model, we used pharmacologic, transcriptomic, and proteomic characterization to find that benzamil, the benzyl derivative of the US Food and Drug Administration-approved diuretic amiloride, effectively reversed keratinocyte-driven inflammatory signaling. Through three independent mouse models of skin inflammation (Rac1 G12V transgenic mice, topical imiquimod, and human skin xenografts from patients with psoriasis), we found that benzamil disrupted pathogenic interactions between the small GTPase Rac1 and its adaptor NCK1. This reduced STAT3 and NF-κB signaling and downstream cytokine production in keratinocytes. Genetic knockdown of sodium channels or pharmacological inhibition by benzamil prevented excess Rac1-NCK1 binding and limited proinflammatory signaling pathway activation in patient-derived keratinocytes without systemic immunosuppression. Both systemic and topical applications of benzamil were efficacious, suggesting that it may be a potential therapeutic avenue for treating skin inflammation.

Recent work demonstrates that epidermal keratinocytes are critical for normal touch sensation. However, it is unknown whether keratinocytes contribute to touch-evoked pain and hypersensitivity after tissue injury. Here, we used a mouse model of paclitaxel treatment to determine the extent to which keratinocyte activity contributes to the severe neuropathic pain that accompanies chemotherapy. We found that keratinocyte inhibition by either optogenetic or chemogenetic methods largely alleviated paclitaxel-induced mechanical hypersensitivity across acute and persistent time points from 2 days through 3 weeks. Furthermore, we found that paclitaxel exposure sensitized mouse and human keratinocytes to mechanical stimulation and enhanced currents of PIEZO1, a mechanosensitive channel highly expressed in keratinocytes. Deletion of PIEZO1 from keratinocytes alleviated paclitaxel-induced mechanical hypersensitivity in mice. These findings suggest that nonneuronal cutaneous cells contribute substantially to neuropathic pain and pave the way for the development of new pain relief strategies that target epidermal keratinocytes and PIEZO1.

Epidermal growth factor receptors (EGFRs) regulate the growth and repair process of epithelia, as well as carcinogenesis. Activation of TRPV3 by carvacrol stimulates skin inflammation and epidermal hyperplasia; the latter can be suppressed by EGFR inhibition. However, whether EGFR signalling is responsible for skin inflammation remains elusive. The current study investigated the effect of erlotinib, an EGFR inhibitor, on skin inflammation in a carvacrol-induced atopic dermatitis mouse model. It was observed that erlotinib significantly attenuated carvacrol-induced overexpression of proinflammatory cytokines and suppressed peripheral blood mononuclear cell recruitment in HaCaT keratinocytes. In addition, it was demonstrated that erlotinib suppressed carvacrol-induced Akt and NF-κB signalling pathways. Furthermore, inhibition of Akt and NF-κB signalling pathways also attenuated the carvacrol-induced keratinocyte proinflammatory response. Finally, it was demonstrated that erlotinib treatment alleviated carvacrol-induced dermatitis. These data demonstrate that erlotinib ameliorates skin inflammation by regulating Akt and NF-κB-mediated keratinocyte proinflammation, suggesting the therapeutic potential of erlotinib, a clinically used EGFR inhibitor, in skin inflammatory diseases.

Chitosan, a biopolymer derived from chitin, exhibits significant antifungal properties, making it a valuable compound for various applications in agriculture food preservation, and biomedicine. The present study aimed to assess the antifungal properties of chitosan-modified films using sol-gel derivatives (CS:ZnO) or graphene-filled chitosan, (CS:GO and CS:rGO) against two strains of fungi that are the most common cause of food spoilage: Aspergillus flavus ATCC 9643 and Penicillium expansum DSM 1282. The results indicate important differences in the antifungal activity of native chitosan films and zinc oxide-modified chitosan films. CS:ZnO nanocomposites (2:1 and 5:1) completely inhibited spore germination of the two tested fungal strains. Furthermore, a decrease in spore viability was observed after exposure to CS:Zn films. Significant differences in the permeability of cell envelopes were observed in the A. flavus . Moreover, the genotoxicity of the materials against two cell lines, human BJ fibroblasts and human KERTr keratinocytes, was investigated. Our studies showed that the tested nanocomposites did not exhibit genotoxicity towards human skin fibroblasts, and significant damage in the DNA of keratinocytes treated with CS:ZnO composites. Nanocomposites based on chitosan may help reduce synthetic fungicides and contribute to sustainable food production and food preservation practices.

Recent advancements have highlighted the potential of cannabis and its phytocannabinoids (pCBs) in skin health applications. These compounds, through their interaction with the endocannabinoid system (ECS), show promise for skin health products. Their ability to regulate inflammation, oxidative stress and cell proliferation makes them useful in addressing skin problems such as inflammation, scarring, healing, acne and aging, positioning them as valuable tools for innovative skincare solutions. In the present work, the cellular and molecular effects of proprietary pCB-based formulations on ECS modulation, inflammation and skin regeneration were investigated. Using human dermal fibroblasts (HDF) and keratinocytes (HaCaT), the effect of formulations in both pre-treatment and treatment scenarios following exposure to stress-inducing agents was assessed. Key molecular markers were analyzed to tackle their efficacy in mitigating inflammation and promoting structural integrity and regeneration. In vitro results showed that these formulations significantly reduced inflammation, promoted skin regeneration and improved structural functions. In vivo studies confirmed that the formulations were well-tolerated and led to noticeable improvements in skin health, including enhanced barrier function. This study demonstrates the safety and efficacy of pCB-based formulations for cosmeceutical applications. By combining molecular analysis with in vivo testing, this research provides new insights into the therapeutic potential of pCBs for managing various skin conditions.

Purpose: Melanin's pivotal role in skin protection and its overproduction leading to hyperpigmentation disorders highlight the necessity of regulating melanogenesis, with autophagy identified as a key degradation pathway. Imperatorin, a compound from Angelica dahurica, has been revealed to reduce melanin in epidermal keratinocytes, with the specific effects and mechanisms unknown. The purpose of this study was to investigate the mechanism by which imperatorin, reduces melanin production in HaCaT cells, with a focus on its potential role in promoting autophagy and regulating the PI3K/Akt signaling pathway., Methods: The study used HaCaT cells to investigate the effects of imperatorin on melanin production, autophagy, and PI3K/Akt signaling. Melanin content was measured using a spectrophotometric method. Protein levels of PMEL, ATG1, ATG5, and LC3B II were assessed by Western blotting. Autophagy was further visualized by GFP-LC3B puncta formation. The autophagy inhibitor 3-MA, the PI3K/Akt inhibitor LY294002 and PI3K/Akt activator 740 Y-P were used to assess the role of autophagy and PI3K/Akt signaling in imperatorin's effects. Cell viability was monitored to ensure that imperatorin's effects were not due to cytotoxicity., Results: Imperatorin reduced melanin content in HaCaT cells in a dose-dependent manner without compromising cell viability. This reduction in melanin was accompanied by decreased levels of PMEL protein, a key player in melanosome formation. Additionally, imperatorin promoted autophagy in HaCaT cells, as evidenced by increased levels of autophagy-associated markers ATG1, ATG5, and LC3B II, as well as an increase in GFP-LC3B puncta. The autophagy inhibitor 3-MA partially reversed the effects of imperatorin on both autophagy markers and PMEL levels, indicating that autophagy plays a crucial role in imperatorin's depigmentation action. Furthermore, imperatorin inhibited Akt and mTOR phosphorylation, which are downstream targets of PI3K/Akt signaling, enhancing autophagy and further reducing melanin levels. The PI3K/Akt inhibitor LY294002 amplified imperatorin's effects on PI3K and Akt phosphorylation, autophagy, and melanin levels. While, PI3K/Akt activator 740 Y-P reversed imperatorin's effects on these factors., Conclusions: Imperatorin reduces melanin in HaCaT cells via promoting autophagy and melanin degradation, possibly via the PI3K/Akt signaling. Taken together, imperatorin has the therapeutic potential for the treatment of hyperpigmentation disorders., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The phase separation of N 6 -methyladenosine (m 6 A) binding protein YTHDF2 plays a vital role in arsenic-induced skin damage, and YTHDF2 can bind to m 6 A-methylated mRNA of tumor suppressor PTEN. However, whether and how YTHDF2 phase separation regulates PTEN involved in arsenic-induced malignant transformation of keratinocytes remains blank. Here, we established arsenite-induced transformation models with stable expression of wild-type YTHDF2 or mutant YTHDF2 protein in vitro and in vivo. We found that the YTHDF2 protein underwent phase separation during arsenite-induced malignant transformation of keratinocytes, and YTHDF2 phase separation promoted the malignant phenotype of keratinocytes. Mechanically, YTHDF2 phase separation reduced PTEN protein levels, which in turn activated the pro-survival AKT signal. The binding of YTHDF2 to multiple m 6 A sites on PTEN mRNA drove YTHDF2 phase separation, inhibiting PTEN translation initiation and thus reducing PTEN protein levels. YTHDF2 phase separation recruited translation-initiation-factor kinase EIF2AK1 to phosphorylate eIF2α, thereby inhibiting translation initiation of poly-m 6 A-methylated PTEN mRNA. Furthermore, arsenite-induced oxidative stress triggered YTHDF2 phase separation by increasing m 6 A levels of PTEN mRNA. Our results demonstrated that YTHDF2 phase separation promotes arsenite-induced malignant transformation by inhibiting PTEN translation in a poly-m 6 A-dependent manner. This study sheds light on arsenic carcinogenicity from the novel aspect of m 6 A-mediated YTHDF2 phase separation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nano- and microplastics (NMPs), ubiquitous in the environment, pose significant health risks. We report for the first time a comprehensive study using in-vitro, in-vivo, and ex-vivo models to investigate the penetration and inflammatory effects of fragmented polystyrene (fPS) on human skin, including the analysis of both penetration depth and fPS amounts that penetrate the skin. Human keratinocyte (HaCaT) and human dermal fibroblast (HDF) cells exposed to fPS exhibited notable internalization and cytotoxicity. In a 3D human skin model, fPS particles penetrated the dermal layer within one hour, with an average maximum penetration of 4.7 μg for particles smaller than 2 µm. Similarly, mouse dorsal skin and human abdominal skin models confirmed fPS penetration. RNA sequencing revealed substantial upregulation of inflammatory genes, including IL-1α, IL-1β, IL-18, IL-6, IL-8, ICAM-1, FOS, and JUN, following fPS exposure. These findings were validated at both the mRNA and protein levels, indicating a robust inflammatory response. Notably, the inflammatory response in both the 3D human skin and mouse models increased in a dose-dependent manner, underscoring the toxicological impact of fPS on skin health. This study provides crucial insights into the mechanisms through which NMPs affect human health and underscores the need for further research to develop effective mitigation strategies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Inorganic ultraviolet filters such as titanium dioxide nanoparticles are frequently used in sunscreens. Numerous toxicological studies in vitro and in vivo have been conducted using pristine standard reference nanomaterials of these inorganic filters. While convenient, this approach is not realistic because the complex environment of sunscreen formulations could change the physicochemical properties of the nanoparticles and lead to vastly different toxicological outcomes. Therefore, this study focused on characterizing nanoparticles extracted from commercial sunscreen and evaluating the associated toxicological impacts upon exposure to human keratinocytes and human skin explants., Results: Titanium dioxide nanoparticles were extracted from commercial sunscreens and thoroughly characterized. The identity of the associated molecular corona on the extracted nanoparticles was also evaluated. Cell metabolic and proliferation profiles, mitochondrial superoxide activity, reactive oxygen species levels, and genotoxicity induced through exposure to the nanoparticles were studied in vitro using a human keratinocyte cell line. The cell response was significantly different after treatment with pristine nanoparticles compared to corresponding sunscreen-extracted nanoparticles. Pristine spherical nanoparticles resulted in more pronounced toxicity in 2D cultured keratinocytes compared to extracted nanoparticles but did not impact wound-edge migration significantly in 3D ex vivo human skin explant models. Additionally, extracted rod-shaped nanoparticles had greater toxic impacts in keratinocytes in vitro and retarded wound-edge migration in the ex vivo model compared to the extracted spherical nanoparticles. Nevertheless, these heightened cell responses were not associated with any increase in phosphorylated γH 2 AX (which is indicative of DNA damage) both in vitro and ex vivo., Conclusions: This study shows the feasibility of extracting nanoparticles from personal care products such as sunscreens to obtain relevant forms to model real-life exposure scenarios. Overall, sunscreen-extracted nanoparticles were found to be less toxic compared to pristine equivalents but retarded wound-edge migration more significantly. Skin explant cultures provide a more realistic alternative to monolayer cell cultures, although the differential outcomes between the models need more in-depth evaluation., Competing Interests: Declarations. Ethics approval and consent to participate: All experimental procedures involving donated patient samples were reviewed and approved by the National Healthcare Group Domain Specific Review Board (NHG DSRB ref: 2016/00370). Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Psoriasis is a chronic inflammatory skin disease characterized by a complex pathogenesis involving various types of cells and cytokines. Among those, the pro-inflammatory cytokine IL-23/IL-17A axis plays a crucial role in the development and rapid progression of psoriasis. Phenformin, a derivative of metformin and a member of the biguanide class of drugs, exhibits superior anti-inflammatory and anti-tumor efficacy compared to metformin. However, the potential role of phenformin in anti-psoriatic skin inflammation has not been explored., Methods: In this study, we utilized a mouse model of psoriasis and an in vitro model using human keratinocytes to investigate whether phenformin can suppress psoriasis-like inflammatory responses., Results: Our results demonstrate that the topical application of phenformin significantly inhibited acute skin inflammatory responses in the psoriasis mouse model induced by imiquimod (IMQ). Additionally, phenformin suppressed the expression of psoriasis-related cytokines IL-17, IL-23, IL-8, and S100A8/S100A9 in an in vitro psoriatic keratinocyte model induced by IMQ. Furthermore, we found that IMQ-induced psoriatic skin and IMQ-treated keratinocytes exhibited high expression of the c-Myc gene, which was downregulated by phenformin. The c-Myc inhibitor JQ1 similarly inhibited the psoriatic inflammatory response and the expression of psoriasis-related cytokines in both in vitro and in vivo models., Conclusion: phenformin ameliorates the psoriasis-like inflammatory response by inhibiting c-Myc expression in keratinocytes, suggesting its potential as a topical drug for the treatment of psoriasis., Competing Interests: Declaration of competing interest All authors declare no potential conflict of interest with respect to the research, authorship and publication of this article., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Antimicrobial peptides (AMPs) are crucial for protecting human skin from infection. Therefore, the expression levels of beneficial AMPs such as ribonuclease 7 (RNase 7) must be appropriately regulated in healthy human skin. However, there is limited understanding regarding the regulating AMP expression, especially when using applications directly to healthy human skin. Here, we investigated the effects of the extract of Ruscus aculeatus (RAE), a medicinal plant native to Mediterranean Europe and Africa that is known to have a high safety level, on AMP expression in primary human keratinocytes. Treatment with RAE induced RNase 7 expression, which was suppressed by an extracellular signal-regulated kinase (ERK) inhibitor. The autophagic flux assay and the immunofluorescence analysis of microtubule-associated protein 1 light chain 3 (LC3)-Ⅱ and p62 showed that RAE inhibited late-phase autophagy. Moreover, both the inhibition of early-phase autophagy by EX-527, an inhibitor of silent information regulator of transcription 1 (SIRT1) and its enhancement by resveratrol, an activator of SIRT1 inhibited RNase 7 and ERK expression, indicating that autophagosome accumulation is necessary for RAE-induced RNase 7 expression. Additionally, spilacleoside was identified as the active component in RAE. These findings suggest that RAE promotes RNase 7 expression via ERK activation following inhibition of late-phase autophagy in primary human keratinocytes and that this mechanism is a novel method of regulation of AMP expression., Competing Interests: The authors have declarted that no competing interests exist., (Copyright: © 2024 Ono et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This study investigates the effects of environmentally-relevant concentrations of fluoxetine (FLX, commercial name: Prozac) on wound healing. Pollution of water systems with pharmaceutical and personal care products, including antidepressants such as FLX and other selective serotonin reuptake inhibitors, is a growing environmental concern. Environmentally-relevant FLX concentrations are known to impact physiological functions and behaviour of aquatic animals, however, the effects of exposure on humans are currently unknown. Using a combination of human skin biopsies and a human keratinocyte cell line, we show that exposure to environmental FLX promotes wound closure. We show dose-dependent increases in wound closure with FLX concentrations from 125 ng/l. Using several -omics and pharmaceutical approaches, we demonstrate that the mechanisms underlying enhanced wound closure are increased cell proliferation and serotonin signalling. Transcriptomic analysis revealed 350 differentially expressed genes after exposure. Downregulated genes were enriched in pathways related to mitochondrial function and metabolism, while upregulated genes were associated with cell proliferation and tissue morphogenesis. Kinase profiling showed altered phosphorylation of kinases linked to the MAPK pathway. Consistent with this, phosphoproteomic analyses identified 235 differentially phosphorylated proteins after exposure, with enriched GO terms related to cell cycle, division, and protein biosynthesis. Treatment of skin biopsies and keratinocytes with ketanserin, a serotonin receptor antagonist, reversed the increase in wound closure observed upon exposure. These findings collectively show that exposure to environmental FLX promotes wound healing through modulating serotonin signalling, gene expression and protein phosphorylation, leading to enhanced cell proliferation. Our results justify a transition from the study of behavioural effects of environmental FLX in aquatic animals to the investigation of effects of exposure on wound healing in aquatic and terrestrial animals, including direct impacts on human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The retention capacity of polymers is related to the development of systems that combine high surface-to-volume ratio with good handling and specific functionality. Biodegradability and biocompatibility are also key features for extending the field of applications to areas such as biomedicine. With this in mind, the aim of this work is to develop biodegradable, biocompatible, and highly functionalized porous films, that ensure suitable handling and a good surface-to-volume ratio. Polylactic acid (PLA) is applied as a polymer matrix to which a polycaprolactone with a star-shaped architecture (PCL-COOH) to ensure a high concentration of carboxylic end functionalities is added. The porous films are prepared using the phase inversion technique, which, as shown by Scanning Electron Microscopy (SEM) analysis, promotes good dispersion of the PCL-COOH domains. Absorption and release measurements performed with a positively charged model molecule show that the retention capacity and release rate can be tuned by changing the PCL-COOH concentration in the systems. Moreover, the adsorption properties for the formulation with the highest PCL-COOH content are also demonstrated with a real and widely used drug, namely doxorubicin. Finally, the bio- and hemocompatibility of the films, which are enzymatically degradable, are evaluated by using human keratinocytes and red blood cells, respectively., (© 2024 Wiley‐VCH GmbH.)

Background: Primary endpoints of clinical studies investigating treatments for actinic keratosis (AK) are mainly based on clinical evaluation, but a recent study showed that in AK, clinical classification according to Olsen and the extent of keratinocyte atypia do not necessarily correlate. The influence of the epidermal extent of atypia on treatment efficacy is usually not investigated and therefore remains largely unknown., Objective: To evaluate whether the extent of keratinocyte atypia influences efficacy of photodynamic therapy (PDT) when treating AK., Methods: We performed a post-hoc analysis of histological (keratinocyte intraepithelial neoplasia (KIN)), and clinical (Olsen) data of biopsied lesions of three pivotal studies evaluating PDT using 10 % aminolevulinic acid (ALA) gel or vehicle and narrow- or broad-spectrum red light lamps., Results: Overall, 514 biopsied lesions were considered. Clearance rates after red light PDT with 10 % ALA gel were comparable for KIN I-III (88.2 %, 92.0 % and 87.9 %) and Olsen I-II lesions for any given lamp type. Generally, clearance rates were higher using narrow- compared to broad-spectrum lamps. For both lamp types, the variation in clearance rates from KIN I-III was low. Clearance was lower with vehicle., Limitations: Varying lesion numbers in the subgroups and a remaining risk of bias due to the biopsies are potential limitations., Conclusion: Our results suggest that red light PDT with 10 % ALA gel is an effective treatment option for AK regardless of the extent of keratinocyte atypia., Competing Interests: Declaration of competing interest R.-M.S. has received grants from Almirall, Biofrontera, Dr. Wolff-Group, Galderma, Leo Pharma, Novartis, and photonamic for clinical studies; has received consulting fees and speakers’ honoraria from Abbvie, Almirall, Eli Lilly, Galderma, Janssen, and Leo Pharma, and is Vice-President of the EURO-PDT Society; T.D. has received funding from Almirall, Biofrontera, Galderma, Meda, Schulze & Böhm GmbH for research support; has received consulting fees from Almirall, Biofrontera, GSK, Dr. Pfleger, Galderma, Janssen-Cilag, Leo, Meda, Neracare, Novartis, Scibase, smartinmedia AG, UCB, Vichy; and has received speakers honoraria from Almirall, Biofrontera, Galderma, GSK, infectopharm, Leo, Meda, Neracare, Novartis, Janssen-Cilag, Riemser; E.B. and U.R. have no conflict of interest to declare., (Copyright © 2024. Published by Elsevier B.V.)

Urushiol-induced allergic contact dermatitis (ACD) is a chronic inflammatory skin disease in which skin barrier dysfunction leads to pruritus and eczematous lesions. ACD is triggered by immune imbalance. Aloe emodin is an anthraquinone derivative extracted from rhubarb, aloe and other traditional Chinese medicines. It has a wide range of pharmacological effects, including anti-inflammatory, anti-tumor, and anti-allergic effects. The purpose of our study was to demonstrate the effectiveness of aloe-emodin on urushiol-induced acute pruritus and allergic contact dermatitis. The results showed that urushiol could stimulate keratinocytes to release chemokines CXCL1, CXCL2, CCL2, TSLP, and TNF-α, which recruit or activate mast cells. Aloe-emodin treatment inhibited inflammatory-response-induced mast cell degranulation in skin lesions and suppressed the expression of inflammatory cytokines, such as interleukin-4, and interleukin-6. Therefore, the results indicate that aloe-emodin can improve urushiol-induced acute pruritus and allergic contact dermatitis in mice by inhibiting mast cell degranulation., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.)

Dry skin induced chronic pruritus is an increasingly common and debilitating problem, especially in the elderly. Although keratinocytes play important roles in innate and adaptive immunity and keratinocyte proliferation is a key feature of dry skin induced chronic pruritus, the exact contribution of keratinocytes to the pathogenesis of dry skin induced chronic pruritus is poorly understood. In this study, we generated the acetone-ether-water induced dry skin model in mice and found that epidermal hyperplasia induced by this model is partly dependent on the β-catenin signaling pathway. XAV939, an antagonist of β-catenin signaling pathway, inhibited epidermal hyperplasia in dry skin model mice. Importantly, dry skin induced chronic pruritus also dramatically reduced in XAV939 treated mice. Moreover, acetone-ether-water treatment-induced epidermal hyperplasia and chronic itch were decreased in Trpv4 -/- mice. In vitro, XAV939 inhibited hypo-osmotic stress induced proliferation of HaCaT cells, and hypo-osmotic stress induced proliferation of in HaCaT cells and primary cultured keratinocytes were also significantly reduced by blocking TRPV4 function. Finally, thymic stromal lymphopoietin release was examined both in vivo and in vitro, which was significantly inhibited by XAV939 treatment and Trpv4 deficiency, and anti-TSLP antibody treatment significantly decreased AEW-induced scratching behavior. Overall, our study revealed a unique ability of TRPV4 expressing keratinocytes in the skin, which critically mediated dry skin induced epidermal hyperplasia and chronic pruritus, thus provided novel insights into the development of therapies for chronic pruritus in the elderly., Competing Interests: Declaration of competing interest The authors have declared that no conflict of interest exists., (Copyright © 2024. Published by Elsevier B.V.)

Fine particulate matter (PM 2.5 ) induces a range of diseases, including skin disorders, through inflammatory responses. In this study, we investigated the novel mechanisms by which PM 2.5 causes skin inflammation in human keratinocytes HaCaT. We observed increased protein expression of cyclooxygenase-2 (COX-2) and the production of prostaglandin E2 (PGE2) in PM 2.5 -treated HaCaT cells. To identify the pathways promoting the expression of these inflammatory proteins, we conducted a phospho-kinase antibody array and confirmed that the phosphorylation levels of JNK and p38 were increased by PM 2.5 -treated HaCaT cells. Further investigation of the phosphorylation levels of mitogen-activated protein kinases (MAPKs) and upstream signals revealed that PM 2.5 activated the MKK4/7-JNK-c-Jun and MKK3/6-p38-p70 S6K signaling pathways, while the phosphorylation level of ERK1/2 remained unchanged. HaCaT cells treated with PM 2.5 phosphorylated Mixed-lineage kinase 3 (MLK3), an upstream regulator of p38 and JNK. Furthermore, inhibition of ROS production by N-Acetylcysteine (NAC) treatment inhibited MLK3 phosphorylation. Taken together, ROS production induced by PM 2.5 activated the MLK3 signaling pathway and induced skin inflammation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Hair loss is linked to dysfunction of the growth (anagen), regression (catagen) and rest (telogen) phases of the hair follicle (HF) cycle., Aims: To evaluate the effects of a Silybum marianum extract (SME), manganese PCA (MnPCA), and a Lespedeza capitata extract (LCE) on markers of hair growth and anchorage in human follicle dermal papilla cells (HFDPCs), and to investigate the ability of a topical serum containing these active ingredients to improve HF growth in an ex vivo human scalp skin model., Methods: In HFDPCs, we assessed receptor tyrosine kinase phosphorylation and Wnt/β-catenin pathway activation; quantified versican, vascular endothelial growth factor (VEGF) and Dickkopf-1 (DDK1) secretion; and evaluated 5α-reductase (5αR) activity. Using scalp skin biopsies from two female donors, we measured hair shaft elongation, analyzed hair matrix keratinocyte proliferation and apoptosis, and determined HF cycle stage and score., Results: Compared to untreated HFDPCs, SME upregulated phosphorylation of growth factor receptors (EGFR:1.9 × and PDGFR: 2.8 ×) and their downstream effectors (ERK, GSK3, Akt, and STAT: 1.2-2.0 ×); MnPCA enhanced versican (33.0 ×) and VEGF (3.3 ×) secretion, and stimulated the Wnt/β-catenin pathway (+80%); and LCE reduced DKK1 secretion (-72%) and 5αR activity (dihydrotestosterone/testosterone ratio: -60%). Compared to untreated scalp skin biopsies, the serum enhanced hair shaft elongation (+102%), and significantly prolonged the anagen phase by improving hair cycle scores and stimulating hair matrix keratinocyte proliferation (+58%)., Conclusions: SME, MnPCA, and LCE displayed complementary anti-hair loss properties. The serum combining these active ingredients may be useful in hair loss treatment., (© 2024 LABORATOIRES PIERRE FABRE. Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

5-Fluorouracil (5-FU) is a commonly used chemotherapy drug that effectively destroys cancer cells. Despite its widespread use and efficacy, it also presents considerable challenges, particularly with adverse effects on rapidly dividing normal cells, such as keratinocytes. These detrimental effects are attributed to inflammatory, oxidative, and apoptotic potentials, leading to severe skin disorders. Due to the lack of specific remedies for 5-FU-induced dermatological side effects, conventional treatments are applied instead, which provide limited relief and have drawbacks. This study investigated the impact of acetyl tributyl citrate (ATBC) in 5-FU-treated human keratinocytes. The findings indicated that ATBC substantially reduced inflammation caused by 5-FU, as demonstrated by nuclear translocation of nuclear factor kappa B and expression of its downstream genes, including tumor necrosis factor, interleukin 1 beta (IL1B), and IL6. ATBC also markedly decreased oxidative stress, indicated by reactive oxygen species levels and the antioxidant gene expression such as superoxide dismutase 1 (SOD1), SOD2, and heme oxygenase 1 in 5-FU-treated cells. Furthermore, ATBC attenuated 5-FU-induced apoptosis, as determined by lactate dehydrogenase release and Annexin V/propidium iodide flow cytometry, with the potential involvement of interferon-related genes. Following this, protein kinase C delta was predicted as a possible molecular target of ATBC. These findings propose ATBC as a therapeutic agent for managing the cutaneous side effects associated with 5-FU treatment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Taesun Park has patent pending to Yonsei University. Wesuk Kang has patent pending to Yonsei University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

A new biological activity was discovered for marine fungal meroterpenoid meroantarctine A with unique 6/5/6/6 polycyclic system. It was found that meroantarctine A can significantly reduce biofilm formation by Staphylococcus aureus with an IC 50 of 9.2 µM via inhibition of sortase A activity. Co-cultivation of HaCaT keratinocytes with a S. aureus suspension was used as an in vitro model of skin infection. Treatment of S. aureus-infected HaCaT cells with meroantarctine A at 10 µM caused a reduction in the production of TNF-α, IL-18, NO, and ROS, as well as LDH release and caspase 1 activation in these cells and, finally, recovered the proliferation and migration of HaCaT cells in an in vitro wound healing assay up to the control level. Thus, meroantarctine A is a new promising antibiofilm compound which can effective against S. aureus caused skin infection., Competing Interests: Compliance with ethical standards. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to the Japan Antibiotics Research Association.)

Objective: Monoamine oxidase (MAO) inhibitors reduce inflammation in a number of in vitro and in vivo models. This finding led to the development of a novel MAO-B selective inhibitor (RG0216) designed to reduce blood-brain barrier penetration. To elucidate RG0216's regulatory role in inflammation-relevant signaling pathways, we employed a transcriptome analytic approach to identify genes that are differentially regulated by RG0216 and then globally identified which inflammation-relevant biological signaling pathways were altered by this drug., Material and Methods: Primary human gingival keratinocyte (HGK) cells were treated with RG0216, and RNA was extracted (4 h). RNAseq transcriptome analysis was utilized to identify differentially expressed genes (DEGs), while Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to identify significantly enriched biological pathways. Relevant genes associated with these pathways and RG0216 regulation of Porphyromonnas gingivalis lipopolysaccharide (PgLPS)-induced cytokine/chemokine expression were evaluated using the real-time quantitative reverse-transcription polymerase chain reaction (RT-qPCR) approach., Results: RG0216 significantly altered the expression of 50 DEGs in HGK cells. Using GO and KEGG analytic approaches, these genes were associated with the biological pathways relevant to mitogen-activated protein kinase (MAPK) and MAPK phosphatases. These phosphatases are part of the 10-member catalytically active dual-specificity phosphatase (DUSP) family. RG0216 induced the expression of DUSP10, reduced the expression of DUSP4 and DUSP6, and decreased IL-6 and IL-8 expression in control and PgLPS-stimulated cultures., Conclusions: In HGK cells, a novel MAO-B inhibitor (RG0216) significantly altered DUSP4, DUSP6, and DUSP10 expression. DUSPs play a regulatory role in MAPK activity and, therefore, can alter cellular inflammatory responses. We found that RG0216 inhibited IL-6 and IL-8 expression. Further studies are planned to examine RG0216's regulatory role in DUSP expression and its impact on the regulation of cytokine/chemokine expression.

Methotrexate (MTX) is a folic acid antagonist routinely used in cancer treatment, characterized by poor water solubility and low skin permeability. These issues could be mitigated by using drug delivery systems, such as functionalized gold nanoparticles (AuNPs), known for their versatility and unique properties. This study aimed to develop multi-shell AuNPs functionalized with MTX for the improvement of MTX antitumoral, antioxidant, and biocompatibility features. Stable phosphine-coated AuNPs were synthesized and functionalized with tailored polyethylene glycol (PEG) and short-branched polyethyleneimine (PEI) moieties, followed by MTX covalent binding. Physicochemical characterization by UV-vis and Fourier-transform infrared spectroscopy (FTIR) spectroscopy, dynamic light scattering (DLS), scanning transmission electron microscopy (STEM), and X-ray photoelectron spectroscopy (XPS) confirmed the synthesis at each step. The antioxidant activity of functionalized AuNPs was determined using DPPH radical scavenging assay, ferric ions' reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. Biocompatibility and cytotoxicity were assessed using MTT and LDH assays on HaCaT human keratinocytes and CAL27 squamous cell carcinoma. MTX functionalized AuNPs demonstrated enhanced antioxidant activity and a pronounced cytotoxic effect on the tumoral cells compared to their individual components, highlighting their potential for improving cancer therapy.

Objectives: To achieve a more beautiful and younger appearance, reducing wrinkles is a key concern. The process of wrinkle formation is complex and the development of truly effective cosmetic ingredients to reduce wrinkles remains a challenge. Recent studies have revealed a close relationship between wrinkles and skin thinning, suggesting that preventing skin thinning could also prevent wrinkle formation. In this study, we examined the role of extracellular adenosine triphosphate (eATP) in the progression of thinning, as eATP reportedly increases skin ageing factors, such as senescence-associated secreted phenotype (SASP) factors in epidermal cells. We determined the effects of Mentha piperita leaf extract on suppressing eATP to reduce thinning and wrinkles., Methods: Adenosine triphosphate (ATP) levels were measured in normal human epidermal keratinocytes (NHEK) in the presence of M. piperita leaf extract. Dryness, high pH, and UVB radiation were used as extrinsic ageing factors. Intrinsic skin ageing was evaluated by comparing cells from adults (AD-NHEK) and newborns (NB-NHEK). A placebo-controlled in vivo study was carried out with a formulation containing 1% M. piperita leaf extract., Results: The eATP levels were significantly higher in AD-NHEK compared with that in NB-NHEK cells. M. piperita leaf extract significantly decreased eATP levels in adult cells. Extrinsic ageing factors increased eATP levels in NHEK, whereas M. piperita leaf extract significantly suppressed eATP under all conditions. The active components of M. piperita leaf extract, luteolin glucuronide and rosmarinic acid, also decreased eATP. Moreover, compared with placebo lotion, M. piperita leaf extract-formulated lotion markedly increased dermal thickness and reduced wrinkles associated with crow's feet and the neck area., Conclusion: We demonstrated for the first time that M. piperita leaf extract containing rosmarinic acid and luteolin-7-O-glucuronide has the potential to reduce eATP release from epidermal keratinocytes. An increase in eATP was observed not only during inflammation but also during natural ageing. Furthermore, the in vivo experiment revealing that 1% M. piperita leaf extract-containing lotion improved dermal thinning and wrinkles across multiple areas is attributed to the amelioration of dermal thinning. Thus, our data suggest the possibility of a novel cosmetic approach for reducing skin ageing by reducing eATP-mediated dermal thinning., (© 2024 Society of Cosmetic Scientists and Societe Francaise de Cosmetologie.)

Ultraviolet (UV) B irradiation is closely related to skin aging and skin damage. Here, we report the photoprotective mechanism of action of ginseng berry rare saponins (GFRS) on UVB-induced damage to human keratinocytes and mouse skin. Several UVB irradiation-induced cytotoxicity and oxidative stress responses were assessed. GFRS preconditioning significantly improved HaCaT cell survival and reduced the levels of the DNA damage markers histone H2AX and cyclobutane pyrimidine dimer. Under oxidative stress, GFRS could reduce the transformation and loss of the mitochondrial membrane potential to the monomer form; effectively clear the expression of lipid reactive oxygen species, malondialdehyde, and other peroxides, and restore total superoxide dismutase, glutathione peroxidase, and catalase levels. The occurrence of ferroptosis after UVB induction was also studied. Erastin exacerbated the induced cellular iron overload, whereas GFRS and Fer-1 reversed this response to varying degrees. Mechanistically, GFRS activated the Nrf2/HO-1/GPX4 pathway and inhibited the phenomenon of ferroptosis in cells. Our findings were confirmed using a mouse model of UV induced skin injury. GFRS not only mitigated lipid peroxides and iron overload in tissues but also prevented skin barrier damage and collagen loss. Therefore, GFRS shows potential as a novel functional product as it protects the skin from UVB light-induced damage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Solar dermatitis (SD) is an acute, damaging inflammation of the skin caused by UV exposure, especially UVB. Therefore, the discovery of novel anti-SD therapeutic agents is crucial. Andrographis paniculata (AP) is a medicinal plant with a wide range of pharmacological effects. Increased evidence shows that AP has potential therapeutic effects on SD. However, the therapeutic mechanisms of AP against SD have not yet been completely elucidated, which is an unexplored field., Purpose: This study employed network pharmacology, molecular docking and experimental verification to ascertain the active constituents, possible targets, and biological pathways associated with AP in the treatment of SD., Methods: AP-related active ingredients and their potential targets were screened from TCMSP and Swiss Target Prediction database, respectively. Potential therapeutic targets of SD were collected using the GeneCards, DrugBank and OMIM databases. Then, we established protein-protein interaction (PPI), compound-target-disease (D-C-T-D) through Cytoscape to identify the major components, core targets of AP against SD. Next, the GO and KEGG pathway was identified by the David database of AP in the treatment of SD. Molecular docking techniques were used to estimate the binding force between the components and the hub genes. In this paper, we used UVB-irradiated HaCaT keratinocytes as an in vitro model and established the dorsal skin of UVB-irradiated ICR mice as an in vivo model to explore the mechanism for further verification., Results: There were 24 active components and 63 related target genes in AP against SD. PPI analysis showed that AKT-1, TNF-α, IL6, MMP9, EGFR, and PTGS2 shared the highest centrality among all target genes. KEGG pathway analysis revealed that the PI3K-Akt signaling pathway may be central in the anti-SD system. The molecular docking results showed that the main active components of AP have strong binding affinity with hub genes. In vitro results showed that WG had a protective effect on UVB-intervened HaCat cells. Western blot analysis showed that WG intervention achieved anti-inflammation by reducing the phosphorylated expression of AKT, PI3K proteins in the PI3K-AKT signaling pathway and downregulating the expression of TNF-α, IL-6, EGFR. Furthermore, Histological analysis confirmed that administration of WG to ICR mice significantly ameliorated UVB-induced skin roughness, epidermal thickening, disturbed collagen fiber alignment and wrinkles. Meanwhile, immunohistochemistry showed that administration of WG to ICR mice significantly reduced UVB-induced expression of MMP9, MPO, F4/80 in the skin. These results provide new insights into the contribution of WG to the development of clinical treatment modalities for UVB-induced SD., Conclusion: The crucial element in the fight against SD is WG, with the primary route being PI3K/Akt. The main components and hub genes had robust binding abilities. In vitro and vivo experiments showed that WG could inhibit the expression level of the hub genes by inhibiting the PI3K/Akt pathway. In summary, the information presented in this study indicates that WG might be utilised as a treatment for UVB-induced SD., Competing Interests: Declaration of competing interest The authors declare that there have no conflicts of interest., (Copyright © 2024. Published by Elsevier GmbH.)

This study compares the effects of vitamins - including ascorbic acid, its derivative 3-O-ethyl-ascorbic acid (EAA), and tocopherol - as well as the main non-psychoactive phytocannabinoids on the viability of various skin cells, including healthy (keratinocytes/melanocytes/fibroblasts) and cancer cells (melanoma/SCC), under standard culture conditions and after the exposure to UVA radiation. All the conducted tests (MTT, SRB, and LDH) consistently indicate that the regenerative effect of EAA is stronger than that of ascorbic acid, while tocopherol acts selectively on healthy/cancer cells, inducing or inhibiting their proliferation, respectively. In the case of phytocannabinoids, only cannabidiol shows protective/regenerative properties for healthy cells. Moreover, the response of melanocytes to cannabigerol is divergent; however, only the LDH test indicates that cannabigerol strongly increases the membrane permeability of those cells. In summary it should be emphasized that various tests may give partially divergent results due to a variety of measured parameters. Nevertheless, despite the positive viability test results for the potential protective compound, caution should be taken as it may promote healthy skin cells but also protect cancer cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Epoxytiglianes are a novel class of diterpene esters. The prototype epoxytigliane, EBC-46 (tigilanol tiglate), is a potent anti-cancer agent in clinical development for local treatment of a range of human and animal tumors. EBC-46 also consistently promotes wound re-epithelialization at the treatment sites, mediated via activation of classical protein kinase C (PKC) isoforms. We have previously shown that epoxytiglianes stimulate proliferative and wound repopulation responses in immortalized human skin keratinocytes (HaCaTs) in vitro, abrogated by pan-PKC inhibitor, bisindolylmaleimide-1. In this study, we further investigate the specific PKC isoforms responsible for inducing such wound healing responses, following HaCaT treatment with 1.51 nM-15.1 µM EBC-46 or analogue, EBC-211. Classical PKC inhibition by GӦ6976 (1 μM), significantly attenuated epoxytigliane induced, HaCaT proliferation and wound repopulation at all epoxytigliane concentrations. PKC-βI/-βII isoform inhibition by enzastaurin (1 μM), significantly inhibited HaCaT proliferation and wound repopulation responses induced by both epoxytiglianes, especially at 1.51-151 nM. PKC-α inhibitor, Ro 31-8220 mesylate (10 nM), exerted lesser inhibitory effects on HaCaT responses. Epoxytigliane changes in key keratin (KRT17) and cell cycle (cyclin B1, CDKN1A) protein levels were partly attenuated by GӦ6976 and enzastaurin. GӦ6976 also inhibited increases in matrix metalloproteinase (MMP-1, MMP-7, MMP-10) activities. Phospho-PKC (p-PKC) studies confirmed that epoxytiglianes transiently activated classical PKC isoforms (p-PKCα, p-PKC-βI/-βII, p-PKCγ) in a dose- and time-dependent manner. By identifying how epoxytiglianes stimulate classical PKCs to facilitate keratinocyte healing responses and re-epithelialization, these findings support further epoxytigliane development as topical therapeutics for clinical situations involving impaired re-epithelialization, such as non-healing wounds in skin., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This work was conducted with financial support from QBiotics Group. P.R. and V.G. are employees and possess ownership interests in QBiotics Group. R.M., R.S., R.L.M., P.R., V.G., G.M.B. and QBiotics Group have filed patents on the work disclosed within this manuscript. E.L.W., J.D., J.P.J. and V.K. have no conflict of interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Psoriasis is a kind of severe immune-mediated systemic skin disorder, becoming a worldwide public health concern. Daturataturin A (DTA), a withanolide compound, exerts excellent anti-inflammatory and anti-proliferative properties. The objective of this study is to elucidate the effect of DTA on psoriasis and its potential mechanism. We established psoriasis-like keratinocytes model by stimulating HaCaT cells with M5 cocktail cytokines including Interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α), followed by intervention with DTA. The potential effects and mechanisms of DTA on psoriasis were evaluated in vitro. DTA was found to be able to inhibit hyperproliferation, promote apoptosis, decrease the release of pro-inflammatory cytokines, downregulate keratin expression, and improve lipid metabolism via regulating the peroxisome proliferator-activated receptor (PPAR) signaling pathway by M5 cocktail cytokines stimulation in HaCaT cells. DTA ameliorated lipid metabolism of psoriasis and exerted the potential anti-psoriasis effects by regulating PPAR pathway in vitro, suggesting that DTA may act as a new therapeutic agent for psoriasis., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no conflict of interests. Ethical Approval: Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To provide an advanced therapy for wound recovery, in this study, pasteurized bovine milk-derived exosomes (mEXO) are immobilized onto a polydopamine (PDA)-coated hyaluronic acid (HA)-based electrospun nanofibrous matrix (mEXO@PMAT) via a simple dip-coating method to formulate an mEXO-immobilized mesh as a wound-healing biomaterial. Purified mEXOs (∼82 nm) contain various anti-inflammatory, cell proliferation, and collagen synthesis-related microRNAs (miRNAs), including let-7b, miR-184, and miR-181a, which elicit elevated mRNA expression of keratin5, keratin14, and collagen1 in human keratinocytes (HaCaT) and fibroblasts (HDF). The mEXOs immobilized onto the PDA-coated meshes are gradually released from the meshes over 14 days without burst-out effect. After treatment with HaCaT and HDF, the degree of in vitro cell migration increases significantly in the mEXO@PMAT-treated HaCaT and HDF cells compared to the unmodified or PDA-coated meshes-treated cells. Additionally, the mEXO@PMAT provides significantly faster wound closure in vivo without notable toxicity. Thus, the sustained liberation of bioactive mEXO from the meshes can effectively enhance cell proliferation in vitro and accelerate wound closure in vivo, which could be harnessed mEXO@PMAT as a promising wound-healing biomaterial., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest exist., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe adverse drug reactions with extensive keratinocyte death. Carbamazepine (CBZ), the most commonly implicated drug in SJS/TEN, is metabolized by the cytochrome P450 enzyme 3A4 (CYP3A4) into carbamazepine-10,11-epoxide (CBZE) in the liver. While CD8 + cytotoxic T cells play an important role in SJS/TEN, the underlying mechanism of exuberant immune response by CD8 + T cells in these conditions remains incompletely understood., Objectives: To examine the expression of NLRP3 inflammasome and their skin migration in CBZE-induced SJS/TEN., Methods: The expression of the NLRP3 inflammasome complex in skin lesions, sera, and blister fluids of SJS/TEN patients were analyzed by immunohistochemistry and enzyme-linked immunosorbent assay. NLRP3 formation and CD8 + T cell activation status and their functions were examined by immunoblotting, immunofluorescence, and chemotaxis assays., Results: The expression of the NLRP3 inflammasome complex was greatly increased in skin lesions of SJS/TEN patients. Moreover, IL-1β and IL-18 levels in sera and blister fluids of SJS/TEN patients were approximately 3-fold higher than those in healthy individuals, with a linear correlation between IL-1β levels and disease activity. CBZE induced NLRP3 inflammasome formation, upregulated CXCL9/CXCL10 levels, and activated CD8 + cytotoxic T cell functions via IL-1β/IL-1R or IL-18/IL-18R signaling in SJS/TEN keratinocytes, which promoted CD8 + cytotoxic T cell migration in SJS/TEN patients., Conclusion: This study showed that CBZE promoted NLRP3 inflammasome formation and strengthened the activation and function of CD8 + cytotoxic T cells in the skin, which contributed to the initiation and progression of SJS/TEN., (Copyright © 2024 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

Nano-titanium dioxide (Nano-TiO 2 ) is extensively utilized across various industries and has the capacity to penetrate human tissues through multiple biological barriers. The HaCaT cell line, as one of human immortalized keratinocytes, is usually used as a model for studying skin drug toxicology. The objective was to assess the toxic effects of nano-TiO 2 on HaCaT cells and to trigger pyroptosis. We used MTT method to evaluate the effects of three nano-TiO 2 particle sizes (15 nm, 30 nm and 80 nm) on cell viability at different concentrations. Subsequently, we used LDH, Hoechst 33342 and propidium iodide (PI) double staining, scanning electron microscopy (SEM), Western blotting (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) to evaluate the effects of different particle sizes on cells at the same concentration. Our findings indicated that HaCaT cell viability diminished with increasing nano-TiO 2 concentrations. Moreover, nano-TiO 2 increased LDH level in cellular supernatant. Fluorescence double staining, SEM, WB and RT-qPCR showed that nano-TiO 2 induced cell membrane damage by activating pyroptosis pathway of NLRP3/caspase-1/GSDMD. These results suggest that nano-TiO 2 toxicity in HaCaT cells is influenced by both dose and particle size, and is associated with the induction of pyroptosis. Frequent and large exposures to nano- TiO 2 in daily life may cause serious health hazards., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lingyun Xu reports financial support was provided by Medical Products Administration of Hubei Province. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The pharmaceutical and cosmetic industries are encountering a challenge in adopting new study models for product development. there has been a growing interest in organ-on-a-chip systems, and particularly for generating skin models. While numerous alternatives replicating high-fidelity skin models exist, there is a notable absence of melanoma study's methodology specifically on these microfluidic chips. This work introduces a novel skin-on-a-chip device featuring two microfluidic chambers, facilitating a 3D cell co-culture involving fibroblasts, keratinocytes, and melanoma cells. The design of this organ-on-a-chip has enabled the administration of the anticancer treatment Gemcitabine using an injection system within the chip. The results of this work have shown a significant impact on the co-culture distribution of cells, decreasing the population of cancerous cells after the administration of Gemcitabine. The work presented in this article demonstrates the effectiveness of the chip and the administration method for testing anti-melanoma therapies and position this technology as an enhanced fidelity model for studying melanoma while providing an alternative for real-time monitoring of drug testing., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Miguel Holgado reports financial support was provided by Ministerio de ciencia e innovacion of spain. Miguel Holgado reports financial support was provided by European Project H2020. Miguel Holgado reports financial support was provided by Community of Madrid Ministry of Health. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Sodium lauryl sulfate (SLS) is used as a control irritant in patch testing for allergic contact dermatitis (ACD). However, up to 20% of those tested react to SLS, whereby the pathophysiological basis of this reaction is still unclear. To mimic patch test reactions, we repeatedly applied SLS to the skin of wild-type mice. Reactions were compared with those in a classical ACD model induced by oxazolone and an irritant contact dermatitis (ICD) model induced by croton oil. Skin inflammation was assessed with ear thickness measurements, immunohistochemistry, qRT-PCR, and flow cytometry. Topical SLS treatment was further investigated in Flg/Hrnr -/- , Myd88/Tlr3 -/- , and Rag1 -/- mouse models. All three compounds caused ear swelling with different courses. Oxazolone treatment, compared with the ICD model, resulted in a greater influx of immune cells (CD4 + , MHCII + , CD11b + ). Similarly, SLS did not induce immune cell infiltration or expression of selected inflammatory and regulatory cytokines. SLS induced the most pronounced keratinocyte proliferation. Compared with wild-type mice, topical SLS application did not increase ear swelling in skin barrier deficient Flg/Hrnr -/- mice, but led to significantly delayed swelling in mice with defects in innate or adaptive immune functions (Myd88/Tlr3 -/- , Rag1 -/- ). SLS-induced contact dermatitis differed from classical ACD and ICD, as it elicited less pronounced immune alterations. Skin barrier impairment does not affect SLS-induced contact dermatitis, whereas both innate and adaptive components are involved in SLS skin reactions., (© 2024 Wiley‐VCH GmbH.)

Excessive proliferation of keratinocytes is a crucial pathological risk feature of psoriasis. Focal adhesion kinase (FAK) is a non-receptor protein that primarily regulates cell proliferation and migration. However, the expression and regulatory mechanism of FAK in psoriasis remains unclear. This study aimed to investigate the regulation of FAK in psoriasis and examined the potential impact of FAK inhibitor on psoriasis. A small molecular selective FAK inhibitor, defactinib, was used to evaluate the effect of FAK on psoriasis in in vitro and in vivo functional assays. In our experiments, imiquimod (IMQ)-induced psoriasis mice and human keratinocytes cells were used to study the potential roles and mechanisms of FAK in psoriasis. FAK phosphorylation has been weakly detected in normal intact skin and is markedly elevated upon IMQ treatment. By reducing FAK phosphorylation (p-FAK), defactinib treatment could attenuate psoriasiform inflammation and epidermal hyperplasia in IMQ-treated mice compared with IMQ-induced mice treated with the vehicle. In in vitro studies, resiquimod (R848) increased (p-FAK) and promoted cell proliferation in human keratinocytes cells, while defactinib reversed this effect. Mechanistically, defactinib can alleviate the proliferation via JNK/YB1 pathway in vitro and in vivo. Defactinib significantly attenuates psoriasiform inflammation and epidermal hyperproliferation through the inhibition of the FAK-mediated axis. The downregulation of phosphorylated FAK then suppressed the activation of JNK/YB1 protein signaling pathway in psoriasis. Our work highlights targeting FAK as a potentially effective strategy for the treatment of psoriasis., (© 2024 Japanese Dermatological Association.)

Skin equivalents (SE) that recapitulate biological and mechanical characteristics of the native tissue are promising platforms for assessing cosmetics and studying fundamental biological processes. Methods to achieve SEs with well-organized structure, and ideal biological and mechanical properties are limited. Here, the combination of melt electrowritten PCL scaffolds and cell-laden Matrigel to fabricate SE is described. The PCL scaffold provides ideal structural and mechanical properties, preventing deformation of the model. The model consists of a top layer for seeding keratinocytes to mimic the epidermis, and a bottom layer of Matrigel-based dermal compartment with fibroblasts. The compressive modulus and the biological properties after 3-day coculture indicate a close resemblance with the native skin. Using the SE, a testing system to study the damage caused by UVA irradiation and evaluate antioxidant efficacy is established. The effectiveness of Tea polyphenols (TPs) and L-ascorbic acid (Laa) is compared based on free radical generation. TPs are demonstrated to be more effective in downregulating free radical generation. Further, T1 relaxometry is used to detect the generation of free radicals at a single-cell level, which allows tracking of the same cell before and after UVA treatment., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Background: Accelerated pace of modern work and lifestyles subject individuals to various external and psychological stressors, which, in turn, can trigger additional stress through visible signs of fatigue, hair loss, and obesity. As the primary stress hormone affecting skin health, cortisol connects to the glucocorticoid receptor (GR) to aggravate skin issues induced by stress. This activation depends on the expression of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) in skin cells, which locally converts cortisone-produced by the central and peripheral hypothalamic-pituitary-adrenal axis-into its active form., Methods: Our study delves deeper into stress's adverse effects on the skin, including the disruption of keratinocyte structural proteins, the loss of basement membrane proteins, and the degradation of collagen., Results: Remarkably, we discovered that Ectoin, an amino acid derivative obtained from halophilic bacteria, is capable of mitigating the inhibitory impacts of cortisone on the expression of cutaneous functional proteins, including involucrin, loricrin, laminin-5, and claudin-1. Moreover, Ectoin reduces the suppressive effect of stress on collagen and hyaluronic acid synthesis by impeding GR signal transduction. Additionally, Ectoin counterbalances the UVB-induced overexpression of 11β-HSD1, thereby diminishing the concentration of endogenous glucocorticoids., Conclusion: Our findings illuminate the significant potential of Ectoin as a preventative agent against stress-induced skin maladies., (© 2024 The Author(s). Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

Shikonin, an herbal naphthoquinone, demonstrates a broad spectrum of pharmacological properties. Owing to increasingly adverse environmental conditions, human skin is vulnerable to harmful influences from dust particles. This study explored the antioxidant capabilities of shikonin and its ability to protect human keratinocytes from oxidative stress induced by fine particulate matter (PM 2.5 ). We found that shikonin at a concentration of 3 µM was nontoxic to human keratinocytes and effectively scavenged reactive oxygen species (ROS) while increasing the production of reduced glutathione (GSH). Furthermore, shikonin enhanced GSH level by upregulating glutamate-cysteine ligase catalytic subunit and glutathione synthetase mediated by nuclear factor-erythroid 2-related factor. Shikonin reduced ROS levels induced by PM 2.5 , leading to recovering PM 2.5 -impaired cellular biomolecules and cell viability. Shikonin restored the GSH level in PM 2.5 -exposed keratinocytes via enhancing the expression of GSH-synthesizing enzymes. Notably, buthionine sulphoximine, an inhibitor of GSH synthesis, diminished effect of shikonin against PM 2.5 -induced cell damage, confirming the role of GSH in shikonin-induced cytoprotection. Collectively, these findings indicated that shikonin could provide substantial cytoprotection against the adverse effects of PM 2.5 through direct ROS scavenging and modulation of cellular antioxidant system., (© 2024 The Author(s). Cell Biology International published by John Wiley & Sons Ltd on behalf of International Federation of Cell Biology.)

Background: Skin aging is one of the most abundant aging-related disorders that can be accelerated by excessive exposure to ultraviolet irradiation. Topically applied fermented skincare ingredients have gained mounting attentions due to their high concentration of various skin nourishing nutrients and bioactive components and low skin irritation potency., Aims: In the present study, we aim to fully demonstrate the skin-related benefits of a novel extract of Thermus thermophilus and Bacillus subtilis mixed-culture ferment (TBFE)., Methods: TBFE was prepared through an innovative mixed-culture fermentation process. The contents of nutrients and bioactive ingredients were quantified by different methods accordingly. Both in vitro tests and randomized controlled human trial were utilized to further demonstrate multifaceted beneficial effects on human skin, as well as the potential mechanisms., Results: Our results showed that TBFE upregulated the expression of type IV collagen, elastin, aquaporin-3, and dermal-epidermal junction markers, while inhibited production of melanin, in different skin cell models. Moreover, TBFE inhibited the generation of reactive oxygen species and pro-inflammatory mediators induced by ultraviolet irradiation in normal human keratinocytes, while stimulated autophagy in senescent keratinocytes. Results from clinical studies confirmed those in vitro findings, demonstrating that TBFE at 5% and 20% concentration provides anti-aging properties in subjects with sensitive skin, in terms of improving wrinkles, moisturization, and skin lightening., Conclusions: In summary, we demonstrate that a novel mixed-culture ferment extract has promising anti-aging effects, which may be attributed to anti-oxidation, anti-inflammation, and promotion of autophagy in skin cells., (© 2024 The Author(s). Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

Background/objectives: Particulate matter (PM) is an environmental pollutant that negatively affects human health, particularly skin health. In this study, we investigated the inhibitory effects of broccoli sprout extract (BSE) on PM-induced skin aging and inflammation in human keratinocytes., Methods: HaCaT keratinocytes were pretreated with BSE before exposure to PM. Cell viability was assessed using the MTT assay. The expression of skin aging and inflammation markers (MMP-1, COX-2, IL-6) was measured using Western blot, ELISA, and qRT-PCR. Reactive oxygen species levels were determined using the DCF-DA assay. Kinase assays and pull-down assays were conducted to investigate the interaction between BSE and p38α MAPK., Results: Our findings demonstrate that BSE effectively suppressed the expression of MMP-1, COX-2, and IL-6-critical skin aging and inflammation markers-by inhibiting p38 MAPK activity. BSE binds directly to p38α without competing with ATP, thereby selectively inhibiting its activity and downstream signaling pathways, including MSK1/2, AP-1, and NF-κB., Conclusions: These results suggest that BSE is a potential functional ingredient in skincare products to mitigate PM-induced skin damage.

Despite the abundance of natural biological resources in Aronia melanocarpa, there is still insufficient research specifically exploring the potential for developing cosmeceutical compositions utilizing this plant. To develop the ingredient with the cosmeceutical function, the anti-wrinkle effect of the ethanol extract of A. melanocarpa was investigated. The ethanol extract was prepared from the dried A. melanocarpa. DPPH radical scavenging activity was significantly increased by the ethanol extract of A. melanocarpa. Cell viability on CCD986Sk human fibroblast was not affected by the ethanol extract of A. melanocarpa. Moreover, the ethanol extract of A. melanocarpa demonstrated inhibition of both collagenase and elastase enzymes. Analysis through ELISA and western blotting revealed an elevation in collagen expression levels in CCD986Sk human fibroblasts treated with ethanol extract. Additionally, the extract induced migration and invasion in HaCaT human keratinocytes, potentially associated with the activation of tight junctions. These results offer insights for the development of innovative cosmeceutical formulations utilizing A. melanocarpa extract.

The skin hydration level is a key factor that influences the physical and mechanical properties of the skin. The stratum corneum (SC), the outermost layer of the epidermis, is responsible for the skin's barrier function. In this study, we investigated the role of a unique composition of Viola yedoensis extract for its ability to activate CD44, a cell-surface receptor of hyaluronic acid, and aquaporin-3, a water-transporting protein, in human keratinocytes (HaCaT). An ELISA assay evaluating the protein expression levels of CD44, aquaporin-3 (AQP3), filaggrin, and keratin-10 revealed that V. yedoensis extract upregulated the levels of CD44 and AQP3 by 15% and 78%, respectively. Additionally, V. yedoensis extract demonstrated a comparative effect on water vapor flux in TEWL and lipid perturbation in DSC versus the reference, glycerin. In light of this new biological efficacy, a detailed phytochemical characterization was undertaken using an integrated LC-HRMS/MS-based metabolomics approach, which provided further insights on the chemistry of V. yedoensis . This led to the identification of 29 secondary metabolites, 14 of which are reported here for the first time, including esculetin, aesculin, apigenin and kaempferol C-glycosides, megastigmane glycosides, roseoside, platanionoside B, and an eriojaposide B isomer, along with the rare, calenduloside F and esculetin diglucoside, which are reported for the first time from the genus, Viola . Notably, two active components identified in the V. yedoensis extract, namely, aesculin and schaftoside, showed an upregulation of the protein expression of CD44 in HaCaT cells by 123% and 193% within 24 h of treatment, respectively, while aesculin increased AQP3 levels by 46%. Aesculin and schaftoside also significantly upregulated the expression of K-10 levels by 299% and 116%, which was considerably higher than sodium hyaluronate, the positive control. The rationale used to characterize the new structures is outlined along with the related biosynthetic pathways envisioned to generate roseoside and Eriojaposide B. These findings provide new molecular insights to deepen the understanding of how V. yedoensis extract, along with the biomarkers aesculin and schaftoside, restores the skin barrier and skin hydration benefits.

Here, we investigated the potential interaction between bromodomain-containing protein 4 (BRD4), an established epigenetic modulator and transcriptional coactivator, and p63, a member of the p53 transcription factor family, essential for epithelial development and skin homeostasis. Our protein-protein interaction assays demonstrated a strong and conserved physical interaction between BRD4 and the p53 family members-p63, p73, and p53-suggesting a shared binding region among these proteins. While the role of BRD4 in cancer development through its interaction with p53 has been explored, the effects of BRD4 and Bromodomain and Extra Terminal (BET) inhibitors in non-transformed cells, such as keratinocytes, remain largely unknown. Our functional analyses revealed changes in cellular proliferation and differentiation in keratinocytes depleted of either p63 or BRD4, which were further supported by using the BRD4 inhibitor JQ1. Transcriptomic analyses, chromatin immunoprecipitation, and RT-qPCR indicated a synergistic mechanism between p63 and BRD4 in regulating the transcription of keratinocyte-specific p63 target genes, including HK2, FOXM1, and EVPL. This study not only highlights the complex relationship between BRD4 and p53 family members but also suggests a role for BRD4 in maintaining keratinocyte functions. Our findings pave the way for further exploration of potential therapeutic applications of BRD4 inhibitors in treating skin disorders., Competing Interests: Declarations. Ethics approval and comsent to participate: Not applicable., (© 2024. The Author(s).)

Background: Photoaging, induced by chronic ultraviolet B (UVB) exposure, results in the degradation of extracellular matrix (ECM) components, leading to skin roughness, wrinkle formation, and reduced elasticity. Recent studies have explored probiotics as potential inhibitors of extrinsic aging, primarily through mechanisms that protect the skin barrier and reduce collagen breakdown., Methods: This study investigates the anti-photoaging effects of Limosilactobacillus fermentum MG5368 ( L. fermentum MG5368) and Lactiplantibacillus plantarum MG989 ( L. plantarum MG989) in UVB-exposed keratinocytes and an SKH-1 hairless mice model., Results: Both strains demonstrated significant efficacy in preserving collagen through the inhibition of activating protein-1 (AP-1) and reducing the expression of matrix metalloproteinase (MMP)-1 and MMP-3. Additionally, both strains restored COL1A1 protein expressions, thereby enhancing collagen synthesis and ECM stability. Enhanced skin elasticity was observed, attributed to restored levels of hyaluronic acid and hyaluronan synthase 2 (HAS2) protein expressions., Conclusions: These findings suggest that L. fermentum MG5368 and L. plantarum MG989 may serve as promising probiotic-based agents for anti-photoaging applications.