Ultraviolet B regulation of transcription factor families: roles of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1) in UVB-induced skin carcinogenesis

Seabuckthorn (Hippophae rhamnoides, L.) pulp oil prevents ultraviolet-induced damage in human fibroblasts

Seabuckthorn pulp oil (SBO) is used in beauty products because of its rich lipophilic substances with high nutraceutical and cosmeceutical potential. However, the mechanism through which SBO enhances skin elasticity remains unclear. Therefore, in this study, we examined the anti-photoaging activity of SBO in normal human dermal fibroblasts (NHDF) under ultraviolet (UV) irradiation. Pretreatment with SBO significantly suppressed UV-B-induced cell toxicity and collagen degradation, suggesting that SBO contains anti-photoaging substances. Further, palmitoleic acid, the main component of SBO, maintained cell viability and collagen levels in UV-B-irradiated NHDF by suppressing the expression of matrix metalloproteinase 1 and acted on the inhibition of p38 and JNK phosphorylation and nuclear translocation of nuclear factor-kappa B. These findings suggest the utility of SBO as an anti-photoaging agent.

Seabuckthorn pulp extract alleviates UV-B-induced skin photo-damage by significantly reducing oxidative stress-mediated endoplasmic reticulum stress and DNA Damage in human primary skin fibroblasts and Balb/c mice skin

Skin homeostasis is predominantly compromised by exposure to UV-B irradiation, leading to several physiopathological processes at cellular and tissue levels that deteriorate skin function and integrity. The current study investigated the photo-protective role of seabuckthorn fruit pulp (SBT) extract against UV-B-induced damage in primary human skin fibroblasts (HDFs) and Balb/C mice skin. We subjected HDFs and Balb/C mice to UV-B irradiation and measured multiple cellular damage indicators. We found that UV-B-irradiated HDFs treated with SBT had a considerably greater survival rate than cells exposed to UV-B radiation alone. The UV-B irradiation-induced ROS generation led to the degradation of the extracellular matrix, inflammation, DNA damage, endoplasmic reticulum (ER) stress, and apoptosis. SBT treatment significantly reduced these manifestations. Topical application of SBT alleviated UV-B-induced epidermal thickening, leukocyte infiltration, and degradation of extracellular matrix in Balb/c mice skin. Based on our results, we conclude that SBT has the potential to be developed as a therapeutic/cosmetic remedy for the prevention of skin photo-damage.

Study of biomarkers p53, Ki-67, Bcl-2, and VEGF in pterygium

PURPOSE

To study the biomarkers present in primary pterygium samples of patients of Indian ethnicity and compare it with the samples obtained from the unaffected conjunctiva of the same eye.

METHODS

A prospective case-control study of 17 eyes in patients above 10 years of age with primary pterygium who underwent pterygium excision using limbal conjunctival autograft technique. The pterygium samples (cases) and conjunctival samples (controls) were sent for immunohistochemical (IHC) staining for the following biomarkers: p53, Bcl-2, Ki-67, and vascular endothelial growth factor (VEGF).

RESULT

The immunohistochemistry of the samples and the controls revealed p53 positivity in 47.05% of pterygium samples and 29.4% of controls ( P < 0.587). Nine cases each in pterygium and control samples were positive for Ki-67 expression. Differences in the staining pattern between the two groups were not statistically significant ( P < 1.000). Bcl-2 positivity was seen in 10 pterygium samples (58.8%) and 12 controls (70.5%), with no statistical difference between the two groups ( P < 0.455). VEGF expression was seen in both epithelial and endothelial cells of the samples and controls, with no statistical difference between the two groups, with P = 1.000 for the epithelial staining and P = 0.637 for endothelial staining.

CONCLUSION

The expression of biomarkers was comparable in both groups. We conclude that pterygium, against common belief, might not be a localized disease process but a global ocular phenomenon where the apparently healthy tissue also has some ongoing disease process at a molecular level.

Combination of red ginseng and velvet antler extracts prevents skin damage by enhancing the antioxidant defense system and inhibiting MAPK/AP-1/NF-κB and caspase signaling pathways in UVB-irradiated HaCaT keratinocytes and SKH-1 hairless mice

Background

Studies have reported that the combination of two or more therapeutic compounds at certain ratios has more noticeable pharmaceutical properties than single compounds and requires reduced dosage of each agent. Red ginseng and velvet antler have been extensively used in boosting immunity and physical strength and preventing diseases. Thus, this study was conducted to elucidate the skin-protective potentials of red ginseng extract (RGE) and velvet antler extract (VAE) alone or in combination on ultraviolet (UVB)-irradiated human keratinocytes and SKH-1 hairless mice.

Methods

HaCaT cells were preincubated with RGE/VAE alone or in combination for 2 h before UVB (30 mJ/cm2) irradiation. SKH-1 mice were orally given RGE/VAE alone or in combination for 15 days before exposure to single dose of UVB (600 mJ/cm2). Treated cells and treated skin tissues were collected and subjected to subsequent experiments.

Results

RGE/VAE pretreatment alone or in combination significantly prevented UVB-induced cell death, apoptosis, reactive oxygen species production, and DNA damage in keratinocytes and SKH-1 mouse skins by downregulating mitogen-activated protein kinases/activator protein 1/nuclear factor kappa B and caspase signaling pathways. These extracts also strengthened the antioxidant defense systems and skin barriers in UVB-irradiated HaCaT cells and SKH-1 mouse skins. Furthermore, RGE/VAE co-administration appeared to be more effective in preventing UVB-caused skin injury than these extracts used alone.

Conclusion

Overall, these findings suggest that the consumption of RGE/VAE, especially in combination, offers a protective ability against UVB-caused skin injury by preventing inflammation and apoptosis and enhancing antioxidant capacity.

Feasibility analysis of inactivating influenza A(H1N1) virus using UVC robot in classroom environment

Background

Starting from 2009, H1N1 has been one of the respiratory diseases that afflict the global population. Concurrently, due to the influence of COVID-19, it has become widely accepted that preventing the virus's spread necessitates personal protection measures and disinfection in public spaces.

Experiments

This study conducted two experiments. In the classroom experiment, six UVC dose test points were calibrated to test whether the UVC dose at each testing point met the standards for inactivating IAVs and the time required to meet the standards. In the simulated classroom experiment, seven square slides made of IAVs were placed. After 10 min of robot movement, irradiated sterile square slides were made into suspension and injected into chicken embryos. Cultivate chicken embryos and conduct IAVs testing.

Results

Classroom experiment has shown that 5 testing points can meet the standards for inactivating IAVs(3 mJ/cm2), with a required time of 80 min, 40 min, 15 min, 5 min and 10 min. The UVC dose for testing points that do not meet the standards in 80 min is only 0.5 mJ/cm2. The simulation classroom experiment outcomes revealed that 99.99 % of IAVs were deactivated. Furthermore, this study established both a desktop control group and a chair arm control group, both of which yielded identical results, indicating an inactivation logarithm of IAVs≥4log.

Conclusion

The study presented that IAVs on the surface of an object can be effectively and rapidly deactivated at an irradiation density of 1.8 mW/cm2. Meanwhile, the study provides evidence of the feasibility of using the GXU robot to inactivate IAVs in a classroom environment.

Inhibition of UV-Induced Stress Signaling and Inflammatory Responses in SKH-1 Mouse Skin by Topical Small-Molecule PD-L1 Blockade

The immune checkpoint ligand PD-L1 has emerged as a molecular target for skin cancer therapy and might also hold promise for preventive intervention targeting solar UV light-induced skin damage. In this study, we have explored the role of PD-L1 in acute keratinocytic photodamage testing the effects of small-molecule pharmacological inhibition. Epidermal PD-L1 upregulation in response to chronic photodamage was established using immunohistochemical and proteomic analyses of a human skin cohort, consistent with earlier observations that PD-L1 is upregulated in cutaneous squamous cell carcinoma. Topical application of the small-molecule PD-L1 inhibitor BMS-202 significantly attenuated UV-induced activator protein-1 transcriptional activity in SKH-1 bioluminescent reporter mouse skin, also confirmed in human HaCaT reporter keratinocytes. RT-qPCR analysis revealed that BMS-202 antagonized UV induction of inflammatory gene expression. Likewise, UV-induced cleavage of procaspase-3, a hallmark of acute skin photodamage, was attenuated by topical BMS-202. NanoString nCounter transcriptomic analysis confirmed downregulation of cutaneous innate immunity- and inflammation-related responses, together with upregulation of immune response pathway gene expression. Further mechanistic analysis confirmed that BMS-202 antagonizes UV-induced PD-L1 expression both at the mRNA and protein levels in SKH-1 epidermis. These data suggest that topical pharmacological PD-L1 antagonism using BMS-202 shows promise for skin protection against photodamage.

Photoprotective Effects of Processed Ginseng Leaf Administration against UVB-Induced Skin Damage in Hairless Mice

Although ginseng leaves contain a larger amount of ginsenosides than the roots, studies on the protective effect of oral administration of ginseng leaves against photoaging are lacking. Processed ginseng leaves (PGL) prepared by acid reaction to increase effective ginsenoside content showed higher levels of Rg3 (29.35 mg/g) and Rk1 (35.16 mg/g) than ginseng leaves (Rg3 (2.14 mg/g) and Rk1 (ND)), and ginsenosides Rg3 and Rk1 were evaluated as active ingredients that protected human keratinocytes against UVB-induced cell damage by increasing cell proliferation and decreasing matrix metalloproteinase (MMP)-2 and 9 secretion. Herein, the effect of oral PGL administration (50, 100, or 200 mg/kg, daily) against photoaging in HR-1 hairless mice was assessed by measuring wrinkle depth, epidermal thickness, and trans-epidermal water loss for 16 weeks. The PGL treatment group showed reduced skin wrinkles, inhibited MMP-2 and MMP-9 expression, and decreased IL-6 and cyclooxygenase-2 levels. These data suggest that oral PGL administration inhibits photoaging by inhibiting the expression of MMPs, which degrade collagen, and inhibiting cytokines, which induce inflammatory responses. These results reveal that ginseng leaves processed by acid reaction may serve as potential functional materials with anti-photoaging activities.

Bone marrow mesenchymal stem cell-derived exosome miR-29b-3p alleviates UV irradiation-induced photoaging in skin fibroblast

BACKGROUND

Mesenchymal stem cells-derived exosome (MSCs-exo) was identified to reduce photoaging. The purpose of this study was to investigate the potential role of microRNA (miR)-29b-3p derived from bone marrow MSCs-exo (BMSCs-exo) in photoaging.

METHODS

Exosomes were isolated from BMSCs and verified by Western blot. A photoaging cell model was constructed by UVB irradiation of human dermal fibroblasts (HDFs). Quantitative real-time PCR (RT-qPCR) was performed to detect the mRNA levels of miR-29b-3p, collagen type I and matrix metalloproteinases (MMPs). CCK-8, Transwell and flow cytometry were applicated to examine cell viability, migration and apoptosis. Commercial kits are used to measure levels of oxidative stress indicators. Finally, a dual-luciferase reporter assay was applied to validate the target of miR-29b-3p.

RESULTS

Extracted exosomes were positive for HSP70 and CD9. Survival of HDFs increased in an exosome concentration-dependent manner. UVB irradiation inhibited miR-29b-3p levels compared with controls, but BMSCs-exo treatment restored miR-29b-3p levels (p < .05). Additionally, BMSCs-exo-miR-29b-3p reversed the inhibition of HDFs migration and oxidative stress by UVB irradiation, as well as the promotion of apoptosis. However, this reversal was attenuated by the suppression of miR-29b-3p (p < .05). Furthermore, BMSCs-exo-miR-29b-3p also inhibited the degradation of collagen type I and the production of MMPs in photoaging, and they were also eliminated by the reduced miR-29b-3p. Finally, MMP-2 was the target gene of miR-29b-3p.

CONCLUSION

Our study presented a novel role for BMSCs-exo-miR-29b-3p in improving skin photoaging function, and these findings may provide new insights into the targeted treatment of skin photoaging.

Preparation of CPD Photolyase Nanoliposomes Derived from Antarctic Microalgae and Their Effect on UVB-Induced Skin Damage in Mice

UVB radiation is known to trigger the block of DNA replication and transcription by forming cyclobutane pyrimidine dimer (CPD), which results in severe skin damage. CPD photolyase, a kind of DNA repair enzyme, can efficiently repair CPDs that are absent in humans and mice. Although exogenous CPD photolyases have beneficial effects on skin diseases, the mechanisms of CPD photolyases on the skin remain unknown. Here, this study prepared CPD photolyase nanoliposomes (CPDNL) from Antarctic Chlamydomonas sp. ICE-L, which thrives in harsh, high-UVB conditions, and evaluated their protective mechanisms against UVB-induced damage in mice. CPDNL were optimized using response surface methodology, characterized by a mean particle size of 105.5 nm, with an encapsulation efficiency of 63.3%. Topical application of CPDNL prevented UVB-induced erythema, epidermal thickness, and wrinkles in mice. CPDNL mitigated UVB-induced DNA damage by significantly decreasing the CPD concentration. CPDNL exhibited antioxidant properties as they reduced the production of reactive oxygen species (ROS) and malondialdehyde. Through activation of the NF-κB pathway, CPDNL reduced the expression of pro-inflammatory cytokines including IL-6, TNF-α, and COX-2. Furthermore, CPDNL suppressed the MAPK signaling activation by downregulating the mRNA and protein expression of ERK, JNK, and p38 as well as AP-1. The MMP-1 and MMP-2 expressions were also remarkably decreased, which inhibited the collagen degradation. Therefore, we concluded that CPDNL exerted DNA repair, antioxidant, anti-inflammation, and anti-wrinkle properties as well as collagen protection via regulation of the NF-κB/MAPK/MMP signaling pathways in UVB-induced mice, demonstrating that Antarctic CPD photolyases have the potential for skincare products against UVB and photoaging.

Rosa davurica inhibits skin photoaging via regulating MAPK/AP-1, NF-κB, and Nrf2/HO-1 signaling in UVB-irradiated HaCaTs

Rosa davurica is widely used to treat various kinds of diseases because of its high antioxidant, antiviral and anti-inflammatory activities. This use of plant-based materials as medicine is called phytomedicine and has been widely practiced since time immemorial. However, the pharmacological mechanism of R. davurica in skin photoaging is not yet fully understood. Therefore, this study was carried out to evaluate the recovery effects of R. davurica leaf extracts (RDE) in UVB-irradiated human skin keratinocytes (HaCaTs) and investigate whether RDE is a potential therapeutic agent against skin photoaging. The expression of aging-related markers including mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1), nuclear factor-κB (NF-κB), and nuclear factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) was evaluated using Western blot analysis. The reactive oxygen species (ROS) was also used by FACS in HaCaTs. Findings indicated that RDE is efficient in scavenging free radicals and dose-dependently reducing ROS generation. Furthermore, RDE notably decreased UVB-induced matrix metalloproteinase-1 (MMP-1) expression through inhibition of MAPK/AP-1 and NF-κB signaling pathways as well as induced blocking of extracellular matrix (ECM) degradation in UVB-irradiated HaCaTs. In addition, RDE improved Nrf2/HO-1 signaling that increases oxidative defense capacity and enhances transforming growth factor-beta (TGF-β) signaling activation to promote procollagen type I synthesis, relieving UVB-induced skin cell damage. In conclusion, the protective effects of RDE on skin cellular components suggest that it has a high biological potential for skin protection from UVB-induced skin photoaging and is a good candidate for drug and cosmetic application.

Targeting oncogenic transcription factors in skin malignancies: An update on cancer stemness and therapeutic outcomes

The skin is the largest organ of the human body and prone to various diseases, including cancer; thus, provides the first line of defense against exogenous biological and non-biological agents. Skin cancer, a complex and heterogenic process, with steep incidence rate often metastasizes due to poor understanding of the underlying mechanisms of pathogenesis and clinical challenges. Indeed, accumulating evidence indicates that deregulation of transcription factors (TFs) due to genetic, epigenetic and signaling distortions plays essential role in the development of cutaneous malignancies and therapeutic challenges including cancer stemness features and reprogramming. This review highlights the recent developments exploring underlying mechanisms how deregulated TFs (e.g., NF-κB, AP-1, STAT etc.,) orchestrates cutaneous onco-pathogenesis, reprogramming, stemness and poor clinical outcomes. Along this line, bioactive drugs, and their derivatives from natural and or synthetic origin has gained attention due to their multitargeting potential, potentially safer and effective therapeutic outcome for human malignancies. We also discussed therapeutic importance of targeting aberrantly expressed TFs in skin cancers with bioactive natural products and or synthetic agents.

Streptomyces spp. Isolated from Rosa davurica Rhizome for Potential Cosmetic Application

Streptomyces species are widely studied and used in different fields, including antibiotics and pesticides, and are spread in several places as soil-derived microorganisms. However, research on anti-aging, including antioxidants obtained from Streptomyces, has not been performed as much. Skin aging due to bacterial infection, especially methicillin-resistant Staphylococcus aureus (MRSA), is challenging to recover, so it is essential to prevent aging by preventing or inhibiting infection. Therefore, this study was conducted to isolate Streptomyces species from Rosa davurica rhizome soil and to determine the effect of the ethyl acetate extract of the isolated strain Streptomyces chattanoogensis THA-663 (THA-663S) on the inhibition of MRSA and UVB-irradiated human skin keratinocytes, to determine whether it could be a treatment for skin aging. The MRSA inhibition and antioxidant activities were evaluated using disc diffusion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), and a reactive oxygen species (ROS) assay. The expression of aging-related markers, including mitogen-activated protein kinases/activator protein 1 (MAPK)/AP-1) and transforming growth factor-β/suppressor of mothers against decapentaplegic (TGF-β/Smad) was assessed using Western blotting. The antibacterial effect on four MRSA strains, CCARM 0204, CCARM 0205, CCARM 3855, and CCARM 3089, showed that THA-663S could greatly inhibit MRSA growth. Moreover, the findings showed that THA-663S is efficient in scavenging free radicals and dose-dependently reducing ROS generation. Furthermore, THA-663S notably reduced UVB-induced matrix metalloproteinase-1 (MMP-1) expression by inhibiting the MAPK/AP-1 signaling pathways and blocking extracellular matrix (ECM) degradation in UVB-irradiated HaCaT cells. Additionally, THA-663S improved and enhanced transforming growth factor-beta (TGF-β) signaling activation to promote procollagen type I synthesis, relieving UVB-induced skin cell damage. In conclusion, THA-663S has a high potential to protect skin cells from aging, and, simultaneously, it can prevent or treat aging caused by infection due to pathogen inhibition.

Naphthoquinones and derivatives as potential anticancer agents: An updated review

One of the leading global causes of death is cancer; even though several treatment methods have improved survival rates, the incidence and fatality rates remain high. Naphthoquinones are a type of quinone that is found in nature and has vital biological roles. These chemicals have anticancer (antineoplastic), analgesic, anti-inflammatory, antimalarial, antifungal, antiviral, antitrypanosomal, antischistosomal, leishmanicidal, and anti-ulcerative effects. Direct addition of a substituent group to the 1,4-naphthoquinone ring can alter the naphthoquinone's oxidation/reduction and acid/base characteristics, and the activity can be altered. Because of their pharmacological properties, such as anticancer activity and probable therapeutic application, naphthoquinones have greatly interested the scientific community. Some chemicals having a quinone ring in malignant cells have been found to have antiproliferative effects. Naphthoquinones' deadly impact is connected with the inhibition of electron transporters, the uncoupling of oxidative phosphorylation, the creation of ROS, and the formation of protein adducts, notably with -SH enzyme groups. This review article aims to discuss naphthoquinones and their derivatives, which act against cancer and their future perspectives. This review covers several studies highlighting the potent anticancer properties of naphthoquinones. Further, various proposed mechanisms of anticancer actions of naphthoquinones have been summarized in this review.

NRF2 in dermatological disorders: Pharmacological activation for protection against cutaneous photodamage and photodermatosis

The skin barrier and its endogenous protective mechanisms cope daily with exogenous stressors, of which ultraviolet radiation (UVR) poses an imminent danger. Although the skin is able to reduce the potential damage, there is a need for comprehensive strategies for protection. This is particularly important when developing pharmacological approaches to protect against photocarcinogenesis. Activation of NRF2 has the potential to provide comprehensive and long-lasting protection due to the upregulation of numerous cytoprotective downstream effector proteins that can counteract the damaging effects of UVR. This is also applicable to photodermatosis conditions that exacerbate the damage caused by UVR. This review describes the alterations caused by UVR in normal skin and photosensitive disorders, and provides evidence to support the development of NRF2 activators as pharmacological treatments. Key natural and synthetic activators with photoprotective properties are summarized. Lastly, the gap in knowledge in research associated with photodermatosis conditions is highlighted.

Oxidative-Stress-Sensitive microRNAs in UV-Promoted Development of Melanoma

Simple Summary

Exposure to ultraviolet (UV) rays from the sun is one of the most important modifiable risk factors for skin cancer. Melanoma is the most life-threatening type of skin cancer. UV-induced DNA damage and oxidative stress represent two main mechanisms that, directly and indirectly, contribute to melanomagenesis. In addition, an interplay of abnormally expressed microRNAs (miRNAs) and redox imbalance is a hallmark in several cancers, including melanoma. UV radiation can be the central hub between these two cellular aberrations, as it is able to stimulate both. Here, to gain new mechanistic insights into melanomagenesis and identify new therapeutic targets for the prevention and treatment of melanoma, we report current evidence suggesting a complex interaction between UV-promoted deregulation of redox-sensitive miRNAs and known signal-transduction pathways underlying malignant transformation of melanocytes to melanoma.

Abstract

Melanoma is the most aggressive and life-threatening form of skin cancer. Key molecular events underlying the melanocytic transformation into malignant melanoma mainly involve gene mutations in which exposure to ultraviolet (UV) radiation plays a prominent role. However, several aspects of UV-induced melanomagenesis remain to be explored. Interestingly, redox-mediated signaling and perturbed microRNA (miRNA) profiles appear to be interconnected contributing factors able to act synergistically in melanoma initiation and progression. Since UV radiation can promote both redox imbalance and miRNA dysregulation, a harmful crosstalk between these two key cellular networks, with UV as central hub among them, is likely to occur in skin tissue. Therefore, decoding the complex circuits that orchestrate the interaction of UV exposure, oxidative stress, and dysregulated miRNA profiling can provide a deep understanding of the molecular basis of the melanomagenesis process. Furthermore, these mechanistic insights into the reciprocal regulation between these systems could have relevant implications for future therapeutic approaches aimed at counteracting UV-induced redox and miRNome imbalances for the prevention and treatment of malignant melanoma. In this review, we illustrate current information on the intricate connection between UV-induced dysregulation of redox-sensitive miRNAs and well-known signaling pathways involved in the malignant transformation of normal melanocytes to malignant melanoma.

Nuclear factor-kappa B and effector molecules in photoaging

Nuclear factor-kappa B (NF-κB) has important but complex functions in the photoaging of the human skin. This protein complex is activated upon UV irradiation and plays a key role in the signalling pathway of the inflammatory cascade. NF-κB induces the expression of various proinflammatory cytokines, such as tumour necrosis factor (TNF) and interleukin-1 (IL-1). These proinflammatory cytokines can in turn stimulate the activation of NF-κB, forming a vicious cycle. These processes cause chronic inflammation and contribute to skin ageing. In addition, the activation of NF-κB upregulates the expression of matrix metalloproteinases (MMPs) and leads to the degradation of structural proteins in the dermis. NF-κB disrupts the barrier function of the skin under prolonged and repeated UV stimulations in these ways. Such activity causes chronic skin damage, followed by the formation of wrinkles, dryness, roughness, laxity, and other photoaging manifestations. This study on the NF-κB signalling pathway and effector molecules provides a new perspective to understand and prevent photoaging.

Are TRPA1 and TRPV1 channel-mediated signalling cascades involved in UVB radiation-induced sunburn?

Burn injuries are underappreciated injuries associated with substantial morbidity and mortality. Overexposure to ultraviolet (UV) radiation has dramatic clinical effects in humans and is a significant public health concern. Although the mechanisms underlying UVB exposure are not fully understood, many studies have made substantial progress in the pathophysiology of sunburn in terms of its molecular aspects in the last few years. It is well established that the transient receptor potential ankyrin 1 (TRPA1), and vanilloid 1 (TRPV1) channels modulate the inflammatory, oxidative, and proliferative processes underlying UVB radiation exposure. However, it is still unknown which mechanisms underlying TRPV1/A1 channel activation are elicited in sunburn induced by UVB radiation. Therefore, in this review, we give an overview of the TRPV1/A1 channel-mediated signalling cascades that may be involved in the pathophysiology of sunburn induced by UVB radiation. These data will undoubtedly help to explain the various features of sunburn and contribute to the development of novel therapeutic approaches to better treat it.

The Potential Anti-Photoaging Effect of Photodynamic Therapy Using Chlorin e6-Curcumin Conjugate in UVB-Irradiated Fibroblasts and Hairless Mice

Photodynamic therapy (PDT) has been used to treat cancers and non-malignant skin diseases. In this study, a chlorin e6–curcumin conjugate (Ce6-PEG-Cur), a combination of chlorin e6 (Ce6) and curcumin via a PEG linker, was used as a photosensitizer. The in vitro and in vivo effects of PDT using Ce6-PEG-Cur were analyzed in UVB-irradiated fibroblasts and hairless mice. The UVB-induced expression of MMPs was reduced in Hs68 fibroblast cells, and procollagen type Ⅰ expression was enhanced by Ce6-PEG-Cur-mediated PDT on a Western blotting gel. Moreover, UVB-induced collagen levels were restored upon application of Ce6-PEG-Cur-mediated PDT. Ce6-PEG-Cur-mediated PDT inhibited the expression of phosphorylated p38 in the MAPK signaling pathway, and it reduced the expression of phosphorylated NF-κB. In animal models, Ce6-PEG-Cur-mediated PDT inhibited the expression of MMPs, whereas procollagen type Ⅰ levels were enhanced in the dorsal skin of UVB-irradiated mice. Moreover, UVB-induced dorsal roughness was significantly reduced following Ce6-PEG-Cur-mediated PDT treatment. H&E staining and Masson’s trichrome staining showed that the thickness of the epidermal region was reduced, and the density of collagen fibers increased. Taken together, Ce6-PEG-Cur-mediated PDT might delay and improve skin photoaging by ultraviolet light, suggesting its potential for use as a more effective photo-aging treatment.

Clinical Evidence of Effects of Green Mandarin (Putgyul) Extract on Skin Aging: A Randomized, Double Blind, Placebo-Controlled Study

Green mandarins are widely consumed unripe as mandarin oranges (Citrus unshiu Marcov.), which exhibit anti-inflammatory and anti-wrinkle effects by inhibiting the production of inflammatory cytokines and matrix metalloproteinase. A randomized, double-blind, placebo-controlled clinical study was performed to verify the skin improvement efficacy and safety of green mandarin extract (PTE). For the standardization of PTE, narirutin was set as a marker compound, and PTE with a constant narirutin content was prepared for the study. After randomizing subjects with periorbital wrinkles, they were orally administered PTE (300 mg/day) or a placebo for 12 weeks. Periorbital wrinkles were measured using PRIMOS^CR SF. Skin elasticity, moisture content, transepidermal water loss, and gloss were also measured. In the study results, the depth, volume, and skin roughness of the periorbital wrinkles were significantly improved compared to the control group (p = 0.011, 0.009, and 0.004, respectively). The survey confirmed that the skin condition improved after PTE consumption for 12 weeks. No adverse reactions associated with PTE were observed during the study period. Thus, the results demonstrate that PTE effectively improves UV-induced skin wrinkles. Therefore, it is considered that PTE has sufficient value as a functional food ingredient that can prevent skin aging.

Reparative Effects of Dandelion Fermentation Broth on UVB-Induced Skin Inflammation

Objective

To evaluate the efficacy of the dandelion fermentation broth in repairing UVB-induced skin inflammation.

Methods

Detection of active ingredients in dandelion fermentation broth and water extract. The antioxidant capacity of dandelion fermentation broth was investigated by in vitro antioxidant experiments. The influence of the broth on the content of inflammatory factors interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-1β (IL-1β), and tumor necrosis factor (TNF-α), in human immortalized epidermal cells (HaCaT) is discussed on the basis of a UVB-induced HaCaT damage model. The effects of the broth on the contents of skin barrier-related proteins kallikrein-7 (KLK-7), filaggrin (FLG) and aquaporin (AQP3) in the UVB-induced damage and repair of the HaCaT mechanism are also comprehensively discussed. The effect of DF on the activation of MAPK pathway proteins was detected by PCR. A chicken embryo chorioallantoic membrane test is used to explore the safety of the dandelion fermentation broth.

Results

The results show that the dandelion fermentation broth is rich inTotal sugar, with good free radical scavenging ability and antioxidant effects; it can regulate the MAPK pathway, reduce the expression of inflammatory factors, adjust the skin barrier factors and good safety.

Conclusion

Dandelion fermentation broth exhibits repairing effect on UVB-induced skin inflammation.

Herbal products as skincare therapeutic agents against ultraviolet radiation-induced skin disorders

This paper aims to highlight the pharmacological aspects of listed herbal skincare products used for the treatment of various disorders caused due to ultraviolet radiation. The pharmacological aspects include safety and efficacy validation as per regulatory guidelines following internationally accepted scientific principles for their development of skincare products. Herbal products have always been used traditionally for the treatment of various skin ailments and have become more prevalent because of their safety and high efficacy benefits. The incorporation of synthetic molecules and chemical substances in the different medicinal and pharmaceutical formulations is the leading cause of the dermal toxicity. Therefore, the developments of herbal skincare products containing scientifically validated herbal ingredients have better acceptance, respect, and belief in the society. The listed herbal products in this review can help take forward the commercial development of skincare products for therapeutic as well as beauty care purposes from such plants.

In Vitro Photoprotective, Anti-Inflammatory, Moisturizing, and Antimelanogenic Effects of a Methanolic Extract of Chrysophyllum lucentifolium Cronquist

UVB exposure causes DNA mutation and ROS generation, which lead to skin photoaging, skin wrinkling, skin sagging, and uneven skin pigmentation. ROS activate the NF-κB and MAPK signaling pathways leading to production of inflammatory molecules such as COX-2, collagen-degrading proteins such as matrix metalloproteinases (MMPs), and moisture-deficiency-related proteins such as hyaluronidases (HYALs). UVB exposure also induces irregular skin pigmentation though melanin overproduction, related to CREB transcription factor activity and transcription of melanogenesis genes. Here, we demonstrate that Chrysophyllum lucentifolium methanol extract (Cl-ME) has antioxidant activity; it dose-dependently decreased the expression of COX-2, MMP-1, MMP-9, HYAL-1, and HYAL-4 by downregulating the NF-κB (IKKα/β, IκBα) and MAPK (ERK, JNK, and p38) pathways and increased the expression of Col1a1, which encodes a protein important for maintaining skin elasticity. Cl-ME also showed promising antimelanogenic activity by decreasing the expression of CREB, a transcription factor, which in turn inhibited the expression of genes encoding tyrosinase, MITF, TYRP1, and TYRP2. In summary, a methanol extract of C. lucentifolium exhibited antiphotoaging and antimelanogenic activity and could be useful in the cosmeceutical industry.

Photoprotective Effects of a Hyperoside-Enriched Fraction Prepared from Houttuynia cordata Thunb. on Ultraviolet B-Induced Skin Aging in Human Fibroblasts through the MAPK Signaling Pathway

Ultraviolet-B (UVB) irradiation causes skin damage via deleterious effects including oxidative stress, inflammation, and collagen degradation. The photoprotective effects of a hyperoside-enriched fraction obtained from Houttuynia cordata Thunb. (H. cordata) on the attenuation of UVB-induced skin aging in human fibroblasts were investigated. The solvent-partition technique was used to establish the hyperoside-enriched fraction of H. cordata (HcEA). The active compounds identified in the H. cordata extracts were hyperoside, quercitrin, chlorogenic acid, and rutin. With regard to the photoprotective effects of H. cordata on UVB-irradiated dermal fibroblasts, HcEA and hyperoside inhibited intracellular ROS production and inflammatory cytokine secretions (IL-6 and IL-8), while increasing collagen type I synthesis along with downregulating MMP-1 gene and protein expressions. Mechanistically, the hyperoside-enriched fraction obtained from H. cordata inhibited UVB-irradiated skin aging through regulation of the MAPK signaling pathway by attenuating the activation of JNK/ERK/c-Jun in human dermal fibroblasts. The hyperoside-enriched fraction of H. cordata exerted potent anti-skin aging properties against UVB exposure. The findings of this study can be applied in the cosmetics industry, as H. cordata extract can potentially be used in pharmaceutical or cosmetic formulations as a photoprotective or anti-skin aging agent.

Antiphotoaging properties of Zingiber montanum essential oil isolated by solvent-free microwave extraction against ultraviolet B-irradiated human dermal fibroblasts

Maintaining youthful skin from photoaging with natural products, including essential oils, is a vital strategy that has piqued the interest of researchers in the pharmaceutical and cosmetic industries. This research aimed to investigate the protective properties of Zingiber montanum (J. Koenig) Link ex A. Dietr. essential oil against ultraviolet B (UVB)-induced skin damage and photoaging in normal human dermal fibroblast (HDFn) cells. The essential oil was extracted from fresh plant rhizomes using solvent-free microwave extraction. Its antiphotoaging properties in HDFn cells were investigated using reactive oxygen species (ROS)-scavenging, wound healing, matrix metalloproteinases (MMP-1, MMP-3, and MMP-9) expression, procollagen synthesis, and elastase and tyrosinase inhibitory assays. The results showed that the test oil exhibited no significant toxicity in HDFn at concentrations up to 10 mg/mL, with cell viability exceeding 90%. Following UVB irradiation at 30 mJ/cm², Z. montanum oil demonstrated time and concentration-dependent ROS radical scavenging capabilities. In a cell migration assay, the essential oil demonstrated wound-healing properties. Z. montanum oil suppressed the expression of MMPs and enhanced the synthesis of type I procollagen at a concentration of 0.1-1 mg/mL. In addition, 0.1-1 mg/mL Z. montanum oil inhibited elastase activity in a concentration-dependent manner but did not affect tyrosinase activity. From these findings, the essential oil of Z. montanum could have potential applications in developing cosmeceutical products to prevent skin photoaging.

The circular RNA circBCL2L1 regulates innate immune responses via microRNA-mediated downregulation of TRAF6 in teleost fish

Growing numbers of studies have shown that circular RNAs (circRNAs) can function as regulatory factors to regulate the innate immune response, cell proliferation, cell migration, and other important processes in mammals. However, the function and regulatory mechanism of circRNAs in lower vertebrates are still unclear. Here, we discovered a novel circRNA derived from the gene encoding Bcl-2-like protein 1 (BCL2L1) gene, named circBCL2L1, which was related to the innate immune responses in teleost fish. Results indicated that circBCL2L1 played essential roles in host antiviral immunity and antibacterial immunity. Our study also identified a microRNA, miR-30c-3-3p, which could inhibit the innate immune response by targeting inflammatory mediator TRAF6. And TRAF6 is a key signal transduction factor in innate immune response mediated by TLRs. Moreover, we also found that the antiviral and antibacterial effects inhibited by miR-30c-3-3p could be reversed with the expression of circBCL2L1. Our data revealed that circBCL2L1 functioned as a competing endogenous RNA (ceRNA) of TRAF6 by competing for binding with miR-30c-3-3p, leading to activation of the NF-κB/IRF3 inflammatory pathway and then enhancing the innate immune responses. Our results suggest that circRNAs can play an important role in the innate immune response of teleost fish.

Stem cell-derived exosomes: A supernova in cosmetic dermatology

INTRODUCTION

Stem cell-derived exosomes are cell-free vesicles secreted by stem cells. Exosomes play a pivotal role in cell-to cell communication due to the functional proteins and genetic information which they carry. In addition, studies on cell migration, tumor invasion, tissue regeneration, myocardial repair after injury, and fracture healing have been widely reported.

OBJECTIVES

The purpose of this review is to sum up the current state of research on multiple stem cell-derived exosomes in cosmetic dermatology and to discuss the current challenges and future directions.

METHODS

We searched "skin" and "exosome" from PubMed to find the application of stem cell exosomes in cosmetic dermatology.

RESULTS

We found that stem cell-derived exosomes have an important place in skin cosmetology such as wound healing, skin aging, and scar formation.

CONCLUSION

Stem cell derived exosomes supply a potential tool to cosmetic dermatology. The performance of stem cell derived exosomes in regulating skin physiological and pathobiological functions suggests that stem cell derived exosomes have potential in cosmetic dermatology.

Pterygium: an update on pathophysiology, clinical features, and management

Pterygium is a relatively common ocular surface disease. The clinical aspects and the treatment options have been studied since many years ago, but many uncertainties still exist. The core pathologic pathway and the role of heredity in the development of pterygium are still attractive fields for the researchers. The role of pterygium in corneal irregularities, in addition to the refractive properties of pterygium removal, has been increasingly recognized through numerous studies. The association between pterygium and ocular surface neoplasia is challenging the traditional beliefs regarding the safe profile of the disease. The need for a comprehensive clinical classification system has encouraged homogenization of trials and prediction of the recurrence rate of the pterygium following surgical removal. Evolving surgical methods have been associated with some complications, whose diagnosis and management are necessary for ophthalmic surgeons. According to the review, the main risk factor of pterygium progression remains to be the ultraviolet exposure. A major part of the clinical evaluation should consist of differentiating between typical and atypical pterygia, where the latter may be associated with the risk of ocular surface neoplasia. The effect of pterygium on astigmatism and the aberrations of the cornea may evoke the need for an early removal with a purpose of reducing secondary refractive error. Among the surgical methods, conjunctival or conjunctival-limbal autografting seems to be the first choice for ophthalmic surgeons because the recurrence rate following the procedure has been reported to be lower, compared with other procedures. The use of adjuvant options is supported in the literature, where intraoperative and postoperative mitomycin C has been the adjuvant treatment of choice. The efficacy and safety of anti–vascular endothelial growth factor agents and cyclosporine have been postulated; however, their exact role in the treatment of the pterygium requires further studies.

Potential Use of Amla (Phyllanthus emblica L.) Fruit Extract to Protect Skin Keratinocytes from Inflammation and Apoptosis after UVB Irradiation

Ultraviolet B (UVB) exposure is the primary risk factor for the deadliest type of skin cancer—melanoma. Incorporating natural antioxidants in skin protection products is currently a favored research theme. For this study, we selected Phyllanthus emblica L. fruit extract (PE) to assess its potential use in dermal protection against UVB-induced keratinocyte inflammation and apoptosis. High-performance liquid chromatography (HPLC) was used to investigate PE’s phytochemical constituents (ascorbic acid, ellagic acid, gallic acid, chlorogenic acid, and quercetin), while ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total ROS, OH^•, O₂^•−, and H₂O₂-scavenging activities were used to determine the antioxidant properties. PE significantly increased the cell viability (MTT assay) and reduced apoptosis (Hoechst staining) in HaCaT cells exposed to UVB (40 mJ/cm²). PE abolished oxidative stress by reducing the production of intracellular ROS, O₂^•− and H₂O₂ production. Catalase activity (but not superoxide dismutase or glutathione peroxidase activity) was enhanced in keratinocytes incubated with PE prior to UVB exposure. Western blot analysis suggested that PE inhibited cytochrome c release and inhibited the dysregulation of PI3K/Akt without any impact on p38 activation. PE attenuated the inflammatory response to UVB irradiation by inhibiting AP-1, NF-κB, and the mediator PGE₂. Thus, PE is a candidate with great potential for use as an active ingredient in skin care products.

β-Ionone Attenuates Dexamethasone-Induced Suppression of Collagen and Hyaluronic Acid Synthesis in Human Dermal Fibroblasts

Stress is a major contributing factor of skin aging, which is clinically characterized by wrinkles, loss of elasticity, and dryness. In particular, glucocorticoids are generally considered key hormones for promoting stress-induced skin aging through binding to glucocorticoid receptors (GRs). In this work, we aimed to investigate whether β-ionone (a compound occurring in various foods such as carrots and almonds) attenuates dexamethasone-induced suppression of collagen and hyaluronic acid synthesis in human dermal fibroblasts, and to explore the mechanisms involved. We found that β-ionone promoted collagen production dose-dependently and increased mRNA expression levels, including collagen type I α 1 chain (COL1A1) and COL1A2 in dexamethasone-treated human dermal fibroblasts. It also raised hyaluronic acid synthase mRNA expression and hyaluronic acid levels. Notably, β-ionone inhibited cortisol binding to GR, subsequent dexamethasone-induced GR signaling, and the expression of several GR target genes. Our results reveal the strong potential of β-ionone for preventing stress-induced skin aging and suggest that its effects are related to the inhibition of GR signaling in human dermal fibroblasts.

Increased PD-L1 Expression in Human Skin Acutely and Chronically Exposed to UV Irradiation

Overexpression of PD-L1 (CD274) on tumor cells may represent a hallmark of immune evasion, and overexpression has been documented in several tumors including cutaneous squamous cell carcinoma (cSCC). While PD-L1/PD-1 activity in the skin has been primarily described in inflammatory models, our goal was to examine PD-L1 expression in human keratinocytes exposed to UV irradiation. We assessed PD-L1 expression in human sun-protected (SP) and sun-damaged (SD) skin, actinic keratosis (AK), and cSCC using IHC and protein microarray. Both methods found low baseline levels of PD-L1 in SP and SD skin and significantly increased expression in cSCC. Next, we examined PD-L1 expression in acute models of UV exposure. In human SP skin exposed to 2-3 MED of UV (n = 20), epidermal PD-L1 was induced in 70% of subjects after 24 h (P = 0.0001). SKH-1 mice exposed to acute UV also showed significant epidermal PD-L1 induction at 16, 24 and 48 h. A time- and dose-dependent induction of PD-L1 was confirmed in cultured human keratinocytes after UV, which was markedly reduced in the presence of MEK/ERK, JNK or STAT3 inhibitors. These findings suggest that UV induces upregulation of PD-L1 through established, pharmacologically targetable stress-signaling pathways in keratinocytes.

Protective effect of oral treatment with Cordia verbenacea extract against UVB irradiation deleterious effects in the skin of hairless mouse

Photochemoprotection of the skin can be achieved by inhibiting inflammation and oxidative stress, which we tested using Cordia verbenacea extract, a medicinal plant known for its rich content of antioxidant molecules and anti-inflammatory activity. In vitro antioxidant evaluation of Cordia verbenacea leaves ethanolic extract (CVE) presented the following results: ferric reducing antioxidant power (886.32 μM equivalent of Trolox/g extract); IC50 of 19.128 μg/ml for scavenging 2,2-diphenyl-1-picrylhydrazyl; IC50 of 12.48 μg/mL for scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); decrease of hydroperoxides from linoleic acid (IC50 of 10.20 μg/mL); inhibition of thiobarbituric acid reactive substances (IC50 8.90 μg/mL); iron-chelating ability in bathophenanthroline iron assay (IC50 47.35 μg/mL); chemiluminescence triggered by free radicals in the H2O2/horseradish peroxidase/luminol (IC50 0.286 μg/mL) and xanthine/xanthine oxidase/luminol (IC50 0.42 μg/mL) methods. CVE (10-100 mg per kg, 30 min before and immediately after UVB exposure) treatment was performed by gavage in hairless mice. CVE inhibited skin edema, neutrophil infiltration, and overproduction of MMP-9; reduced levels of TNF-α, IL-1β, and IL- 6; numbers of skin mast cells, epidermal thickening, number of epidermal apoptotic keratinocytes, and collagen degradation. CVE increased the skin's natural antioxidant defenses as observed by Nrf-2, NAD(P)H quinone oxidoreductase 1, and heme oxygenase 1 mRNA expression enhancement. Furthermore, CVE inhibited lipid peroxidation and superoxide anion production and recovered antioxidant reduced glutathione, catalase activity, and ROS scavenging capacity of the skin. Concluding, CVE downregulates the skin inflammatory and oxidative damages triggered by UVB, demonstrating its potentialities as a therapeutic approach.

A preliminary gene expression analysis on Paracentrotus lividus embryos exposed to UVB, Cadmium and their combination

Paracentrotus lividus is a Mediterranean and Eastern Atlantic sea urchin species, very sensitive to chemical and physical environmental changes and widely used in eco-toxicological studies. Here, we applied a high throughput screening approach on P. lividus embryos exposed to UVB radiation (UV), Cadmium Chloride (Cd) and their combination (Cd/UV), to deeply characterize the molecular responses adopted by embryos to cope with these stressors. in vitro eco-toxicological assays were performed by exposing embryos to Cd (10-4 M) soon after fertilization, to UV (200 and 400J/m2) at early stage of development, while in co-exposure experiments, Cd-exposed embryos were irradiated with UV at 200 J/m2. By NanoString nCounter technology, custom-made probes were developed and hybridized on total RNA extracted from exposed embryos at 51h after fertilization. By in silico analyses, we selected and retrieved at the NCBI nucleotide database a panel of P. lividus transcripts encoding for many regulatory and structural proteins that we ranked in categories, i.e., Apoptosis, Biomineralization, Defense, Development, Immunity, Signaling and Transcription Factors. The analysis of 127 transcripts highlighted the dysregulation of many genes, some specifically activated to cope with stress agents, others involved in the complex molecular network of genes that regulate embryo development. We revealed the downregulation of Biomineralization and Development genes and the upregulation of Defensive genes in Cd and Cd/UV embryos. Our approach, using sea urchin embryo as an in vivomodel, contributes to advance our knowledge about cellular responses to UV, Cd and their combination.

Acer tataricum subsp. ginnala Inhibits Skin Photoaging via Regulating MAPK/AP-1, NF-κB, and TGFβ/Smad Signaling in UVB-Irradiated Human Dermal Fibroblasts

Skin, the organ protecting the human body from external factors, maintains structural and tensile strength by containing many collagen fibrils, particularly type I procollagen. However, oxidative stress by ultraviolet (UV) exposure causes skin photoaging by activating collagen degradation and inhibiting collagen synthesis. Acer tataricum subsp. ginnala extract (AGE) is a herbal medicine with anti-inflammatory and anti-oxidative effects, but there is no report on the protective effect against skin photoaging. Therefore, we conducted research concentrating on the anti-photoaging effect of Acer tataricum subsp. ginnala (AG) in UVB (20 mJ/cm²)-irradiated human dermal fibroblasts (HDF). Then, various concentrations (7.5, 15, 30 µg/mL) of AGE were treated in HDF for 24 h following UVB irradiation. After we performed AGE treatment, the matrix metalloproteinase1 (MMP1) expression was downregulated, and the type I procollagen level was recovered. Then, we investigated the mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1) and nuclear factor-κB (NF-κB) pathway, which induce collagen breakdown by promoting the MMP1 level and pro-inflammatory cytokines. The results indicated that AGE downregulates the expression of the MAPK/AP-1 pathway, leading to MMP1 reduction. AGE inhibits nuclear translocation of NF-κB and inhibitor of nuclear factor-κB (IκB) degradation. Therefore, it downregulates the expression of MMP1 and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 increased by UVB. Besides, the TGFβ/Smad pathway, which is mainly responsible for the collagen synthesis in the skin, was also analyzed. AGE decreases the expression of Smad7 and increases TGFβRII expression and Smad3 phosphorylation. This means that AGE stimulates the TGFβ/Smad pathway that plays a critical role in promoting collagen synthesis. Thus, this study suggests that AGE can be a functional material with anti-photoaging properties.

Anti-Inflammatory and Photoaging-Protective Effects of Olea europaea through Inhibition of AP-1 and NF-[Formula: see text] B Pathways

Olea europaea is a beneficial edible plant with a number of biological activities like anti-inflammatory, anti-oxidant, antithrombic, antihyperglycemic, and anti-ischemic activities. The mechanisms behind the antiphotoaging and anti-inflammatory effects of Olea europaea are not fully understood. To investigate how an ethanol extract of Olea europaea (Oe-EE) exerts these effects, we explored its activities in human keratinocytes and dermal fibroblasts. We assessed the anti-oxidant effects of Oe-EE via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2[Formula: see text]-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays and measured the expression levels of matrix metalloproteinases (MMPs), cyclooxygenase-2, interleukin (IL)-6, tumor necrosis factor (TNF)-[Formula: see text], and moisturizing factors. Antiphotoaging and anti-inflammatory mechanisms of Oe-EE were explored by assessing signaling molecule activation via immunoblotting. Oe-EE treatment decreased the mRNA expression level of MMPs, cyclooxygenase-2, IL-6, and TNF-[Formula: see text] and restored type I collagen, filaggrin, and sirtuin 1 expression in UVB-irradiated cells. Furthermore, Oe-EE inhibited the activities of several activator protein 1 regulatory enzymes, including extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK), and inhibited nuclear factor (NF)-[Formula: see text]B pathway signaling proteins. Therefore, our results indicate that Oe-EE has photoaging-protective and anti-inflammatory effects.

Cellulose nanocrystal preparation from Gelidium amansii and analysis of its anti-inflammatory effect on the skin in vitro and in vivo

Treated Gelidium amansii cellulose nanocrystal (TGa CNC) was prepared from treated Gelidium amansii (TGa) and evaluated for its anti-inflammatory effect on human keratinocytes and mice skin. Using three independent cell lines, TGa CNC showed no cytotoxicity in HaCaT, Beas-2B, and Raw 264.7 cells. A non-toxic dose of TGa CNC suppressed ultraviolet (UV) B-induced AP (activated protein)-1, and subsequent cyclooxygenase (COX)-2 gene and protein expression in HaCaT cells. TGa CNC suppressed translocation of c-Jun from the cytosol to the nucleus responds to UVB irradiation. Additionally, TGa CNC suppressed UVB-induced extracellular signal-regulated kinases (ERKs)1/2/MEK/2/B-Raf, c-Jun N-terminal kinase (JNK)1/2/MKK4/7, Akt, and epidermal growth factor receptor (EGFR) phosphorylation in HaCaT cells. Dorsal treatment of TGa CNC significantly suppressed acute UVB-induced increase in epidermal thickness and COX-2 expression in mice skin. Overall, these results indicate that TGa CNC exerts potent anti-inflammatory activity through the inhibition of abnormal COX-2 expression and mitogen-activated protein kinases (MAPK)s signaling pathways.

2,4-Dihydroxyphenyl-benzo[d]thiazole (MHY553), a synthetic PPARα agonist, decreases age-associated inflammatory responses through PPARα activation and RS scavenging in the skin

We previously reported that 2,4-dihydroxyphenyl-benzo[d]thiazole (MHY553) is a PPARα agonist, which has been shown to inhibit tyrosinase activity in murine melanocyte and alleviate hepatic steatosis in aged rats. This study investigated the effects of MHY553 on the age-related occurrence of inflammatory responses via the molecular modulation of the nuclear factor-κB (NF-κB) signaling pathway in the skin of aged rats and skin fibroblast cells. Moreover, we investigated the antioxidant effect of MHY553 via in vitro assays of reactive oxygen species (ROS) and peroxynitrite (ONOO^-) scavenging activities. We also scrutinized the ability of MHY553 as a PPARα activator in aged rat skin and H₂O₂-induced Hs27 fibroblast cells. In vivo experiments were performed in young, aged, and MHY553-fed aged rats (3 mg or 5 mg∙kg ^-1∙day ^-1 for 4 weeks). MHY553 dose-dependently scavenged ROS and ONOO^-. Furthermore, we found that MHY553 suppressed the NF-κB transcription factor and downregulated mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) signaling. MHY553 also inhibited the expression of pro-inflammatory cytokines including COX-2, iNOS, IL-1β, and IL-6. Our findings indicate the MHY553 scavenges ROS/reactive nitrogen species and inhibits inflammatory cytokines through PPARα activation in the skin. Thus, these results suggest that MHY553 may be of therapeutic interest for protecting skin from oxidative stress-induced damage and intrinsic aging.

Antioxidant and anti-inflammatory effects of piperine on UV-B-irradiated human HaCaT keratinocyte cells

The increase in intracellular reactive oxygen and nitrogen species plays a key role in ultraviolet B (UV-B)-induced inflammatory responses in the human skin. Piperine exhibits many pharmacological benefits. In the present study, the photoprotective effects and the possible underlying mechanisms of the anti-inflammatory effects of piperine on UV-B-irradiated keratinocytes were investigated. Piperine exerted strong, direct scavenging effects on DPPH radicals and exhibited free radical scavenging capabilities as demonstrated by the DCFH-DA and Griess assays. Consistent with these results, 10, 20, and 40 μM piperine pretreatments attenuated UV-B irradiation-induced keratinocyte cytotoxicity as reported by the resazurin assay. The highest concentration of piperine inhibited UV-B irradiation-induced cell apoptosis, as revealed by Hoechst 33342 staining. Moreover, we demonstrated the anti-inflammatory effects of piperine using western blot analysis, real-time PCR, and ELISA. Pretreatment with piperine suppressed the activation of phosphorylated p38, JNK, and AP-1 as well as the levels of COX-2/PGE₂ and iNOS synthesis, while UV-B-irradiated cells triggered the induction of these signaling molecules. These results indicated that the inhibition of these inflammatory signaling pathways might play a key role in the regulation of the anti-inflammatory effects of piperine. In addition, piperine showed stronger anti-inflammatory effects than celecoxib which served as a positive control at the same concentration. All these results suggested that the anti-inflammatory properties of piperine protected keratinocytes from UV-B-induced damage, which might be due to its antioxidant properties. Therefore, piperine may be an effective therapeutic candidate compound for the treatment of UV irradiation-induced skin inflammation.

Skin photo-protection with phytochemicals against photo-oxidative stress, photo-carcinogenesis, signal transduction pathways and extracellular matrix remodeling-An overview

Excessive exposure of skin to UV radiation triggers the generation of oxidative stress, inflammation, immunosuppression, apoptosis, matrix-metalloproteases production, and DNA mutations leading to the onset of photo ageing and photo-carcinogenesis. At the molecular level, these changes occur via activation of several protein kinases as well as transcription pathways, formation of reactive oxygen species, and release of cytokines, interleukins and prostaglandins together. Current therapies available on the market only provide limited solutions and exhibit several side effects. The present paper provides insight into scientific studies that have elucidated the positive role of phytochemicals in counteracting the UV-induced depletion of antioxidant enzymes, increased lipid peroxidation, inflammation, DNA mutations, increased senescence, dysfunctional apoptosis and immune suppression. The contribution of phytochemicals to the downregulation of expression of oxidative-stress sensitive transcription factors (Nrf2, NF-Kb, AP-1 and p53) and protein kinases (MSK, ERK, JNK, p38 MAPK, p90RSK2 and CaMKs) involved in inflammation, apoptosis, immune suppression, extracellular matrix remodelling, senescence, photo ageing and photo-carcinogenesis, is also discussed. Conclusively, several phytochemicals hold potential for the development of a viable solution against UV irradiation-mediated photo ageing, photo-carcinogenesis and related manifestations.

Inhibitory effect of oyster hydrolysate on wrinkle formation against UVB irradiation in human dermal fibroblast via MAPK/AP-1 and TGFβ/Smad pathway

The skin keeps the human body healthy from extrinsic stimuli such as ultraviolet (UV) irradiation. However, chronic exposure of these stimuli reduces the number of proteins that constitute the extracellular matrix (ECM) and causes wrinkle formation. The amount of collagen, the main protein that constitutes connective tissue, is reduced in the human skin due to UV radiation. When human dermal fibroblasts were damaged by UVB, UVB increased the MMPs expressions and degraded type I collagen and other ECM proteins. Oyster (Crassostrea gigas) hydrolysate (OH) is known to have anticancer, antioxidant, and anti-apoptotic effects. To scrutinize the anti-wrinkle effect of the OH in the viewpoint of the balance between collagen degradation and synthesis, we conducted the study in UVB damaged human dermal fibroblasts. We determined type I procollagen, MMPs and related proteins using ELISA kit, qRT-PCR and western blot. In our study, we discovered that OH inhibits collagen degradation by regulating MAPKs, AP-1 and MMPs expression. Also, we found that OH promotes collagen production by enhancing TGFβ receptor II expression and Smad3 phosphorylation. These results showed that OH regulates collagen degradation and stimulates collagen synthesis. Through this study, we found that OH is effective in inhibiting wrinkle formation and restore photo-aged human skin. It indicates that OH can be one of the functional materials in the fields of anti-wrinkle research.

Ameliorative Effects of Peptides from the Oyster (Crassostrea hongkongensis) Protein Hydrolysates against UVB-Induced Skin Photodamage in Mice

Chronic exposure to ultraviolet B (UVB) irradiation is a major cause for skin photoaging. UVB induces damage to skin mainly by oxidative stress, inflammation, and collagen degradation. This paper investigated the photo-protective effects of peptides from oyster (Crassostrea hongkongensis) protein hydrolysates (OPs) by topical application on the skin of UVB-irradiated mice. Results from mass spectrometry showed that OPs consisted of peptides with a molecular weight range of 302.17–2936.43 Da. In vivo study demonstrated that topical application of OPs on the skin significantly alleviated moisture loss, epidermal hyperplasia, as well as degradation of collagen and elastin fibers caused by chronic UVB irradiation. In this study, OPs treatment promoted antioxidant enzymes (SOD and GPH-Px) activities, while decreased malondialdehyde (MDA) level in the skin. In addition, OPs treatment significantly decreased inflammatory cytokines (IL-1β, IL-6, TNF-α) content, and inhibited inflammation related (iNOS, COX-2) protein expression in the skin. Via inhibiting metalloproteinase 1(MMP1) expression, OPs treatment markedly decreased the degradation of collagen and elastin fibers as well as recovered the altered arrangement of extracellular matrix network in the dermis of skin. Our study demonstrated for the first time that OPs protected against UVB induced skin photodamage by virtue of its antioxidative and anti-inflammatory properties, as well as regulating the abnormal expression of MMP-1. The possible molecular mechanism underlying OPs anti-photoaging is possibly related to downregulating of the MAPK/NF-κB signaling pathway, while promoting TGF-β production in the skin.

Protective Effect of Diphlorethohydroxycarmalol Isolated from Ishige okamurae Against Particulate Matter-Induced Skin Damage by Regulation of NF-κB, AP-1, and MAPKs Signaling Pathways In Vitro in Human Dermal Fibroblasts

Particulate matters (PM), the main contributor to air pollution, have become a serious issue that threatens human's health. Skin is the largest organ in humans, as well as the primary organ exposed to PM. Overexposure of PM induces skin damage. Diphlorethohydroxycarmalol (DPHC), an algal polyphenol with the potential of skin protection, has been isolated from the edible brown seaweed Ishige okamurae. The purpose of the present study is to investigate the protective effect of DPHC against PM (ERM-CZ100)-induced skin damage in human dermal fibroblasts (HDF) cells. The results indicated that DPHC significantly and dose-dependently reduced intracellular reactive oxygen species generation in HDF cells. In addition, DPHC significantly induced collagen synthesis and inhibited collagenase activity in ERM-CZ100-stimulated HDF cells. Further study demonstrated that DPHC remarkably reduced the expression of human matrix metalloproteinases through regulation of nuclear factor kappa B, activator protein 1, and mitogen-activated protein kinases signaling pathways in ERM-CZ100-stimulated HDF cells. This study suggested that DPHC is a potential candidate to protect skins against PM-induced damage, and it could be used as an ingredient in pharmaceutical and cosmeceutical industries.

Dietary Suberic Acid Protects Against UVB-Induced Skin Photoaging in Hairless Mice

Ultraviolet (UV) radiation is a major cause of skin photoaging, which is mainly characterized by dryness and wrinkle formation. In the current study, we investigated the anti-photoaging effects of dietary suberic acid, a naturally occurring photochemical, using UVB-irradiated hairless mice. Mice were exposed to UVB three times weekly and fed diets containing three different suberic acid concentrations (0.05%, 0.1% and 0.2%) for 10 weeks. It was found that suberic acid inhibited UVB-induced skin dryness, wrinkle formation, and epidermal thickness in hairless mice. In parallel with phenotypic changes, suberic acid attenuated UVB-induced matrix metalloproteinase (MMP) genes (MMP1a, MMP1b, MMP3, and MMP9), while accelerating collagen genes including collagen type I alpha 1 chain (COL1A1), COL1A2, and COL3A1 and hyaluronic acid synthases genes (HAS1, HAS2 and HAS3). We further demonstrated that suberic acid upregulated the molecules involved in the transforming growth factor-β (TGF-β)/SMAD pathway, but downregulated the molecules participating in the mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) signaling in UVB-irritated hairless mice. Collectively, we propose that suberic acid may be a promising agent for treating skin photoaging.

Quercetin Directly Targets JAK2 and PKCδ and Prevents UV-Induced Photoaging in Human Skin

Quercetin is a naturally occurring polyphenol present in various fruits and vegetables. The bioactive properties of quercetin include anti-oxidative, anti-cancer, anti-inflammatory, and anti-diabetic effects. However, the effect of quercetin on skin aging and the direct molecular targets responsible have remained largely unknown. Herein, we investigated the protective effect of quercetin against UV-mediated skin aging and the molecular mechanisms responsible. Treatment with quercetin suppressed UV-induced matrix metalloproteinase-1 (MMP-1) and cyclooxygenase-2 (COX-2) expression and prevented UV-mediated collagen degradation in human skin tissues. Quercetin exerted potent inhibitory effects towards UV-induced activator protein-1 (AP-1) and nuclear factor-kappa B (NF-κB) activity. Further examination of the upstream signaling pathways revealed that quercetin can attenuate UV-mediated phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N terminal kinases (JNK), protein kinase B (Akt), and signal transducer and activator of transcription 3 (STAT3). Kinase assays using purified protein demonstrated that quercetin can directly inhibit protein kinase C delta (PKCδ) and Janus kinase 2 (JAK2) kinase activity. Quercetin was observed to bind to PKCδ and JAK2 in pull-down assays. These findings suggest that quercetin can directly target PKCδ and JAK2 in the skin to elicit protective effects against UV-mediated skin aging and inflammation. Our results highlight the potential use of quercetin as a natural agent for anti-skin aging applications.

Asiatic Acid Glucosamine Salt Alleviates Ultraviolet B-induced Photoaging of Human Dermal Fibroblasts and Nude Mouse Skin

Herbal extracts including asiatic acid (AA) have become popular candidates of anti-photoaging agents due to their anti-inflammatory and antioxidant properties and minimal side effect. Nevertheless, low bioavailability due to poor solubility limits their practical application. In this study, a highly bioavailable form of AA called AAGS (compounded by asiatic acid and glucosamine) was investigated for its anti-photoaging effect using both in vitro and in vivo models along with UVB irradiation. The results showed that AAGS alleviated UVB-induced cell proliferation inhibition by reducing G2 phase arrest and cell apoptosis rate as well as the gene expressions of P53, BAX, CASPASE 3 and CASPASE 9, but enhancing BCL-2 expression. It also reduced the production of reactive oxygen species along with increased gene expression of GPX-1 and downregulated the gene expression of IL-1β, IL-6, IL-8, IL-17 and TNF-α compared to nontreated cells. In vivo results demonstrated the antiphotodamaging effects by restoring skin thickness, collagen content and reducing MMPs expression, which are also supported by reduced MMPs gene expression and enhanced collagen I and TGF-β1 gene expression in vitro. Thus, AAGS may become a potential anti-photoaging agent for topical use due to its capability of self-assembling into a water gel.

Protective Effects of Sesamin against UVB-Induced Skin Inflammation and Photodamage In Vitro and In Vivo

Ultraviolet (UV) exposure has been demonstrated as the most critical factor causing extrinsic skin aging and inflammation. This study explored the protective effects and mechanisms of sesamin against skin photodamage. Sesamin reduced intracellular reactive oxygen species production after UVB irradiation in human dermal fibroblasts. The sesamin treatment attenuated mitogen-activated protein (MAP) kinase phosphorylation and matrix metalloproteinase (MMPs) overexpression induced by UVB exposure, and it significantly enhanced the tissue inhibitor of metalloproteinase-1 protein expression. Sesamin also elevated the total collagen content in human fibroblasts by inhibiting UVB-induced mothers against decapentaplegic homolog 7 (Smad7) protein expression. Sesamin reduced UVB-induced inducible nitric oxide synthase (i-NOS) and cyclooxygenase-2 (COX-2) overexpression and inhibited nuclear factor-kappa B (NF-κB) translocation. Moreover, sesamin may regulate the c-Jun N-terminal kinases (JNK) and p38 MAP kinase pathways, which inhibit COX-2 expression. Sesamin could reduce UVB-induced inflammation, epidermal hyperplasia, collagen degradation, and wrinkle formation in hairless mice. It also reduced MMP-1, interleukin (IL-1), i-NOS, and NF-κB in the mouse skin. These results demonstrate that sesamin had antiphotodamage and anti-inflammatory activities. Sesamin has potential for use as a skin protection agent in antiphotodamage and skin care products.

Use of Natural Components Derived from Oil Seed Plants for Treatment of Inflammatory Skin Diseases

The incidence of inflammatory skin diseases is increasing, so the search for relevant therapeutics is of major concern. Plants are rich in phytochemicals which can alleviate many symptoms. In this review, we concentrate on compounds found in the seeds of widely cultivated plants, regularly used for oil production. The oils from these plants are often used to alleviate the symptoms of inflammatory diseases through synergetic action of unsaturated fatty acids and other phytochemicals most commonly derived from the terpenoid pathway. The knowledge of the chemical composition of oil seeds and the understanding of the mechanisms of action of single components should allow for a more tailored approach for the treatment for many diseases. In many cases, these seeds could serve as an efficient material for the isolation of pure phytochemicals. Here we present the content of phytochemicals, assumed to be responsible for healing properties of plant oils in a widely cultivated oil seed plants and review the proposed mechanism of action for fatty acids, selected mono-, sesqui-, di- and triterpenes, carotenoids, tocopherol and polyphenols.

Upregulation of PD-L1 via HMGB1-Activated IRF3 and NF-κB Contributes to UV Radiation-Induced Immune Suppression

Solar ultraviolet radiation (UVR) suppresses skin immunity, which facilitates initiation of skin lesions and establishment of tumors by promoting immune evasion. It is unclear whether immune checkpoints are involved in the modulation of skin immunity by UVR. Here, we report that UVR exposure significantly increased expression of immune checkpoint molecule PD-L1 in melanoma cells. The damage-associated molecular patterns molecule HMGB1 was secreted by melanocytes and keratinocytes upon UVR, which subsequently activated the receptor for advanced glycation endproducts (RAGE) receptor to promote NF-κB- and IRF3-dependent transcription of PD-L1 in melanocytes. UVR exposure significantly reduced the susceptibility of melanoma cells to CD8⁺ T-cell-dependent cytotoxicity, which was mitigated by inhibiting the HMGB1/TBK1/IRF3/NF-κB cascade or by blocking the PD-1/PD-L1 checkpoint. Taken together, our findings demonstrate that UVR-induced upregulation of PD-L1 contributes to immune suppression in the skin microenvironment, which may promote immune evasion of oncogenic cells and drive melanoma initiation and progression. SIGNIFICANCE: These findings identify PD-L1 as a critical component of UV-induced immune suppression in the skin, which facilitates immunoevasion of oncogenic melanocytes and development of melanoma.See related commentary by Sahu, p. 2805.

Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis

The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.