Photoageing: mechanism, prevention and therapy

Low-dose ionizing radiation exposure and its impact on skin ageing among healthcare workers

BACKGROUND

Exposure to ionizing radiation (IR) is an occupational risk for healthcare professionals and can result in a range of health issues.

OBJECTIVES

To assess the relationship between chronic low-dose IR exposure and the development of early ageing-related facial skin wrinkles in healthcare workers.

METHODS

Facial skin wrinkles present in 70 healthcare workers who had been exposed to low-dose IR for at least 5 years were compared with those of 70 nonexposed healthcare workers. Skin wrinkles were assessed using the Lemperle wrinkle assessment scale and the scores of the IR-exposed healthcare workers were compared with those of the nonexposed controls.

RESULTS

There were no statistically significant differences in sociodemographic factors and Fitzpatrick skin types between the IR-exposed healthcare workers and the control group. Analysis of the Lemperle wrinkle assessment scale scores revealed significant differences, with IR-exposed workers showing higher scores for all facial wrinkle categories evaluated (all P < 0.001) and for horizontal neck folds (P = 0.002).

CONCLUSIONS

To our knowledge, this is the first study to assess healthcare workers with long-term exposure to low-dose IR for facial skin wrinkles, a visible consequence of skin ageing. Chronic low-dose IR exposure can lead to increased skin wrinkles, representative of advanced skin ageing in healthcare workers. These findings underscore the need for enhanced protective measures and regular monitoring for individuals exposed to occupational radiation.

Dysregulation of autophagy during photoaging reduce oxidative stress and inflammatory damage caused by UV

Photoaging, the premature aging of skin due to chronic ultraviolet (UV) exposure, is a growing concern in dermatology and cosmetic science. While UV radiation is known to induce DNA damage, oxidative stress, and inflammation in skin cells, recent research unveils a promising countermeasure: autophagy. This review explores the intricate relationship between autophagy and photoaging, highlighting how this cellular recycling process can mitigate UV-induced damage. We begin by examining the differential impacts of UVA and UVB radiation on skin cells and the role of oxidative stress in accelerating photoaging. Next, we delve into the molecular mechanisms of autophagy, including its various forms and regulatory pathways. Central to this review is the discussion of autophagy's protective functions, such as the clearance of damaged organelles and proteins, and its role in maintaining genomic integrity. Furthermore, we address the current challenges in harnessing autophagy for therapeutic purposes, including the need for selective autophagy inducers and a deeper understanding of its context-dependent effects. By synthesizing recent advancements and proposing future research directions, this review underscores the potential of autophagy modulation as a novel strategy to prevent and treat photoaging. This comprehensive analysis aims to inspire further investigation into autophagy-based interventions, offering new hope for preserving skin health in the face of environmental stressors.

Salvianolic acid B protects against UVB-induced HaCaT cell senescence and skin aging through NRF2 activation and ROS scavenging

BACKGROUND

Prolonged sunlight exposure can cause skin photoaging. The epidermis, the outermost layer of the skin, protects the body from the environment. This study explored the protective effect of salvianolic acid B (Sal-B), a bioactive compound from Salvia miltiorrhiza, against photoaging and examined its specific mechanism.

METHODS

In vitro, HaCaT cells were treated with various doses of Sal-B before ultraviolet B (UVB) light exposure. Assessments in HaCaT cells included cellular senescence, apoptotic cell ratio, reactive oxygen species (ROS) levels, mitochondrial function, superoxide dismutase activity, and gene and protein expression. Immunofluorescence labeling, nuclear factor erythroid 2-related factor 2 (NRF2) knockdown, and Western blotting analysis were used. To assess Sal-B's protective effects on skin photoaging in vivo, we employed a nude mouse model and an ex vivo human skin model.

RESULTS

In vitro, Sal-B significantly activated NRF2, scavenged ROS, protected mitochondrial function, and inhibited nuclear factor kappa B and mitogen-activated protein kinase pathways. Ultimately, Sal-B prevented UVB-induced photoaging and keratinocyte apoptosis. In vivo, we confirmed that Sal-B improved skin wrinkles and epidermal thickness in nude mice following UVB irradiation, displaying greater efficacy than tretinoin.

CONCLUSION

We identified the preventive implications of Sal-B against UVB-induced senescence in skin photoaging and revealed its potential as a regulator of the NRF2 signaling pathway.

Photoaging: Current Concepts on Molecular Mechanisms, Prevention, and Treatment

Photoaging is the consequence of chronic exposure to solar irradiation, encompassing ultraviolet (UV), visible, and infrared wavelengths. Over time, this exposure causes cumulative damage, leading to both aesthetic changes and structural degradation of the skin. These effects manifest as rhytids, dyschromia, textural changes, elastosis, volume loss, telangiectasias, and hyperkeratosis, collectively contributing to a prematurely aged appearance that exceeds the skin's chronological age. The hallmarks of photoaging vary significantly by skin phototype. Skin of color tends to exhibit dyschromia and features associated with "intrinsic" aging, such as volume loss, while white skin is more prone to "extrinsic" aging characteristics, including rhytids and elastosis. Moreover, susceptibility to different wavelengths within the electromagnetic spectrum also differs by skin phototype, influencing the clinical presentation of photoaging, as well as prevention and treatment strategies. Fortunately, photoaging-and its associated adverse effects-is largely preventable and, to some extent, reversible. However, effective prevention and treatment strategies require careful tailoring to an individual's skin type. In this review, we summarize molecular mechanisms underlying photoaging, examine its clinical manifestations, outline risk factors and prevention strategies, and highlight recent advancements in its treatment.

Squalane as a Promising Agent Protecting UV-Induced Inhibition of Collagen Biosynthesis and Wound Healing in Human Dermal Fibroblast

Squalane, a highly stable derivative of squalene, has received attention for its potential application in dermatology and cosmetics due to its biocompatibility, moisturizing properties, and antioxidant activity. This study investigates the effects of squalane on UVA-induced oxidative stress, inflammation, deregulation of collagen metabolism, and some growth signaling pathways in human dermal fibroblasts (HDFs). It has been found that squalane at concentrations of 0.005-0.015% counteracted the UVA-induced inhibition of oxidative stress, collagen biosynthesis, prolidase activity, expression of the β1-integrin receptor, insulin-like growth factor-I receptor (IGFR), transforming growth factor-β (TGF-β), phosphorylated kinases ERK1/2, and increase in the expression of p38 kinase in HDFs. Moreover, squalane at the studied concentrations counteracted UVA-induced increase in the expression of NF-κB and COX-2 in HDFs, suggesting its anti-inflammatory activity. Interestingly, squalane augmented the UVA-induced expression of nuclear factor erythroid 2-related factor 2 (Nrf2). The functional significance of squalane activities was found in a model of wound healing in HDFs. Squalane at the studied concentrations stimulated fibroblast migration, facilitating the repair process following exposure of the cells to UVA radiation. These results demonstrate the ability of squalane to counteract UVA-induced cell damage and suggest its potential to support skin regeneration, highlighting its application in anti-aging, post-sun repair, and regenerative care formulations.

Photoaging and Cosmetic Result with Artificial Daylight Photo-dynamic Therapy Using Methyl Aminolevulinate

Artificial daylight photodynamic therapy with methyl aminolevulinate is an effective and almost painless treatment approach for actinic keratoses. The objective of the prospective, non-interventional, multicentre study ArtLight (NCT05725213) was to gain comprehensive insights into the cosmetic effect of methyl aminolevulinate-artificial daylight photodynamic therapy in patients with actinic keratoses using different artificial daylight systems under real-world conditions. The study enrolled patients with Olsen grade 1 or 2 actinic keratoses on the face and scalp in Germany. Patients were treated with methyl aminolevulinate-artificial daylight photodynamic therapy. The cosmetic effect was assessed via photodamage parameters (global score for photoaging, mottled pigmentation, tactile roughness, telangiectasias, fine lines). Each photodamage variable was recorded on a 5-point scale (0-4). In total, 224 patients (median age: 75.0 years [range 50-91], 85.3% male, 62.5% Olsen grade 2, 55.4% treatment-naive) were treated with methyl aminolevulinate-artificial daylight photodynamic therapy. At month 3, all 5 parameters of photoaging were significantly reduced from baseline (p < 0.001). The majority of patients (81.3%) and investigators (83.6%) rated the cosmetic result as good or very good. Beyond effective eradication of actinic keratoses, field-directed methyl aminolevulinate-artificial daylight photodynamic therapy can improve photoaging symptoms, including tactile roughness, mottled pigmentation, telangiectasis, and fine lines. Thus methyl aminolevulinate-artificial daylight photodynamic therapy provides additional benefits, particularly for patients concerned with cosmetic outcomes during or after treatment.

Correlating Optical Coherence Tomography and Other Noninvasive Imaging Features With Atrophic and Hypertrophic Skin Photoaging

BACKGROUND

According to morphological and clinical differences, atrophic (AP) and hypertrophic (HP) skin photoaging types have been reported. The current study examines the correlation between optical coherence tomography (OCT) and dynamic-OCT (D-OCT) features in subjects with skin photoaging types classified as AP, HP, or controls. Furthermore, we aim to define the correlations between OCT/D-OCT and other noninvasive skin imaging features (standardized clinical photography and reflectance confocal microscopy [RCM]).

METHODS

We explored the correlations between skin photoaging types, OCT/D-OCT, and noninvasive skin imaging features. A total of 58 patients were clinically classified as AP (n = 17), HP (n = 24), or controls (n = 17).

RESULTS

AP subjects showed higher D-OCT vessel assets and vessel densities (p < 0.05) compared to HP and control subjects. A significant correlation was established between standardized clinical evidence of wrinkles and RCM collagen scores. Dermal variations in HP subjects represent the underlying substrate of wrinkles.

CONCLUSIONS

Despite the limited cohort, these results contribute to the current knowledge of morphologic differences between AP and HP subjects. Treatment should consider morphologic changes according to skin photoaging phenotypes for optimal personalized medicine.

Sunscreen and 25-Hydroxyvitamin D Levels: Friends or Foes? A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the impact of sunscreen use on 25-hydroxyvitamin D (25(OH)D) levels, addressing conflicting findings from observational and interventional studies.

METHODS

Potentially eligible studies were identified from the PubMed/MEDLINE, Scopus, and Web of Science databases from inception to November 2024, utilizing a search strategy incorporating terms related to "sunscreen" and "vitamin D." The studies eligible addressed the questions define based on the Population, Intervention, Comparator, Outcome framework: What are 25(OH)D levels in patients exposing to sun applying or not sunscreen? This review followed Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality assessment and the risk of bias were analyzed using Quality Assessment of Diagnostic Accuracy Studies version 2.

RESULTS

We included 22 studies in the qualitative synthesis, and 7 in the quantitative one, encompassing a total of 9470 participants. In vitro studies consistently showed that sunscreen blocks UV-B radiation, crucial for vitamin D3 production, while population-based studies reported mixed findings. Some studies linked sunscreen use to lower 25(OH)D levels, particularly in individuals with limited sun exposure, while others observed no significant impact. Meta-analysis showed that the adoption of sunscreen is associated to a reduction of 25(OH)D serum concentration (standardized mean difference = -2 ng/mL, 95% confidence interval -3, -1) with a not important heterogeneity across studies (I-square = 37%, P = .15).

CONCLUSION

The existing evidence supports that sunscreen can impair vitamin D3 synthesis, and as a result decrease serum 25(OH)D levels, but further research is necessary to determine the broader health implications and guide public health recommendations.

Enhanced Antioxidant and Protective Effects of Fermented Solanum melongena L. Peel Extracts Against Ultraviolet B-Induced Skin Damage

Background/Objectives: The skin, being the body's outermost organ, plays a vital role in protecting against various external stimuli. Ultraviolet generates reactive oxygen species (ROS), promoting the secretion of matrix metalloproteinases (MMPs) and inducing collagen degradation. Many studies have been conducted to identify natural substances that can prevent or delay the harmful effects of UV. Methods: A wound healing assay, DCF-DA reactive oxygen species (ROS) assay, and JC-1 assay were performed to assess the effects of bio-converted eggplant peels (BEPs) on human dermal fibroblasts (HDFs). Western blot analysis was also conducted to understand the underlying mechanisms for their effects. Finally, hematoxylin-eosin staining and immunohistochemistry were also performed in animal studies. Results: Our study evaluated the antioxidant efficacy of BEPs fermented with Lactobacillus plantarum in hydrogen peroxide (H2O2)-HDFs and UVB-induced skin damage in hairless mice. We demonstrated that BEPs exhibited enhanced antioxidant properties compared to non-fermented eggplant peels (EPs). BEPs facilitated wound healing in H2O2-damaged HDFs, reduced ROS levels, and restored mitochondrial membrane potential. BEPs suppressed the phosphorylation of ERK, p38, and JNK as their underlying mechanism. We further demonstrated that dietary supplementation of BEPs also downregulated matrix metalloproteinase 1 (MMP1) expression and upregulated collagen I (COL1) in UVB-damaged hairless mice, indicating that BEPs were more effective compared to EPs. Conclusions: Our studies suggest that BEPs fermented with Lactobacillus plantarum hold significant potential as a protective agent for mitigating UVB-induced damage and promoting skin health.

Design and Synthesis of Hydroxamate-Based Matrix Metalloproteinase-2 Inhibitors for Anti-Photoaging

Matrix metalloproteinases-2 (MMP-2) is crucial for collagen degradation at the dermal-epidermal junction, contributing to skin aging and photoaging. This study presents a series of hydroxamate-based inhibitors selectively targeting MMP-2. Through structure-activity relationship analysis, we systematically modified the N-arylsulfonyl group and amino acid backbone to enhance MMP-2 selectivity. Compounds 1ad, 1af, and 4an showed strong MMP-2 inhibition, with 1ad demonstrating nanomolar-level selectivity. Zymogram assays revealed 30-60% MMP-2 activity reduction, while gene expression analysis confirmed post-transcriptional inhibition. These hydroxamate-based inhibitors are promising candidates for anti-photoaging applications, combining potent MMP-2 inhibition with simplified synthesis, supporting their potential for large-scale cosmetic formulations aimed at improving skin firmness and reducing wrinkles.

Influences on Skin and Intrinsic Aging: Biological, Environmental, and Therapeutic Insights

BACKGROUND/AIM

Aging involves a progressive deterioration in physiological functions and increased disease susceptibility, impacting all organs and tissues, especially the skin. Skin aging is driven by intrinsic factors (genetics, cellular metabolism) and extrinsic factors (environment, lifestyle). Understanding these mechanisms is vital for promoting healthy aging and mitigating skin aging effects. This review aims to summarize the key factors influencing skin and intrinsic aging, providing a comprehensive understanding of the underlying mechanisms and contributing elements.

METHODS

A comprehensive literature review was conducted, focusing on peer-reviewed journals, clinical studies, and scientific reviews published within the last two decades. The inclusion criteria prioritized studies that addressed intrinsic and extrinsic mechanisms of skin aging. To ensure the relevance and quality of the selected sources, a systematic approach was used to assess study design, sample size, methodology, and the significance of the findings in the context of skin aging.

FINDINGS

The review identifies major internal factors, such as cellular senescence, genetic predisposition, telomere shortening, oxidative stress, hormonal changes, metabolic processes, and immune system decline, as pivotal contributors to intrinsic aging. External factors, including UV radiation, pollution, lifestyle choices (diet, smoking, alcohol consumption, and sleep patterns), and skincare practices, significantly influence extrinsic skin aging. The interplay between these factors accelerates aging processes, leading to various clinical manifestations like wrinkles, loss of skin elasticity, pigmentation changes, and texture alterations.

CONCLUSION

A comprehensive understanding of both extrinsic and intrinsic factors contributing to skin aging is essential for developing effective prevention and intervention strategies. The insights gained from this review highlight the importance of a multifaceted approach, incorporating lifestyle modifications, advanced skincare routines, and emerging therapeutic technologies, to mitigate the effects of aging and promote healthier, more resilient skin.

Mitigation of ultraviolet-induced erythema and inflammation by para-hydroxycinnamic acid in human skin

OBJECTIVE

To evaluate whether p-hydroxycinnamic acid (pHCA) alone and in combination with niacinamide (Nam) can mitigate UV-induced erythema, barrier disruption, and inflammation.

METHODS

Three independent placebo-controlled double-blinded studies were conducted on female panellists who were pretreated on sites on their backs for 2 weeks with skin care formulations which contained 0.3% or 1% pHCA with 5% Nam, 1% pHCA alone, 1.8% octinoxate, or control formula. Treated sites were then exposed to 1.5 minimal erythemal dose (MED) solar simulated radiation (SSR) and had chromameter and expert grading measures for erythema, barrier integrity via TEWL, and the skin surface IL-1RA/IL-1α inflammatory biomarkers isolated from D-Squame tapes.

RESULTS

Across the three independent studies, pHCA alone or in combination with Nam showed a significant mitigation of UV-induced erythema, barrier disruption, and levels of the surface inflammatory biomarkers IL-1RA/IL-1α. The cinnamate analogue Octinoxate did not replicate the effects of pHCA.

CONCLUSION

The study results show that pHCA alone or in combination with Nam can mitigate UV-induced damage to skin. These include mitigation of UV-induced erythema as measured by instrument and expert grade visualization. Additionally, pHCA with Nam protected damage to the barrier and reduced the induction of the SASP-related surface inflammatory biomarker IL-1RA/IL-1α. The inability of Octinoxate to have any protective effect and the detection of low levels of pHCA on skin surface after 24 h of application supports that these effects are based on a biological response to pHCA. These findings add to the body of evidence that pHCA alone or in combination with Nam can enhance the skin's biological response to UV-induced damage. This supports pHCA can potentially impact aging and senescence, thereby maintain skin's functionality and appearance.

Low-Crosslinked Hyaluronic Acid Injections in the Superficial Fat Layer for Facial Rejuvenation in Chinese Patients: A Retrospective Clinical Study

Objective To evaluate the clinical efficacy of low-crosslinked hyaluronic acid (HA) injections in the superficial fat layer for facial rejuvenation in Chinese patients. Methods A total of 30 patients were treated between July 2023 and October 2024, with three sessions of low-crosslinked HA injections spaced one month apart. The injections were administered using the fanning technique into the superficial fat layer. Patients were followed up at one month and three months post-treatment. Skin improvements were assessed using smart skin analysis equipment, while overall aesthetic improvement was evaluated using the Global Aesthetic Improvement Scale (GAIS). Patient pain levels, satisfaction, and adverse reactions were also recorded. Results Significant improvements in facial wrinkles, pore size, and pigmentation were observed at one and three months post-treatment, as measured by skin analysis equipment, compared to baseline. GAIS scores confirmed facial rejuvenation in all patients. Patient satisfaction was 100% at one month and 93.3% at three months. Mild discomfort was reported by 90% of patients, with an average pain score of 3.40 ± 1.55, resolving within 24 hours. Two patients experienced mild bruising, which resolved within a week. No other adverse reactions were noted. Conclusion Low-crosslinked HA injection in the superficial fat layer is an effective and safe method for facial rejuvenation, offering high patient satisfaction. No serious adverse events were reported during the follow-up period.

Epigenetics in Skin Homeostasis and Ageing

The skin, the largest organ of the human body, plays numerous essential roles, including protection against environmental hazards and the regulation of body temperature. The processes of skin homeostasis and ageing are complex and influenced by many factors, with epigenetic mechanisms being particularly significant. Epigenetics refers to the regulation of gene expression without altering the underlying DNA sequence. The dynamic nature of the skin, characterized by constant cellular turnover and responsiveness to environmental stimuli, requires precise gene activity control. This control is largely mediated by epigenetic modifications such as DNA methylation, histone modification, and regulation by non-coding RNAs. The present review endeavours to provide a comprehensive exploration and elucidation of the role of epigenetic mechanisms in regulating skin homeostasis and ageing. By integrating our current knowledge of epigenetic modifications with the latest advancements in dermatological research, we can gain a deeper comprehension of the complex regulatory networks that govern skin biology. Understanding these mechanisms also presents promising avenues for therapeutic interventions aimed at improving skin health and mitigating age-related skin conditions.

Stress-Driven Production of γ-Aminobutyric Acid Using Non-Conventional Yeast Strains Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075

γ-Aminobutyric acid (GABA) is a valuable amino acid widely used in food, healthcare, and agriculture. GABA bioproduction by budding yeasts has been commonly reported, but related studies using non-conventional yeasts remain limited. In this study, two non-conventional natural yeast strains, namely, Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075, were identified as promising GABA producers, and M. reukaufii JMY075 was discovered to be a GABA producer. Enhanced GABA production was observed in the two yeast strains under stress conditions, including high temperature and high ethanol and acetic acid levels. In particular, K. marxianus JMY140K showed 7.93 times higher GABA titers under thermal stress than that of the control. External stress conditions significantly influenced the GABA production of these two yeast strains. The culture filtrate of K. marxianus JMY140K also showed promising activities in human skin cells. In addition, K. marxianus JMY140K could also produce GABA using rice straw hydrolysate, which indicated that it has the potential to produce GABA using renewable biomass. Our studies provide insight for further enhancing the GABA production of natural yeasts and promoting its biotechnology applications.

Novel peptide inhibitor of matrix Metalloproteinases-1 from pufferfish skin collagen hydrolysates and its potential Photoprotective activity via the MAPK/AP-1 signaling pathway

Takifugu bimaculatus, a pufferfish species farmed in Fujian Province, is known for its non-toxic flesh and collagen-rich skin. We identified a novel collagen-derived matrix metalloproteinase 1 (MMP-1) inhibitory peptide, from T. bimaculatus skin with potent anti-photoaging properties. Using multistage membrane and gel filtration chromatography, we purified low-molecular-weight collagen peptides from T. bimaculatus skin (TBSCH-L). Nano-HPLC-MS/MS and virtual molecular docking screening were employed to identify peptides targeting MMP-1. Four anti-photoaging peptide sequences, GDRGFPGE, GPAGPRGA, FPGGPGAK, and RGFPGGDGAA, were identified by assessing the viability of UVB-induced L929 cells. GPAGPRGA (GP8) exhibited the highest MMP-1 inhibitory activity and cellular photoprotection. Surface plasmon resonance confirmed high-affinity binding between MMP-1 and GP8. GP8 significantly reduced intracellular reactive oxygen species (ROS) levels and enhanced superoxide dismutase activity at concentrations of 100-200 μM in UVB-exposed L929 cells. At 200 μM, GP8 significantly decreased malondialdehyde content. GP8 also accelerated migration of L929 cells, demonstrating its wound-healing potential, markedly reduced intracellular β-galactosidase levels, and downregulated phosphorylation levels of extracellular signal-regulated kinases, c-Jun N-terminal kinases, p38 proteins, and c-Jun protein expression within the MAPK/AP-1 signaling pathway, thereby lowering MMP expression in L929 cells. Exposure of zebrafish to 25-100 μM GP8 effectively mitigated UVB-induced damage, restoring up to 31.2 % of caudal fin integrity, while significantly reducing ROS levels, lipid peroxidation, and cellular apoptosis. GP8, a novel marine-derived anti-photoaging peptide, holds promise for applications in cosmetic and functional food sectors.

Adipose tissue protects against skin photodamage through CD151- and AdipoQ- EVs

To clarify the protective effects of subcutaneous adipose tissue (SAT) against photodamage, we utilized nude mouse skin with or without SAT. Skin and fibroblasts were treated with adipose tissue-derived extracellular vesicles (AT-EVs) or extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) to demonstrate that SAT protects the overlying skin from photodamage primarily through AT-EVs. Surprisingly, AT-EVs stimulated fibroblast proliferation more rapidly than ADSC-EVs did. The yield of AT-EVs from the same volume of AT was 200 times greater than that of ADSC-EVs. To compare the differences between AT-EVs and ADSC-EVs, we used a proximity barcoding assay (PBA) to analyze the surface proteins on individual particles of these two types of EVs. PBA analysis revealed that AT-EVs contain diverse subpopulations, with 83.42% expressing CD151, compared to only 1.98% of ADSC-EVs. Furthermore, AT-EVs are internalized more rapidly by cells than ADSC-EVs, as our study demonstrated that CD151-positive AT-EVs were endocytosed more quickly than their CD151-negative counterparts. Additionally, adiponectin in AT-EVs activated the AMPK pathway and inhibited the NF-κB pathway, enhancing fibroblast protection against photodamage. The significantly higher yield and faster acquisition of AT-EVs compared to ADSC-EVs underscore their potential for broader applications.

Integration of transcriptomics and spatial biology analyses reveals Galactomyces ferment filtrate promotes epidermal interconnectivity via induction of keratinocyte differentiation, proliferation and cellular bioenergetics

OBJECTIVE

Human skin is the first line of defence from environmental factors such as solar radiation and is susceptible to premature ageing, including a disruption in epidermal differentiation and homeostasis. We evaluated the impact of a Galactomyces Ferment Filtrate (GFF) on epidermal differentiation and response to oxidative stress.

METHODS

We used transcriptomics, both spatial and traditional, to assess the impact of GFF on epidermal biology and homeostasis in keratinocytes (primary or immortalized) and in ex vivo skin explant tissue. The effect of GFF on cell adhesion rates, cellular ATP levels and proliferation rates were quantitated. Oxidative phosphorylation and glycolytic rates were measured under normal and stress-induced conditions.

RESULTS

Transcriptomics from keratinocytes and ex vivo skin explants from multiple donors show GFF induces keratinocyte differentiation, skin barrier development and cell adhesion while simultaneously repressing cellular stress and inflammatory related processes. Spatial transcriptomics profiling of ex vivo skin indicated basal keratinocytes at the epidermal-dermal junction and cornifying keratinocytes in the top layer of the epidermis as the primary cell types influenced by GFF treatment. Additionally, GFF significantly increases crosstalk between suprabasal and basal keratinocytes. To support these findings, we show that GFF can significantly increase cell adhesion and proliferation in keratinocytes. GFF also protected overall cellular bioenergetics under metabolic or oxidative stress conditions.

CONCLUSION

Our findings provide novel insights into cellular differences and epidermal spatial localization in response to GFF, supporting previous findings that this filtrate has a significant impact on epidermal biology and homeostasis, particularly on spatially defined crosstalk. We propose that GFF can help maintain epidermal health by enhancing keratinocyte crosstalk and differentiation/proliferation balance as well as promoting an enhanced response to stress.

Age-dependent changes in skin features and perceived facial appearance in women of five ethnic groups

OBJECTIVE

Research documents effects of skin features on assessments of age, health and attractiveness of female faces. Ethnic variation also has been reported for the impact of age-related changes in skin features on face assessments. Here, we investigate women's self-ratings across age cohorts and ethnic groups and discrepancies with (non-expert) assessor ratings of facial appearance together with age-dependent changes in skin features.

METHODS

Faces of women 20-65 years from five ethnic groups (each n = 36) were imaged. Participants provided self-ratings of age, health and attractiveness, and were judged on these attributes by members of the same ethnic group (each n = 120). Digital image analysis was used to quantify skin gloss, tone evenness, wrinkling and sagging. Age-dependent changes in ratings and skin features within and between ethnic groups were assessed by comparing information from 10-year cohorts. We also tested whether menopausal status could be predicted by self-ratings, assessor ratings and image-based skin features.

RESULTS

Women of all ethnic groups judged themselves younger and higher in attractiveness and health compared to third-party assessors, with the largest discrepancies for age in French women and for attractiveness and health in South African women. In Indian and South African women, specular gloss and skin tone evenness were lower compared to other participants, and sagging was higher in Indian, Japanese and South African women compared to Chinese and French women. Women's menopausal status could be predicted from assessor ratings and image-based skin features but not from self-ratings.

CONCLUSION

There are differences between women's self-ratings and assessor ratings of facial appearance. These discrepancies vary with female age and ethnicity. Age and ethnicity effects also are evident in age-dependent changes in skin features within and across ethnic groups, which together with assessor (but not self-) ratings of facial appearance predict menopausal status.

Comparative study between the efficacy of prabotulinum toxin-A versus onabotulinum toxin-A for the treatment of upper facial expression lines

BACKGROUND

Botulinum Toxin (BoNTA) is the most used nonsurgical aesthetic procedure to treat facial expression lines.

AIMS

This study compared the efficacy of Prabotulinum toxin-A, a novel BoNTA that originates from Clostridium botulinum Hall-A, with onabotulinum toxin-A in treating facial expression lines using the Facial Wrinkle Scale (FWS) and FACE-Q questionnaires.

METHODS

This was an experimental, comparative, longitudinal, open-label, and prospective study. Patients aged between 25 and 40 years with upper-third facial expression lines were included. Follow-ups were made at three, seven, 30, and 120 days.

RESULTS

A total of 26 patients were included: 20 female, and six males, with a mean age of 28.26 years. An average of 31.00 IU and 31.38 IU were administered to the onabotulinum and prabotulinum groups, respectively. The prabotulinum group demonstrated superiority in FWS and Face-Q scores between the first and third days (p ≤ 0.001, p < 0.001, respectively), which continued on day 7. By day 30, there were no differences in the scores of the two questionnaires.

CONCLUSIONS

Prabotulinum toxin-A is a safe and effective treatment for upper-third facial wrinkles. On day three and seven, the results suggest that prabotulinum toxin-A has a quicker onset of action than onabotulinum toxin-A. On days 30 and 120, both groups showed similar FWS and Face-Q scores.

Differences in cell subsets between sun-exposed and unexposed skin: preliminary single-cell sequencing and biological analysis from a single case

Introduction

The composition and subsets of skin cells continuously change in a dynamic manner. However, the specific microcosmic alterations of human photoaged skin, independent of chronologic aging, remain unclear and have been infrequently analyzed. This study aimed to evaluate the biological processes and mechanisms underlying cell-subgroup alterations in skin photoaging.

Methods

We utilized single-cell sequencing and biological analysis from a single case to investigate the effects of photoaging. Skin punch biopsies were taken from sun-exposed forearm skin and unexposed buttock skin from the same individual for comparative analysis.

Results

Our analysis identified 25 cell clusters and 12 skin cell types, revealing significant changes in unique gene expressions between the sun-exposed and unexposed skin samples. A comparison of cell numbers within each cluster revealed 9 dominant cell clusters in sun-exposed skin and 16 dominant cell clusters in unexposed skin. Enrichment analysis indicated that PD-L1 expression and the PD-1 checkpoint pathway were more prominent in sun-exposed skin, while MAPK, TNF-alpha, TGF-beta, and apoptosis pathways were more enriched in hair follicle cells of sun-exposed skin.

Discussion

This study reveals changes in cell components in photoaged skin from a single case and provides novel insights into cellular subpopulations and pathology during repeated UVA-induced skin damage. These findings enhance our understanding of the complex interplay between different cells in photoaged skin and offer potential targets for preventing human skin photoaging and UV-induced skin cancers.

Ultraviolet (UV) radiation: a double-edged sword in cancer development and therapy

It has long been widely acknowledged that ultraviolet (UV) light is an environment risk factor that can lead to cancer, particularly skin cancer. However, it is worth noting that UV radiation holds potential for cancer treatment as a relatively high-energy electromagnetic wave. With the help of nanomaterials, the role of UV radiation has caught increasing attention in cancer treatment. In this review, we briefly summarized types of UV-induced cancers, including malignant melanoma, squamous cell carcinoma, basal cell carcinoma, Merkel cell carcinoma. Importantly, we discussed the primary mechanisms underlying UV carcinogenesis, including mutations by DNA damage, immunosuppression, inflammation and epigenetic alterations. Historically limited by its shallow penetration depth, the introduction of nanomaterials has dramatically transformed the utilization of UV light in cancer treatment. The direct effect of UV light itself generally leads to the suppression of cancer cell growth and the initiation of apoptosis and ferroptosis. It can also be utilized to activate photosensitizers for reactive oxygen species (ROS) production, sensitize radiotherapy and achieve controlled drug release. Finally, we comprehensively weigh the significant risks and limitations associated with the therapeutic use of UV radiation. And the contradictory effect of UV exposure in promoting and inhibiting tumor has been discussed. This review provides clues for potential clinical therapy as well as future study directions in the UV radiation field. The precise delivery and control of UV light or nanomaterials and the wavelength as well as dose effects of UV light are needed for a thorough understanding of UV radiation.

Picosecond Alexandrite Laser With Diffractive Lens Array Combined With Long-Pulse Alexandrite Laser for the Treatment of Facial Photoaging in Chinese Women: A Retrospective Study

BACKGROUND AND OBJECTIVES

Facial photoaging is a type of facial skin aging induced mainly by exogenous factors (ultraviolet radiation) and often manifests itself in the form of hyperpigmentation, telangiectasia, roughness, increase in fine lines/wrinkles, and enlarged pores. Recently, picosecond lasers have become an emerging option for the treatment of facial photoaging, and long-pulse alexandrite lasers (LPAL) have demonstrated promising potential in the treatment of photoaging-related symptoms. This study aimed to evaluate the efficacy and safety of picosecond alexandrite laser (PSAL) with diffractive lens array (DLA) combined with LPAL for facial photoaging.

METHODS

This is a retrospective study of 20 Chinese female patients with facial photoaging who received PSAL with DLA combined with LPAL during a 1-year period. All patients were treated every 4 weeks for a total of three treatments. Objective indicators of facial photoaging and patient satisfaction were evaluated before each treatment, and pain scores and adverse effects were recorded after each treatment.

RESULTS

Compared with baseline, patients showed significant differences in all facial photoaging indices (p < 0.01). After receiving three treatments, there was a 20.1% decrease in the pigmentation index, a 23.9% decrease in the erythema index, a 34.5% decrease in the texture index, a 28.4% decrease in the fine lines index, a 56% decrease in the pore index, a 9.3% elevation and a 17.1% decrease in elasticity R2 and F4, respectively, and a 55% decrease in sebum content. The mean satisfaction score for the three treatments was 4.67 (3.33, 5.00), and the mean visual analogue scale (VAS) pain score was 7.00. No serious adverse effects such as post-inflammatory hyperpigmentation (PIH), hypopigmentation, or blistering were observed at the treatment site during the treatment period.

CONCLUSION

PSAL with DLA combined with LPAL for the treatment of facial photoaging with significant efficacy, high patient satisfaction, and minimal adverse effects.

Water-Responsive Self-Contractive Silk-Based Skin Anti-Aging Tensioners with Customizable Biofunctions

Skin anti-aging treatments have become increasingly popular. Currently, the prevalent treatment method involves implanting skin tension regulation threads (skin lifting threads) under the skin, and radiofrequency treatments. In this study, inspired by the natural supercontraction of spider silk, the molecular structure of silk fibroin fibers is modulated into an oriented configuration. This modification endows silk proteins with water-responsive self-contraction capabilities, leading to the development of innovative self-contracting silk-based skin tensioners (SSSTs). To align with clinical requirements, skin tension regulation materials are functionalized by testing for their self-contraction, near-infrared laser heating function, and bacteriostatic properties. The SSSTs exhibited remarkable self-contraction properties, drug-loading and sustained-release capabilities, notable antibacterial effects, controllable degradation, and good biocompatibility. Moreover, the near-infrared light heating function effectively increased subcutaneous temperature, demonstrating its potential for enhancing and prolonging skin lifting effects. Therefore, SSSTs can be applied for skin tension regulation to improve and delay skin aging. The results may pave the way for novel strategies in skin rejuvenation, with broad implications for the field of skin anti-aging.

Cosmeceuticals in photoaging: A review

BACKGROUND

Photoaging is a process of the architecture of normal skin damaged by ultraviolet radiation. Topical cosmeceuticals have been used to treat this condition. The authors aimed to understand the mechanism and level of evidence of different commonly used cosmeceuticals used to treat photodamaged skin.

OBJECTIVE

A range of commonly used topical cosmeceuticals (botanicals, peptides, and hydroquinone) has been used in cosmetic medicine for many years to treat photodamaged skin. This review article compares their efficacy and level of evidence.

MATERIAL AND METHODS

This study was a systematic review to evaluate the efficacy of different topical cosmeceuticals. Keywords including "Photoaging," "Azelaic acid," "Soy," "Green Tea," "Chamomile," "Ginkgo," "Tea Tree Oil," "Resveratrol," "Cucumber," "Ginseng," "Centella asiatica," "Licorice Root," "Aloe Vera," "Peptides," "Argireline," "Hydroquinone," were typed on OVID, PUBMED, MEDLINE for relevant studies published on photoaging treatment.

RESULTS

Most of the evidence behind cosmeceuticals is of high-quality ranging from Level I to Level II. In particular, the evidence base behind peptides is the strongest with most studies achieving Level Ib status in the evidence hierarchy.

CONCLUSION

Topical cosmeceuticals like botanicals, peptides and hydroquinone can effectively treat photodamaged skin.

Mechanisms of Senescence and Anti-Senescence Strategies in the Skin

The skin is the layer of tissue that covers the largest part of the body in vertebrates, and its main function is to act as a protective barrier against external environmental factors, such as microorganisms, ultraviolet light and mechanical damage. Due to its important function, investigating the factors that lead to skin aging and age-related diseases, as well as understanding the biology of this process, is of high importance. Indeed, it has been reported that several external and internal stressors contribute to skin aging, similar to the aging of other tissues. Moreover, during aging, senescent cells accumulate in the skin and express senescence-associated factors, which act in a paracrine manner on neighboring healthy cells and tissues. In this review, we will present the factors that lead to skin aging and cellular senescence, as well as ways to study senescence in vitro and in vivo. We will further discuss the adverse effects of the accumulation of chronic senescent cells and therapeutic agents and tools to selectively target and eliminate them.

The protection role of human growth hormone on skin cells following ultraviolet B exposure

BACKGROUND

Ultraviolet-B (UVB) radiation is the leading environmental cause of skin damage and photoaging. The epidermis and dermis layers of the skin mainly absorb UVB. UVB stimulates apoptosis, cell cycle arrest, generation of reactive oxygen species, and degradation of collagen and elastin fibers.

OBJECTIVE

This study investigated the potential of human growth hormone (hGH) in protecting the skin fibroblasts and keratinocytes (HFFF-2 and HaCaT cell lines) from UVB-induced damage.

METHODS

The MTT assay was performed to evaluate UVB-induced mitochondrial damage via assessing the mitochondrial dehydrogenase activity, and flow cytometry was carried out to investigate the effects of UVB and hGH on the cell cycle and apoptosis of UVB-irradiated cells. In addition, the fold change mRNA expression levels of Type I collagen and elastin in HFFF-2 cells were evaluated using the qRT-PCR method following UVB exposure.

RESULTS

We observed that treatment of cells with hGH before UVB exposure inhibited UVB-induced loss of mitochondrial dehydrogenase activity, apoptosis, and sub-G1 population formation in both cell lines. We also found that hGH-treated HFFF-2 cells showed up-regulated mRNA expression of Type I collagen, elastin, and IGF-1 in response to UVB irradiation.

CONCLUSION

These findings suggest hGH as a potential anti-UVB compound that can protect skin cells from UVB-induced damage. Our findings merit further investigation and can be used to better understand the role of hGH in skin photoaging.

Para-Hydroxycinnamic Acid Mitigates Senescence and Inflammaging in Human Skin Models

Para-hydroxycinnamic acid (pHCA) is one of the most abundant naturally occurring hydroxycinnamic acids, a class of chemistries known for their antioxidant properties. In this study, we evaluated the impact of pHCA on different parameters of skin aging in in vitro skin models after H2O2 and UV exposure. These parameters include keratinocyte senescence and differentiation, inflammation, and energy metabolism, as well as the underlying molecular mechanisms. Here we demonstrate that pHCA prevents oxidative stress-induced premature senescence of human primary keratinocytes in both 2D and 3D skin models, while improving clonogenicity in 2D. As aging is linked to inflammation, referred to as inflammaging, we analyzed the release of IL-6, IL-8, and PGE2, known to be associated with senescence. All of them were downregulated by pHCA in both normal and oxidative stress conditions. Mechanistically, DNA damage induced by oxidative stress is prevented by pHCA, while pHCA also exerts a positive effect on the mitochondrial and glycolytic functions under stress. Altogether, these results highlight the protective effects of pHCA against inflammaging, and importantly, help to elucidate its potential mechanisms of action.

Salvianolic acid B protects against UVB-induced skin aging via activation of NRF2

BACKGROUND

Prolonged exposure to sun radiation may result in harmful skin photoaging. Therefore, discovering novel anti-photoaging treatment modalities is critical. An active component isolated from Salvia miltiorrhiza (SM), Salvianolic acid B (Sal-B), is a robust antioxidant and anti-inflammatory agent. This investigation aimed to discover the therapeutic impact and pathways of salvianolic acid B for UVB-induced skin photoaging, an area that remains unexplored.

METHODS

We conducted in vitro experiments on human dermal fibroblasts (HDFs) exposed to UVB radiation, assessing cellular senescence, superoxide dismutase (SOD) activity, cell viability, proliferation, migration, levels of reactive oxygen species (ROS), and mitochondrial health. The potential mechanism of Sal-B was analyzed using RNA sequencing, with further validation through Western blotting, PCR, and nuclear factor erythroid 2-related factor 2 (NRF2) silencing methods. In vivo, a model of skin photoaging induced by UVB in nude mice was employed. The collagen fiber levels were assessed utilizing hematoxylin and eosin (H&E), Masson, and Sirus red staining. Additionally, NRF2 and related gene and protein expression levels were identified utilizing PCR and Western blotting.

RESULTS

Sal-B was found to significantly counteract photoaging in UVB-exposed skin fibroblasts, reducing aging-related decline in fibroblast proliferation and an increase in apoptosis. It was observed that Sal-B aids in protecting mitochondria from excessive ROS production by promoting NRF2 nuclear translocation. NRF2 knockdown experiments established its necessity for Sal-B's anti-photoaging effects. The in vivo studies also verified Sal-B's anti-photoaging efficacy, surpassing that of tretinoin (Retino-A). These outcomes offer novel insights into the contribution of Sal-B in developing clinical treatment modalities for UVB-induced photodamage in skin fibroblasts.

CONCLUSION

In this investigation, we identified the Sal-B protective impact on the senescence of dermal fibroblasts and skin photoaging induced by radiation of UVB. The outcomes suggest Sal-B as a potential modulator of the NRF2 signaling pathway.

Prevention of UVB-Induced Photoaging by an Ethyl Acetate Fraction from Allomyrina dichotoma Larvae and Its Potential Mechanisms in Human Dermal Fibroblasts

Allomyrina dichotoma larvae (ADL) is an insect type that is used ethnopharmacologically to treat various diseases; however, its use as an antiaging treatment has not been widely studied. Previously, we found that an ethyl acetate (EA) fraction derived from an ADL extract (ADLE) has a high polyphenol content and antioxidant properties. In this study, we identified the underlying molecular mechanism for the protective effect of the EA fraction against UVB-induced photodamage in vitro and ex vivo. UVB treatment increased intracellular reactive oxygen species levels and DNA damage; the latter of which was significantly decreased following cotreatment with the EA fraction. Biological markers of aging, such as p16INK4a, p21WAF1, and senescence-associated β-gal levels, were induced by UVB treatment but significantly suppressed following EA-fraction treatment. UVB-induced upregulation of matrix metalloproteinase (MMP)-1 and downregulation of COL1A1 were also reversed by EA-fraction treatment in both cells and a 3D skin model, which resulted in increased keratin and collagen deposition. Moreover, EA-fraction treatment inhibited the phosphorylation of MAPKs (p38, ERK, and JNK) and nuclear factor (NF-)-kB and decreased the levels of inflammatory cytokines in UVB-treated cells. The results indicate that an EA fraction from ADLE ameliorates UVB-induced degradation of COL1A1 by inhibiting MMP expression and inactivating the MAPK/NF-κB p65/AP-1 signaling pathway involved in this process.

Sunproofing from within: A deep dive into oral photoprotection strategies in dermatology

BACKGROUND

Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others.

METHODS

A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health.

RESULTS

Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection.

CONCLUSION

Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.

New Insights into the Role of PPARγ in Skin Physiopathology

Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor expressed in many tissues, including skin, where it is essential for maintaining skin barrier permeability, regulating cell proliferation/differentiation, and modulating antioxidant and inflammatory responses upon ligand binding. Therefore, PPARγ activation has important implications for skin homeostasis. Over the past 20 years, with increasing interest in the role of PPARs in skin physiopathology, considerable effort has been devoted to the development of PPARγ ligands as a therapeutic option for skin inflammatory disorders. In addition, PPARγ also regulates sebocyte differentiation and lipid production, making it a potential target for inflammatory sebaceous disorders such as acne. A large number of studies suggest that PPARγ also acts as a skin tumor suppressor in both melanoma and non-melanoma skin cancers, but its role in tumorigenesis remains controversial. In this review, we have summarized the current state of research into the role of PPARγ in skin health and disease and how this may provide a starting point for the development of more potent and selective PPARγ ligands with a low toxicity profile, thereby reducing unwanted side effects.

The Potential of Exercise on Lifestyle and Skin Function: Narrative Review

BACKGROUND

The skin is an important organ of the human body and has moisturizing and barrier functions. Factors such as sunlight and lifestyle significantly affect these skin functions, with sunlight being extremely damaging. The effects of lifestyle habits such as smoking, diet, and sleep have been studied extensively. It has been found that smoking increases the risk of wrinkles, while excessive fat and sugar intake leads to skin aging. Lack of sleep and stress are also dangerous for the skin's barrier function. In recent years, the impact of exercise habits on skin function has been a focus of study. Regular exercise is associated with increased blood flow to the skin, elevated skin temperature, and improved skin moisture. Furthermore, it has been shown to improve skin structure and rejuvenate its appearance, possibly through promoting mitochondrial biosynthesis and affecting hormone secretion. Further research is needed to understand the effects of different amounts and content of exercise on the skin.

OBJECTIVE

This study aims to briefly summarize the relationship between lifestyle and skin function and the mechanisms that have been elucidated so far and introduce the expected effects of exercise on skin function.

METHODS

We conducted a review of the literature using PubMed and Google Scholar repositories for relevant literature published between 2000 and 2022 with the following keywords: exercise, skin, and life habits.

RESULTS

Exercise augments the total spectrum power density of cutaneous blood perfusion by a factor of approximately 8, and vasodilation demonstrates an enhancement of approximately 1.5-fold. Regular exercise can also mitigate age-related skin changes by promoting mitochondrial biosynthesis. However, not all exercise impacts are positive; for instance, swimming in chlorinated pools may harm the skin barrier function. Hence, the exercise environment should be considered for its potential effects on the skin.

CONCLUSIONS

This review demonstrates that exercise can potentially enhance skin function retention.

The Skin Molecular Ecosystem Holds the Key to Nevogenesis and Melanomagenesis

Early detection of melanoma is critical to good patient outcomes, but we still know little about the mechanisms of early melanoma development. Normal epidermis has many of the sequence variants and genetic architecture disruptions found in both benign nevi, melanomas, and other skin cancers, yet continues to behave more or less normally. One hypothesis is that many melanocytes in this context are "tumor competent" but are regulated by the microenvironment provided by the surrounding keratinocytes to inhibit progress to nevi or melanoma. There is evidence of accumulating disorder in several measures of the genomic and epigenomic landscape from normal skin through nevi to melanoma that may be key to promoting nevogenesis and melanomagenesis.

Nanotechnology as a Promising Method in the Treatment of Skin Cancer

The incidence of skin cancer continues to grow. There are an estimated 1.5 million new cases each year, of which nearly 350,000 are melanoma, which is often fatal. Treatment is challenging and often ineffective, with conventional chemotherapy playing a limited role in this context. These disadvantages can be overcome by the use of nanoparticles and may allow for the early detection and monitoring of neoplastic changes and determining the effectiveness of treatment. This article briefly reviews the present understanding of the characteristics of skin cancers, their epidemiology, and risk factors. It also outlines the possibilities of using nanotechnology, especially nanoparticles, for the transport of medicinal substances. Research over the previous decade on carriers of active substances indicates that drugs can be delivered more accurately to the tumor site, resulting in higher therapeutic efficacy. The article describes the application of liposomes, carbon nanotubes, metal nanoparticles, and polymer nanoparticles in existing therapies. It discusses the challenges encountered in nanoparticle therapy and the possibilities of improving their performance. Undoubtedly, the use of nanoparticles is a promising method that can help in the fight against skin cancer.

Skin Protection by Carotenoid Pigments

Sunlight, despite its benefits, can pose a threat to the skin, which is a natural protective barrier. Phototoxicity caused by overexposure, especially to ultraviolet radiation (UVR), results in burns, accelerates photoaging, and causes skin cancer formation. Natural substances of plant origin, i.e., polyphenols, flavonoids, and photosynthetic pigments, can protect the skin against the effects of radiation, acting not only as photoprotectors like natural filters but as antioxidant and anti-inflammatory remedies, alleviating the effects of photodamage to the skin. Plant-based formulations are gaining popularity as an attractive alternative to synthetic filters. Over the past 20 years, a large number of studies have been published to assess the photoprotective effects of natural plant products, primarily through their antioxidant, antimutagenic, and anti-immunosuppressive activities. This review selects the most important data on skin photodamage and photoprotective efficacy of selected plant carotenoid representatives from in vivo studies on animal models and humans, as well as in vitro experiments performed on fibroblast and keratinocyte cell lines. Recent research on carotenoids associated with lipid nanoparticles, nanoemulsions, liposomes, and micelles is reviewed. The focus was on collecting those nanomaterials that serve to improve the bioavailability and stability of carotenoids as natural antioxidants with photoprotective activity.

Amaranthus cruentus L. Seed Oil Counteracts UVA-Radiation-Induced Inhibition of Collagen Biosynthesis and Wound Healing in Human Skin Fibroblasts

The effect of Amaranthus cruentus L. seed oil (AmO) on collagen biosynthesis and wound healing was studied in cultured human dermal fibroblasts exposed to UVA radiation. It was found that UVA radiation inhibited collagen biosynthesis, prolidase activity, and expression of the β1-integrin receptor, and phosphorylated ERK1/2 and TGF-β, while increasing the expression of p38 kinase. The AmO at 0.05-0.15% counteracted the above effects induced by UVA radiation in fibroblasts. UVA radiation also induced the expression and nuclear translocation of the pro-inflammatory NF-κB factor and enhanced the COX-2 expression. AmO effectively suppressed the expression of these pro-inflammatory factors induced by UVA radiation. Expressions of β1 integrin and IGF-I receptors were decreased in the fibroblasts exposed to UVA radiation, while AmO counteracted the effects. Furthermore, AmO stimulated the fibroblast's migration in a wound healing model, thus facilitating the repair process following exposure of fibroblasts to UVA radiation. These data suggest the potential of AmO to counteract UVA-induced skin damage.

Q-switched 1064 nm Nd: YAG laser restores skin photoageing by activating autophagy by TGFβ1 and ITGB1

Excessive ultraviolet B ray (UVB) exposure to sunlight results in skin photoageing. Our previous research showed that a Q-switched 1064 nm Nd: YAG laser can alleviate skin barrier damage through miR-24-3p. However, the role of autophagy in the laser treatment of skin photoageing is still unclear. This study aims to investigate whether autophagy is involved in the mechanism of Q-switched 1064 nm Nd: YAG in the treatment of skin ageing. In vitro, primary human dermal fibroblast (HDF) cells were irradiated with different doses of UVB to establish a cell model of skin photoageing. In vivo, SKH-1 hairless mice were irradiated with UVB to establish a skin photoageing mouse model and irradiated with laser. The oxidative stress and autophagy levels were detected by western blot, immunofluorescence and flow cytometer. String was used to predict the interaction protein of TGF-β1, and CO-IP and GST-pull down were used to detect the binding relationship between TGFβ1 and ITGB1. In vitro, UVB irradiation reduced HDF cell viability, arrested cell cycle, induced cell senescence and oxidative stress compared with the control group. Laser treatment reversed cell viability, senescence and oxidative stress induced by UVB irradiation and activated autophagy. Autophagy agonists or inhibitors can enhance or attenuate the changes induced by laser treatment, respectively. In vivo, UVB irradiation caused hyperkeratosis, dermis destruction, collagen fibres reduction, increased cellular senescence and activation of oxidative stress in hairless mice. Laser treatment thinned the stratum corneum of skin tissue, increased collagen synthesis and autophagy in the dermis, and decreased the level of oxidative stress. Autophagy agonist rapamycin and autophagy inhibitor 3-methyladenine (3-MA) can enhance or attenuate the effects of laser treatment on the skin, respectively. Also, we identified a direct interaction between TGFB1 and ITGB1 and participated in laser irradiation-activated autophagy, thereby inhibiting UVB-mediated oxidative stress further reducing skin ageing. Q-switched 1064 nm Nd: YAG laser treatment inhibited UVB-induced oxidative stress and restored skin photoageing by activating autophagy, and TGFβ1 and ITGB1 directly incorporated and participated in this process.

Durability of the improvement of collagen I and collagen III with the use of oral isotretinoin in the treatment of photoaging

BACKGROUND

Oral isotretinoin (ISO) is the drug of choice for the treatment of severe acne. For photoaging treatment, ISO has been proved to be effective in some controlled and noncontrolled trials and is an alternative to topical retinoic acid (RA) therapy, which causes an expected skin irritation.

OBJECTIVE

To evaluate and compare the skin remodeling in patients taking ISO 20 mg 3 times a week for 12 weeks and 12 weeks after the end of the treatment to quantify collagen I and collagen III augmentation.

MATERIAL AND METHODS

Immunohistochemical studies were performed to evaluate the expression of collagen I and collagen III, metalloproteinases (MMPs) -1, -3, -7, -9, -12, and the tissue inhibitor of MMP type-1 (TIMP-1) of the skin of 20 45 to 50-year-old women through morphometry in a semiquantitative method. The inclusion criteria were facial aging 2 and 3 of Glogau's classification, with phototypes between II and V who had not entered menopause. Biopsies of the skin of the left preauricular region were performed at three different times: pre-treatment (T0), end of 12-week treatment (T1), and 12 weeks posttreatment (T2).

RESULTS

Collagen fibers I and III increased with statistical significance in T1 (50.7%; P = 0.012) but not in T2 (49.7%), which in turn was higher than in T0 (47.2%) for collagen I and T1 (33.3%; P = 0.002) but not in T2 (32.7%), and also was higher than T0 (32.0%) for collagen III. MMP-9 presented a decreased activity with statistical significance in T1 (P = 0.047) and T2 (P = 0.058). MMP-1 showed a reduction in T2 only (P = 0.015). MMPs -3, -7, -12, and TIMP-1 did not present significant modification in their expressions during or after the treatment.

CONCLUSIONS

Low-dose ISO is effective in remodeling the extracellular matrix (ECM). This study found that the increase of collagen occurs through the augmentation of both collagen I and collagen III fibers. With originality, it was possible to verify the durability of these fibers for at least 12 weeks. This may be related to the decrease in MMP-9 expression verified at the end of the treatment and 12 weeks posttreatment.

Antimicrobial Effects of Platelet-Rich Plasma and Platelet-Rich Fibrin: A Scoping Review

Platelet-rich plasma (PRP), derived from the centrifugation and subsequent separation of whole blood, results in an unusually high concentration of platelets. A newer form of platelet concentrate, platelet-rich fibrin (PRF), has also been developed. There has been significant research into the therapeutic effects of PRP, particularly in enhancing wound healing and preventing infections in surgical wounds. This scoping review aims to thoroughly evaluate preclinical and clinical evidence regarding the antimicrobial effects of PRP and PRF. In conducting this review, 612 records were examined, and 36 articles were selected for inclusion. The studies reviewed include preclinical research, such as in-vitro and in-vivo studies, and clinical trials involving human participants. The current clinical evidence suggests a notable trend towards the antimicrobial capabilities of PRP and PRF, underscoring their potential benefits in treating wounds. The application of PRP and PRF in wound management shows encouraging outcomes, but further investigation is needed to optimize their use as antimicrobial agents. Additional research, particularly randomized controlled trials, is essential to substantiate their antimicrobial effectiveness in specific diseases and types of wounds, considering their potential impact on clinical results.

In vitro and in vivo efficacy of a cosmetic product formulated with new lipid particles for the treatment of aged skin

BACKGROUND

The cumulative oxidative damage causes an acceleration in the skin aging.

OBJECTIVES

To evaluate the ability of a new patented matrix of lipid particles (SIREN CAPSULE TECHNOLOGY™) to have superior anti-aging properties due to its high sensitivity to reactive oxygen species (ROS), testing its efficacy versus free or encapsulated vitamins.

METHODS

An in vitro study was conducted to evaluate the protective effects of lipid particles using menadione as an enhancer of oxidative stress. Subsequently, in vivo studies evaluated skin hydration, skin barrier function, and smoothness and wrinkle depth. For this purpose, gels containing free or encapsulated vitamins were used as controls.

RESULTS

In vitro, the SIREN CAPSULE TECHNOLOGY™ gel shows inhibitory activity against ROS production through menadione induction. In fact, at both tested concentrations, ROS production is lower than in the control samples (placebo, free vitamins, encapsulated vitamins). In vivo, the net effect of SIREN CAPSULE TECHNOLOGY™ gel versus the others permitted to conclude that lipid particles exert a higher skin moisturizing effect (20.17%) and a stronger effect in reducing transepidermal water loss (-16.29%) after 4 weeks of treatment. As for surface analysis, a gel based on SIREN CAPSULE TECHNOLOGY™ improves the skin texture in a similar way than gel containing encapsulated vitamins (Ra and Rz variations in 4 weeks).

CONCLUSIONS

SIREN CAPSULE TECHNOLOGY™ represents an advance and a successful strategy to develop cosmetic products for the treatment of skin conditions associated with an accumulation of ROS. SIREN CAPSULE TECHNOLOGY™ represents a result-oriented breakthrough in the effective delivery of active ingredients to the skin.

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

Single-Walled Carbon Nanotube-Guided Topical Skin Delivery of Tyrosinase to Prevent Photoinduced Damage

When the skin is exposed to ultraviolet radiation (UV), it leads to the degradation of the extracellular matrix (ECM) and results in inflammation. Subsequently, melanocytes are triggered to induce tyrosinase-mediated melanin synthesis, protecting the skin. Here, we introduce a proactive approach to protect the skin from photodamage via the topical delivery of Streptomyces avermitilis-derived tyrosinase (SaTy) using single-walled carbon nanotube (SWNT). Utilizing a reverse electrodialysis (RED) battery, we facilitated the delivery of SaTy-SWNT complexes up to depths of approximately 300 μm, as analyzed by using confocal Raman microscopy. When applied to ex vivo porcine skin and in vivo albino mouse skin, SaTy-SWNT synthesized melanin, resulting in 4-fold greater UV/vis absorption at 475 nm than in mice without SaTy-SWNT. The synthesized melanin efficiently absorbed UV light and alleviated skin inflammation. In addition, the densification of dermal collagen, achieved through SaTy-mediated cross-linking, reduced photoinduced wrinkles by 66.3% in the affected area. Our findings suggest that SWNT-mediated topical protein delivery holds promise in tissue engineering applications.

Efficacy and mechanism of retinyl palmitate against UVB-induced skin photoaging

Retinyl palmitate (RP) is a vitamin A derivative that has been widely used in anti-aging and skin treatment. The aim of this study is to investigate the effect of RP on UVB (Ultraviolet radiation B) induced photoaging and its potential mechanism. Immunofluorescence assay demonstrates that RP can reduce collagen degradation in skin cells by UVB radiation and reduce apoptosis of skin cells. Cell migration assay reveals that RP can increase cell migration rate, helping to repair skin damage and restore cell viability. Immunohistochemical assays indicate that RP can significantly reduce the expression of IL-6, IL-1β, TNF-α induced by UVB radiation. Moreover, metabolomics and transcriptomics results suggest that RP regulates several metabolic pathways and gene expression, particularly in inflammatory signaling pathways, collagen synthesis and apoptosis, exhibiting significant regulatory effects. Furthermore, network pharmacological analysis predicts that RP may affect UVB-induced photoaging by regulating multiple key proteins and signaling pathways. Overall, this study demonstrates that RP has significant anti-photoaging ability, acting through several pathways including inhibition of inflammatory response, promotion of collagen synthesis and inhibition of apoptosis. These results provide a scientific basis for the application of RP in skin anti-photoaging and therapy, enabling the potential usage of RP to skin care products.

A Cost-Based Analysis of Anti-aging Products Across Four Major United States Retailers

Background In the field of aesthetic dermatology, there is currently very little data on affordability and cost analysis regarding cosmeceuticals as more demand from patients showing interest in cosmeceutical products to reduce and prevent aging continues to grow. Photoaging, a form of extrinsic aging from sun exposure, can be ameliorated by applying sunscreen and retinol products. Topical ascorbic acid and niacinamide have been shown to target the oxidative stress process that contributes to photoaging. These four products have been identified as the cosmeceutical ingredients with the most evidence-based data on photoaging prevention and treatment. Objective Given the demand for effective skin care, the paucity of data on cost differentiation, and the availability of cosmeceutical products, we analyzed the unit cost of four anti-aging products from major online and physical retailers in the United States. Such a cost comparison may facilitate more economically appropriate recommendations on skin care to consumers. Methods and materials We analyzed sunscreen, topical vitamin C (ascorbic acid), topical vitamin B3 (niacinamide), and topical vitamin A (retinol) products sold by four major United States retailers: Walmart, Ulta, Walgreens, and Amazon. The average cost in dollars per ounce (dollar/oz) was calculated for each product category at each retailer. Statistical analyses were done to determine statistical significance for each product category between retailers as well as between each category of product. Results Between the four retailers, Walmart offered the lowest cost per ounce for every product. In contrast, Amazon offered the highest cost per ounce for every product except for sunscreen. We also found that sunscreen products are less expensive per ounce as compared to retinol, ascorbic acid, and niacinamide products. Conclusion Dermatologists should be knowledgeable of product costs when providing patients with anti-aging product recommendations. Our study provides data on the financial cost by retail location of evidence-based anti-aging cosmeceuticals to better guide physicians in patient consulting and economical resource sharing.

Signaling mechanisms underlying lymphatic vessel dysfunction in skin aging and possible anti-aging strategies

Aging-related skin diseases are gradually increasing due to the imbalance of cutaneous homeostasis in the aging population. Skin aging-induced inflammation promotes systemic inflammation and may lead to whole-body aging. Lymphatic vessels play an important role in maintaining fluid and homeostasis balance. In intrinsically aged skin, the number of lymphatic vessels decrease and their functions decline, which is related to the reduced adhesion junctions between lymphatic endothelial cells, particularly VE-cadherin. VEGFC/VEGFR-3 signal pathway plays an important role in remodeling and expansion of lymphatic vessels; the downregulation of this pathway contributes to the dysfunction of lymphatic vessels. Meanwhile, we proposed some additional mechanisms. Decline of the pumping activity of lymphatic vessels might be related to age-related changes in extracellular matrix, ROS increase, and eNOS/iNOS disturbances. In extrinsically aged skin, the hyperpermeability of lymphatic vessels results from a decrease in endothelial-specific tight junction molecules, upregulation of VEGF-A, and downregulation of the VEGFC/VEGFR-3 signaling pathway. Furthermore, some of the Phyto therapeutics could attenuate skin aging by modulating the lymphatic vessels. This review summarized the lymphatic vessel dysfunction in skin aging and anti-aging strategies based on lymphatic vessel modulation.

A systematic review and meta-analysis of efficacy, safety, and satisfaction rates of laser combination treatments vs laser monotherapy in skin rejuvenation resurfacing

Laser therapies have been well-established in ameliorating skin-aging consequences. This systematic review aims to determine the efficacy, safety profile, and satisfaction rates of laser combination therapies on skin rejuvenation resurfacing. A systematic search was performed in four major databases up to September 2022. Skin rejuvenation studies were eligible comprising at least one laser combination arm, inclusive of all laser types (ablative or non-ablatives), and one monotherapy arm selected from one of the combined modalities. Studies combining one laser modality with radiofrequency (RF) or intense pulse light (IPL) were also assessed. Trials that did not encompass a monotherapy control arm were evaluated independently as single-arm studies. Eighteen clinical trials recruiting 448 cases were included after screening. A total of 532 nm KTP + 1064 nm Nd:YAG and 2940 nm Er:YAG + Nd:YAG were the two most utilized laser combinations and exerted higher improvements and milder adverse events, compared to their monotherapy in most studies. Combining CO2 with rhodamine-IPL or gallium arsenide laser increased efficacy and satisfaction and brings about faster skin recovery time. Augmenting CO2 + RF did not increase improvement vs CO2 laser alone but prolonged skin erythema. Our meta-analysis revealed the pooled prevalence of quartile improvement rates as 0%, 28%, 40%, 27% in laser combination group, and 0%, 9%, 31%, 17% in laser monotherapy group, respectively. The satisfaction within each quartile category was 39%, 25%, 15%, 7% in laser combination and 20%, 25%, 16%, 17% in laser monotherapy, respectively, suggestive of the higher efficacy and satisfaction of laser combination group. The pain scores were lower in laser combination group than monotherapy (4.8 ± 1.18 vs 7.18 ± 0.7, converted on a scale of 0 to 10). Post-laser skin erythema lasted less longer in the combination group (12.8 vs 15.24 days). Laser combination therapies were discovered to be superior to their monotherapies in terms of clinical improvement rates, diminished adverse events such as pain and erythema and patients satisfaction rates. Due to paucity of high-quality reportings, additional trials are warranted to corroborate these results.

Chlorin E6-Curcumin-Mediated Photodynamic Therapy Promotes an Anti-Photoaging Effect in UVB-Irradiated Fibroblasts

Skin photoaging due to ultraviolet B (UVB) exposure generates reactive oxygen species (ROS) that increase matrix metalloproteinase (MMP). Chlorin e6-photodynamic therapy (Ce6-PDT), in addition to being the first-line treatment for malignancies, has been shown to lessen skin photoaging, while curcumin is well known for reducing the deleterious effects of ROS. In the current study, PDT with three novel Ce6-curcumin derivatives, a combination of Ce6 and curcumin with various linkers, including propane-1,3-diamine for Ce6-propane-curcumin; hexane-1,6-diamine for Ce6-hexane-curcumin; and 3,3'-((oxybis(ethane-2,1-diyl))bis(oxy))bis(propan-1-amine) for Ce6-dipolyethylene glycol (diPEG)-curcumin, were studied for regulation of UVB-induced photoaging on human skin fibroblast (Hs68) and mouse embryonic fibroblast (BALB/c 3T3) cells. We assessed the antiphotoaging effects of Ce6-curcumin derivatives on cell viability, antioxidant activity, the mechanism of matrix metalloproteinase-1 and 2 (MMP-2) expression, and collagen synthesis in UVB-irradiated in vitro models. All three Ce6-curcumin derivatives were found to be non-phototoxic in the neutral red uptake phototoxicity test. We found that Ce6-hexane-curcumin-PDT and Ce6-propane-curcumin-associated PDT exhibited less cytotoxicity in Hs68 and BALB/c 3T3 fibroblast cell lines compared to Ce6-diPEG-curcumin-PDT. Ce6-diPEG-curcumin and Ce6-propane-curcumin-associated PDT showed superior antioxidant activity in Hs68 cell lines. Further, in UVB-irradiated in vitro models, the Ce6-diPEG-curcumin-PDT greatly attenuated the expression levels of MMP-1 and MMP-2 by blocking mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and tumor necrosis factor-α (NF-κB) signaling. Moreover, Ce6-diPEG-curcumin effectively inhibited inflammatory molecules, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, while accelerating collagen synthesis. These results demonstrate that Ce6-diPEG-curcumin may be a potential therapy for treating skin photoaging.

Cycloastragenol exerts protective effects against UVB irradiation in human dermal fibroblasts and HaCaT keratinocytes

BACKGROUND

Cycloastragenol (CAG) is a triterpene aglycone of astragaloside IV that possesses various pharmacological actions including improving telomerase activity, inhibiting inflammation and cell proliferation, inducing apoptosis.

OBJECTIVE

CAG has also shown effect to significantly improve the appearance of aging skin but, its molecular mechanism of protective effect against UVB induced-damage have not been elucidated. We investigated the potential effect of CAG on UVB wrinkle promoting activities and skin-moisturizing effects in human dermal fibroblasts (HDF) and HaCaT keratinocytes.

METHODS

After UVB irradiation or H2O2 treatment, the levels of matrix metalloproteinases (MMPs) and ROS generation were measured in CAG-treated HDF cells. In addition, after UVB irradiation, hyaluronic acid and skin hydration factors (filaggrin and SPT) were also analyzed in CAG (0-0.5-1-2 µM)-treated HDF and HaCaT cells.

RESULTS

We found that CAG caused a significant decrease in the levels of UVB-induced MMP-1, MMP-9, MMP-13 and ROS generation, also increased UVB-damaged Collagen Ⅰ. We also noted that CAG increased cell viability and can regulate MMP-1, MMP-9, MMP-13and Collagen Ⅰ in H2O2-damaged HDF cells. Moreover, we noticed that CAG effectively enhanced levels of hyaluronic acid and expression of skin hydration factors (filaggrin and serine palmitoyltransferase (SPT)) in UVB-damaged HDF and HaCaT cells.

CONCLUSION

This is first report indicating that CAG can exhibit protective effect against UVB and H2O2-induced damages and can contribute in maintenance of healthy skin.