Skin aging and photoaging: an overview

Poly-L-Lactic Acid Reduces the Volume of Dermal Adipose Tissue Through its Metabolite Lactate

Poly-L-lactic acid (PLLA), a well-established biostimulator that induces collagenases, is widely used among clinical practice to treat skin aging. However, the precise regulatory effect of PLLA on different dermal cell subsets beyond fibroblast has not been fully elucidated. In this study, we constructed in vivo PLLA injection and in vitro PLLA-adipocyte co-culture models to analyze the regulatory effects of PLLA on the volume, differentiation, lipolysis, and thermogenic capacity of dermal adipocyte. We found that PLLA injection significantly reduced the thickness of dermal fat in mice. In co-culture assay, PLLA showed no effect on adipogenesis, but stimulated the lipolysis activity. Interestingly, PLLA also enhanced the differentiation of fat cells into beige fat cells, which possess higher thermogenic capacity. In mechanical study, we blocked adipocyte lactate uptake with a monocarboxylate transporter (MCT1/4) inhibitor and found that the regulatory effect of PLLA on dermal adipocyte relies on its metabolite lactate. In summary, our results suggest that PLLA has complex regulatory effects on the dermal cells, and its ability to improve skin aging is not fully attributed to stimulating collagen synthesis, but also partially involves adipocytes.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Strategies to make human skin models based on cellular senescence for ageing research

Human skin ageing is closely related to the ageing of the whole organism, and it's a continuous multisided process that is influenced not only by genetic and physiological factors but also by the cumulative impact of environmental factors. Currently, there is a scientific community need for developing skin models representing ageing processes to (i) enhance understanding on the mechanisms of ageing, (ii) discover new drugs for the treatment of age-related diseases, and (iii) develop effective dermo-cosmetics. Bioengineers worldwide are trying to reproduce skin ageing in the laboratory aiming to better comprehend and mitigate the senescence process. This review provides details on the main ageing molecular mechanisms and procedures to obtain in vitro aged skin models.

Chemical Profiling and Enzyme Inhibitory Activities of Essential Oil Isolated from Pistacia khinjuk Leaves: Insights On GC-MS Analysis and Skin Aging-Relevant Enzymes

Pistacia khinjuk is a species of flowering plants belonging to family Anacardiaceae, with promising pharmacological activities like antioxidants, anti-inflammatory, antiviral, and antimicrobial. This study aimed to investigate the GC-MS chemical composition of essential oil isolated from Pistacia khinjuk leaves and its inhibitory properties against aging-relevant enzymes such a collagenase and elastase. The isolated oil showed predominance of β-cadinene (15.34 %), γ-amorphene (8.50 %), α-cadinol (8.14 %), τ-cadinol (7.57 %), (E)-β-caryophyllene (5.77 %), α-pinene (4.70 %), phytol (4.57 %), α-muurolene (3.30 %), (+)-epi-bicyclosesquiphellandrene (3.21 %), and cubenene (3.16 %). Further, it showed remarkable inhibitory activities against collagenase and elastase with IC50 values of 15.61±0.69 and 41.12±2.09 μg/mL, respectively compared to epigallocatechin gallate (IC50=29.52±1.3 μg/mL and 26.86±1.37 μg/mL). as a conclusion, the leaf oil is recommended for topical cosmetic preparations to retard skin aging symptoms such as wrinkles. However, the bioavailability assessment and toxicological profile should be considered in the future studies.

The effects of Jawoongo soap on skin improvement

BACKGROUND

Jawoongo is used to treat and prevent skin issues such as dry and keratinization disorders, burns, trauma, pigmentation, scarring, and inflammatory skin conditions. In this study, the efficacy and safety of 0.47% Jawoongo extract-containing soap (JAUN-CS) were assessed in terms of skin improvement effects such as cleansing, moisturizing, sebum secretion management, and skin elasticity enhancement.

METHODS

Twenty healthy adult men and women aged 20-60 years old took part in the study. Before and after using JAUN-CS, the participants were divided into groups, and various skin improvement effects were measured utilizing machines such as the Corneometer, Tewameter TM 300, and Visioscan. A dermatologist analyzed the product's safety in accordance with Frosch & Kligman and the Cosmetic, Toiletry, and Fragrance Association (CTFA) rules.

RESULTS

Using JAUN reduced the amount of base and point makeup by 25.7% and 76.7%, respectively. Also, JAUN showed a great facial exfoliation effect by removing the old and lifted skin keratins by 84.7% and 20.3%, respectively. Impurities in facial pores decreased by 58%, too. Furthermore, JAUN increased the moisture content of deep skin and skin surface by 3.5% and 74.0%, and skin elasticity by 2.8%. Skin tone, skin texture, skin radiance, and skin barrier all showed improvements of 3.3%, 20.0%, 15.0%, and 115.2%, respectively. Lastly, cleansing with JAUN successfully enhanced the condition of the youth triangle by 7.6%, while TEWL significantly decreased by 52.7%. Neither the JAUN nor the control group soap showed any adverse reactions, such as erythema or allergies, during the testing period.

CONCLUSIONS

The results of this study demonstrated that JAUN is safe for human use and has various skin-improving properties, making Jawoongo a promising natural material for the development of functional cosmetics in the future.

Considerations for managing elderly patients with atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) diagnosis in elderly is challenging, due to its clinical polymorphism and the lack of diagnostic biomarkers. Moreover, the chronicity of the disease and the complex pathogenetic mechanism, make elderly AD management challenging.

AREAS COVERED

A narrative review of the current literature was performed using the PubMed, Medline, Embase, and Cochrane Skin databases, by researching the following terms: 'atopic dermatitis,' 'clinical phenotypes,' 'eczema,' 'elderly patients,' 'elderly type atopic dermatitis,' 'eczema clinical presentation.' The aim was to report the current knowledge on pathogenesis, clinical presentation, and treatment options of elderly AD.

EXPERT OPINION

Elderly type AD has recently been identified as a separate entity, with an increasing prevalence. With aging, both immunosenescence and barrier alterations can cause or modify AD presentation. Moreover, a chronic proinflammatory state (so-called 'inflammaging') is often present in elderly subjects. Older patients with AD may present with peculiar immunophenotypic profile, making AD diagnosis challenging. Similarly, the chronicity of the disease and the complex pathogenetic mechanism, make AD management a challenge. Indeed, systemic therapies for AD are often contraindicated or not tolerated and the management of elderly type AD is often burdened with numerous difficulties, leading to undertreated disease. Even if dupilumab and tralokinumab represent a valuable therapeutic weapon, more data on safety of JAK inhibitors are required.

Characterization of the collagen network of human cheek skin using ultrasonic microscopy

Dermal collagen is the most abundant component of human skin and has a network structure that regulates the mechanical properties of the skin. Therefore, non-invasive characterization of the collagen network would be beneficial for the evaluation of skin conditions. The microscopic substructures of the network, which are individual bundles and fibers, have been optically investigated. However, the macroscopic structure of the collagen network has not been assessed. To evaluate the dermal collagen network, we developed two new indicators, volume filling factor (VFF) and collagen fiber texture (CFT), to analyze three-dimensional echo intensity maps of high-frequency ultrasonic microscopy. By identifying the difference in the elastic modulus components of the dermal layer of facial skin, the density and texture of the collagen network were characterized using VFF and CFT, respectively. These new indicators revealed that the density decreased and the texture became fine with facial age. This study demonstrates that ultrasonic microscopy is useful for investigating skin conditions, paving the way for diagnostic applications in dermatology and aesthetic medicine.

Aquaporin-8 promotes human dermal fibroblasts to counteract hydrogen peroxide-induced oxidative damage: A novel target for management of skin aging

The skin is subjected to various external factors that contribute to aging including oxidative stress from hydrogen peroxide (H2O2). This study investigated the distribution of aquaporin-8 (AQP8), a protein that transports H2O2 across biological membranes, in skin cells, and its effects in mitigating H2O2-induced oxidative damage. Human dermal fibroblasts were treated with increasing concentrations of H2O2 to evaluate oxidative damage. Cell viability, reactive oxygen species (ROS) generation, and the expression of specific genes associated with skin aging (IL-10, FPR2, COL1A1, KRT19, and Aggrecan) were evaluated and AQP8 expression was assessed via quantitative polymerase chain reaction and western blotting. Small-interfering RNA was used to silence the AQP8 gene and evaluate its significance. The results show that H2O2 treatment reduces cell viability and increases ROS generation, leading to oxidative damage that affects the expression of target molecules. Interestingly, H2O2-treated cells exhibit high levels of AQP8 expression and gene silencing of AQP8 reverses high levels of ROS and low levels of COL1A1, KRT19, and Aggrecan expression in stressed cells, indicating that AQP8 plays a vital role in preventing oxidative damage and consequent aging. In conclusion, AQP8 is upregulated in human dermal fibroblasts during H2O2-induced oxidative stress and may help prevent oxidative damage and aging. These findings suggest that AQP8 could be a potential therapeutic target for skin aging. Further research is necessary to explore the feasibility of using AQP8 as a preventive or therapeutic strategy for maintaining skin health.

Pulsed electrical stimulation and amino acid derivatives promote collagen gene expression in human dermal fibroblasts

Several collagen types are important for maintaining skin structure and function. Previous reports show that l-hydroxyproline (Hyp), N-acetyl-l-hydroxyproline (AHyp), and l-alanyl-l-glutamine (Aln-Gln) are biological active substances with collagen synthesis-promoting effects. In this study, we combined the promotive effects of pulsed electrical stimulation (PES) with three amino acid derivatives in human dermal fibroblasts. Fibroblasts were exposed to PES with a 4,800 Hz pulse frequency and a voltage at 1 or 5 V for 15 min. The gene expression of type I and III collagen (fibrillar collagen), type IV and VII collagen (basement membrane collagen and anchoring fibril collagen) were measured by RT-PCR 48 h after PES. PES alone promoted the expression of COL1A1 and COL3A1 at 5 V but did not alter that of COL4A1 and COL7A1. Each AAD and the AAD mixture promoted the expression of COL4A1 and COL7A1 but either repressed, or did not alter, that of COL1A1 and COL3A1. Compared to treatment with each AAD, PES at 5 V with Hyp promoted the expression of COL1A1 and COL3A1, enhanced COL3A1 expression with AHyp, and stimulated COL3A1 expression with Aln-Gln, while COL4A1 and COL7A1 expressions were not affected. PES and the AAD mixture significantly promoted COL4A1 expression in a voltage-dependent manner, and COL1A1 and COL3A1 demonstrated a similar but nonsignificant trend, whereas COL7A1 expression was not affected. The combination of PES with each AAD or the AAD mixture may improve skin structure and function by increasing the expression of basement membrane collagen and dermal fibrillar collagen.

Ascorbic Acid Treatments as Effective and Safe Anti-Aging Therapies for Sensitive Skin

The most common signs of aging skin include a decrease in firmness and density, uneven skin tone, and a tendency to erythema. There is an ever-increasing interest in aesthetic treatments that maintain the skin's favorable appearance. However, such therapies are difficult in the case of sensitive skin, defined as a set of stimuli-triggered symptoms (stinging, erythema, burning, and itching) that would not appear in healthy skin. Sensitive skin is common and affects, to varying degrees, about half of the European population. This study was aimed at evaluating the effects of ascorbic acid-a known antioxidant-applied with sonophoresis and microneedling on the signs of photoaging in reactive and erythematous skin. A significant improvement in skin elasticity was observed after a series of tests. A significant reduction in erythema was observed after both therapies. The greatest reduction was observed on the cheeks after applying vitamin C combined with microneedling. At the same time, the results showed an excellent tolerance of both treatments, which proved them to be safe and effective.

Aging Hallmarks and Progression and Age-Related Diseases: A Landscape View of Research Advancement

Aging is a dynamic, time-dependent process that is characterized by a gradual accumulation of cell damage. Continual functional decline in the intrinsic ability of living organisms to accurately regulate homeostasis leads to increased susceptibility and vulnerability to diseases. Many efforts have been put forth to understand and prevent the effects of aging. Thus, the major cellular and molecular hallmarks of aging have been identified, and their relationships to age-related diseases and malfunctions have been explored. Here, we use data from the CAS Content Collection to analyze the publication landscape of recent aging-related research. We review the advances in knowledge and delineate trends in research advancements on aging factors and attributes across time and geography. We also review the current concepts related to the major aging hallmarks on the molecular, cellular, and organismic level, age-associated diseases, with attention to brain aging and brain health, as well as the major biochemical processes associated with aging. Major age-related diseases have been outlined, and their correlations with the major aging features and attributes are explored. We hope this review will be helpful for apprehending the current knowledge in the field of aging mechanisms and progression, in an effort to further solve the remaining challenges and fulfill its potential.

Research on the anti-aging efficacy of fermented lysate VHProbi® MixA as the functional skincare ingredient

AIMS

This study aimed to investigate the efficacy of a cream containing VHProbi® MixA for improving skin aging.

METHODS AND RESULTS

In vitro studies demonstrated that the lysate produced from Lacticaseibacillus paracasei E12 (E12) exhibited immunoregulatory effects in a 3D skin model, with significant reductions in levels of interleukin (IL)-1α, IL-1β, and IL-8 (P < 0.05) compared with the control group. In addition, the lysate of E12 mitigated the hydrogen peroxide-induced mortality of 3D skin cells and enhanced the transepithelial electrical resistance to show significant differences in comparison with control (P < 0.05), suggesting favorable antioxidant effects. The antioxidant capacity of the lysate of E12 was also confirmed using the Caenorhabditis elegans N2 model. C. elegans N2 fed the E12 strain showed a significantly higher % survival than those fed Escherichia coli OP50 (P < 0.05). Subsequently, VHProbi® MixA was formulated using the fermented lysates of E12, Lactiplantibacillus plantarum E15, and Limosilactobacillus reuteri E18. In a clinical study to ascertain if a cream containing VHProbi® MixA could improve the skin aging trends, participants were asked to use the investigational products for 60 days, and six indicators, transepidermal water loss (TEWL), hydration, elasticity, wrinkles, skin texture (roughness), and pores were measured at baseline and the endpoint of the study. A self-evaluation questionnaire analysis was also provided. TEWL, wrinkles, skin texture, and thickness of pores decreased significantly after treatment with the cream for 60 days (P < 0.01), whereas hydration and elasticity increased significantly (P < 0.01), in comparison to the baseline measurements.

CONCLUSIONS

We hypothesize that the use of the cream containing VHProbi® MixA could be favorable for skin anti-aging management.

Causal Relationship Between Blood Triglyceride Levels and Age Spots: A Mendelian Randomization Analysis

Objective

This study examined the association between blood triglyceride (TG) levels (TLIB) and age spots (AS).

Methods

We acquired data from the Mendelian randomization (MR) Base database and evaluated the causal association between TLIB and AS.

Results

From genome-wide association studies, we selected 33 single nucleotide polymorphisms (SNPs) that were significantly associated with TLIB and AS. The inverse variance-weighted (IVW) and weighted median estimation methods showed that TLIB had a protective effect on AS (IVW: β=-0.214, P=0.019, odds ratio [OR]=0.807, 95% confidence interval [CI]=0.674-0.966; weighted median: β=-0.277, P=0.032, OR=0.758, 95% CI=0.589-0.977). However, the MR-Egger analysis suggested no causal association (β=-0.234, P=0.085, OR=0.792, 95% CI=0.612-1.024). The greater precision of the weighted median estimation and IVW suggests that our results support a potential causal association between TLIB and AS.

Conclusion

The MR analysis proved that TLIB has a protective effect against AS and that triglycerides have potential preventive and therapeutic effects against AS. However, the specific dose-effect relationship requires further study.

9-Hydroxyoctadecadienoic acid plays a crucial role in human skin photoaging

Human skin is regularly exposed to ultraviolet (UV) rays from sunlight, leading to photoaging, which differs from intrinsic aging. Although the acute effects of UV exposure have been extensively studied, limited research has addressed the long-term consequences of chronic UV exposure. This study aimed to investigate the underlying causes of chronic photoaging. A questionnaire-based assessment of sunlight exposure was conducted among volunteers in their 20s and 50s, and the stratum corneum of their skin was analyzed for bioactive lipid content. Volunteers were categorized into low and high UV exposure groups based on the questionnaire scores. The analysis results revealed a significant increase in 9-hydroxyoctadecadienoic acid (9-HODE) levels in the skin of individuals in their 50s with high UV exposure. However, UV exposure did not affect 9-HODE levels in the skin of individuals in their 20s. In vitro experiments further indicated that 9-HODE contributes to chronic inflammation, pigmentary changes, and extracellular matrix alterations during photoaging. Specifically, 9-HODE stimulated cytokine production [interleukin-6 (IL6), IL8, and granulocyte-macrophage colony-stimulating factor (GM-CSF)] and reduced dickkopf-1 (DKK1) production in keratinocytes. In fibroblasts, 9-HODE stimulated matrix metalloproteinase-1 (MMP1) and MMP3 production while reducing collagen I (COL1) production. The expression of G2A, the receptor for 9-HODE, was also confirmed in fibroblasts, suggesting that 9-HODE exerts its effects via G2A, as observed in keratinocytes. Overall, these findings indicate that 9-HODE is a mediator of chronic photoaging and highlight its potential significance in photoaging prevention.

LncRNA-miRNA-mRNA regulatory networks in skin aging and therapeutic potentials

Skin aging is a complex process influenced by intrinsic and extrinsic factors. Although dermatology offers advanced interventions, molecular mechanisms in skin aging remain limited. Competing endogenous RNAs (ceRNAs), a subset of coding or non-coding RNAs, regulate gene expression through miRNA competition. Several ceRNA networks investigated up to now offer insights into skin aging and wound healing. In skin aging, RP11-670E13.6-miR-663a-CDK4/CD6 delays senescence induced by UVB radiation. Meg3-miR-93-5p-epiregulin contributes to UVB-induced inflammatory skin damage. Predicted ceRNA networks reveal UVA-induced photoaging mechanisms. SPRR2C sequesters miRNAs in epidermal aging-associated alteration of calcium gradient. H19-miR-296-5p-IGF2 regulates dermal fibroblast senescence. PVT1-miR-551b-3p-AQP3 influences skin photoaging. And bioinformatics analyses identify critical genes and compounds for skin aging interventions. In skin wound healing, MALAT1-miR-124 aids wound healing by activating the Wnt/β-catenin pathway. Hair follicle MSC-derived H19 promotes wound healing by inhibiting pyroptosis. And the SAN-miR-143-3p-ADD3 network rejuvenates adipose-derived mesenchymal stem cells in wound healing. Thus, ceRNA networks provide valuable insights into the molecular underpinnings of skin aging and wound healing, offering potential therapeutic strategies for further investigation. This comprehensive review serves as a foundational platform for future research endeavors in these crucial areas of dermatology.

Photoaging's portrait: The road map towards its photoprotection

OBJECTIVE

To summarize key research published by the author's group, dealing with skin photoaging and its photoprotection.

MATERIALS AND METHODS

Two methodologies (standard photographs and selfies imaging) resulting from referential skin ageing atlases were applied on 2487 subjects of different ancestries, ages and gender. These aimed at first to best assess and grade the variable severities of some facial signs (texture/wrinkles, pigmentary spots, sagging and vascular disorders) that occur progressively during the photoaging process. Second, such methodologies were used to record the benefits brought by a photoprotective regimen (671 women and men).

RESULTS

In all studied ancestries, each facial sign show an increase severity along decades, at its own pace, some showing a linear like progression, whereas some plateau at early ages. These changes differed according to skin innate colour (phototype) and with individual behaviours vis-à-vis sun exposures, more so among European women than North-East Asian women. An effect of gender (less severe alterations) was observed on Chinese men, as compared to Chinese women. Pigmentary disorders were found hallmarks of photo-aged North-East Asian women. Globally, photoaging impact the apparent age of the different subjects. The counteracting effects of strong topical Photoprotective regimens were evidenced along a 6-month seasonality in Chinese and French women or 1-year period in Brazilian women with phototypes II to VI. Photoprotection led to a more even skin complexion among Indian subjects with pigment irregularities.

CONCLUSION

Two factors clearly hamper a better assessment of the efficiency of photoprotection of the sun-induced cutaneous ageing: short durations (months) of the studies with regard to the global fate of photoaging by decades and the number of studied subjects, limited to hundreds for practical reasons. The methodology based on the automatic analysis of facial signs through selfies images could theoretically bypass both factors, allowing thousands of subjects to be studied along years.

Applications of Probiotic Constituents in Cosmetics

Over the past few decades, research on the benefits of beneficial microorganisms on skin health has expanded and attracted a lot of attention. Today, a wide range of probiotic products are becoming available. With their extensive component profiles and varied physiological effects, probiotics, as well as extracts of them, have a significant impact on cosmetics. However, the present boom in consumer interest in alternatives has broadened the probiotic industry's research and development frontiers. Considering the foregoing, it should come as no surprise that probiotics are highly valued for their proven anti-aging, skin whitening, anti-inflammatory, and photoprotective effects. This review aims to compile information on probiotics' properties, their extracts, and preparations used in cosmetics. It also further summarizes research and applications on probiotic fermentation to promote the use of probiotic fermentation products in cosmetics. Notably, this review also adds information on particular properties and mechanisms of action of probiotics, which fills a gap in the research and application of probiotics in skin treatment and care. Their antioxidant and anti-aging qualities have received particular consideration. This review provides a new basis for the broad application of probiotics in cosmetics.

Skincare potential of a sustainable postbiotic extract produced through sugarcane straw fermentation by Saccharomyces cerevisiae

Postbiotics are defined as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host." They can be produced by fermentation, using culture media with glucose (carbon source), and lactic acid bacteria of the genus Lactobacillus, and/or yeast, mainly Saccharomyces cerevisiae as fermentative microorganisms. Postbiotics comprise different metabolites, and have important biological properties (antioxidant, anti-inflammatory, etc.), thus their cosmetic application should be considered. During this work, the postbiotics production was carried out by fermentation with sugarcane straw, as a source of carbon and phenolic compounds, and as a sustainable process to obtain bioactive extracts. For the production of postbiotics, a saccharification process was carried out with cellulase at 55°C for 24 h. Fermentation was performed sequentially after saccharification at 30°C, for 72 h, using S. cerevisiae. The cells-free extract was characterized regarding its composition, antioxidant activity, and skincare potential. Its use was safe at concentrations below ~20 mg mL-1 (extract's dry weight in deionized water) for keratinocytes and ~ 7.5 mg mL-1 for fibroblasts. It showed antioxidant activity, with ABTS IC50 of 1.88 mg mL-1 , and inhibited elastase and tyrosinase activities by 83.4% and 42.4%, respectively, at the maximum concentration tested (20 mg mL-1 ). In addition, it promoted the production of cytokeratin 14, and demonstrated anti-inflammatory activity at a concentration of 10 mg mL-1 . In the skin microbiota of human volunteers, the extract inhibited Cutibacterium acnes and the Malassezia genus. Shortly, postbiotics were successfully produced using sugarcane straw, and showed bioactive properties that potentiate their use in cosmetic/skincare products.

Non-invasive Microneedle Application Increases Ceramide and Natural Moisturizing Factors in a Reconstructed Human Skin Model

Recently, microneedling as a cosmetic product has attracted attention as one way to improve skin barrier function and moisturizing function to reduce wrinkle formation. However, some cases of erythema and edema have been reported as side effects. In order to develop safer microneedle cosmetics, we investigated whether microneedles can improve skin barrier function and moisturizing function even when applied in a non-invasive manner that does not penetrate the stratum corneum. We established the condition of non-penetrating microneedle application on reconstructed human full-thickness skin models and examined the effect on the skin models when microneedles were applied under this condition. Microneedle application increased the gene expression of serine palmitoyltransferase long chain base subunit (SPTLC) 3, filaggrin, and transglutaminase 1. The amount of ceramide produced by SPTLC was also increased by microneedle application. Gene expression of filaggrin-degrading enzymes and the amount of free amino acids, a product of filaggrin degradation, were also increased by microneedling. These results suggest that non-invasive microneedle application can improve skin barrier function and moisturizing function by increasing the amount of ceramide and natural moisturizing factors.

Walnut Protein: A Rising Source of High-Quality Protein and Its Updated Comprehensive Review

Recently, plant protein as a necessary nutrient source for human beings, a common ingredient of traditional processed food, and an important element of new functional food has gained prominence due to the increasing demand for healthy food. Walnut protein (WP) is obtained from walnut kernels and walnut oil-pressing waste and has better nutritional, functional, and essential amino acids in comparison with other vegetable and grain proteins. WP can be conveniently obtained by various extraction techniques, including alkali-soluble acid precipitation, salting-out, and ultrasonic-assisted extraction, among others. The functional properties of WP can be modified for desired purposes by using some novel methods, including free radical oxidation, enzymatic modification, high hydrostatic pressure, etc. Moreover, walnut peptides play an important biological role both in vitro and in vivo. The main activities of the walnut peptides are antihypertensive, antioxidant, learning improvement, and anticancer, among others. Furthermore, WP could be applied in the development of functional foods or dietary supplements, such as delivery systems and food additives, among others. This review summarizes recent knowledge on the nutritional, functional, and bioactive peptide aspects of WP and possible future products, providing a theoretical reference for the utilization and development of oil crop waste.

Anti-Aging Constituents from Pinus morrisonicola Leaves

Pinus morrisonicola Hayata is a unique plant species found in Taiwan. Previous studies have identified its anti-hypertensive, anti-oxidative, and anti-inflammatory effects. In this study, a bioactivity-guided approach was employed to extract 20 compounds from the ethyl acetate fraction of the ethanol extract of Pinus morrisonicola Hayata's pine needles. The anti-aging effects of these compounds were investigated using HT-1080 cells. The structures of the purified compounds were confirmed through NMR and LC-MS analysis, revealing the presence of nine flavonoids, two lignans, one coumarin, one benzofuran, one phenylic acid, and six diterpenoids. Among them, PML18, PML19, and PML20 were identified as novel diterpene. Compounds 3, 4, and 5 exhibited remarkable inhibitory effects against MMP-2 and showed no significant cell toxicity at 25 μM. Although the purified compounds showed lower activity against Pro MMP-2 and Pro MMP-9 compared to the ethyl acetate fraction, we speculate that this is the result of synergistic effects.

Acetyl Zingerone: A Photostable Multifunctional Skincare Ingredient That Combats Features of Intrinsic and Extrinsic Skin Aging

The cumulative damage skin sustains from exposure to environmental stressors throughout life exerts significant effects on skin aging and cancer development. One of the main ways by which environmental stressors mediate their effects within skin is through induction of reactive oxygen species (ROS). In this review, we chronicle the multiple properties by which acetyl zingerone (AZ) as a skincare ingredient can benefit skin (1) by helping manage overproduction of ROS through multiple routes as an antioxidant, physical quencher and selective chelator, (2) by fortifying protection after UV exposure ends to prevent the type of epidermal DNA damage that correlates with development of skin cancer, (3) by modulating matrisome activity and nurturing the integrity of the extracellular matrix (ECM) within the dermis and (4) through its proficient ability to neutralize singlet oxygen, by stabilizing the ascorbic acid precursor tetrahexyldecyl ascorbate (THDC) in the dermal microenvironment. This activity improves THDC bioavailability and may blunt pro-inflammatory effects of THDC, such as activation of type I interferon signaling. Moreover, AZ is photostable and can sustain its properties during UV exposure, in contrast to α-tocopherol. All these properties of AZ translate into measurable clinical benefits to improve the visual appearance of photoaged facial skin and to strengthen the skin's own defenses against sun damage.

Hydrangea serrata Hot Water Extract and Its Major Ingredient Hydrangenol Improve Skin Moisturization and Wrinkle Conditions via AP-1 and Akt/PI3K Pathway Upregulation

Hydrangea serrata is a plant grown in Korea and Japan with a particular natural compound, hydrangenol. H. serrata has been researched for its anti-fungal properties, and ability to attenuate allergies and promote muscle growth. Its ability to reduce skin dryness is poorly understood. For that reason, we investigated whether H. serrata hot water extracts (Hs-WE) can moisturize keratinocytes. In clinical studies (Approval Code: GIRB-21929-NY and approval Date: 5 October 2021), skin wrinkles and skin moisturizing levels were improved in subjects applying 0.5% Hs-WE compared to the placebo group. We confirmed the components of Hs-WE from the LC/MS-MS analysis. Hs-WE and hydrangenol did not show cytotoxicity in HaCaT cells at all concentrations. Cell growth was also promoted by Hs-WE (5-20 µg/mL) and hydrangenol (15-60 µM) in a wound healing assay. Skin moisturizing factors were upregulated by the presence of Hs-WE or hydrangenol, and the hyaluronidases (HYAL) were inhibited at the mRNA level. Meanwhile, COL1A1 was increased by the presence of Hs-WE or hydrangenol. MAPK, AP-1, and Akt/PI3k signaling proteins, which are associated with cell proliferation and moisturizing factors, were increased by the administration of Hs-WE and hydrangenol. Has-1, 2, and 3 levels were enhanced via JNK when using the inhibitors of MAPK proteins and Hs-WE and hydrangenol, respectively. Taken together, Hs-WE could be used as cosmeceutical materials for improving skin conditions.

Smart nanostructures for targeted oxygen-producing photodynamic therapy of skin photoaging and potential mechanism

Background: Photodynamic therapy increases collagen and decreases solar fibrosis in photoaged skin; however, the efficacy of photodynamic therapy is limited in tissues with a hypoxic microenvironment. Methods: A novel autogenous oxygen-targeted nanoparticle, named MCZT, was synthesized based on the zeolitic imidazole framework material ZIF-8, methyl aminolevulinate, catalase and an anti-TRPV1 monoclonal antibody, and its effects on skin photoaging were investigated. Results: MCZT was successfully synthesized and showed uniform particle size, good dispersion, and excellent biocompatibility and safety. Moreover, MCZT effectively alleviated UV-induced inflammation, cellular senescence and apoptosis in HFF-1 cells. In in vivo models, MCZT ameliorated UV-evoked erythema and wrinkling, inflammation and oxidative stress, as well as the loss of collagen fibers and water, in the skin of mice. Conclusion: These findings suggest that MCZT holds promising potential for the treatment of skin photoaging.

Relationships between circulating metabolites and facial skin aging: a Mendelian randomization study

BACKGROUND

Blood metabolites are important to various aspects of our health. However, currently, there is little evidence about the role of circulating metabolites in the process of skin aging.

OBJECTIVES

To examine the potential effects of circulating metabolites on the process of skin aging.

METHOD

In the primary analyses, we applied several MR methods to study the associations between 249 metabolites and facial skin aging risk. In the secondary analyses, we replicated the analyses with another array of datasets including 123 metabolites. MR Bayesian model averaging (MR-BMA) method was further used to prioritize the metabolites for the identification of predominant metabolites that are associated with skin aging.

RESULTS

In the primary analyses, only the unsaturation degree of fatty acids was found significantly associated with skin aging with the IVW method after multiple testing (odds ratio = 1.084, 95% confidence interval = 1.049-1.120, p = 1.737 × 10^-06). Additionally, 11 out of 17 unsaturation-related biomarkers showed a significant or suggestively significant causal effect [p < 0.05 and > 2 × 10^-4 (0.05/249 metabolites)]. In the secondary analyses, seven metabolic biomarkers were found significantly associated with skin aging [p < 4 × 10^-4 (0.05/123)], while six of them were related to the unsaturation degree. MR-BMA method validated that the unsaturation degree of fatty acids plays a dominant role in facial skin aging.

CONCLUSIONS

Our study used systemic MR analyses and provided a comprehensive atlas for the associations between circulating metabolites and the risk of facial skin aging. Genetically proxied unsaturation degree of fatty acids was highlighted as a dominant factor correlated with the risk of facial skin aging.

Mechanism of action and therapeutic effects of oxidative stress and stem cell-based materials in skin aging: Current evidence and future perspectives

Aging is associated with multiple degenerative diseases, including atherosclerosis, osteoporosis, and Alzheimer's disease. As the most intuitive manifestation of aging, skin aging has received the most significant attention. Skin aging results from various intrinsic and extrinsic factors. Aged skin is characterized by wrinkles, laxity, elastosis, telangiectasia, and aberrant pigmentation. The underlying mechanism is complex and may involve cellular senescence, DNA damage, oxidative stress (OS), inflammation, and genetic mutations, among other factors. Among them, OS plays an important role in skin aging, and multiple antioxidants (e.g., vitamin C, glutathione, and melatonin) are considered to promote skin rejuvenation. In addition, stem cells that exhibit self-replication, multi-directional differentiation, and a strong paracrine function can exert anti-aging effects by inhibiting OS. With the further development of stem cell technology, treatments related to OS mitigation and involving stem cell use may have a promising future in anti-skin aging therapy.

Kaempferide Prevents Photoaging of Ultraviolet-B Irradiated NIH-3T3 Cells and Mouse Skin via Regulating the Reactive Oxygen Species-Mediated Signalings

Kaempferide (KFD) is a naturally occurring flavonoid that exists in various medicinal plants. The pharmaceutical properties of KFD, including its anti-cancer, antioxidant and anti-diabetic effects, have been noted, but the effects of KFD on photoaging and their underlying molecular mechanism have yet to be elucidated. In this study, we investigated the effects of KFD on Ultraviolet-B (UVB)-mediated photoaging processes using in vitro and in vivo photoaging model systems. The topical administration of KFD on mouse dorsal areas suppressed UVB-mediated wrinkle formation and epidermal thickening. In addition, the UVB-mediated reduction of dermal collagen content, which was estimated by Masson's trichrome staining, was recovered through KFD treatments. Furthermore, we found that UVB-induced abnormal values of procollagen type-1 (COL1A1), metalloproteinases (MMP-1a and MMP-3) and proinflammatory cytokines (IL-8, MCP-3 and IL-6) on mouse skin tissue as well as NIH-3T3 cells was recovered through KFD treatment. The administration of KFD to NIH-3T3 cells suppressed the UVB-mediated upregulation of reactive oxygen species (ROS), mitogen-activated protein kinases (MAPKs) and AKT phosphorylation. Furthermore, the treatment of ROS inhibitor restored the UVB-induced MAPKs and AKT phosphorylation as well as the abnormal expression of photoaging related genes. These findings indicate that KFD can attenuate UVB-induced ROS elevation to elicit anti-photoaging activity. Taken together, our data suggest that KFD could be developed as a potential natural anti-photoaging agent.

Skin Photodamage Lesions in a Bilateral Feline Auricular Primary Fibrosarcoma

As with human species, recent studies also suggest a photoinduced etiopathology for non-epithelial cutaneous tumors in feline species. We report a recent case of a ten-year-old male cat with a white-hair coat and mesenchymal neoplasms of both auricles. Cytology, complete blood count (CBC), serum biochemistry and imaging examinations were performed. After surgery, the samples underwent routinary histopathology and were additionally stained with orcein. A routine analysis yielded values within a normal range and the imaging examination showed no abnormalities, suggesting that the bilateral presentation of neoplasms was primary rather than metastatic. The cytology was inconclusive, but, through histopathology, two well-differentiated fibrosarcomas were diagnosed and histopathological changes related to chronic UV exposure (such as epidermal hyperplasia, stratification disorders, keratinocyte dysplasia and an accumulation of elastotic material) were documented in the skin adjacent to the lesions. An orcein stain succeeded in highlighting elastosis. The elastic fibers lost their regular structure and orientation and appeared to be fragmented, wavy to branched and knotted. A morphometric analysis showed that the amount of elastotic material in the dermis close to the tumors was more than double compared with the more distant areas. Elastosis is considered to be a hallmark of photodamage; thus, an involvement of UV rays in the carcinogenic process of the tumors may be suspected.

Alpinia officinarum Rhizome ameliorates the UVB induced photoaging through attenuating the phosphorylation of AKT and ERK

Background

Chronic ultraviolet (UV) exposure is one of the major external factors in skin aging, and repetitive UVB exposure induces extracellular matrix (ECM) damage as well as metabolic disease. Alpinia officinarum Rhizome (AOR) is a medicinal plant that has been traditionally used for treating rheumatism and whooping cough. However, the antiphotoaging effects of AOR remain unclear. We investigated the protective effects of water extracts of AOR (WEAOR) in terms of UVB-mediated ECM damage, wrinkle formation, inflammatory responses, and intracellular signaling on hairless mice and NIH-3T3 skin fibroblast cells.

Methods

WEAOR was administered to UVB-irradiated hairless mice. Wrinkle formation was assessed using the replica assay, epidermal changes through H&E staining, and collagen contents in mice skin through Masson’s trichrome staining. The expression of procollagen type-1 (COL1A1), metalloproteinase-1a (MMP-1a), and inflammatory cytokines (IL-6, IL-8, and MCP-3) in hairless mice skin and NIH-3T3 cells was investigated through qRT-PCR. The effects of WEAOR or signaling inhibitors on UVB-induced expression of intracellular mitogen-activated protein kinases (MAPKs) were estimated by Western blotting and qRT-PCR, respectively.

Results

Topical WEAOR significantly attenuated the UVB-induced wrinkle formation and epidermal thickening in the skin of hairless mice. WEAOR treatment also attenuated the UVB-induced expression of MMP-1a and COL1A1 and recovered the reduction of collagen content in mouse skin. These effects were confirmed in NIH-3T3 skin fibroblast cells. WEAOR treatment restored the UVB-induced COL1A1 and MMP-1a gene expression and attenuated the UVB-induced expression of IL-6, IL-8, and MCP-3 in NIH-3T3 cells. Notably, WEAOR attenuated UVB-induced phosphorylation of AKT and ERK, but not that of p38 and JNK in NIH-3T3 cells. In addition, the administration of AKT and ERK inhibitors restored the UVB-induced expression of MMP-1a and COL1A1 to an equal extent as WEAOR in NIH-3T3 cells.

Conclusions

The antiphotoaging properties of WEAOR were first evaluated in this study. Our results suggest that WEAOR may be a potential antiphotoaging agent that ameliorates UVB-induced photoaging processes via the AKT and ERK signaling pathways.

Efficacy of a novel microneedle patch for rejuvenation of the nasolabial fold

BACKGROUND

Skin rejuvenation plays a significant role in the esthetic medicine market. Microneedle patches have been developed for a wide range of applications based on the principles of transdermal drug delivery; however, clinical trials of microneedle patches for skin rejuvenation remain limited.

AIMS

This study was conducted to examine the efficacy of microneedle patches for improving nasolabial folds.

METHODS

A total of 23 Thai women completed this prospective clinical trial. The participants were treated according to a split-face design, with application of microneedle patch plus 1.8% hyaluronic acid solution to the right nasolabial fold and microneedle patch alone to the left nasolabial fold. The treatments were applied to the nasolabial fold for 8 weeks. The test areas were measured before treatment and at 2, 4, 8, 12, and 16 weeks after the use of the test product.

RESULTS

Combination treatment using the microneedle patch plus hyaluronic acid solution and use of the microneedle patch alone both significantly improved the Merz esthetic scales for nasolabial folds. Measurement of the nasolabial fold showed an improvement in the two groups, with no significant differences between the groups. No adverse effects were reported during the study period.

CONCLUSIONS

Application of a microneedle patch with 1.8% hyaluronic acid solution or a microneedle patch alone were both effective treatments for improving facial wrinkles in the nasolabial folds.

Anti-Photoaging Activity of Scutellaria barbata D. Don (Family Lamiaceae) on Ultraviolet B-Irradiated NIH-3T3 Skin Fibroblast and SKH-1 Hairless Mouse

We investigated whether Scutellaria barbata D. Don (Family Lamiaceae) (SBD), a traditional medicine used for heat clearing and detoxification, possesses antiphotoaging properties. Pretreatment of NIH-3T3 skin fibroblast cells with non-toxicological levels of water extract of SBD (WESBD) and ethanol extract of SBD (EESBD) restored the expression of procollagen type-1 (COL1A1), matrix metalloproteinase-1a (MMP-1a), interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemotactic protein-3 (MCP-3) genes following abnormal expression induced by ultraviolet B (UVB) irradiation. WESBD/EESBD administration to the dorsal skin area of hairless mice significantly (p < 0.05) inhibited UVB-induced wrinkle formation and epidermal thickness. The WESBD and EESBD treatments also restored the dermal collagen content, which was decreased by the UVB treatment, and normal COL1A1 and MMP-1a expression. Interestingly, both the WESBD and EESBD pretreatments significantly attenuated UVB-induced phosphorylation of protein kinase B (AKT) but not that of mitogen-activated protein kinases (MAPKs). This finding indicates that the antiphotoaging effects of WESBD and EESBD may be related to attenuation of UVB-induced overactivation of AKT phosphorylation. High performance liquid chromatography (HPLC) and mass spectrometry analysis revealed that isorhamentin and scutebarbatine I were major single components of EESBD. These results suggest that WESBD and EESBD may have potential in development as antiphotoaging agents.

Usage Patterns and Self-Esteem of Female Consumers of Antiaging Cosmetic Products

Aging is an irreversible process of the human body, resulting from a progressive decrease in the biological functions of the organs, including the skin. This study analyzed the relationship between usage patterns of different types of anti-aging cosmetic products, sociodemographic variables, appearance schemes, psychological morbidity, perfectionism, and aging perception of aging with self-esteem. This cross-sectional study included a sample of 260 women, aged between 25 and 64 years, who are users of anti-aging cosmetics and/or aesthetic treatments. Participants were assessed on psychological morbidity (Hospital Anxiety and Depression Scale), appearance schemes (Appearance Schemas Inventory—Revised), perfectionism (Frost Multidimensional Perfectionism Scale), aging perceptions (Brief Aging Perceptions Questionnaire), and self-esteem (Rosenberg Self-Esteem Scale). The use of facial-firming cosmetics positively correlated with self-esteem. The results of regression analysis revealed that psychological morbidity and perfectionism contribute negatively to self-esteem, while marital status, professional status, and aging perceptions (positive consequences) contribute positively. According to the results, intervention programs to promote women’s self-esteem should focus on the reduction in psychological morbidity and the promotion of adaptive patterns of perfectionism and address aging perceptions. Longitudinal studies might help explain the complex relationship between the use of anti-aging cosmetic products and psychological variables, particularly self-esteem in women.

Anti-skin Aging Activities of Sideritis scardica and 3 Flavonoids With an Uncommon 8-Hydroxyl Moiety

The skin plays various crucial biological functions and gradually degenerates due to the process of skin aging. Hence, the development of new ingredients for delaying or even reversing skin aging is an essential subject that needs to be addressed. Our screening effort for anti-skin aging ingredients has led to the discovery that Sideritis scardica extract (SSE) possesses collagenase inhibition, advanced glycation end product (AGE) formation inhibition, antioxidative, and antiallergic activities, as well as ultraviolet B (UVB)-induced matrix metalloproteinase-1 (MMP-1) expression inhibition activity. However, the effect of S. scardica, commonly known as a mountain herb, on skin aging is unknown and needs additional study. Further studies on SSE have led to the isolation of 3 flavonoids with an uncommon 8-hydroxyl moiety, isoscutellarein (1), 4′- O-methylhypolaetin (2), and 4′- O-methylisoscutellarein (3). Biological evaluations also revealed that 1-3 possess SSE collagenase inhibition, AGE formation inhibition, antioxidative, and antiallergic activities, while 3 was identified to possess SSE UVB-induced MMP-1 expression inhibition activity. Moreover, the AGE formation inhibition activity and antiallergic activity of 1-3 were speculated to be derived from their antioxidative activity, while direct inhibition of the collagenase enzyme led to their observed collagenase inhibition activity. Regarding the inhibition activity of 1-3 on UVB-induced MMP-1 expression, further studies are necessary to reveal their possible mechanism of action. Collectively, the biological activities of SSE and the isolated flavonoids 1-3 highlight the potential of S. scardica to be further developed as an agent to delay or reverse skin aging.

4,4'-Dimethoxychalcone protects the skin from AAPH-induced senescence and UVB-induced photoaging by activating autophagy

Aging can lead to the occurrence of many degenerative diseases, and the most intuitive consequences are mainly manifested on the skin, which is affected by both endogenous and exogenous aging factors and can be used as an ideal model organ for studying aging. 4,4'-Dimethoxychalcone (DMC), a natural flavonoid compound from Angelica sinensis, has been proven to prolong the lifespan of multiple species. However, it is not clear whether it has the effect of delaying skin aging. This study aimed to establish a skin senescent cell model induced by oxidative stress, and further, to analyze the inhibitory effect of DMC on cellular senescence, and explore its molecular mechanisms. We found that treatment of HaCaT cells with 1 mM 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) for 48 h showed significant senescent characteristics, which could be effectively alleviated by pretreatment with the antioxidant N-acetyl-L-cysteine (NAC). DMC significantly inhibited AAPH-induced senescence, and further mechanism studies showed that the activation of autophagy which depended on the phosphorylation of ULK1 at Ser555 was necessary for DMC to alleviate senescence of HaCaT cells. In addition, the mitogen-activated protein kinase (MAPK) signal pathway was also involved in the regulation of autophagy induced by DMC. These results were also validated in UVB-induced photoaging mice. In conclusion, we successfully establish a skin senescent cell model and prove that DMC can be used as a potential therapeutic agent to intervene in skin aging.

Clinical features of eczema and dermatitis in the elderly: A cross-sectional study in mainland China

Purpose: The clinical features of eczema and dermatitis in the elderly have not been fully studied. To investigate the proportion and clinical features of geriatric eczema patients in mainland China.

Patients and methods: A multicenter cross-sectional study conducted in outpatients with eczema from 39 tertiary hospitals in 15 provinces.

Results: 1128 elderly patients (12.88%) had eczema and dermatitis. The mean age of those was 68.2 ± 6.8 years (range, 60–90 years) with a median course of 5.5 ± 8.9 years, which is much longer than that of non-geriatric patients (2.6 ± 4.1 years, p < 0.001). Compared to non-geriatric patients, more patients involved in extremities (76.2% vs 61.5%, p < 0.001) and trunk (37.2% vs 26.4%, p < 0.001), but less in head and neck (18.3% vs 30.4%, p < 0.001; 25.3% vs 20.6%, p < 0.001). 13.4% of eczema and dermatitis in the elderly was widespread, which is much higher than that of 8% in non-geriatric group (13.4% vs 8%, p < 0.001). 22.9% of geriatric eczema patients reported severe itching, which is much higher than that of 14% in counterparts (22.9% vs 14%, p < 0.001). A positive correlation was observed between age and severe itching (Spearman’s rank correlation test, p < 0.001). More geriatric patients had xerosis (39.6% vs 30.4%, p < 0.001) and more lichenification was found (25.6% vs 13.3%, p < 0.001).

Conclusion: More than 10% of eczema occurs in the elderly patients. Longer disease duration, more severe itching, more extremities and trunk involvement, and prone to widespread, xerosis, and lichenification make it a special entity which should be studied further.

Auricular Non-Epithelial Tumors with Solar Elastosis in Cats: A Possible UV-Induced Pathogenesis

The photoinduced etiopathology of actinic keratosis and squamous cell carcinoma in feline species is well known. This etiology has also been reported for non-epithelial cutaneous tumors in other species. To date, no cases of auricular non-epithelial cutaneous neoplasms erased in a contest of actinic keratosis in cats have been reported. The aim of this study was to describe feline auricular non-epithelial cutaneous neoplasms associated with typical UV-induced cutaneous lesions and solar elastosis. The study was conducted on five feline cases diagnosed with auricular non-epithelial cutaneous tumors (two fibrosarcomas, one mixosarcoma, one epithelioid melanoma and one hemangiosarcoma), selected from the Tumor Registry of the Department of Veterinary Sciences of the University of Pisa (1998–2018). Ten and six feline auricular biopsies of normal skin and skin with actinic keratosis, respectively, were used as controls. Orcein stain was used to investigate solar elastosis. Histological changes related to chronic solar irradiation were documented in the skin adjacent to the neoplastic lesions in the five cats. Considering the anatomical localization and the results of histopathology, this study suggests that non-epithelial cutaneous neoplasms may have a UV-induced etiopathogenesis in the feline species.

Attenuation of UV-induced skin photoaging in rats by walnut protein hydrolysates is linked to the modulation of MAPK/AP-1 and TGF-β/Smad signaling pathways

There is growing evidence that prevention of skin photoaging by oral administration of food-derived proteins hydrolysates is intricately linked to its alleviation against oxidative stress through modulation of the signaling pathway. Previously, walnut protein hydrolysates (WPHs) were prepared by enzymatic hydrolysis by our group and exhibited excellent anti-photoaging effect through regulation of extracellular matrix metabolism and the NF-κB signaling pathway. However, its response to oxidative stress and cascade mechanism remain unknown. In the present study, Sprague-Dawley rats were exposed periodically to UV irradiation and orally administered with WPHs to further examine the effects of WPHs on the redox state, MAPK/AP-1 and TGF-β/Smad signaling pathways, type I procollagen synthesis, and histopathological impairments in photoaging skin. Intervention with WPHs for 18 weeks significantly alleviated the photoaging morphology, enhanced the antioxidant components, and downregulated the phosphorylation levels of extracellular signal-regulated kinase (ERK) and C-Jun N-terminal kinase (JNK and p38 proteins) in photoaging tissues, while significant alterations on the gene expression levels of ERK, JNK and p38 were not observed. Meanwhile, WPHs significantly activated the TGF-β/Smad signaling pathway and type I procollagen production. Furthermore, histopathological analysis illustrated that WPHs predominately attenuated epidermal hyperplasia, reduced inflammatory filtration, and promoted the deposition of collagen fibers in photoaging skin. Altogether, the underlying mechanism of WPHs attenuating skin photoaging might lie in the synergistic modulation by increasing the antioxidant capacity, modulating the MAPK/AP-1/MMP-1 and TGF-β/Smad signaling pathways, stimulating the synthesis of type I procollagen, and restoring the impaired architecture structure. Our findings suggest that WPHs are promising agents for preventing skin photoaging.

Development of an Aged Full-Thickness Skin Model Using Flexible Skin-on-a-Chip Subjected to Mechanical Stimulus Reflecting the Circadian Rhythm

The skin is subject to both intrinsic aging caused by metabolic processes in the body and extrinsic aging caused by exposure to environmental factors. Intrinsic aging is an important obstacle to in vitro experimentation as its long-term progression is difficult to replicate. Here, we accelerated aging of a full-thickness skin equivalent by applying periodic mechanical stimulation, replicating the circadian rhythm for 28 days. This aging skin model was developed by culturing a full-thickness, three-dimensional skin equivalent with human fibroblasts and keratinocytes to produce flexible skin-on-a-chip. Accelerated aging associated with periodic compressive stress was evidenced by reductions in the epidermal layer thickness, contraction rate, and secretion of Myb. Increases in β-galactosidase gene expression and secretion of reactive oxygen species and transforming growth factor-β1 were also observed. This in vitro aging skin model is expected to greatly accelerate drug development for skin diseases and cosmetics that cannot be tested on animals.

Defining skin aging and its risk factors: a systematic review and meta-analysis

Skin aging has been defined to encompass both intrinsic and extrinsic aging, with extrinsic aging effected by environmental influences and overlaying the effects of chronological aging. The risk factors of skin aging have been studied previously, using methods of quantifying skin aging. However, these studies have yet to be reviewed. To better understand skin aging risk factors and collate the available data, we aimed to conduct a systematic review and meta-analysis. We conducted our systematic review in compliance with Preferred Reporting Item for Systematic Review and Meta-Analyses (PRISMA) guidelines. Embase, PubMed and Web of Science databases were searched in October 2020 using specific search strategies. Where odds ratios were reported, meta-analyses were conducted using the random effects model. Otherwise, significant factors were reported in this review. We identified seven notable risk factors for various skin aging phenotypes: age, gender, ethnicity, air pollution, nutrition, smoking, sun exposure. This review's results will guide future works, such as those aiming to examine the interaction between genetic and environmental influences.

Aspergillus oryzae-Fermented Wheat Peptone Enhances the Potential of Proliferation and Hydration of Human Keratinocytes through Activation of p44/42 MAPK

Identifying materials contributing to skin hydration, essential for normal skin homeostasis, has recently gained increased research interest. In this study, we investigated the potential benefits and mechanisms of action of Aspergillus oryzae-fermented wheat peptone (AFWP) on the proliferation and hydration of human skin keratinocytes, through in vitro experiments using HaCaT cell lines. The findings revealed that compared to unfermented wheat peptone, AFWP exhibited an improved amino acid composition, significantly (p < 0.05) higher DPPH scavenging capability and cell proliferation activity, and reduced lipopolysaccharide-induced NO production in RAW 264.7 cells. Furthermore, we separated AFWP into eleven fractions, each ≤2 kDa; of these, fraction 4 (AFW4) demonstrated the highest efficacy in the cell proliferation assay and was found to be the key component responsible for the cell proliferation potential and antioxidant properties of AFWP. Additionally, AFW4 increased the expression of genes encoding natural moisturizing factors, including filaggrin, transglutaminase-1, and hyaluronic acid synthase 1–3. Furthermore, AFW4 activated p44/42 MAPK, but not JNK and p38 MAPK, whereas PD98059, a p44/42 MAPK inhibitor, attenuated the beneficial effects of AFW4 on the skin, suggesting that the effects of AFW4 are mediated via p44/42 MAPK activation. Finally, in clinical studies, AFW4 treatment resulted in increased skin hydration and reduced trans-epidermal water loss compared with a placebo group. Collectively, these data provide evidence that AFW4 could be used as a potential therapeutic agent to improve skin barrier damage induced by external stresses.

Topical Delivery of Geranium/Calendula Essential Oil-Entrapped Ethanolic Lipid Vesicular Cream to Combat Skin Aging

The present study deals with the evaluation of the age-defying potential of topical cream formulations bearing Geranium essential oil/Calendula essential oil-entrapped ethanolic lipid vesicles (ELVs). Two types of cream formulations were prepared, viz., conventional and ELVs spiked o/w creams. Essential oil- (EO-) loaded ELVs were characterized by vesicle size, polydispersity index, encapsulation efficiency, and scanning electron microscopy. The cream formulations were evaluated for homogeneity, spreadability, viscosity, pH, in vitro antioxidant capacity, sun protection factor, and in vitro collagenase and elastase inhibition capacity. Confocal laser scanning microscopy (CLSM) was performed to ascertain skin permeation of conventional and vesicular cream. The results of in vitro antioxidant studies showed that GEO-/CEO-loaded vesicular creams have notable antioxidant capacity when compared to nonvesicular creams. GEO- or CEO-loaded vesicular creams exhibited the highest SPF value 10.26 and 18.54, respectively. Both the EO-based vesicular creams showed in vitro collagenase and elastase enzyme inhibition capacity. CLSM images clearly depicted that vesicular cream deep into the skin layers. From the research findings, the age-defying potential and photoprotective effects of GEO and CEO were confirmed. It can be concluded that ELVs are able to preserve the efficiency of EOs and have the potential to combat skin aging.

Ultrapulsed CO2 Resurfacing of Photodamaged Facial Skin in Vegan and Omnivore Patients: A Multicentric Study

BACKGROUND AND OBJECTIVES

Skin photoaging is related to extrinsic environmental exposures, mainly represented by ultraviolet radiation. One of the treatment options is laser resurfacing. As nutritional status is involved in cutaneous photodamage, we evaluated whether dietary patterns can also influence the response to facial resurfacing. Our prospective multicentric study involves three dermatologic centers specialized in laser therapy in northern Italy. The study aims to compare the outcome of a CO₂ ablative laser therapy between omnivore and vegan patients.

STUDY DESIGN/MATERIALS AND METHODS

Fifty-three omnivore and fifty-three vegan women undergoing ultrapulsed CO₂ resurfacing for photodamaged facial skin were enrolled in this study. Clinical improvement was evaluated 3 and 6 months after the treatment using the modified Dover score.

RESULTS

After laser treatment, vegans showed slower complete re-epithelialization (P < 0.001*) and disappearance of the erythema (P < 0.001*). After 3 and 6 months, vegans showed worse outcomes in terms of fine lines (P < 0.001* and P < 0.001*, respectively) and tactile roughness (P = 0.003* and ​​​​P = 0.002*, respectively) compared with omnivores, while they did not differ in mottled pigmentation.

CONCLUSIONS

The present study suggests that diet influences the clinical outcome of fractioned CO₂ laser treatment. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Ellagitannins from Rosa roxburghii suppress poly(I:C)-induced IL-8 production in human keratinocytes

The anti-inflammatory effects of a 50% aqueous extract of Rosa roxburghii fruit (RRFE) and two ellagitannins (strictinin and casuarictin) isolated from the RRFE were evaluated in a cell model of skin inflammation induced by self-RNA released from epidermal cells damaged by UV ray (UVR) irradiation. The RRFE inhibited interleukin-8 (IL-8) mRNA expression in normal human epidermal keratinocytes (NHEKs) stimulated with polyinosinic:polycytidylic acid (poly(I:C)), a ligand of toll-like receptor-3 (TLR-3). The plant-derived anti-inflammatory agents, dipotassium glycyrrhizinate (GK2) and allantoin, had no influence on the IL-8 expression. The purified compounds, strictinin and casuarictin, inhibited the IL-8 mRNA expression and IL-8 release induced in NHEKs by poly(I:C). These ellagitannins were thus found to be responsible for the biological activity exhibited by the RRFE. This study demonstrates that RRFE and isolated RRFE compounds show promise as ingredients for products formulated to improve skin disorders induced by UVR irradiation.

Molecular modeling for potential cathepsin L inhibitor identification as new anti-photoaging agents from tropical medicinal plants

Ultraviolet exposure can cause photoaging toward the human skin which is begun by the inflammation on the exposure area, also resulting in activation of a degradative enzyme cathepsin L. This enzyme is one of the interesting novel therapeutic targets for antiaging agents. Three plants, named Kleinhovia hospita, Aleurites moluccana, and Centella asiatica, are well-known in the tropical region as anti-inflammatory herbs. The aims of this study were to predict the antiaging activity of the 31 compounds from these plants via inhibition of cathepsin L. All compounds were minimized their energies and then used in molecular docking. After that, molecular dynamics (MD) simulation was employed for the 5 candidate ligands and the positive control; schinol. Interaction analysis results of the pre-MD and post-MD simulation structures were obtained. Furthermore, a toxicity test was performed using ADMET Predictor 7.1. Based on the molecular docking and the MD simulation results, kleinhospitine A, β-amyrin, and castiliferol exhibited lower binding free energy than schinol (-27.0925, -28.6813, -26.0037 kcal/mol) and also had interactions with the S´ region binding site. The toxicity test indicated that β-amyrin is the most potential candidate since it exhibited the lowest binding energy and the high safety level.

Characterization of skin aging through high-frequency ultrasound imaging as a technique for evaluating the effectiveness of anti-aging products and procedures: A review

INTRODUCTION

High-frequency ultrasound skin imaging analysis (HFUS) is a non-invasive technique that allows a unique approach to the analysis of skin aging, as well as in evaluating the effectiveness of dermatological and cosmetic products, especially for skin rejuvenation.

OBJECTIVE

To describe the impact of skin aging and different anti-aging strategies from the perspective of high-frequency ultrasound.

METHODS

A bibliographic survey was carried out, selecting relevant articles that evaluated the characterization of the skin features from different points of view such as gender (male and female), age (young skin and mature skin), and ethnicity, in addition to individual variations between body regions and daily variations.

RESULTS

Some studies also evaluated the impact of cosmetic treatments and esthetic procedures in the skin. Parameters such as dermal thickness, echogenicity, skin texture, and subepidermal low-echogenic band (SLEB) were analyzed. It can be concluded that there is a trend, although not unanimous in the consequences of aging on the skin, being different between men and women, plus the individual nuances resulted from each one's lifestyle and exposure to the sun.

CONCLUSION

As for the technique, it is concluded that high-frequency ultrasound is an important evaluative alternative for dermatological studies and the effectiveness of anti-aging products and treatments.

Tissue Mechanics in Haired Murine Skin: Potential Implications for Skin Aging

During aging, the skin undergoes changes in architecture and composition. Skin aging phenotypes occur due to accumulated changes in the genome/epigenome, cytokine/cell adhesion, cell distribution/extracellular matrix (ECM), etc. Here we review data suggesting that tissue mechanics also plays a role in skin aging. While mouse and human skin share some similarities, their skin architectures differ in some respects. However, we use recent research in haired murine skin because of the available experimental data. Skin suffers from changes in both its appendages and inter-appendage regions. The elderly exhibit wrinkles and loose dermis and are more likely to suffer from wounds and superficial abrasions with poor healing. They also have a reduction in the number of skin appendages. While telogen is prolonged in aging murine skin, hair follicle stem cells can be rejuvenated to enter anagen if transplanted to a young skin environment. We highlight recent single-cell analyses performed on epidermis and aging human skin which identified new basal cell subpopulations that shift in response to wounding. This may be due to alterations of basement membrane stiffness which would change tissue mechanics in aging skin, leading to altered homeostatic dynamics. We propose that the extracellular matrix (ECM) may play a key role as a chemo-mechanical integrator of the multi-layered senescence-associated signaling pathways, dictating the tissue mechanical landscape of niche microenvironments in aging phenotypes. We show examples where failed chemo-mechanical signaling leads to deteriorating homeostasis during skin aging and suggest potential therapeutic strategies to guide future research to delay the aging processes.

Spermidine-induced recovery of human dermal structure and barrier function by skin microbiome

An unbalanced microbial ecosystem on the human skin is closely related to skin diseases and has been associated with inflammation and immune responses. However, little is known about the role of the skin microbiome on skin aging. Here, we report that the Streptococcus species improved the skin structure and barrier function, thereby contributing to anti-aging. Metagenomic analyses showed the abundance of Streptococcus in younger individuals or those having more elastic skin. Particularly, we isolated Streptococcus pneumoniae, Streptococcus infantis, and Streptococcus thermophilus from face of young individuals. Treatment with secretions of S. pneumoniae and S. infantis induced the expression of genes associated with the formation of skin structure and the skin barrier function in human skin cells. The application of culture supernatant including Streptococcal secretions on human skin showed marked improvements on skin phenotypes such as elasticity, hydration, and desquamation. Gene Ontology analysis revealed overlaps in spermidine biosynthetic and glycogen biosynthetic processes. Streptococcus-secreted spermidine contributed to the recovery of skin structure and barrier function through the upregulation of collagen and lipid synthesis in aged cells. Overall, our data suggest the role of skin microbiome into anti-aging and clinical applications.

Human Induced Pluripotent Stem Cell-Derived Exosomes as a New Therapeutic Strategy for Various Diseases

Recently, an increasing number of studies have demonstrated that induced pluripotent stem cells (iPSCs) and iPSC-derived cells display therapeutic effects, mainly via the paracrine mechanism in addition to their transdifferentiation ability. Exosomes have emerged as an important paracrine factor for iPSCs to repair injured cells through the delivery of bioactive components. Animal reports of iPSC-derived exosomes on various disease models are increasing, such as in heart, limb, liver, skin, bone, eye and neurological disease and so forth. This review aims to summarize the therapeutic effects of iPSC-derived exosomes on various disease models and their properties, such as angiogenesis, cell proliferation and anti-apoptosis, with the hopes of improving their potential role in clinical applications and functional restoration.

Ursodeoxycholic Acid May Inhibit Environmental Aging-Associated Hyperpigmentation

Extrinsic aging of the skin caused by ultraviolet (UV) light or particulate matter is often manifested by hyperpigmentation due to increased melanogenesis in senescent skin. Ursodeoxycholic acid (UDCA), which has been commonly used as a health remedy for liver diseases, is known to possess antioxidant properties. This study was done to investigate whether UDCA inhibits cellular aging processes in the cells constituting human skin and it reduces melanin synthesis. ROS, intracellular signals, IL-1α, IL-8, TNF-α, cyclooxygenase (COX)-2, type I collagen, and matrix metalloproteinases (MMPs) levels were measured in human dermal fibroblasts treated with or without UDCA after UV exposure. Melanin levels and mechanistic pathways for melanogenesis were investigated. UDCA decreased ROS, senescence-associated secretory phenotype (SASP), and proinflammatory cytokines induced by UV treatment. UDCA reduced melanogenesis in normal human melanocytes cocultured with skin constituent cells. Our results suggest that UDCA could be a comprehensive agent for the treatment of environmental aging-associated hyperpigmentation disorders.

In vivo evaluation of novel particle-free polycaprolactone fillers for safety, degradation, and neocollagenesis in a rat model

Dermal fillers have become popular due to the increased demand for skin rejuvenation products. Polycaprolactone (PCL), a newly developed bioresorbable medical polymer, has emerged as a durable and safe dermal filler. However, available PCL fillers cause irritation; carrier gels can coagulate PCL particles, block the injection needle, and cause nonhomogeneity of particle suspensions that could be responsible for the observed side effects. To relieve pain, premixing PCL filler with lidocaine. However, this formulation changes the property of the CMC portion of the PCL filler, and possibly results in an uneven suspension of the PCL particles. Hence, a particle-free PCL homogeneously solubilized in water was developed to overcome these limitations. This study aimed to assess the in vivo safety, biodegradability, and neocollagenesis ability of a novel PCL filler, DLMR01 using a rat model. Fillers were characterized after injecting a vehicle control or DLMR01 using a digital camera, folliscope, and a three-dimensional profiling system. Biopsy was performed to evaluate biocompatibility and neocollagenesis. Skin elasticity was measured using a Cutometer. DLMR01 caused no needle occlusion by particle aggregation or laborious injectability. Filler nodules dispersed to surrounding tissues within 6 hours without further granuloma formation. Histological inspection revealed no tissue residual material or foreign body reaction during the 12-week test period. DLMR01 increased dermal thickness, collagen regeneration, and skin elasticity. In conclusion, this study demonstrates the potential of DLMR01 for dermal rejuvenation in a rat model.