Aging- and photoaging-dependent changes of enzymic and nonenzymic antioxidants in the epidermis and dermis of human skin in vivo

Mastering the formulation of an unstable vitamin C (VC) as anti-aging skin care ingredient. Part I: A new approach

OBJECTIVE

To develop a stabilized 12% pure Vitamin C-based serum at a pH close to that of the skin for use in anti-aging.

MATERIAL AND METHODS

At acidic pH (<3), under oxidative conditions, the ascorbate anionic form of VC rapidly undergoes transformations leading to a Xylosone by-product, resulting in important chemical losses of VC. Buffering the ascorbate anionic moiety with alkaline agents largely decreases its transformation and the loss of VC. The use of a cationic polymer (Polyquaternium 67, PQ67) enables binding of the ascorbate anion by creating an ionic network, at pH 6 and slows down the slight yellowing of the serum.

RESULTS

By exposing this complex to a temperature of 45°C for a two-month period, more acceptable degradation was obtained, with less VC chemical loss (approx. 5%-10%). Although a slight yellowish colour developed, it was found non redhibitory through consumer tests. As a result, such combination still leaves an important concentration of pure VC (over 10%) likely able to express its efficacy as anti-aging ingredient. Further refinements of this association were performed to reach adequate organoleptic properties of the formula, in view of a future clinical test, as proof of performance of VC efficacy at pH 6.

CONCLUSION

The stabilized formulation of VC at a pH close to that of the skin, apt at being tested in vivo, offers new possibilities for skin anti-aging routines strategy, by avoiding too acidic conditions (∼pH 3 or below) in daily use cosmetics and thereby allowing better tolerance and an increased adherence of the consumers.

The Role and Implications of Epidermal Dysfunction in the Pathogenesis of Inflammaging

Inflammaging has long been linked to the pathogenesis of various aging-associated disorders, including cardiovascular disease, obesity, type 2 diabetes, and dementia. Yet, the origins of inflammaging remain unclear. Although inflammatory dermatoses such as psoriasis and atopic dermatitis predispose to the development of certain aging-associated disorders, suggesting a pathogenic role of cutaneous inflammation in these disorders, the great majority of aged humans do not have inflammatory dermatoses. Nonetheless, recent studies point to epidermal dysfunction as contributing to inflammaging, even in otherwise normal aged humans. Chronologically aged skin exhibits reduced stratum corneum hydration levels, delayed permeability barrier recovery, and an elevated stratum corneum pH, all of which can provoke and exacerbate cutaneous inflammation. Owing to the prolonged release of proinflammatory cytokines (including TNFα, IL-1β, and IL-6) from the epidermis into the circulation in response to these functional abnormalities, cutaneous inflammation can lead to extracutaneous inflammation, resulting in the downstream development of inflammaging and its accompanying disorders. In support of this concept, topical therapies that improve epidermal function can mitigate some aging-associated disorders, such as mild cognitive impairment. In this perspective, we discuss the link between epidermal dysfunction and inflammaging and highlight the potential management of inflammaging-associated sequelae by enhancing epidermal functions.

Lipid-Based Gels for Delivery of 3-O-Ethyl L-Ascorbic acid in Topical Applications

This study explores the incorporation of 10% 3-O-ethyl L-ascorbic acid (ETVC), a derivative of vitamin C, into two lipid gel systems: a hydrogel (HG) consisting exclusively of lipids and water and a bigel (BG) combining the hydrogel with an oleogel made from olive oil and beeswax. We investigated the ETVC release profiles from both materials using synthetic membranes and measured their permeation through porcine skin in vitro. Additionally, the interaction of these lipid gel systems with the stratum corneum (SC) was determined. Results from the release study indicate that the BG exhibited slower ETVC release compared to the HG. The permeation experiments showed that the presence of lipids in the formulations enhanced ETVC retention in the skin. The HG delivered a higher amount to the SC, while the BG achieved greater retention in the epidermis. This difference is attributed to the different lipophilic nature of each material. The structural analysis of SC lipids revealed that the organization of surface lipids remained unaltered by the application of the gels. Finally, an in vitro efficacy test in porcine skin using methylene blue indicated that our ETVC gels exhibited antioxidant activity. These findings provide valuable insights into the potential of lipid-based gels for topical applications.

Prospective randomized double-blind comparative study of topical acetyl zingerone with tetrahexyldecyl ascorbate versus tetrahexyldecyl ascorbate alone on facial photoaging

BACKGROUND

Tetrahexydecyl ascorbate (THDA) is a lipophilic precursor to ascorbic acid that may be stabilized by acetyl zingerone (AZ). Studies have shown that the topical application of THDA may have photoprotective effects. Similarly, AZ has been shown to mitigate oxidative and inflammatory stress, thereby improving the appearance of photoaging.

AIMS

To examine the effects of THDA and AZ (THDA-AZ) on skin photoaging compared to THDA alone.

PATIENTS/METHODS

In this double-blind, randomized controlled trial, healthy individuals aged 30 to 65 were included and 44 participants were randomized to receive either THDA-AZ (THDA 5% + AZ 1%) or THDA only (THDA 5%) for 8 weeks. Facial photographs were taken at 0, 4, and 8 weeks to analyze wrinkle severity, pigment intensity, and redness intensity. A skin colorimeter was used to assess infraorbital pigmentation and erythema. Self-perception of skin and tolerability were assessed through questionnaires.

RESULTS

Average wrinkle severity was significantly decreased in the THDA-AZ group at Weeks 4 and 8 by 0.75% (p = 0.023) and 3.72% (p = 0.048), respectively, compared to the THDA group where wrinkle severity at Weeks 4 and 8 was increased by 7.88% and 4.48%, respectively. Facial pigment intensity was significantly decreased in the THDA-AZ group by 4.10% (p = 0.0002) at Week 8 compared to a 0.69% decrease in the THDA group. Facial redness intensity was decreased in the THDA-AZ group at Weeks 4 and 8 by 3.73% (p = 0.0162) and 14.25% (p = 0.045), respectively, compared to the THDA group where at Weeks 4 and 8 erythema increased by 27.5% and 8.34%, respectively. There were no significant differences in either group for infraorbital pigmentation or erythema.

CONCLUSIONS

Daily use of combined THDA and AZ may improve facial wrinkle severity, pigment intensity, and erythema to a greater extent than THDA. While THDA alone increases facial wrinkle severity and erythema, the addition of AZ reduces both.

Treatment of menopausal skin - A narrative review of existing treatments, controversies, and future perspectives

Menopause is a state of estrogen deficiency that affects numerous estrogen-dependent tissues in the female body. Skin is one of the most affected organs. Many consider menopausal skin changes to be merely an aesthetic problem; however, they can significantly affect women's quality of life. Currently, there are no approved effective treatments to prevent or alleviate skin changes associated with estrogen deficiency. Standard systemic hormone replacement therapy used to treat menopausal symptoms may be effective to some degree for skin treatment. In addition, compounded bioidentical hormone replacement therapy, selective estrogen receptor modulators, and phytoestrogens could also be used for skin treatment, although this is only hypothetical due to lack of data. Many questions therefore remain unanswered. On the other hand, topical, low-dose estrogen that would act only on the skin without systemic effects could be a possible option, as could be skin-only acting topical phytoestrogens. Such topical products without systemic effects could play a role in the treatment of menopausal skin. However, they are not currently approved because there is insufficient data on their safety and efficacy. A healthy lifestyle could have a positive effect on the menopausal skin. In this review, we provide an overview of the characteristics of menopausal skin, an outlook on the future treatment of menopausal skin with estrogens and other approaches, and the associated controversies and speculations. Overall, the importance of menopausal skin changes should not be neglected, and high-quality research is needed to gain new insights into the treatment of menopausal skin.

A mechanistic review on growing multiple therapeutic applications of lutein and its global market research

Lutein is a naturally occurring carotenoid synthesized by plants and algae that has a beneficial effect on several biological processes and associated ailments. Its immediate application is in ophthalmology, where it significantly lowers the incidences of age-related macular degeneration (AMD). It also has anti-inflammatory action, treatment of diabetic retinopathy, and cataracts, and enhancement of visual contrast. To critically assess lutein biosynthesis, therapeutic applicability, and market research literature. We have discussed its theoretical frameworks, experimental evidence, limitations, as well as clinical trial results, and future research prospects. The literature for this review article was mined and compiled by collecting and analyzing articles from several databases, including ScienceDirect, Google Scholar, PubMed, Wiley Online Library, Patentscope, and ClinicalTrials.gov published until March 30, 2022. Patent publications were identified using the search terms like IC:(C07C67/56) AND EN_AB:(lutein) OR EN_TI:(lutein) OR EN_AB:(extraction) OR EN_TI:(process). According to the literature, lutein is an essential nutrient given that it cannot be synthesized in the human body and acts as an antioxidant, affecting AMD, diabetic retinopathy, Rheumatic diseases, inflammation, and cancer. Due to inadequate production and laborious extraction, lutein is expensive despite its high demand and applicability. Market research predicts a 6.3% compound annual growth rate for lutein by 2032. Optimizing lutein extraction for high yield and purity is necessary. Lutein has proven applicability in various ailments as well as cosmetics that can be developed as a candidate drug for various diseases discussed in the review.

Unveiling the mechanisms for the development of rosehip-based dermatological products: an updated review

Rosa spp., commonly known as rosehips, are wild plants that have traditionally been employed as herbal remedies for the treatment of a wide range of disorders. Rosehip is a storehouse of vitamins, including A, B complex, C, and E. Among phytonutrients, vitamin C is found in the highest amount. As rosehips contain significant levels of vitamin C, they are perfect candidates for the development of skincare formulations that can be effectively used in the treatment of different skin disorders (i.e., scarring, anti-aging, hyperpigmentation, wrinkles, melasma, and atopic dermatitis). This research focuses on the vitamin C content of several Rosa sp. by their botanical and geographic origins, which according to research studies are in the following order: R. rugosa > R. montana > R. canina > R. dumalis, with lower levels in R. villosa and R. arvensis, respectively. Among rosehip species, R. canina is the most extensively studied species which also displays significant amounts of bioactive compounds, but also antioxidant, and antimicrobial activities (e.g., against Propionibacterium acnes, Staphylococcus aureus, S, epidermis, and S. haemolyticus). The investigation also highlights the use of rosehip extracts and oils to minimise the harmful effects of acne, which primarily affects teenagers in terms of their physical appearance (e.g., scarring, hyperpigmentation, imperfections), as well as their moral character (e.g., low self-confidence, bullying). Additionally, for higher vitamin C content from various rosehip species, the traditional (i.e., infusion, maceration, Soxhlet extraction) and contemporary extraction methods (i.e., supercritical fluid extraction, microwave-assisted, ultrasonic-assisted, and enzyme-assisted extractions) are highlighted, finally choosing the best extraction method for increased bioactive compounds, with emphasis on vitamin C content. Consequently, the current research focuses on assessing the potential of rosehip extracts as medicinal agents against various skin conditions, and the use of rosehip concentrations in skincare formulations (such as toner, serum, lotion, and sunscreen). Up-to-date studies have revealed that rosehip extracts are perfect candidates as topical application products in the form of nanoemulsions. Extensive in vivo studies have revealed that rosehip extracts also exhibit specific activities against multiple skin disorders (i.e., wound healing, collagen synthesis, atopic dermatitis, melasma, and anti-aging effects). Overall, with multiple dermatological actions and efficacies, rosehip extracts and oils are promising agents that require a thorough investigation of their functioning processes to enable their safe use in the skincare industry.

Antioxidants in Photoaging: From Molecular Insights to Clinical Applications

Photoaging (PA) is considered a silent disease affecting millions of people globally and is defined as skin damage due to prolonged exposure to ultraviolet radiation (UVR) from the sun. Physiologically, the skin is in a state of renewal and synthesis of components of the extracellular matrix (ECM). However, exposure to UVR affects the production of the ECM, and the functioning and response of skin cells to UVR begins to change, thus expressing clinical and phenotypic characteristics of PA. The primary mechanisms involved in PA are direct damage to the DNA of skin cells, increases in oxidative stress, the activation of cell signaling pathways responsible for the loss of skin integrity, and cytotoxicity. The medical and scientific community has been researching new therapeutic tools that counteract PA, considering that the damage caused by UVR exceeds the antioxidant defense mechanisms of the skin. Thus, in recent years, certain nutraceuticals and phytochemicals have been found to exhibit potential antioxidant and photoprotective effects. Therefore, the main objective of this review is to elucidate the molecular bases of PA and the latest pharmaceutical industry findings on antioxidant treatment against the progression of PA.

The Promising Role of Polyphenols in Skin Disorders

The biochemical characteristics of polyphenols contribute to their numerous advantageous impacts on human health. The existing research suggests that plant phenolics, whether consumed orally or applied directly to the skin, can be beneficial in alleviating symptoms and avoiding the development of many skin disorders. Phenolic compounds, which are both harmless and naturally present, exhibit significant potential in terms of counteracting the effects of skin damage, aging, diseases, wounds, and burns. Moreover, polyphenols play a preventive role and possess the ability to delay the progression of several skin disorders, ranging from small and discomforting to severe and potentially life-threatening ones. This article provides a concise overview of recent research on the potential therapeutic application of polyphenols for skin conditions. It specifically highlights studies that have investigated clinical trials and the use of polyphenol-based nanoformulations for the treatment of different skin ailments.

Enzymes for dermatological use

Skin is the ultimate barrier between body and environment and prevents water loss and penetration of pathogens and toxins. Internal and external stressors, such as ultraviolet radiation (UVR), can damage skin integrity and lead to disorders. Therefore, skin health and skin ageing are important concerns and increased research from cosmetic and pharmaceutical sectors aims to improve skin conditions and provide new anti-ageing treatments. Biomolecules, compared to low molecular weight drugs and cosmetic ingredients, can offer high levels of specificity. Topically applied enzymes have been investigated to treat the adverse effects of sunlight, pollution and other external agents. Enzymes, with a diverse range of targets, present potential for dermatological use such as antioxidant enzymes, proteases and repairing enzymes. In this review, we discuss enzymes for dermatological applications and the challenges associated in this growing field.

Bioactive Compounds for Combating Oxidative Stress in Dermatology

There are extensive studies that confirm the harmful and strong influence of oxidative stress on the skin. The body's response to oxidative stress can vary depending on the type of reactive oxygen species (ROS) or reactive nitrogen species (RNS) and their metabolites, the duration of exposure to oxidative stress and the antioxidant capacity at each tissue level. Numerous skin diseases and pathologies are associated with the excessive production and accumulation of free radicals. title altered Both categories have advantages and disadvantages in terms of skin structures, tolerability, therapeutic performance, ease of application or formulation and economic efficiency. The effect of long-term treatment with antioxidants is evaluated through studies investigating their protective effect and the improvement of some phenomena caused by oxidative stress. This article summarizes the available information on the presence of compounds used in dermatology to combat oxidative stress in the skin. It aims to provide an overview of all the considerations for choosing an antioxidant agent, the topics for further research and the answers sought in order to optimize therapeutic performance.

Decreased oxidative stress response and oxidant detoxification of skin during aging

Oxidative stress plays an important role in the skin aging process; however, the mechanisms are not fully elucidated. Especially the changes in various types of skin cells with aging and the key oxidative stress-related genes that play a regulatory role are not clear. In this study, single-cell RNA sequencing data and microarray transcriptome data were used to explore the changes in oxidative stress response and oxidant detoxification capacity of skin cells during aging and oxidative stress-related genes potentially involved in regulating skin aging were searched. The oxidative stress response and oxidant detoxification ability were weakened in the elderly compared with those of the young. Among the different types of skin cells, keratinocytes, melanocytes, vascular endothelial cells, fibroblasts, and lymphatic endothelial cells exhibited a stronger oxidative stress response and oxidant detoxification ability, while immune cells exhibited a weaker oxidative stress response and detoxification capacity. During aging, the oxidative stress response and oxidant detoxification capacity of keratinocytes, fibroblasts, macrophages, and vascular endothelial cells were significantly weakened. Annexin A1 (ANXA1) and Apolipoprotein E (APOE) may be key oxidative stress-related genes affecting skin aging.

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.

Modulatory role of vitamins A, B3, C, D, and E on skin health, immunity, microbiome, and diseases

Disruption of the skin barrier and immunity has been associated with several skin diseases, namely atopic dermatitis (AD), psoriasis, and acne. Resident and non-resident immune cells and the barrier system of the skin are integral to innate immunity. Recent advances in understanding skin microbiota have opened the scope of further understanding the various communications between these microbiota and skin immune cells. Vitamins, being one of the important micronutrients, have been reported to exert antioxidant, anti-inflammatory, and anti-microbial effects. The immunomodulatory action of vitamins can halt the progression of skin diseases, and thus, understanding the immuno-pharmacology of these vitamins, especially for skin diseases can pave the way for their therapeutic potential. At the same time, molecular and cellular markers modulated with these vitamins and their derivatives need to be explored. The present review is focused on significant vitamins (vitamins A, B3, C, D, and E) consumed as nutritional supplements to discuss the outcomes and scope of studies related to skin immunity, health, and diseases.

Role of Enzymic Antioxidants in Mediating Oxidative Stress and Contrasting Wound Healing Capabilities in Oral Mucosal/Skin Fibroblasts and Tissues

Unlike skin, oral mucosal wounds are characterized by rapid healing and minimal scarring, attributable to the "enhanced" healing properties of oral mucosal fibroblasts (OMFs). As oxidative stress is increasingly implicated in regulating wound healing outcomes, this study compared oxidative stress biomarker and enzymic antioxidant profiles between patient-matched oral mucosal/skin tissues and OMFs/skin fibroblasts (SFs) to determine whether superior oral mucosal antioxidant capabilities and reduced oxidative stress contributed to these preferential healing properties. Oral mucosa and skin exhibited similar patterns of oxidative protein damage and lipid peroxidation, localized within the lamina propria/dermis and oral/skin epithelia, respectively. SOD1, SOD2, SOD3 and catalase were primarily localized within epithelial tissues overall. However, SOD3 was also widespread within the lamina propria localized to OMFs, vasculature and the extracellular matrix. OMFs were further identified as being more resistant to reactive oxygen species (ROS) generation and oxidative DNA/protein damage than SFs. Despite histological evaluation suggesting that oral mucosa possessed higher SOD3 expression, this was not fully substantiated for all OMFs examined due to inter-patient donor variability. Such findings suggest that enzymic antioxidants have limited roles in mediating privileged wound healing responses in OMFs, implying that other non-enzymic antioxidants could be involved in protecting OMFs from oxidative stress overall.

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.

Efficacy of topical vitamin C in melasma and photoaging: A systematic review

BACKGROUND

Vitamin C is a micronutrient present in high concentrations in normal skin and a highly prescribed cosmeceutical, well known for protecting against ultraviolet-induced pigmentation and regulating collagen production. However, there is a lack of studies evaluating the efficacy of topical vitamin C in photoaging and melasma, with this systematic review being the first to assess the existing evidence.

AIM

This systematic review aims to assess whether topical vitamin C could be effective in reversing photoaging signs and treating melasma.

METHODS

Prospective, randomized controlled trials assessing protocols with topically applied vitamin C in patients with melasma or photodamage were searched in Medline, CENTRAL, and Scopus databases until the 12th of May 2022. Risk of bias was conducted in accordance with Cochrane Collaboration's tool for assessing the risk of bias in randomized trials, using RevMan 5.0.

RESULTS

Seven publications were included, with 139 volunteers in total. Studies that evaluated the topography of skin indicated that the treated skin appeared smoother and less wrinkled, which was supported by biopsies data. On objective assessments of pigmentation, there was a significant lightening of the skin treated. Hydration improved equally in the vitamin C and placebo-treated sites.

CONCLUSIONS

This study revealed that vitamin C is effective in treating uneven, wrinkled skin and has depigmenting properties, but long-term use may be needed to achieve noticeable changes. Q-switched Nd:YAG laser-associated protocols appear beneficial in enhancing vitamin C effects. Topical vitamin C may be a suitable alternative for melasma and photoaging, but more studies are needed to confirm these results and assess the ideal vitamin C concentration.

Development and Evaluation of an Innovative Approach Using Niosomes Based Polymeric Microneedles to Deliver Dual Antioxidant Drugs

Ascorbic acid (AA) and caffeine (CAFF) work to protect cells from ultraviolet (UV) radiation and slow down the photoaging process of the skin. However, cosmetic application of AA and CAFF is limited due to poor penetration across the skin and rapid oxidation of AA. The aim of this study was to design and evaluate the dermal delivery of dual antioxidants utilizing microneedles (MNs) loaded with AA and CAFF niosomes. The niosomal nanovesicles were prepared using the thin film method and had particle sizes ranging from 130.6-411.2 nm and a negative Zeta potential of around -35 mV. The niosomal formulation was then combined with polyvinylpyrrolidone (PVP) and polyethylene glycol 400 (PEG 400) to create an aqueous polymer solution. The best skin deposition of AA and CAFF was achieved with the formulation containing 5% PEG 400 (M3) and PVP. Furthermore, the role of AA and CAFF as antioxidants in preventing cancer formation has been well-established. Here we validated the antioxidant properties of ascorbic acid (AA) and caffeine (CAFF) in a novel niosomal formulation referred to as M3 by testing its ability to prevent H₂O₂-indued cell damage and apoptosis in MCF-7 breast cancer cells. Results showed that M3 was able to shield MCF-7 cells from H₂O₂ induced damage at concentrations below 2.1 µg/mL for AA and 1.05 µg/mL for CAFF, and also exhibited anticancer effects at higher concentrations of 210 µg/mL for AA and 105 µg/mL. The formulations were stable for two months at room temperature in terms of moisture and drug content. The use of MNs and niosomal carriers could be a promising approach for dermal delivery of hydrophilic drugs like AA and CAFF.

ELASTIC CATIONIC LIPOSOMES FOR VITAMIN C DELIVERY: DEVELOPMENT, CHARACTERIZATION AND SKIN ABSORPTION STUDY

The influence of hydrophilic surfactants acting on the membrane elasticity of liposomes on the skin absorption of vitamin C is investigated. The purpose of encapsulation inside cationic liposomes is to improve the skin delivery of vitamin C. The properties of elastic liposomes (ELs) are compared to that of conventional liposomes (CLs). ELs are formed by the addition of the "edge activator" Polysorbate 80 to the CLs composed of soybean lecithin, cationic lipid DOTAP (1,2-dioleoyl-3-trimethylammoniopropane chloride), and cholesterol. The liposomes are characterized by dynamic light scattering and electron microscopy. No toxicity is detected in human keratinocyte cells. Evidences of Polysorbate 80 incorporation into liposome bilayers and of the higher flexibility of ELs are given by isothermal titration calorimetry and pore edge tension measurements in giant unilamellar vesicles. The presence of a positive charge in the liposomal membrane increases the encapsulation efficacy by approximately 30% for both CLs and ELs. Skin absorption of vitamin C from CLs, ELs and a control aqueous solution measured in Franz cells shows a high delivery of vitamin C into each skin layer and the acceptor fluid from both liposome types. These results suggest that another mechanism drives skin diffusion, involving interactions between cationic lipids and vitamin C depending on the skin pH.

Photoprotection in skin of color

As populations in many parts of the world are projected to become more racially diverse over the coming decades, we must better understand the unique characteristics of the skin of populations with skin of color (SOC). This review aims to highlight important physiologic and clinical considerations of photoprotection in SOC. Ultraviolet radiation and visible light affect dark and light skin differently. SOC populations have historically not been informed on photoprotection to the same degree as their light skinned counterparts. This has exacerbated dermatologic conditions in which SOC populations are disproportionately affected, such as hyperpigmentary disorders. Patients should be encouraged to utilize multiple methods of photoprotection, ranging from avoidance of sunlight during peak intensity hours, seeking shade, wearing sun-protective clothing and wide-brimmed hat, and applying sunscreen. Ideal sunscreens for SOC populations include those with UVA-PF/SPF ratios ≥ 2/3 and tinted sunscreens to protect against VL. Although there have been increased efforts recently, more research into photoprotection for SOC and targeted public education are required to disseminate photoprotection resources that are patient-centered and evidence-based.

On the Potential Role of the Antioxidant Couple Vitamin E/Selenium Taken by the Oral Route in Skin and Hair Health

The relationship between oxidative stress and skin aging/disorders is well established. Many topical and oral antioxidants (vitamins C and E, carotenoids, polyphenols) have been proposed to protect the skin against the deleterious effect induced by increased reactive oxygen species production, particularly in the context of sun exposure. In this review, we focused on the combination of vitamin E and selenium taken in supplements since both molecules act in synergy either by non-enzymatic and enzymatic pathways to eliminate skin lipids peroxides, which are strongly implicated in skin and hair disorders.

The landscape of photoaging: From bench to bedside in a bibliometric analysis

Background

Bibliometric software exists as a platform providing multiple algorithms to process the data to suffice diverse goals. Interpretation of the result must be based on insight into the meaning of the original data and the algorithm used. Medical Subject Headings (MeSH) terms represent the macro-level meaning of topics, keywords that commonly reflect the micro-level aspects.

Objective

This study attempts to investigate the landscape of photoaging in the recent two decades by using bibliometric analysis.

Methods

Published studies of photoaging were obtained from PubMed and Web of Science Core Collection (WoSCC) from 2000 to 2020. Basic bibliometric information was generated by WoSCC. Major MeSH terms were performed in cluster analysis and displayed as a hierarchical form to induce knowledge structure, detection algorithm on keywords was presented as a timeline form to obtain hotspots, and institutional clusters were labeled with keywords to achieve institutional characteristics.

Results

A total of 2,727 and 2,705 studies were identified in PubMed and WoSCC, respectively. The number of photoaging-related studies at 3-year intervals grew steadily. The studies were performed in about 80 countries/regions. The highly frequent major MeSH terms were distributed in seven clusters, reflecting the etiology, pathophysiology, treatment, and prevention of photoaging. The hotspots changed as time went on, and the hotspots in recent 5 years were mitogen-activated protein kinase (MAPK), nuclear factor erythroid-derived 2-like 2 (Nrf2), and antioxidant activity. The highly productive institutions labeling in the top four clusters were Seoul National University, University of Michigan, China Medical University, and Harvard University, with corresponding keywords of UVB, retinoic acid, Nrf2, and rejuvenation.

Conclusions

This study built a knowledge structure of pathophysiology, treatment and prevention of photoaging, and identified recent hotspots of MAPK, Nrf2, and antioxidant activity. We provide a landscape of photoaging, from the bench (pathophysiology) to bedside (treatment, prevention), and pave the way for future research.

Ascorbic Acid (Vitamin C) as a Cosmeceutical to Increase Dermal Collagen for Skin Antiaging Purposes: Emerging Combination Therapies

Ascorbic acid (AA) is an essential nutrient and has great potential as a cosmeceutical that protects the health and beauty of the skin. AA is expected to attenuate photoaging and the natural aging of the skin by reducing oxidative stress caused by external and internal factors and by promoting collagen gene expression and maturation. In this review, the biochemical basis of AA associated with collagen metabolism and clinical evidence of AA in increasing dermal collagen and inhibiting skin aging were discussed. In addition, we reviewed emerging strategies that have been developed to overcome the shortcomings of AA as a cosmeceutical and achieve maximum efficacy. Because extracellular matrix proteins, such as collagen, have unique amino acid compositions, their production in cells is influenced by the availability of specific amino acids. For example, glycine residues occupy 1/3 of amino acid residues in collagen protein, and the supply of glycine can be a limiting factor for collagen synthesis. Experiments showed that glycinamide was the most effective among the various amino acids and amidated amino acids in stimulating collagen production in human dermal fibroblasts. Thus, it is possible to synergistically improve collagen synthesis by combining AA analogs and amino acid analogs that act at different stages of the collagen production process. This combination therapy would be useful for skin antiaging that requires enhanced collagen production.

Focus on the Contribution of Oxidative Stress in Skin Aging

Skin aging is one of the most evident signs of human aging. Modification of the skin during the life span is characterized by fine lines and wrinkling, loss of elasticity and volume, laxity, rough-textured appearance, and pallor. In contrast, photoaged skin is associated with uneven pigmentation (age spot) and is markedly wrinkled. At the cellular and molecular level, it consists of multiple interconnected processes based on biochemical reactions, genetic programs, and occurrence of external stimulation. The principal cellular perturbation in the skin driving senescence is the alteration of oxidative balance. In chronological aging, reactive oxygen species (ROS) are produced mainly through cellular oxidative metabolism during adenosine triphosphate (ATP) generation from glucose and mitochondrial dysfunction, whereas in extrinsic aging, loss of redox equilibrium is caused by environmental factors, such as ultraviolet radiation, pollution, cigarette smoking, and inadequate nutrition. During the aging process, oxidative stress is attributed to both augmented ROS production and reduced levels of enzymatic and non-enzymatic protectors. Apart from the evident appearance of structural change, throughout aging, the skin gradually loses its natural functional characteristics and regenerative potential. With aging, the skin immune system also undergoes functional senescence manifested as a reduced ability to counteract infections and augmented frequency of autoimmune and neoplastic diseases. This review proposes an update on the role of oxidative stress in the appearance of the clinical manifestation of skin aging, as well as of the molecular mechanisms that underline this natural phenomenon sometimes accelerated by external factors.

Safety Assessment of Ethers and Esters of Ascorbic Acid as Used in Cosmetics

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 7 ethers and esters of ascorbic acid, which collectively function as antioxidants, skin-conditioning agents, skin protectants, fragrance ingredients, and skin bleaching agents in cosmetic products. The Panel reviewed relevant data relating to the safety of these ingredients, and concluded that the ethers and esters of ascorbic acid are safe in the present practices of use and concentration, as described in this safety assessment.

Growth factors-based platelet lysate rejuvenates skin against ageing through NF-κB signalling pathway: In vitro and in vivo mechanistic and clinical studies

Introduction

Platelets benefit tissue regeneration by secreting growth factors, and platelet products, for example, platelet lysate (PL), have been clinically applied for tissue rejuvenation. To determine the anti‐ageing efficacy and mechanism of human PL (hPL) on skin, this study conducted clinical retrospective analysis, nude mice‐based in vivo study and human dermal fibroblasts (HDFs)‐based in vitro study.

Methods

Flow cytometry was employed for quality control of hPL, and ELISA was used for quantification of growth factors (EGF, IGF‐1, PDGF and TGF‐β) in hPL. After d‐galactose modelling, skin texture grading, histopathological observation, immunofluorescence analysis and oxidative stress assays were conducted on nude mice, while SA‐β‐gal staining, CCK‐8 and wound healing assays were conducted on HDFs. qPCR and western blot were conducted to clarify hPL's mechanism.

Results

The clinical retrospective data showed that hPL obviously rejuvenated human skin appearances without adverse events. The animal data showed that hPL exerted rejuvenative effects on skin, and the cellular data showed that hPL significantly promoted the proliferation and migration of HDFs and suppressed senescence‐associated secretory protein secretion and senescence state of senescent HDFs by suppressing NF‐κB pathway. The NF‐κB‐dependent mechanism was verified positively by using P65 siRNA and negatively by using prostratin. Furthermore, EGF, IGF‐1, PDGF and TGF‐β were found as the main ingredients in hPL, which contributed to the efficacy and mechanism of hPL.

Conclusion

This study provided novel knowledge of hPL, making it ideal for skin rejuvenation.

Tissue engineering strategies to bioengineer the ageing skin phenotype in vitro

Human skin ageing is a complex and heterogeneous process, which is influenced by genetically determined intrinsic factors and accelerated by cumulative exposure to extrinsic stressors. In the current world ageing demographic, there is a requirement for a bioengineered ageing skin model, to further the understanding of the intricate molecular mechanisms of skin ageing, and provide a distinct and biologically relevant platform for testing actives and formulations. There have been many recent advances in the development of skin models that recapitulate aspects of the ageing phenotype in vitro. This review encompasses the features of skin ageing, the molecular mechanisms that drive the ageing phenotype, and tissue engineering strategies that have been utilised to bioengineer ageing skin in vitro.

Plant-Derived Antioxidants: Significance in Skin Health and the Ageing Process

Natural substances have traditionally been used in skin care for centuries. There is now an ongoing search for new natural bioactives that not only promote skin health but also protect the skin against various harmful factors, including ultraviolet radiation and free radicals. Free radicals, by disrupting defence and restoration mechanisms, significantly contribute to skin damage and accelerate ageing. Natural compounds present in plants exhibit antioxidant properties and the ability to scavenge free radicals. The increased interest in plant chemistry is linked to the growing interest in plant materials as natural antioxidants. This review focuses on aromatic and medicinal plants as a source of antioxidant substances, such as polyphenols, tocopherols, carotenoids, ascorbic acid, and macromolecules (including polysaccharides and peptides) as well as components of essential oils, and their role in skin health and the ageing process.

Impact of visible light on skin health: The role of antioxidants and free radical quenchers in skin protection

Until recently, the primary focus of photobiology has centered on the impact of UV radiation on skin health, including DNA damage and oncogenesis; however, the significant effects of visible light (VL) on skin remain grossly underreported. VL has been reported to cause erythema in individuals with light skin (Fitzpatrick skin types [FSTs] I-III) and pigmentary changes in individuals with dark skin types (FSTs IV-VI). These effects have importance in dermatologic diseases and potentially play a role in conditions aggravated by sun exposure, including phototoxicity in patients with FSTs I to III and post-inflammatory hyperpigmentation and melasma in patients with FSTs IV to VI. The induction of free radicals, leading to the generation of reactive species, is one driving mechanism of VL-induced skin pathologies, leading to the induction of melanogenesis and hyperpigmentation. Initial clinical studies have demonstrated the effectiveness of topical sunscreen with antioxidant combinations in inhibiting VL + UV-A1-induced erythema in FSTs I to III and reducing pigmentation in FSTs IV to VI. Antioxidants may help prevent the worsening of pigmentary disorders and can be incorporated into photoprotective strategies. It is essential that dermatologists and the public are aware of the impact of VL on skin, especially in patients with skin of color, and understand the available options for VL protection.

Detachable dissolvable microneedles: intra-epidermal and intradermal diffusion, effect on skin surface, and application in hyperpigmentation treatment

Delivering bioactive compounds into skin tissue has long been a challenge. Using ex vivo porcine and rat skins, here we demonstrate that a detachable dissolvable microneedle (DDMN) array, a special dissolvable microneedle that allows needle detachment from the base within 2 min post administration, can effectively embed a model compound into epidermis and dermis. Diffusion of the compound from the needle embedding sites to the nearby skin tissue is demonstrated at various post administration periods. The relationship between the time that a conventional dissolvable microneedle array is left on skin without needle detachment from the base and the degree of skin surface abrasion at each microneedle penetration spot is also demonstrated on skin of human volunteers. Co-loading glutathione with vitamin C (vitC) can stabilize vitC in the DDMN. DDMN loaded with vitC and glutathione can help erasing post-acne-hyperpigmentation spots.

In vivo study of the effects of a portable cold plasma device and vitamin C for skin rejuvenation

Nowadays, cold atmospheric plasma shows interesting results in dermatology. In the present study, a new portable cold plasma was designed for plasma skin rejuvenation (PSR) purposes. This device is safe and easy to use at beauty salons and homes. The effects of this device were investigated on the rat skins. Also, as a new method to improve PSR results, vitamin C ointment was combined with plasma. In this study, there were four groups of 5 Wistar rats. The first group received vitamin C ointment, the second received 5 min of high-voltage plasma, and the third and the fourth groups received 5 min of high- and low-voltage plasma and vitamin C ointment. This process was done every other day (3 sessions per week) for 6 weeks. To evaluate the thermal effect of plasma, the skin temperature was monitored. Also, the presence of reactive species was demonstrated by the use of optical spectroscopy. In addition, mechanical assays were performed to assess the effect of plasma and vitamin C on the tissue's mechanical strength. The mechanical assays showed a positive impact of plasma on the treated tissue compared to the control group. Also, changes in the collagen level and thickness of the epidermal layer were examined in histological studies. The results indicated an increase in collagen levels after using plasma alone and an accelerated skin reaction after using vitamin C combined with plasma therapy. The epidermal layer's thickness increased after applying high-voltage plasma, which indicates an increase in skin elasticity. This study demonstrates the positive effect of using the portable plasma device with vitamin C ointment on effective parameters in skin rejuvenation.

The skin redoxome

Redoxome is the network of redox reactions and redox active species (ReAS) that affect the homeostasis of cells and tissues. Due to the intense and constant interaction with external agents, the human skin has a robust redox signalling framework with specific pathways and magnitudes. The establishment of the skin redoxome concept is key to expanding knowledge of skin disorders and establishing better strategies for their prevention and treatment. This review starts with its definition and progress to propose how the master redox regulators are maintained and activated in the different conditions experienced by the skin and how the lack of redox regulation is involved in the accumulation of several oxidation end products that are correlated with various skin disorders.

Ascorbic acid 2-glucoside: An ascorbic acid pro-drug with longer-term antioxidant efficacy in skin

OBJECTIVE

Deleterious effects of pollutants and ultraviolet radiation on the skin can be attenuated using formulations containing antioxidants. However, these have disadvantages, including chemical instability, photodegradation, poor bioavailability or biological activity. Here, two commercial formulations were evaluated: one optimized to stabilize and deliver ascorbic acid (AA) at 15% and the other containing a glucoside form of AA, namely ascorbic acid 2-glucoside (AA2G), at 1.8% and at a physiological pH. We compared the skin delivery, antioxidative effects and chemical stability of AA2G with AA in their respective formulations.

METHODS

Skin delivery was measured using fresh viable human skin explants, and oxidative stress was measured using a human reconstructed epidermal (RHE) model according to levels of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase.

RESULTS

Ascorbic acid 2-glucoside was completely metabolized to AA by the skin before entering the receptor compartment. The skin contained parent and AA, indicating a reserve of AA2G was present for further metabolism. For AA2G and AA, maximum flux of AA-equivalents was at 12 h, with continued absorption over 24 h. The absolute amount in µg was higher in the skin after application of AA than after application of AA2G. This may suggest a greater antioxidative effect; however, according to all three measurements of oxidative stress, the protective effect of AA and AA2G was similar. Unlike AA, AA2G was chemically stable under storage conditions.

CONCLUSION

A lower concentration of AA2G is as effective as the active metabolite, AA, in terms of antioxidant effects. AA2G was chemically stable and can be applied at a lower concentration than AA, thus avoiding the need for an acidic formulation with a pH below 3.5.

The anti-melanogenic effects of 3-O-ethyl ascorbic acid via Nrf2-mediated α-MSH inhibition in UVA-irradiated keratinocytes and autophagy induction in melanocytes

3-O-ethyl ascorbic acid (EAA) is an ether-derivative of ascorbic acid, known to inhibit tyrosinase activity, and is widely used in skincare formulations. Nevertheless, the molecular mechanisms underlying the EAA's effects are poorly understood. Here, the anti-melanogenic activity of EAA was demonstrated through Nrf2-mediated α-MSH inhibition in UVA-irradiated keratinocytes (HaCaT) and autophagy induction and inhibition of α-MSH-stimulated melanogenesis in melanocytes (B16F10). EAA pretreatment increased the HaCaT cell viability but suppressed ROS-mediated p53/POMC/α-MSH pathways in UVA-irradiated cells. Further, the conditioned medium from EAA-pretreated and UVA-irradiated HaCaT cells suppressed the MITF-CREB-tyrosinase pathways leading to the inhibition of melanin synthesis in B16F10 cells. EAA treatment increased nuclear Nrf2 translocation via the p38, PKC, and ROS pathways leading to HO-1, γ-GCLC, and NQO-1 antioxidant expression in HaCaT cells. However, Nrf2 silencing reduced the EAA-mediated anti-melanogenic activity, evidenced by impaired antioxidant gene expression and uncontrolled ROS (H₂0₂) generation following UVA irradiation. In B16F10 cells, EAA-induced autophagy was shown by enhanced LC3-II levels, AVO formation, Beclin-1 upregulation, and activation of p62/SQSTM1. Further, EAA-induced anti-melanogenic activity was substantially decreased in autophagy inhibitor (3-MA) pretreated or LC3 knockdown B16F10 cells. Notably, transmission electron microscopy data showed increased melanosome-engulfing autophagosomes in EAA-treated B16F10 cells. Moreover, EAA also down-regulated MC1R, TRP-1/-2, tyrosinase expressions, and melanin synthesis by suppressing the cAMP-CREB-mediated MITF expression in B16F10 cells stimulated with α-MSH. In vivo studies on the zebrafish model further confirmed that EAA inhibited tyrosinase expression/activity and endogenous pigmentation. In conclusion, 3-O-ethyl ascorbic acid is an effective skin-whitening agent and could be used as a topical agent for cosmetic purposes.

Tetrahexyldecyl Ascorbate (THDC) Degrades Rapidly under Oxidative Stress but Can Be Stabilized by Acetyl Zingerone to Enhance Collagen Production and Antioxidant Effects

Tetrahexyldecyl Ascorbate (THDC) is an L-ascorbic acid precursor with improved stability and ability to penetrate the epidermis. The stability and transdermal penetration of THDC, however, may be compromised by the oxidant-rich environment of human skin. In this study, we show that THDC is a poor antioxidant that degrades rapidly when exposed to singlet oxygen. This degradation, however, was prevented by combination with acetyl zingerone (AZ) as a stabilizing antioxidant. As a standalone ingredient, THDC led to unexpected activation of type I interferon signaling, but this pro-inflammatory effect was blunted in the presence of AZ. Moreover, the combination of THDC and AZ increased expression of genes associated with phospholipid homeostasis and keratinocyte differentiation, along with repression of MMP1 and MMP7 expression, inhibition of MMP enzyme activity, and increased production of collagen proteins by dermal fibroblasts. Lastly, whereas THDC alone reduced viability of keratinocytes exposed to oxidative stress, this effect was completely abrogated by the addition of AZ to THDC. These results show that AZ is an effective antioxidant stabilizer of THDC and that combination of these products may improve ascorbic acid delivery. This provides a step towards reaching the full potential of ascorbate as an active ingredient in topical preparations.

Reactive Oxygen Species and Pressure Ulcer Formation after Traumatic Injury to Spinal Cord and Brain

Traumatic injuries to the nervous system, including the brain and spinal cord, lead to neurological dysfunction depending upon the severity of the injury. Due to the loss of motor (immobility) and sensory function (lack of sensation), spinal cord injury (SCI) and brain injury (TBI) patients may be bed-ridden and immobile for a very long-time. These conditions lead to secondary complications such as bladder/bowel dysfunction, the formation of pressure ulcers (PUs), bacterial infections, etc. PUs are chronic wounds that fail to heal or heal very slowly, may require multiple treatment modalities, and pose a risk to develop further complications, such as sepsis and amputation. This review discusses the role of oxidative stress and reactive oxygen species (ROS) in the formation of PUs in patients with TBI and SCI. Decades of research suggest that ROS may be key players in mediating the formation of PUs. ROS levels are increased due to the accumulation of activated macrophages and neutrophils. Excessive ROS production from these cells overwhelms intrinsic antioxidant mechanisms. While short-term and moderate increases in ROS regulate signal transduction of various bioactive molecules; long-term and excessively elevated ROS can cause secondary tissue damage and further debilitating complications. This review discusses the role of ROS in PU development after SCI and TBI. We also review the completed and ongoing clinical trials in the management of PUs after SCI and TBI using different technologies and treatments, including antioxidants.

Facial Treatment with 3-O-Cetyl Ascorbic Acid for Improvement of Skin Texture: Uptake, Effectiveness, and In Vitro Carcinogenicity Assessment

Ascorbic acid (AA) is a water-soluble vitamin that is found at high concentrations in normal skin. The important and well-known benefits of using AA in skin health include the stimulation of collagen synthesis and the assistance of protection against photo-oxidative damages. To maintain stability and improve drug delivery to the active site, a variety of AA derivatives have been chemically synthesized. Among these compounds, we focus here on a lipophilic derivative, 3-O-cetyl ascorbic acid (3-CetylAA), which remains poorly characterized for cosmetic applications. Uptake analysis in three healthy human volunteers’ skin was conducted using a serial tape-stripping technique detecting 3-CetylAA (on average, 128 ± 27 pmol per µg) in the stratum corneum after a 5-h topical treatment when treated with 25 mM 3-CetylAA-containing cream for 13 days twice daily and continuously. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging of vertical cryosections of pig skin revealed the presence of 3-CetylAA in the epidermal layer after topical treatment with 3-CetylAA-containing cream. In sun-exposed human skin, 3-CetylAA improved the texture after treatment with 25 mM 3-CetylAA-containing cream for 4 weeks or more when used twice daily or continuously. An in vitro transformation assay using BALB/c 3T3 A31-1-1 cells demonstrated that 10 µM 3-CetylAA, which is the same concentration exhibited in vitro biological activities in another lipophilic AA derivative, 2-O-octadecyl ascorbic acid, was non-carcinogenic and did not potentiate the UVC-induced transformation frequency when applied for 3 days after UVC irradiation. These results demonstrate that 3-CetylAA is a promising candidate as a lipophilic derivative of AA for cosmetic purposes.

In vivo method to evaluate antioxidative activity using UVA-induced carbonylated protein on human skin

BACKGROUND

Skin is continuously exposed to oxidative stress caused by reactive oxygen species (ROS) produced by the ultraviolet (UV) light, and it is important to evaluate the antioxidant activity. Carbonylated proteins (CPs) are candidate markers of oxidative modification as a result from the ROS. We aimed to develop the CP-based method to assess the efficacy of antioxidants in human skin.

METHODS

Ten healthy females were enrolled in the study to determine the UVA dosage for CP production, and another 10 females were included to evaluate the antioxidative activity. The stratum corneum was collected from test skin using D-Squame tape, and CPs from the SC were stained by fluorescence labeling and observed using a fluorescence microscope.

RESULTS

CP level significantly increased with UVA irradiation from 15J/cm² to 50J/cm² compared to the control (non-UVA) area. CP production significantly increased by 34.38% and 35.22% in UVA irradiation and squalene (vehicle) areas. 5% α-tocopherol and β-carotene significantly increased the CP production by 20.77% and 19.34% after 2 hours of 30J of UVA irradiation compared to control area. Inhibition rate of CPs in 5% α-tocopherol and 5% β-carotene showed 41.45% and 45.37% after 2 hours of UVA irradiation.

CONCLUSION

This study developed the simple, visual, and direct in vivo method to evaluate the antioxidative activity for products in human skin by measuring the CP level as an oxidative modification caused by UVA-induced ROS generation.

Oxidative stress, antioxidants, hormesis and calorie restriction: The current perspective in the biology of aging

Aging, in a large measure, has long been defined as the resultant of oxidative stress acting on the cells. The cellular machinery eventually malfunctions at the basic level by the damage from the processes of oxidation and the system starts slowing down because of intrinsic eroding. To understand the initial destruction at the cellular level spreading outward to affect tissues, organs and the organism, the relationship between molecular damage and oxidative stress is required to understand. Retarding the aging process is a matter of cumulatively decreasing the rate of oxidative damage to the cellular machinery. Along with the genetic reasons, the decrease of oxidative stress is somehow a matter of lifestyle and importantly of diet. In the current review, the theories of aging and the understanding of various levels of molecular damage by oxidative stress have been emphasized. A broader understanding of mechanisms of aging have been elaborated in terms of effects of oxidative at molecular, mitochondrial, cellular and organ levels. The antioxidants supplementation, hormesis and calorie restriction as the prominent anti-aging strategies have also been discussed. The relevance and the efficacy of the antiaging strategies at system level have also been presented.

Lumenato protects normal human dermal fibroblasts from neutrophil-induced collagen-3 damage in co-cultures

Collagen is the major structural protein in the extracellular matrix of skin produced by fibroblasts. UV exposure results in infiltration of neutrophils within the epidermis and dermis, inducing collagen damage and contributing to the process of photo-aging. Collagen-3 is an integral structural component with collagen-1, and is an important regulator of collagen-1 fibrillogenesis. Addition of neutrophils activated with TNFα to normal human dermal fibroblast cultures, but not their supernatant, caused significant collagen-3 damage. To study whether Lumenato can protect from collagen-3 damage, it was added to co-cultures of Normal human dermal fibroblasts and neutrophils activated with TNFα. Lumenato prevented collagen-3 damage induced by activated neutrophils in a dose-dependent manner in the co-cultures. Lumenato also induced a low rate of collagen-3 synthesis in a dose-dependent manner detected by pro-collagen-3 secretion, but did not affect fibroblast cell number. Although Lumenato inhibited MMP-8, MMP-9, and elastase secreted from neutrophils, its main effect was in inhibiting both NADPH oxidase-producing superoxides and MPO activity-producing halides in a dose-dependent manner that correlated with protection from collagen-3 damage. In conclusion, the results suggest that Lumenato induces low levels of collagen-3 that may contribute for skin health and is very effective in defending the co-cultures from collagen-3 damage by inhibiting free radicals secreted from neutrophils, thus, indicating Lumenato's possible potential for skin protection.

Bioactive Compounds for Skin Health: A Review

Human skin is continually changing. The condition of the skin largely depends on the individual’s overall state of health. A balanced diet plays an important role in the proper functioning of the human body, including the skin. The present study draws attention to bioactive substances, i.e., vitamins, minerals, fatty acids, polyphenols, and carotenoids, with a particular focus on their effects on the condition of the skin. The aim of the study was to review the literature on the effects of bioactive substances on skin parameters such as elasticity, firmness, wrinkles, senile dryness, hydration and color, and to define their role in the process of skin ageing.

Role of Vitamins in Skin Health: a Systematic Review

PURPOSE OF REVIEW

Skin is the main defense organ of the human body against external insults (ultraviolet radiations, infections by pathogenic microorganisms, and mechanical and chemical stress). The integrity and functions of the skin barrier are supported by an adequate supply of micronutrients, such as several vitamins. The purpose of this review was to analyze all vitamin-related skin problems.

RECENT FINDINGS

The World Health Organization has estimated that more than 2 billion people worldwide experience deficiencies in the intake of essential vitamins and minerals; the percentage of adults all over the world using daily vitamin supplements, for treatment or prevention of chronic disease, has increased very rapidly in recent years. In this review, 65 studies have been selected in order to examine the role of the main vitamins and their derivatives involved in maintaining the well-being of the skin and their use as prophylactic and therapeutic agents in the management of skin disorders.

Application of adipose-derived stem cells in photoaging: basic science and literature review

Photoaging is mainly induced by continuous exposure to sun light, causing multiple unwanted skin characters and accelerating skin aging. Adipose-derived stem cells(ADSCs) are promising in supporting skin repair because of their significant antioxidant capacity and strong proliferation, differentiation, and migration ability, as well as their enriched secretome containing various growth factors and cytokines. The identification of the mechanisms by which ADSCs perform these functions for photoaging has great potential to explore therapeutic applications and combat skin aging. We also review the basic mechanisms of UV-induced skin aging and recent improvement in pre-clinical applications of ADSCs associated with photoaging. Results showed that ADSCs are potential to address photoaging problem and might treat skin cancer. Compared with ADSCs alone, the secretome-based approaches and different preconditionings of ADSCs are more promising to overcome the current limitations and enhance the anti-photoaging capacity.

Red Carrot Cells Cultured in vitro Are Effective, Stable, and Safe Ingredients for Skin Care, Nutraceutical, and Food Applications

Plant biomasses growing in bioreactor could be developed as production systems for cosmetic ingredients, nutraceuticals and food additives. We previously reported that the red carrot cell line R4G accumulates high levels of anthocyanins, which are potent antioxidants with multiple health-promoting properties. To investigate the industrial potential of this cell line in detail, we tested extract for antioxidant and anti-inflammatory activity in the mouse monocyte/macrophage cell-line J774A.1 and in reconstructed skin tissue models. We also compared the R4G extract to commercial carrot extracts in terms of stability and metabolomic profiles. We found that the R4G extract have potent antioxidant and anti-inflammatory activities, protecting mammalian cells from the oxidative stress triggered by exposure to bacterial lipopolysaccharides and H₂O₂. The extract also inhibited the nuclear translocation of NF-κB in an epidermal skin model, and induced the expression of VEGF-A to promote the microcirculation in a dermal microtissue model. The anthocyanins extracted from R4G cells were significantly more stable than those found in natural red carrot extracts. Finally, we showed that R4G extract has similar metabolomic profile of natural extracts by using a combination of targeted and untargeted metabolomics analysis, demonstrating the safety of R4G carrot cells for applications in the nutraceutical and food/feed industries.

Antioxidants as an Epidermal Stem Cell Activator

Antioxidants may modulate the microenvironment of epidermal stem cells by reducing the production of reactive oxygen species or by regulating the expression of extracellular matrix protein. The extracellular membrane is an important component of the stem cell niche, and microRNAs regulate extracellular membrane-mediated basal keratinocyte proliferation. In this narrative review, we will discuss several antioxidants such as ascorbic acid, plant extracts, peptides and hyaluronic acid, and their effect on the epidermal stem cell niche and the proliferative potential of interfollicular epidermal stem cells in 3D skin equivalent models.

Statistical development and in vivo evaluation of resveratrol-loaded topical gel containing deformable vesicles for a significant reduction in photo-induced skin aging and oxidative stress

OBJECTIVE

The present study aims to formulate and evaluate a novel vesicular formulation of resveratrol to achieve its dermatological benefits in terms of antiphotoaging and antioxidant.

METHOD

In this study, resveratrol-loaded deformable vesicular gel was prepared and optimized using Box-Behnken design. Selected critical material attributes were amount of phospholipid (X1), concentration of ethanol (X2), and amount of sodium cholate (X3). The prepared transethosomal vesicles were incorporated into carbopol gel base and evaluated. Ultraviolet radiation-induced skin aging and oxidative stress model in Swiss Albino mice was used to evaluate the clinical potential of the developed formulation and compared with conventional gel. Levels of Super Oxide Dismutase (SOD), catalase, glutathione peroxidase, protein content, and malondialdehyde were measured to assess the extent of lipid peroxidation and reactive oxygen species inhibition in different groups.

RESULT

DoE was successfully employed to optimize the vesicular formulation. Vesicle size was found to be 158.9 ± 7.65 nm, while values of entrapment efficiency and skin deposition were found to be 77.83 ± 2.87% and 371.84 ± 5.12 µg cm^-2, respectively. Visual skin grading and histopathological studies confirmed the higher efficacy of transethosomal resveratrol against oxidative stress. Significant enhancement in the levels of antioxidant enzymes and protein content confirmed the ameliorated potential of flexible transethosomal resveratrol as compared to the plain gel of resveratrol.

CONCLUSION

Restoration of first-line defense mechanism in chronic UV-exposed animal model has proved that transethosomal resveratrol can be developed as an innovative cosmetic product for significant improvement and repair of photo-aged skin.

Copper/Zinc Superoxide Dismutase in Human Skin: Current Knowledge

Superoxide dismutase is widespread in the human body, including skin and its appendages. Here, we focus on human skin copper/zinc superoxide dismutase, the enzyme that protects skin and its appendages against reactive oxygen species. Human skin copper/zinc superoxide dismutase resides in the cytoplasm of keratinocytes, where up to 90% of cellular reactive oxygen species is produced. Factors other than cell type, such as gender, age and diseased state influence its location in skin tissues. We review current knowledge of skin copper/zinc superoxide dismutase including recent studies in an attempt to contribute to solving the question of its remaining unexplained functions. The research described here may be applicable to pathologies associated with oxidative stress. However, recent studies on copper/zinc superoxide dismutase in yeast reveal that its predominant function may be in signaling pathways rather than in scavenging superoxide ions. If confirmed in the skin, novel approaches might be developed to unravel the enzyme's remaining mysteries.

Skin Health from the Inside Out

The skin is the main interface between the body and the environment, providing a biological barrier against an array of chemical and physical pollutants (e.g., ultraviolet light, ozone, etc.). Exposure of the skin to these outdoor stressors generates reactive oxygen species (ROS), which can overwhelm the skin's endogenous defense systems (e.g., catalase, vitamins C and E, etc.), resulting in premature skin aging due to the induction of DNA damage, mitochondrial damage, lipid peroxidation, activation of inflammatory signaling pathways, and formation of protein adducts. In this review, we discuss how topical application of antioxidants, including vitamins C and E, carotenoids, resveratrol, and pycnogenol, can be combined with dietary supplementation of these antioxidant compounds in addition to probiotics and essential minerals to protect against outdoor stressor-induced skin damage, including the damage associated with aging.