Mechanisms of aging and development-A new understanding of environmental damage to the skin and prevention with topical antioxidants

Efficacy in Clinical Studies of a Skin Care Serum Formula Containing 7 Short and Long Saccharides and Bacterial Fractions to Repair and Strengthen the Skin Barrier From Aggressions in Intense Conditions

BACKGROUND

A healthy skin barrier is essential to protect against the entry of harmful substances or the loss of internal fluids, especially water and electrolytes. Various aggressions are known to weaken the skin barrier.

AIMS

To evaluate single or multiple applications of a serum formula designed to mitigate skin barrier dysfunction and improve recovery after exposure to three different external aggressions (including one cumulative aggression under intense conditions).

PATIENTS AND METHODS

Five single-blind, controlled, intra-individual clinical studies in healthy subjects evaluated the effect of serum formula vs. untreated skin after aggression with harsh cleanser, emery paper abrasion, or tape stripping followed by exposure to 4°C or 40°C. Skin barrier function was assessed by transepidermal water loss (TEWL) and skin pH.

RESULTS

After harsh cleanser aggression, significant improvements in pH recovery and TEWL were observed after serum application, vs. untreated control, indicating significantly faster skin barrier recovery. Similarly, after tape stripping followed by intense cold or hot conditions, barrier function recovery was also significantly faster with an application of serum versus untreated control. In addition, serum-treated skin was more resistant against abrasion after serum treatment compared to the untreated control.

CONCLUSIONS

The serum formula, containing a unique combination of seven short and long saccharides and bacterial fractions, helped repair and strengthen the skin barrier to protect against abrasion. Taken together, these studies showed improved skin barrier recovery after exposure to different types of aggression (harsh cleanser or cumulative aggression by tape stripping followed by intense cold or hot conditions).

Air Pollution and Skin Diseases

Air pollution is a widespread environmental issue, with substantial global implications for human health. Recent epidemiological studies have shown that exposure to air pollution exacerbates various inflammatory skin conditions, including atopic dermatitis, psoriasis, or acne. Furthermore, air pollutants are associated with accelerated skin aging, hair loss, and skin cancer. The aim of this review is to elucidate the current understanding of the impact of air pollution on skin health, emphasizing the underlying mechanisms involved and existing therapeutic and cosmetic interventions available to prevent or mitigate these effects. A pivotal factor in the harmful effects of air pollution is the formation of reactive oxygen species and the resulting oxidative stress. The aryl hydrocarbon receptor signaling pathway also substantially contributes to mediating the effects of air pollutants on various skin conditions. Moreover, air pollutants can disrupt the skin barrier function and trigger inflammation. Consequently, antioxidant and anti-inflammatory therapies, along with treatments designed to restore the skin barrier function, have the potential to mitigate the adverse effects of air pollutants on skin health.

Association between household solid fuel use and cognitive frailty in a middle-aged and older Chinese population

Objectives

Our research intended to investigate the association between the solid fuels use and the risk of cognitive frailty (CF).

Methods

The research utilized data from the China Health and Retirement Longitudinal Study (CHARLS), a nationwide longitudinal study focusing on individuals aged 45 and older. A total of 8,563 participants without CF were enrolled from 2011 and followed up to 2015. Household fuel types include solid fuels (such as coal, crop residue, or wood-burning) and clean fuels (such as solar power, natural gas, liquefied petroleum gas, electricity, or marsh gas). CF was defined as the co-existence of cognitive impairment and physical frailty. Cox proportional hazards models were utilized to evaluate the relationship between the solid fuels use and the risk of CF. Furthermore, sensitivity analyses were conducted.

Results

Over a median follow-up of 4.0 years, 131 subjects were diagnosed with CF. We observed that the solid fuels use for cooking or heating increased the risk of developing CF compared to clean fuels, with HRs of 2.02 (95% CI: 1.25 to 3.25) and 2.38 (95% CI: 1.26 to 4.48), respectively. In addition, participants who use solid fuel for heating (HR: 2.38 [95% CI: 1.26, 4.48]) and cooking (HR: 2.02 [95% CI: 1.25, 3.25]) might experience an increased risk of CF. However, transitioning from solid to clean fuels for cooking could potentially reduce these risks (HR: 0.38 [95% CI: 0.16, 0.88]).

Conclusion

Household solid fuels utilization was closely associated with the risk of CF.

Skin sensitizers enhance superoxide formation by polycyclic aromatic hydrocarbons via the aldo-keto reductase pathway

Exposure to combustion-derived airborne polycyclic aromatic hydrocarbons (PAHs) may harm human skin, exacerbate cutaneous inflammatory diseases and accelerate skin aging. The toxicity of PAHs is unleashed upon their metabolic activation by cytochrome P450 (CYP) 1 monooxygenases, resulting in the formation of reactive intermediates that form mutagenic DNA adducts. Moreover, PAHs cause oxidative stress, which is primarily due to aldo-keto reductases (AKRs), such as AKR1C3, which convert CYP1-derived PAH-trans-diols to PAH-catechols. The catechols undergo autooxidation leading to the formation of reactive oxygen species (ROS) and PAH-quinones. The latter are highly reactive, mitotoxic and are reduced back to PAH-catechols, thus facilitating redox cycling. As AKR1C expression is inducible by other NRF2-stimulating chemicals, we tested the hypothesis that co-exposure of HaCaT keratinocytes to skin sensitizers and the PAH benzo[a]pyrene (BaP) enhances ROS formation. We observed a synergistic effect of the skin sensitizers on the BaP-induced expression of the NRF2 target genes heme oxygenase-1, sulfiredoxin-1 and AKR1C3. In fact, co-exposure to the skin sensitizers also enhanced the BaP-induced formation of superoxide anions. Intriguingly, the co-exposure-related ROS formation was abolished upon inhibition of either CYP1A1 or AKR1C3. Testing of additional skin-sensitizing compounds, differing in their mode of action, indicated that especially potent Michael acceptors enhance the toxicity of BaP by increasing AKR1C3 expression and, presumably, downstream BaP-quinone formation. Our study reveals potential health risks associated with the simultaneous exposure to common skin-sensitizing substances and ubiquitous PAHs, and implies a role for NRF2 in mediating PAH toxicity.

Role of microbiota in the GUT-SKIN AXIS responses to outdoor stressors

Beside the respiratory tract, the skin and the gut represent the first defensive lines of our body against the external insults displaying many important biochemical features able to maintain the epithelial barrier integrity and to regulate the tissue immune responses. The human microbiome is essential in maintaining the tissue homeostasis and its dysregulation may lead to tissue conditions including inflammatory pathologies. Among all external insults, air pollutants have been shown to cause oxidative stress damage within the target tissues via an OxInflammatory response. Dysregulation of the gut microbiome (dysbiosis) by outdoor stressors, including air pollutants, may promote the exacerbation of the skin tissue damage via the interplay between the gut-skin axis. The intent of this review is to highlight the ability of exogenous stressors to modulate the human gut-skin axis via a redox regulated mechanism affecting the microbiome and therefore contributing to the development and aggravation of gut and skin conditions.

Kappaphycus alvarezii as a renewable source of kappa-carrageenan and other cosmetic ingredients

Kappa-carrageenan is one of the most traded marine-derived hydrocolloids used in the food-and-beverage, pharmaceuticals, and personal care/cosmetics industries. K. alvarezii (previously known as Kappaphycus alvarezii) is arguably the most important natural producer based on annual production size and near-homogeneity of the product (i.e., primarily being the kappa-type). The anticipated expansion of the kappa-carrageenan market in the coming years could easily generate >100,000 MT of residual K. alvarezii biomass per year, which, if left untreated, can severely affect the environment and economy of the surrounding area. Among several possible valorization routes, turning the biomass residue into anti-photoaging cosmetic ingredients could potentially be the most sustainable one. Not only optimizing the profit (thus better ensuring economic sustainability) relative to the biofuels- and animal feed-routes, the action could also promote environmental sustainability. It could reduce the dependency of the current cosmetic industry on both petrochemicals and terrestrial plant-derived bioactive compounds. Note how, in contrast to terrestrial agriculture, industrial cultivation of seaweeds does not require arable land, freshwater, fertilizers, and pesticides. The valorization mode could also facilitate the sequestration of more greenhouse gas CO2 as daily-used chemicals, since the aerial productivity of seaweeds is much higher than that of terrestrial plants. This review first summarizes any scientific evidence that K. alvarezii extracts possess anti-photoaging properties. Next, realizing that conventional extraction methods may prevent the use of such extracts in cosmetic formulations, this review discusses the feasibility of obtaining various K. alvarezii compounds using green methods. Lastly, a perspective on several potential challenges to the proposed valorization scheme, as well as the potential solutions, is offered.

Differential effects of benzo[a]pyrene exposure on glutathione and purine metabolism in keratinocytes: Dose-dependent and UV co-exposure effects

Polycyclic aromatic hydrocarbons with the key substance benzo[a]pyrene (B[a]P) are widespread pollutants in the environment and at working places. Nonetheless, the exact underlying mechanisms of toxicological effects caused by B[a]P especially in absence and presence of UV irradiation remain uncertain. This study examines variations in exposure conditions: low B[a]P (4 nM), low B[a]P + UV and high B[a]P (4 μM), selected based on pertinent cytotoxicity assessments. Following cell viability evaluations post-treatment with varied B[a]P concentrations and UV irradiation, the identified concentrations underwent detailed metabolomic analysis via gas chromatography-mass spectrometry. Subsequently, resulting changes in metabolic profiles across these distinct exposure groups are comprehensively compared. Chemometric analyses showed modest regulation of metabolites after low B[a]P exposure compared to control conditions. High B[a]P and low B[a]P + UV exposure significantly increased regulation of metabolic pathways, indicating that additional UV irradiation plus low B[a]P is as demanding for the cells as higher B[a]P treatment alone. Further analysis revealed exposure-dependent regulation of glutathione-important for oxidative defence-and purine metabolism-important for DNA base synthesis. Only after low B[a]P, oxidative defence appeared to be able to compensate for B[a]P-induced perturbations of the oxidative homeostasis. In contrast, purine metabolism already responded towards adversity at low B[a]P. The metabolomic results give an insight into the mechanisms leading to the toxic response and confirm the strong effects of co-exposure on oxidative defence and DNA repair in the model studied.

Clean and sustainable environment problems in forested areas related to recreational activities: case of Lithuania and Turkey

Introduction

With the acceleration of social life, people's interest and demand for forestry recreation activities is increasing. However, with this increase, it is inevitable that negative environmental effects will occur. Particularly mass participation poses an important risk for environmental sustainability. In this context, the aim of this study is to determine the recreational activities organized in forest areas in Turkey and Lithuania, the environmental effects of these activities and the precautions to be taken.

Methods

In Turkey and Lithuania, interviews were conducted to determine the attitudes of experts involved in recreational activity processes towards a clean environment and environmental sustainability. A semi-structured interview form was used in the interviews with forest operators and other experts. The sample group of the research consists of 17 experts from Turkey and Lithuania.

Results

According to the results of the research, recreational activities are organized in forest areas in both countries, but the most important problem related to these activities is waste production. In addition, there is also damage to the natural environment. Although there are legal regulations in both countries, there are no definite results in solving environmental problems.

Conclusions

It can be said that necessary measures such as raising awareness of people and ecological education should be taken in order to ensure the right of individuals to live in a safe and clean environment and at the same time to ensure sustainability in forest areas. as the improvement of legal regulation.

Nutritional Supplements for Skin Health-A Review of What Should Be Chosen and Why

Supplementation of micronutrients is considered to be crucial in the reinforcement of the skin's barrier. In this paper, 14 nutritional compounds commonly used in food or pharmaceutic industries were analyzed in terms of influencing skin conditions. The major objective of this paper was to provide a narrative review of the available literature regarding several chosen compounds that are currently widely recommended as supplements that aim to maintain proper and healthy skin conditions. We conducted a review of the literature from PubMed, Scopus, and Web of Science until September 2023 without any other restrictions regarding the year of the publication. Ultimately, we reviewed 238 articles, including them in this review. Each of the reviewed compounds, including vitamin A, vitamin C, vitamin D, vitamin E, curcumin, chlorella, Omega-3, biotin,Ppolypodium leucotomos, Simmondsia chinesis, gamma oryzanol, olive leaf extract, spirulina, and astaxanthin, was observed to present some possible effects with promising benefits for a skin condition, i.e., photoprotective radiation. Adding them to the diet or daily routine might have a positive influence on some skin inflammatory diseases such as atopic dermatitis or psoriasis. Further, UV radiation protection facilitated by some supplements and their impact on human cells might be helpful during chemotherapy or in preventing melanoma development. Further research is needed because of the lack of clear consensus regarding the doses of the described compounds that could provide desirable effects on the skin.

In vitro, ex vivo, and clinical evaluation of anti-aging gel containing EPA and CBD

BACKGROUND

Skin aging manifestation, such as coarse wrinkles, loss of elasticity, pigmentation, and rough-textured appearance, is a multifactorial process that can be exacerbated by air pollution, smoking, poor nutrition, and sun exposure. Exposure to UV radiation is considered the primary cause of extrinsic skin aging and accounts for about 80% of facial aging. Extrinsic skin aging signs can be reduced with demo-cosmetic formulations. Both cannabidiol (CBD) and eicosapentaenoic acid (EPA) have been previously suggested as potent active dermatological ingredients.

AIMS

The objective of the current research was to evaluate the compatibility of both agents in the prevention and treatment of skin aging. First, the impact of both agents was assessed using standard photoaging models of UV-induced damage, both in vitro (HaCaT cells) and ex vivo (human skin organ culture). Then, a clinical validation study (n = 33) was performed using an optimized topical cream formulation tested at different time points (up to Day 56).

RESULTS

EPA was found to potentiate the protective effects of CBD by reducing the secretion of prostaglandin E2 (PGE2 ) and interleukin-8 (IL-8), two primary inflammatory agents associated with photoaging. In addition, a qualitative histological examination signaled that applying the cream may result in an increase in extracellular matrix (ECM) remodeling following UV radiation. This was also evidenced clinically by a reduction of crow's feet wrinkle area and volume, as well as a reduction of fine line wrinkle volume as measured by the AEVA system. The well-established age-dependent subepidermal low-echogenic band (SLEB) was also reduced by 8.8%. Additional clinical results showed significantly reduced red spots area and count, and an increase in skin hydration and elasticity by 31.2% and 25.6% following 56 days of cream application, respectively. These impressive clinical results correlated with high satisfaction ratings by the study participants.

DISCUSSION AND CONCLUSIONS

Collectively, the results show a profound anti-aging impact of the developed formulation and strengthen the beneficial derm-cosmetic properties of CBD-based products.

Promoting New Approach Methodologies (NAMs) for research on skin color changes in response to environmental stress factors: tobacco and air pollution

Aging is one of the most dynamic biological processes in the human body and is known to carry significant impacts on individuals' self-esteem. Skin pigmentation is a highly heritable trait made possible by complex, strictly controlled cellular and molecular mechanisms. Genetic, environmental and endocrine factors contribute to the modulation of melanin's amount, type and distribution in the skin layers. One of the hallmarks of extrinsic skin aging induced by environmental stress factors is the alteration of the constitutive pigmentation pattern clinically defined as senile lentigines and/or melasma or other pigmentary dyschromias. The complexity of pollutants and tobacco smoke as environmental stress factors warrants a thorough understanding of the mechanisms by which they impact skin pigmentation through repeated and long-term exposure. Pre-clinical and clinical studies demonstrated that pollutants are known to induce reactive oxygen species (ROS) or inflammatory events that lead directly or indirectly to skin hyperpigmentation. Another mechanistic direction is provided by Aryl hydrocarbon Receptors (AhR) which were shown to mediate processes leading to skin hyperpigmentation in response to pollutants by regulation of melanogenic enzymes and transcription factors involved in melanin biosynthesis pathway. In this context, we will discuss a diverse range of New Approach Methodologies (NAMs) capable to provide mechanistic insights of the cellular and molecular pathways involved in the action of environmental stress factors on skin pigmentation and to support the design of raw ingredients and formulations intended to counter their impact and of any subsequently needed clinical studies.

Topical Application of M89PF Containing Vichy Mineralising Water and Probiotic Fractions Prevents Cutaneous Damage Induced by Exposure to UV and O3

Purpose

Exposure of the skin to ultraviolet radiation (UV) or ozone (O₃) results in stressed skin, leading to the alteration of the skin physical barrier and defence functions. In this work, the preventive benefit of a dermocosmetic, M89PF, containing Vichy mineralising water, probiotic fractions, antioxidant vitamins and hyaluronic acid, in the alteration of skin physical barrier and skin defence functions after exposure to O₃ and UV, alone or combined, was assessed.

Methods

Untreated and treated (M89PF) skin explants were exposed to O₃, to UV rays or to O₃+UV. Immunofluorescence was performed for skin barrier, oxidative stress, and inflammatory markers after one and four days of exposure to the pollutants.

Results

M89PF significantly (p≤0.05) prevented the decrease of the expression level of different skin barrier markers, and significantly (p≤0.05) prevented the induction of OxInflammatory markers and inflammasome components by UV, O_3, or both combined.

Conclusion

M89PF prevents skin barrier damage, as well as oxidative stress and inflammatory markers induced by exposome factors, such as UV, O_3, or both combined.

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.

Melatonin inhibits senescence-associated melanin pigmentation through the p53-TYR pathway in human primary melanocytes and the skin of C57BL/6 J mice after UVB irradiation

UVB exposure accelerates skin aging and pigmentation. Melatonin effectively regulates tyrosinase (TYR) activity and aging. The purpose of this study was to determine the association between premature senescence and pigmentation, and the mechanism of melanin synthesis effected by melatonin. Primary melanocytes were extracted and identified from the male foreskin. To inhibit TYR expression, primary melanocytes were transduced with the lentivirus pLKD-CMV-EGFP-2A-Puro-U6-TYR. The wild-type TYR^(+/+) and TYR^(-/-) or TYR^(+/-) knockout C57BL/6 J mice were used to determine the role of TYR on melanin synthesis in vivo. Results showed that UVB-induced melanin synthesis is dependent on TYR in primary melanocytes and mice. Furthermore, in primary melanocytes pretreated with Nutlin-3 or PFT-α to up or downregulate p53, results showed that premature senescence and melanin synthesis increased in primary melanocytes after UVB irradiation at 80 mJ/cm², and further increased after being treated with Nutlin-3, while significantly decreased with PFT-α. In addition, melatonin inhibited UVB-induced premature senescence associated with inactivation of p53 and phosphorylation of p53 on Ser15 (ser-15), a decrease of melanin synthesis accompanied by reduced TYR expression. Moreover, skin erythema and pigmentation induced by UVB were reduced in the dorsal and ear skin of mice topically pretreated with 2.5% melatonin. These indicate that melatonin inhibits UVB-induced senescence-associated pigmentation via the p53-TYR pathway in primary melanocytes and prevents pigmentation obviously in the dorsal and ear skin of C57BL/6 J mice after UVB irradiation. KEY MESSAGES: P53 links UVB irradiation-induced senescence and senescence-associated pigmentation and regulates TYR in primary melanocytes after UVB irradiation. Melatonin inhibits senescence-associated pigmentation through the p53-TYR pathway in primary melanocytes. Melatonin prevents skin erythema and melanin pigmentation induced by UVB irradiation in the dorsal and ear skin of C57BL/6J mice.

Effect of Ultraviolet Radiation and Benzo[a]pyrene Co-Exposure on Skin Biology: Autophagy as a Potential Target

The skin is the outermost protective barrier of the human body. Its role is to protect against different physical, chemical, biological and environmental stressors. The vast majority of studies have focused on investigating the effects of single environmental stressors on skin homeostasis and the induction of several skin disorders, such as cancer or ageing. On the other hand, much fewer studies have explored the consequences of the co-exposure of skin cells to two or more stressors simultaneously, which is much more realistic. In the present study, we investigated, using mass-spectrometry-based proteomic analysis, the dysregulated biological functions in skin explants after their co-exposure to ultraviolet radiation (UV) and benzo[a]pyrene (BaP). We observed that several biological processes were dysregulated, among which autophagy appeared to be significantly downregulated. Furthermore, immunohistochemistry analysis was carried out to validate the downregulation of the autophagy process further. Altogether, the output of this study provides an insight into the biological responses of skin to combined exposure to UV + BaP and highlights autophagy as a potential target that might be considered in the future as a novel candidate for pharmacological intervention under such stress conditions.

The development and future frontiers of global ecological restoration projects in the twenty-first century: a systematic review based on scientometrics

Ecological restoration projects are becoming a mainstream of research, and their studies are widely followed by scholars worldwide, yet there is no comprehensive review of this research. Nowadays, bibliometrics has attracted much attention from the scientific community, and its methodological approach allows quantitative and qualitative analysis of research performance in journals or subject areas. This paper provides a systematic and comprehensive description of the progress and hotspots of ecological restoration projects from a bibliometric perspective, based on 1173 articles in the Web of Science Core Collection (WOSCC) database. Research on ecological restoration projects has shown a positive growth trend since the twenty-first century. China and the USA are the most active countries in terms of the number of relevant articles published, and more than half of the top 10 active institutions are from China, but there is less collaboration between different countries/institutions. Research in ecological restoration projects is summarized into three main research areas: the main ecological damage problems, the impact of human beings on ecological damage, and the main methods of ecological restoration. Finally, some challenges and outlooks conducive to the rapid and balanced development of ecological restoration projects are presented, which provide valuable references and help for future researchers.

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.

UV-induced skin's green autofluorescence is a biomarker for both non-invasive evaluations of the dosages of UV exposures of the skin and non-invasive prediction of UV-induced skin damage

It is crucial to discover biomarkers for non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period, and for non-invasive prediction of UV-induced skin damage. Our current study has obtained findings: UVB exposures produced dose-dependent increases in skin's green autofluorescence (AF) intensity of mice, which were significantly associated with the UVB dosages. The UVC-induced green AF increases were dose dependent, which were highly associated with the UVC dosages. Moreover, both previous reports and our current study have collectively shown significant association between UVB/UVC dosages and UVB/UVC-induced skin damage. Collectively, our study has indicated that the UVB/UVC-induced skin's AF are first biomarkers for both non-invasive evaluations of the dosages of UV exposures to a person during post-UV exposure period and non-invasive and label-free prediction of UVB/UVC-induced skin damage.

Benefits of topical hyaluronic acid for skin quality and signs of skin aging: From literature review to clinical evidence

Skin aging goes beyond a chronological process and also results from extrinsic factors referred to as the exposome. Hyaluronic acid (HA) is an important component of the extracellular matrix, with loss starting at 25 years old. While many studies of HA concern topical use, few literature reviews only address the use of topical HA in dermatology. This review describes the different characteristics of HA-containing cosmeceuticals, with a focus on skin aging and the impact of exposome factors on HA synthesis and degradation. A review was performed using the terms HA, hyaluronan, topical, dermatology, cosmetic, aging treatment, exposome, and cosmeceuticals. Results are also presented from a recent randomized controlled trial (RCT), which investigated the additional benefit of using a HA epidermic filler (HA-filler serum) combined with Botulinum toxin type A (BoNTA) to treat signs of skin aging. Subjects were randomized to two groups: HA-filler serum starting 24 h after the BoNTA injection then twice daily for 24 weeks, or the control group, which received BoNTA. HA is a key ingredient used in cosmeceuticals for its hydration/antiaging properties (hygroscopic, rheological, and viscoelastic). Several clinical studies indicate that HA is both well tolerated and effective, adjuvant to both post-surgical and facial rejuvenation procedures. In the RCT, one of few studies to combine BoNTA and HA with a 6-month follow-up, the HA-filler serum lengthened the duration of BoNTA's effect in reducing wrinkles. Numerous studies support HA-based cosmeceuticals as a noninvasive, effective solution for improving skin hydration and rejuvenation.

Biocompatibile nanofiber based membranes for high-efficiency filtration of nano-aerosols with low air resistance

Particulate matter (PMs) from combustion emissions (traffic, power plant, and industries) and the novel coronavirus (COVID-19) pandemic have recently enhanced the development of personal protective equipment against airborne pathogens to protect humans' respiratory system. However, most commercial face masks still cannot simultaneously achieve breathability and high filtration of PMs, bacteria, and viruses. This study used the electrospinning method with polyimide (PI) and polyethersulfone (PES) solutions to form a nanofiber membrane with low-pressure loss and high biocompatibility for high-efficiency bacteria, viruses, and nano-aerosol removal. Conclusively, the optimized nano-sized PI/PES membrane (0.1625 m²/g basis weight) exhibited conspicuous performance for the highest filtration efficiency towards PM from 50 to 500 nm (99.74 %), good filter quality of nano-aerosol (3.27 Pa^-1), exceptional interception ratio against 100-nm airborne COVID-19 (over 99 %), and non-toxic effect on the human body (107 % cell viability). The PI/PES nanofiber membrane required potential advantage to form a medical face mask because of its averaged 97 % BEF on Staphylococcus aureus filiation and ultra-low pressure loss of 0.98 Pa by referring ASTM F2101-01. The non-toxic PI/PES filters provide a new perspective on designing excellent performance for nano-aerosols from air pollution and airborne COVID-19 with easy and comfortable breathing under ultra-low air flow resistance.

Laser-assisted nanoparticle delivery to promote skin absorption and penetration depth of retinoic acid with the aim for treating photoaging

Retinoic acid (RA) is an approved treatment for skin photoaging induced by ultraviolet (UVA). Topically applied RA is mainly located in the stratum corneum (SC) with limited diffusion into the deeper strata. A delivery system capable of facilitating dermal delivery and cellular internalization for RA is critical for a successful photoaging therapy. Two delivery approaches, namely nanoparticles and laser ablation, were combined to improve RA's absorption efficacy and safety. The nanoparticle absorption enhancement by the lasers was compared between full-ablative (Er:YAG) and fractional (CO₂) modalities. We fabricated poly-L-lactic acid (PLA) and PLA/poly(lactic-co-glycolic acid) (PLGA) nanoparticles by an emulsion-solvent evaporation technique. The mean size of PLA and PLA/PLGA nanocarriers was 237 and 222 nm, respectively. The RA encapsulation percentage in both nanosystems was > 96 %. PLA and PLA/PLGA nanocarriers promoted RA skin deposition by 5- and 3-fold compared to free control. The ablative lasers further enhanced the skin deposition of RA-loaded nanoparticles, with the full-ablative laser showing greater permeation enhancement than the fractional mode. The skin biodistribution assay evaluated by confocal and fluorescence microscopies demonstrated that the laser-assisted nanoparticle delivery achieved a significant dermis and follicular accumulation. The cell-based study indicated a facile uptake of the nanoparticles into the human dermal fibroblasts. The nanoparticulate RA increased type I collagen and elastin production in the UVA-treated fibroblasts. A reduction of matrix metalloproteinase (MMP)-1 was also highlighted in the photoaging cells. The calculation of therapeutic index (TI) by multiplying collagen/elastin elevation percentage and skin deposition predicted better anti-photoaging performance in Er:YAG laser-assisted nanoparticle delivery than CO₂ laser. Nanoencapsulation of RA decreased the cytotoxicity against skin fibroblasts. In vivo skin tolerance test on a nude mouse showed less skin damage after topical application of the nanoparticles than free RA. Our results hypothesized that the laser-mediated nanoparticle delivery provided an efficient and safe use for treating photoaging.

Trends and challenges in phytotherapy and phytocosmetics for skin aging

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Free radicals, oxidative stress, and inflammation contribute to the etiology of most chronic diseases.

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Natural products can be incorporated into cosmetics, cosmeceuticals, and nutricosmetics to tackle inflammation-related diseases.

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The use of alternative green extraction solvents such as natural deep eutectic solvents and electrochemically reduced water is trending.

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Delivery systems are important for the enhancement of the bioavailability, stability, solubility, and controlled release profile of the bioactives.

Oxidative stress and inflammation mostly contribute to aging and age-related conditions including skin aging. The potential of natural products in the form of naturally-derived cosmetics, cosmeceuticals, and nutricosmetics have, however, not been fully harnessed. This review, thus, critically analyzes the potential roles of natural products in inflammation-related skin aging diseases due to the increasing consumers’ concerns and demands for efficacious, safe, natural, sustainable, and religiously permitted alternatives to synthetic products. The information and data were collated from various resources and literature databases such as PubMed, Science Direct, Wiley, Springer, Taylor and Francis, Scopus, Inflibnet, Google, and Google Scholar using relevant keywords and Medical Subject Headings (MeSH). The role of green extraction solvents as promising alternatives is also elucidated. The potential enhancements of the bioavailability, stability, solubility and controlled release profile of the bioactives using different delivery systems are also presented. The current potential global market value, motivators, drivers, trends, challenges, halal, and other regulatory certifications for cosmeceuticals and nutricosmetics are equally discussed. The adoption of the suggested extractions and delivery systems would enhance the stability, bioavailability, and target delivery of the bioactives.

Effects of Air Pollution on Cellular Senescence and Skin Aging

The human skin is exposed daily to different environmental factors such as air pollutants and ultraviolet (UV) light. Air pollution is considered a harmful environmental risk to human skin and is known to promote aging and inflammation of this tissue, leading to the onset of skin disorders and to the appearance of wrinkles and pigmentation issues. Besides this, components of air pollution can interact synergistically with ultraviolet light and increase the impact of damage to the skin. However, little is known about the modulation of air pollution on cellular senescence in skin cells and how this can contribute to skin aging. In this review, we are summarizing the current state of knowledge about air pollution components, their involvement in the processes of cellular senescence and skin aging, as well as the current therapeutic and cosmetic interventions proposed to prevent or mitigate the effects of air pollution in the skin.

In Vitro Skin Co-Delivery and Antibacterial Properties of Chitosan-Based Microparticles Containing Ascorbic Acid and Nicotinamide

Vitamins are widely found in nature, for example, in plants and fruits. Ascorbic acid and nicotinamide are examples of these compounds that have potent antioxidant properties, besides stimulating collagen production and depigmenting properties that protect the skin from premature aging. To overcome the skin barrier and reduce the instability of antioxidant compounds, alternative systems have been developed to facilitate the delivery of antioxidants, making them efficiently available to the tissue for an extended time without causing damage or toxicity. The objective of this study was to obtain chitosan biodegradable microparticles containing ascorbic acid and nicotinamide for topical delivery. The microparticles were obtained by spray drying and characterized chemically by means of scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and differential exploratory calorimetry. The drugs were successfully encapsulated and the microparticles showed positive zeta potential. In vitro release assays showed a sustained release profile. The evaluation of ex vivo skin permeation and retention demonstrated low permeation and adequate retention of the compounds in the epidermis/dermis, suggesting the efficient delivery from the obtained microparticles. Antibacterial assays have shown that microparticles can inhibit the growth of microorganisms in a time- and dose-dependent manner, corroborating their use in cosmetic products for application on the skin.

Theragra chalcogramma Hydrolysate, Rich in Gly-Leu-Pro-Ser-Tyr-Thr, Alleviates Photoaging via Modulating Deposition of Collagen Fibers and Restoration of Extracellular Components Matrix in SD Rats

Excessive exposure of the skin to ultraviolet irradiation induces skin photoaging, which seriously deteriorates the barrier functions of skin tissue, and even causes skin damages and diseases. Recently, dietary supplements from marine sources have been found to be useful in modulating skin functions and can be used to alleviate photoaging. Herein, the low-molecular-weight hydrolysates with a photoaging-protection effect were prepared by enzymatic hydrolysis from Theragra chalcogramma (TCH), and the potential mechanism were subsequently explored. The results revealed that TCH desirably improved the barrier functions of photoaged skin and stimulated the deposition of ECM components Col I, Hyp, and HA in the dermal layer. Histologically, TCH reduced the epidermal hyperplasia and restored the impaired architectures in a dose-dependent manner. Meanwhile, the activity of matrix metalloproteinase-1 (MMP-1) in photoaging skin was inhibited, and the expression levels of elastin and fibrillin-1 were elevated accordingly after TCH administration, and the significant improvements were observed at high-dose level (p < 0.05). Taken together, the efficacy of TCH against skin photoaging is highly associated with the regulation on ECM metabolism and the repairing of damaged mechanical structure.

The Aryl Hydrocarbon Receptor in the Pathogenesis of Environmentally-Induced Squamous Cell Carcinomas of the Skin

Cutaneous squamous cell carcinoma (SCC) is one of the most frequent malignancies in humans and academia as well as public authorities expect a further increase of its incidence in the next years. The major risk factor for the development of SCC of the general population is the repeated and unprotected exposure to ultraviolet (UV) radiation. Another important risk factor, in particular with regards to occupational settings, is the chronic exposure to polycyclic aromatic hydrocarbons (PAH) which are formed during incomplete combustion of organic material and thus can be found in coal tar, creosote, bitumen and related working materials. Importantly, both exposomal factors unleash their carcinogenic potential, at least to some extent, by activating the aryl hydrocarbon receptor (AHR). The AHR is a ligand-dependent transcription factor and key regulator in xenobiotic metabolism and immunity. The AHR is expressed in all cutaneous cell-types investigated so far and maintains skin integrity. We and others have reported that in response to a chronic exposure to environmental stressors, in particular UV radiation and PAHs, an activation of AHR and downstream signaling pathways critically contributes to the development of SCC. Here, we summarize the current knowledge about AHR's role in skin carcinogenesis and focus on its impact on defense mechanisms, such as DNA repair, apoptosis and anti-tumor immune responses. In addition, we discuss the possible consequences of a simultaneous exposure to different AHR-stimulating environmental factors for the development of cutaneous SCC.

Clinical Assessment of a Circadian-based Antioxidant System Combined with a Comprehensive Brightening Serum in Diverse Subjects with Moderate to Severe Facial Hyperpigmentation

BACKGROUND

Hyperpigmentation conditions can affect all skin types but occur more frequently in darker skin. Because many factors have been implicated in the etiologies of these disorders, multi-targeted approaches may be required to achieve a better overall outcome in a diverse patient population.

AIMS

The purpose of this study was to investigate the safety and efficacy of a combination regimen of a comprehensive cosmetic brightening agent (LYT2) with a broad blend of antioxidants (LVS) to reduce hyperpigmentation and improve overall skin appearance.

METHODS

The combination of LYT2 and LVS, in addition to a basic skincare routine, was evaluated in subjects of either Caucasian or Asian (a majority of whom were Indian) descent, presenting with moderate to severe hyperpigmentation. Efficacy evaluations consisted of investigator clinical grading of overall hyperpigmentation, skin-tone evenness, and radiance, as well as subject self-assessment questionnaires.

RESULTS

Immediate and progressive improvement was noted by the investigators for all assessed parameters. At the end of the 12-week study, investigators observed a 45% mean decrease from baseline for overall hyperpigmentation. In addition, a 50% improvement in skin tone evenness and a 58% increase in radiance was observed. These investigator assessments were matched by good patient scores for self-perceived efficacy parameters and high overall satisfaction. One patient (7%) showed a treatment-related adverse event.

CONCLUSION

A combination skincare regimen that combines the pigmentation control of LYT2 with the broad antioxidant defense of LVS is a well-tolerated and effective treatment option to improve the appearance of facial hyperpigmentation and make skin more radiant.

The Effect of Narrow-Band Ultraviolet B Irradiation on the Vascularized Composite Allotransplantation Rat Model

INTRODUCTION

Vascularized composite allotransplantation (VCA) allows functional and esthetic reconstruction for patients with complex anatomical defects. However, acute and chronic graft rejections are significant obstacles to VCA. Ultraviolet light is an oncogenic environmental hazard. However, ultraviolet B (UVB) has an immunomodulation effect. Therefore, this study aims to elucidate the impact of UVB irradiation on the VCA rat model.

METHODS

The rat vascularized bone marrow allotransplantation model was used. A vascularized bone marrow from a Brown Norway rat (RT1Ac) was transplanted into a Lewis rat (RT1Ab). The allograft and surrounding abdominal skin were exposed to narrow-band ultraviolet B (NB-UVB) (311 nm) radiation with an energy of 1350 mJ/cm2 3 times a week until the end of the study period. There were 5 study groups: syngeneic transplantation (group 1), allogeneic transplantation (group 2), allogenic transplantation-NB-UVB (group 3), allogenic transplantation-antilymphocyte serum (ALS)-tacrolimus (group 4), and allogenic transplantation-antilymphocyte serum-tacrolimus-NB-UVB (group 5).

RESULTS

Group 5 had decreased graft survival compared with group 4. In the donor cell chimerism analysis, donor cell chimerism decreased significantly after UVB irradiation and was unresponsive to the administered immunosuppressants. After UVB irradiation, the CD8 T-cell ratio was increased, and the regulatory T-cell ratio was decreased.

CONCLUSIONS

The preliminary data showed that NB-UVB irradiation of the VCA rat model may decrease graft survival. However, further studies are needed to elucidate the possible mechanisms of this phenomenon.

Diesel Particulate Extract Accelerates Premature Skin Aging in Human Fibroblasts via Ceramide-1-Phosphate-Mediated Signaling Pathway

Both intrinsic (i.e., an individual’s body clock) and extrinsic factors (i.e., air pollutants and ultraviolet irradiation) accelerate premature aging. Epidemiological studies have shown a correlation between pollutant levels and aging skin symptoms. Diesel particle matter in particular leads to some diseases, including in the skin. Our recent study demonstrates that diesel particulate extract (DPE) increases apoptosis via increases in an anti-mitogenic/pro-apoptotic lipid mediator, ceramide in epidermal keratinocytes. Here, we investigated whether and how DPE accelerates premature skin aging using cultured normal human dermal fibroblasts (HDF). We first demonstrated that DPE increases cell senescence marker β-galactosidase activity in HDF. We then found increases in mRNA and protein levels, along with activity of matrix metalloprotease (MMP)-1 and MMP-3, which are associated with skin aging following DPE exposure. We confirmed increases in collagen degradation in HDF treated with DPE. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) is activated by DPE and results in increased ceramide production by sphingomyelinase activation in HDF. We identified that ceramide-1-phosphate (C1P) (produced from ceramide by ceramide kinase activation) activates MMP-1 and MMP-3 through activation of arachidonate cascade, followed by STAT 1- and STAT 3-dependent transcriptional activation.

Repression of the Antioxidant Pyrroloquinoline Quinone in Skin Aging Induced by Bmi-1 Deficiency

It is uncertain whether Bmi-1 deficiency could lead to skin aging by redox imbalance and DNA damage. In this study, we first confirmed that Bmi-1 had a relatively high expression level in the skin and Bmi-1 expression levels gradually decreased with age. Then, we studied the role of Bmi-1 in the skin using a Bmi-1^−/− mouse model. Bmi-1^−/− mice were supplemented with or without pyrroloquinoline quinone (PQQ) for 5 weeks, and their skin phenotypes were compared with Bmi1^−/− and wild-type littermates. Our results showed that Bmi-1^−/− mice displayed decreased vertical thickness of skin, sparse hair follicles, and thinner and more irregular collagen bundles. Mechanistically, increased oxidative stress with reducing antioxidant capacity and induced DNA damage occurred in Bmi-1^−/− mice. Subsequently, this would lead to reduced cell proliferation, increased cell senescence and matrix metalloproteinases (MMPs), and the degradation of fibroblast function and further reduce collagen synthesis. All pathological alterations in the skin of Bmi-1^−/− mice were alleviated by PQQ supplementation. These results demonstrated that Bmi-1 might play a key role in protection from skin aging by maintaining redox balance and inhibiting DNA damage response and will be a novel and potential target for preventing skin aging.

Protective Effect of the Pearl extract from Pinctada fucata martensii Dunker on UV-induced Photoaging in Mice

Although the effect of pearl powder has been recognized for more than a thousand years from healthcare to beauty care, there has yet to be an in-depth understanding of its anti-photoaging effect. In the present study, the protective effect of pearl extract (PE) on UV-induced photoaging in mice was evaluated. First, the amino acid analysis of PE was carried out. Then, different dosages of pearl extract gel (PEG) were applied topically  on the shaved dorsal skins regions of mice before UV irradiation. Skin physiological and histological analysis, antioxidant enzymes and inflammatory factor test were used to evaluate the anti-photoaging effect of PEG. The results showed that PEG contained 14 amino acids, and could inhibit UV-irritated skin wrinkles, laxity, thickness, and dryness. Moreover, PEG upregulated the activities of CAT, GSH-Px, SOD and decreased MDA level, and suppressed the production of IL-1𝛽, IL-6, PGE 2 , TNF-𝛼, and COX-2 in UV-irradiated mice. The therapeutic effect in high dose PEG group was superior to those of positive control (Vitamin E). This study demonstrated the underlying mechanisms of PEG against UV-irritated photoaging. And PEG possesses a potential use in photoprotective medicines and cosmetics.

Protective Role of Melatonin and Its Metabolites in Skin Aging

The skin, being the largest organ in the human body, is exposed to the environment and suffers from both intrinsic and extrinsic aging factors. The skin aging process is characterized by several clinical features such as wrinkling, loss of elasticity, and rough-textured appearance. This complex process is accompanied with phenotypic and functional changes in cutaneous and immune cells, as well as structural and functional disturbances in extracellular matrix components such as collagens and elastin. Because skin health is considered one of the principal factors representing overall “well-being” and the perception of “health” in humans, several anti-aging strategies have recently been developed. Thus, while the fundamental mechanisms regarding skin aging are known, new substances should be considered for introduction into dermatological treatments. Herein, we describe melatonin and its metabolites as potential “aging neutralizers”. Melatonin, an evolutionarily ancient derivative of serotonin with hormonal properties, is the main neuroendocrine secretory product of the pineal gland. It regulates circadian rhythmicity and also exerts anti-oxidative, anti-inflammatory, immunomodulatory, and anti-tumor capacities. The intention of this review is to summarize changes within skin aging, research advances on the molecular mechanisms leading to these changes, and the impact of the melatoninergic anti-oxidative system controlled by melatonin and its metabolites, targeting the prevention or reversal of skin aging.

Comprehensive characterization of naturally occurring antioxidants from the twigs of mulberry (Morus alba) using on-line high-performance liquid chromatography coupled with chemical detection and high-resolution mass spectrometry

INTRODUCTION

The mulberry tree (Morus alba L.) is a prolific source of biologically active compounds. There is considerable growing interest in probing M. alba twigs as a source of disruptive antioxidant lead candidates for cosmetic skin care product development.

OBJECTIVE

An integrated approach using high-performance liquid chromatography (HPLC) coupled with either chemical detection (CD) or high-resolution mass spectrometry (HRMS) was applied to the hydroalcoholic extract of M. alba to detect and identify lead antioxidant compounds, respectively.

MATERIAL AND METHODS

The twigs were weighed, powdered and homogenized using a mill and the extract was prepared using 70% aqueous ethanol. The antioxidant metabolites were detected with HPLC coupled with CD (based on the ORAC assay) and their structural identification was carried out using a Q-Exactive Orbitrap MS instrument.

RESULTS

Using this approach, 13 peaks were detected as overall contributors to the antioxidant activity of M. alba, i.e. mulberrosides (A & E), oxyresveratrol & its derivatives, moracin & its derivatives and a dihydroxy-octadecadienoic acid, which together accounted for >90% of the antioxidant activity, highlighting the effectiveness of the integrated approach based on HPLC-CD and HPLC-HRMS. Additionally, a (3,4-dimethoxyphenyl-1-O-β-D-apiofuranosyl-(1″ → 6')-O-β-D-glucopyranoside was also discovered for the first time from the twig extract and is presented here.

CONCLUSION

To our knowledge, this is the first report from M. alba twigs using HPLC-CD and HPLC-HRMS that identifies key compounds responsible for the antioxidant property of this native Chinese medicinal plant.

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.

Oleanolic Acid Nanofibers Attenuated Particulate Matter-Induced Oxidative Stress in Keratinocytes

Airborne particulate matter (PM) is one of the indicators of air pollution, and it is also the main factor causing oxidative stress in the skin. Oleanolic acid (OA), a natural terpenoid compound, effectively inhibited PM-induced skin aging; however, OA has poor water solubility and skin absorption, which limit its application in medicines and cosmetics. The aim of this study was to prepare oleanolic acid nanofibers (OAnf) and evaluate the effects of OA and OAnf in PM-treated keratinocytes. The results showed that OA dissolved in dissolved in dimethyl sulfoxide (DMSO) attenuated PM-induced reactive oxygen species overproduction, stress-activated protein kinase/Jun-amino-terminal kinase (SAPK/JNK) activation, and the expressions of inflammatory and skin-aging-related proteins. In addition, the nanofiber process of OA effectively improved the water solubility of OA more than 99,000-fold through changing its physicochemical properties, including a surface area increase, particle size reduction, amorphous transformation, and hydrogen bonding formation with excipients. The skin penetration ability of OAnf was consistently over 10-fold higher than that of OA. Moreover, when dissolved in PBS, OAnf displayed superior antioxidant, anti-inflammatory, and anti-skin aging activities in PM-treated keratinocytes than OA. In conclusion, our findings suggest that OAnf could be a topical antioxidant formulation to attenuate skin problems caused by PM.

The Impact of Vitamin D on Skin Aging

The active metabolites of vitamin D₃ (D₃) and lumisterol (L₃) exert a variety of antiaging and photoprotective effects on the skin. These are achieved through immunomodulation and include anti-inflammatory actions, regulation of keratinocytes proliferation, and differentiation programs to build the epidermal barrier necessary for maintaining skin homeostasis. In addition, they induce antioxidative responses, inhibit DNA damage and induce DNA repair mechanisms to attenuate premature skin aging and cancerogenesis. The mechanism of action would involve interaction with multiple nuclear receptors including VDR, AhR, LXR, reverse agonism on RORα and -γ, and nongenomic actions through 1,25D₃-MARRS receptor and interaction with the nongenomic binding site of the VDR. Therefore, active forms of vitamin D₃ including its canonical (1,25(OH)₂D₃) and noncanonical (CYP11A1-intitated) D₃ derivatives as well as L₃ derivatives are promising agents for the prevention, attenuation, or treatment of premature skin aging. They could be administrated orally and/or topically. Other forms of parenteral application of vitamin D₃ precursor should be considered to avoid its predominant metabolism to 25(OH)D₃ that is not recognized by CYP11A1 enzyme. The efficacy of topically applied vitamin D₃ and L₃ derivatives needs further clinical evaluation in future trials.

Tandem mass spectrometry of aqueous extract from Ficus dubia sap and its cell-based assessments for use as a skin antioxidant

Since 2006, Ficus dubia has been reported as a new Ficus species in Thailand. As per our recent report, the red-brown aqueous extract of F. dubia sap (FDS) has been determined to strongly exhibit in vitro anti-radicals. However, the phytochemicals in the FDS extract related to health-promoting antioxidation have not been explored. Thus, in this study, we aimed to investigate the chemical components of the F. dubia sap extract by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-MS/QTOF-MS) and its potential use in cosmetics in terms of cellular antioxidation on keratinocytes (HaCaT), phototoxicity, and irritation on 3D skin cell models following standard tests suggested by the Organization for Economic Cooperation and Development (OECD). It was found that the sap extract was composed of quinic acid and caffeoyl derivatives (e.g., syringoylquinic acid, 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, and dimeric forms of caffeoylquinic acids). The extract has significantly exhibited antioxidant activity against H2O2-induced oxidative stress in HaCaT cells. The cellular antioxidative effect of the FDS extract was remarkably dependent on the presence of 3- and 4-O-caffeoylquinic acid in the extract. Furthermore, the FDS extract showed negative results on skin phototoxicity and irritation. Overall, the results reveal that the FDS extract could be developed as a new antioxidant candidate for a skin healthcare product.

Ferulic Acid Activity in Topical Formulations: Technological and Scientific Prospecting

INTRODUCTION

Ferulic acid is a phenolic compound widely distributed in monocotyledons, with several applications, especially in pharmaceutical and dermo-cosmetic industries. It has proven antioxidant and anti- inflammatory activities, among others, which are mainly ascribed to its molecular structure. The main factor that can lead to serious skin damages like inflammation, dryness, wrinkles, and cancer is the exposure to UV radiation that is responsible for an increased level of radical oxygen species.

OBJECTIVE

This review aims to evaluate the application of ferulic acid in topical formulations and the technologies used to enhance its bioavailability and stability, as well as to get a clearer picture of its effects by in vivo and in vitro studies.

METHODS

It covers technological publications in the WIPO, EPO, INPI, and USPTO databases and scientific publications in the PubMed, Web of Sciences, and Science Direct databases, exploring the trend and application of this compound by country and year of publication.

RESULTS

Both the scientific and technological analyses showed the importance and tendency in the association of the Ferulic Acid and other vitamins and actives. The synergic effect certainly provides a better result, performance, and stability of the compounds, which cleared the great spectrum and applicability of the Ferulic Acid in topical formulations.

CONCLUSION

The present literature survey revealed that ferulic acid exerts an important activity in several formulations for topical application and improved the stability and bioavailability when combined with new technologies and methods, showing an open path to target the treatment of skin disorders.

The emerging role of nanotechnology in skincare

The role of cosmetic products is rapidly evolving in our society, with their use increasingly seen as an essential contribution to personal wellness. This suggests the necessity of a detailed elucidation of the use of nanoparticles (NPs) in cosmetics. The aim of the present work is to offer a critical and comprehensive review discussing the impact of exploiting nanomaterials in advanced cosmetic formulations, emphasizing the beneficial effects of their extensive use in next-generation products despite a persisting prejudice around the application of nanotechnology in cosmetics. The discussion here includes an interpretation of the data underlying generic information reported on the product labels of formulations already available in the marketplace, information that often lacks details identifying specific components of the product, especially when nanomaterials are employed. The emphasis of this review is mainly focused on skincare because it is believed to be the cosmetics market sector in which the impact of nanotechnology is being seen most significantly. To date, nanotechnology has been demonstrated to improve the performance of cosmetics in a number of different ways: 1) increasing both the entrapment efficiency and dermal penetration of the active ingredient, 2) controlling drug release, 3) enhancing physical stability, 4) improving moisturizing power, and 5) providing better UV protection. Specific attention is paid to the effect of nanoparticles contained in semisolid formulations on skin penetration issues. In light of the emerging concerns about nanoparticle toxicity, an entire section has been devoted to listing detailed examples of nanocosmetic products for which safety has been investigated.

A comprehensive topical antioxidant inhibits oxidative stress induced by blue light exposure and cigarette smoke in human skin tissue

OBJECTIVE

Skin damage from visible light predominantly results from exposure to the blue light spectrum (400-500 nm) which generates Reactive Oxygen Species (ROS) causing a cascade of harmful effects to skin. Topical antioxidants reduce the effects of free radical damage caused by environmental exposures. This study evaluated a comprehensive topical antioxidant's ability to inhibit ROS production induced by blue light and cigarette smoke (CS) in human skin.

METHODS

Two experiments were conducted utilizing human skin (Fitzpatrick Skin Types III and V; N = 3, each). After confirmed reactivity of untreated tissues at 412 nm, 20J/cm2 , untreated and pretreated (WEL-DS, 2 mg/cm2 ) skin tissue was exposed to blue light and blue light plus CS and left overnight. A nonfluorescent probe (DCFH-DA) was added to skin and exposed to blue light (412 nm, 20J/cm2 ) and blue light plus CS. Fluorescent 2',7'-DCF was generated upon enzymatic reduction and subsequent oxidation by ROS.

RESULTS

ROS increased at least tenfold following initial exposure to blue light and blue light plus CS in untreated skin. Pretreatment with WEL-DS decreased ROS in FST III exposed to blue light by 51% and 46% in skin exposed to blue light plus CS vs. untreated skin (both, P < .001). In FST V, pretreatment with WEL-DS decreased ROS exposed to blue light by 54% (P < .001) and 50% in skin exposed to blue light plus CS vs. untreated skin (P < .0001).

CONCLUSION

WEL-DS demonstrated significant reduction in ROS induced by blue light and blue light in combination with CS compared with untreated, exposed skin.

NO2 exposure increases eczema outpatient visits in Guangzhou, China: an indication for hospital management

Background

Ambient nitrogen dioxide (NO₂) is a common air pollutant in developing countries and causes skin conditions, but its effect on eczema in subtropical areas is not clear in China.

Object

To measure the effect of short-term exposure of NO₂ on the incidence of eczema and the change of outpatient visits.

Methods

Data of daily temperature, air pollutants, and outpatient visits from 2013 to 2018 were collected in a row. The generalized additive model (GAM) and Poisson distribution were used to assess the association between short-term exposure of NO₂ and the outpatient visits of patients with eczema. The cumulative exposure effect of lag 0–3 days and the displacement effect of NO₂ and other pollutants were considered as well. A single pollutant model was used to examine the independent association, and a two-pollutant model was adopted to control the confounding effect.

Results

The daily outpatient visits of eczema increased from 75.26 to 190.85 from 2013 to 2018 (P < 0.001). The combined influence of NO₂ and the related pollutant exerted a stronger influence on the incidence of eczema. The maximum effect of NO₂ appeared on the exposed day.

(lag 0) and disappeared on day 4 (lag 3). The children and seniors were more vulnerable to NO₂ exposure.

Conclusion

Exposure to NO₂ is tightly associated with eczema incidence and outpatient visits. The hospitals should react to the visit fluctuations and adjust physician duty shifts to improve outpatient service efficiency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10549-7.

Evaluation of the efficacy and tolerance of a cosmetic mask containing 89% of vichy volcanic mineralizing water and hyaluronic acid after facial laser procedures

BACKGROUND

M89 M (Mineral 89 mask, Laboratoires Vichy, France), containing 89% Vichy volcanic mineralizing water and hyaluronic acid, aims to strengthen and repair skin barrier.

AIMS

To assess the efficacy, tolerance, patient satisfaction, and quality of life (QOL) using M89 M after laser procedures (LP).

METHODS

M89 M was applied immediately post-LP for 10 minutes, then daily for 5 days and 2-3 times a week, up to 28 days on the faces of 51 women. Evaluations were performed immediately post-LP, immediately after M89 M application at D0, D1, D5, and D28, and included criteria such as erythema and skin dryness. Subjects scored burning and warm sensations, itching, skin tightness, and stinging. Skin hydration using a Corneometer, skin barrier integrity using a Tewameter, and erythema using a Chromameter were assessed. Local tolerance and adverse events were recorded. After 28 days, subjects answered a questionnaire regarding the M89 M subjective cosmetic properties and QOL.

RESULTS

All subjects were in their mid-forties with a phototype of II, III, or IV. M89 M significantly (P < .001) reduced the immediate cutaneous discomfort sensation and laser procedure-related symptoms (burning, warmth sensation, itching/stinging, skin tightness). Skin hydration, and erythema, assessed using instrumental measures, were also significantly improved immediately after mask application (P ≤ .01). Subjects highly appreciated M89 M and their QOL improved after 28 days of use. Local tolerance was good to excellent in both studies.

CONCLUSION

M89 M is effective and safe immediately after esthetic procedures such as ablative and nonablative lasers and also improves the subject's QOL.

The impact of air pollution on skin and related disorders: A comprehensive review

As the largest organ in the body, human skin is constantly exposed to harmful compounds existing in the surrounding environment as the first-line barrier. Studies have indicated that exposure to high concentrations of many environmental factors, such as ultraviolet (UV) radiation, outdoor air pollutants, including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), particulate matter (PM), heavy metals, gaseous pollutants, such as carbon monoxide (CO), nitric oxides (NO_x ), sulfur oxide (SO₂ ), ozone (O₃ ), and indoor air pollutants (solid fuels consumption), might interrupt the skin's normal barrier function. Besides, the intensity of the pollutants and the length of exposure might be a contributing factor. Air pollutants are believed to induce or exacerbate a range of skin conditions, such as aging, inflammatory diseases (atopic dermatitis, cellulitis, and psoriasis), acne, hair loss, and even skin cancers (mainly melanoma and Squamous Cell Carcinoma) through various mechanisms. The interaction between pollutants and the skin might differ based on each agent's particular characteristics. Also, damaging the skin barrier seems to be closely related to the increased production of reactive oxygen species (ROS), induction of oxidative stress, activation of aryl hydrocarbon receptor (AhR), and inflammatory cytokines. This article reviews recent studies on the correlation between air pollutants and skin diseases, along with related mechanisms.

UVA-Triggered Drug Release and Photo-Protection of Skin

Light has attracted special attention as a stimulus for triggered drug delivery systems (DDS) due to its intrinsic features of being spatially and temporally tunable. Ultraviolet A (UVA) radiation has recently been used as a source of external light stimuli to control the release of drugs using a "switch on- switch off" procedure. This review discusses the promising potential of UVA radiation as the light source of choice for photo-controlled drug release from a range of photo-responsive and photolabile nanostructures via photo-isomerization, photo-cleavage, photo-crosslinking, and photo-induced rearrangement. In addition to its clinical use, we will also provide here an overview of the recent UVA-responsive drug release approaches that are developed for phototherapy and skin photoprotection.

Circadian Deregulation as Possible New Player in Pollution-Induced Tissue Damage

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality or even the very existence of life. Living organisms are continuously exposed to air pollutants, and among them, ozone or particulate matters (PMs) are considered to be among the most toxic to human health. In particular, exposure to environmental stressors may result not only in pulmonary and cardiovascular diseases, but, as it has been demonstrated in the last two decades, the skin can also be affected by pollution. In this context, we hypothesize that chronodistruption can exacerbate cell vulnerability to exogenous damaging agents, and we suggest a possible common mechanism of action in deregulation of the homeostasis of the pulmonary, cardiovascular and cutaneous tissues and in its involvement in the development of pathological conditions.

The influence of climate change on skin cancer incidence - A review of the evidence

BACKGROUND

Climate change is broadly affecting human health, with grave concern that continued warming of the earth's atmosphere will result is serious harm. Since the mid-20th century, skin cancer incidence rates have risen at an alarming rate worldwide.

OBJECTIVE

This review examines the relationship between climate change and cutaneous carcinogenesis.

METHODS

A literature review used the National Institutes of Health databases (PubMed and Medline), the Surveillance, Epidemiology, and End Results and International Agency for Research on Cancer registries, and published reports by federal and international agencies and consortia, including the Australian Institute of Health and Welfare, Climate and Clean Air Coalition, U.S. Environmental Protection Agency, Intergovernmental Panel on Climate Change, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, United Nations Environment Programme, World Health Organization, and World Meteorological Organization.

RESULTS

Skin cancer risk is determined by multiple factors, with exposure to ultraviolet radiation being the most important. Strong circumstantial evidence supports the hypothesis that factors related to climate change, including stratospheric ozone depletion, global warming, and ambient air pollution, have likely contributed to the increasing incidence of cutaneous malignancy globally and will continue to impose a negative on influence skin cancer incidence for many decades to come.

CONCLUSION

Because much of the data are based on animal studies and computer simulations, establishing a direct and definitive link remains challenging. More epidemiologic studies are needed to prove causality in skin cancer, but the evidence for overall harm to human health as a direct result of climate change is clear. Global action to mitigate these negative impacts to humans and the environment is imperative.

Circular RNA expression profiles significantly altered in UVA-irradiated human dermal fibroblasts

Circular RNAs (circRNAs) have been previously implicated in number of diseases. However, the roles of circRNAs in photoaging remain elusive. In the present study, to understand if photoaging influences the levels of circRNA expression, the expression of circRNAs in ultraviolet A (UVA)-irradiated human dermal fibroblasts were profiled. A total of 128 circRNAs were identified to be differentially expressed (fold change >1.5; P<0.05) after UVA exposure, including 39 upregulated and 89 downregulated circRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes biological pathway analyses indicated that the differentially expressed circRNAs were associated with extracellular matrix organization and metabolism. The present study revealed an altered circRNA expression pattern in human dermal fibroblasts following UVA-irradiation. These results provide not only a basis for in-depth study of the mechanism of skin photoaging but also a new possibility for the prevention and treatment of photoaging and associated skin diseases.