The role of antioxidants in photoprotection: a critical review

Open-label topical application of tetrahexyldecyl ascorbate and acetyl zingerone containing serum improves the appearance of photoaging and uneven pigmentation

BACKGROUND

Skin photoaging and uneven pigmentation are common dermatological concerns. Tetrahexyldecyl ascorbate (THDA) and acetyl zingerone (AZ) are potent antioxidants that have been shown to have anti-photoaging and anti-pigmentation effects. THDA is a more stable and penetrable form of vitamin C. AZ is an antioxidant derived from ginger which has clinical evidence for improving photoaging. However, no studies have assessed how they may synergistically act on the skin.

AIMS

This study aims to assess whether a serum containing both THDA and AZ can improve photoaging and the appearance of uneven facial pigmentation.

PATIENTS/METHODS

This open-label study was conducted on 35 healthy individuals aged 21-55. All subjects were instructed to use three to five drops of the topical serum (Power-C Serum, Image Skincare, Lantana, FL) daily for 12 weeks. Videomicroscopy and high-resolution photography and various skin biophysical measurements were taken at baseline, 1, 4, and 12 weeks. Outcomes included skin tone and pigmentation, transepidermal water loss (TEWL), skin smoothness, firmness, and elasticity.

RESULTS

Compared to baseline, the results at 12 weeks revealed significant decreases in skin pigmentation (p < 0.0001), decreased fine lines and wrinkles (p < 0.0001), and increased smoothness (p < 0.0001), firmness (p < 0.0001), and elasticity (p < 0.0001). Additionally, transepidermal water loss was significantly decreased at 4 weeks compared to baseline (p = 0.01), indicating an increased epidermal barrier integrity.

CONCLUSIONS

Overall, these findings provide evidence for the combined use of THDA and AZ to address skin photoaging and dyspigmentation changes.

Environmental implications and nanotechnological advances in octocrylene-enriched sunscreen formulations: A comprehensive review

Ultraviolet (UV) radiation is a major contributor to skin aging, cancer, and other detrimental health effects. Sunscreens containing FDA-approved UV filters, like avobenzone, offer protection but suffer from photodegradation and potential phototoxicity. Encapsulation, antioxidants, and photostabilizers are strategies employed to combat these drawbacks. Octocrylene, an organic UV filter, utilizes nanotechnology to enhance sun protection factor (SPF). This review examines recent literature on octocrylene-enriched sunscreens, exploring the interplay between environmental impact, nanotechnological advancements, and clinical trial insights. A critical focus is placed on the environmental consequences of sunscreen use, particularly the potential hazards UV filters pose to marine ecosystems. Research in the Mediterranean Sea suggests bacterial sensitivity to these filters, raising concerns about their integration into the food chain. This review aims to guide researchers in developing effective strategies for photostabilization of UV filters. By combining encapsulation, photostabilizers, and antioxidants, researchers can potentially reduce phototoxic effects and contribute to developing more environmentally friendly sunscreens.

Rosarugosides A and D from Rosa rugosa Flower Buds: Their Potential Anti-Skin-Aging Effects in TNF-α-Induced Human Dermal Fibroblasts

This present study investigated the anti-skin-aging properties of Rosa rugosa. Initially, phenolic compounds were isolated from a hot water extract of Rosa rugosa's flower buds. Through repeated chromatography (column chromatography, MPLC, and prep HPLC), we identified nine phenolic compounds (1-9), including a previously undescribed depside, rosarugoside D (1). The chemical structure of 1 was elucidated via NMR, HR-MS, UV, and hydrolysis. Next, in order to identify bioactive compounds that are effective against TNF-α-induced NHDF cells, we measured intracellular ROS production in samples treated with each of the isolated compounds (1-9). All isolates reduced the level of ROS at a concentration of 10 μM. Particularly, two depsides-rosarugosides A and D (2 and 1)-significantly inhibited ROS expression in TNF-α-induced NHDFs compared to the other phenolic compounds. Subsequently, the production of MMP-1 and procollagen type Ι α1 by these two depsides was examined. Remarkably, rosarugoside A (2) significantly decreased MMP-1 secretion at all concentrations. In contrast, rosarugoside D (1) regulated the expression of procollagen type Ι α1. These findings collectively suggest that Rosa rugosa extracts and their isolated compounds, rosarugosides A (2) and D (1), hold significant potential for protecting against aging and skin damage. Overall, these findings suggest that Rosa rugosa extracts and their isolated compounds, rosarugosides A (2) and D (1), have the potential to prevent and protect against aging and skin damage, although more specific quantitative analysis is needed.

Gelatin-based biomaterials and gelatin as an additive for chronic wound repair

Disturbing or disrupting the regular healing process of a skin wound may result in its progression to a chronic state. Chronic wounds often lead to increased infection because of their long healing time, malnutrition, and insufficient oxygen flow, subsequently affecting wound progression. Gelatin-the main structure of natural collagen-is widely used in biomedical fields because of its low cost, wide availability, biocompatibility, and degradability. However, gelatin may exhibit diverse tailored physical properties and poor antibacterial activity. Research on gelatin-based biomaterials has identified the challenges of improving gelatin's poor antibacterial properties and low mechanical properties. In chronic wounds, gelatin-based biomaterials can promote wound hemostasis, enhance peri-wound antibacterial and anti-inflammatory properties, and promote vascular and epithelial cell regeneration. In this article, we first introduce the natural process of wound healing. Second, we present the role of gelatin-based biomaterials and gelatin as an additive in wound healing. Finally, we present the future implications of gelatin-based biomaterials.

Ameliorative effects of elderberry (Sambucus nigra L.) extract and extract-derived monosaccharide-amino acid on H2O2-induced decrease in testosterone-deficiency syndrome in a TM3 Leydig cell

With aging, men develop testosterone-deficiency syndrome (TDS). The development is closely associated with age-related mitochondrial dysfunction of Leydig cell and oxidative stress-induced reactive oxygen species (ROS). Testosterone-replacement therapy (TRT) is used to improve the symptoms of TDS. However, due to its various side effects, research on functional ingredients derived from natural products that do not have side effects is urgently needed. In this study, using the mitochondrial dysfunction TM3 (mouse Leydig) cells, in which testosterone biosynthesis is reduced by H2O2, we evaluated the effects of elderberry extract and monosaccharide-amino acid (fructose-leucine; FL) on mRNA and protein levels related to steroidogenesis-related enzymes steroidogenic acute regulatory protein (StAR), cytochrome P450 11A1(CYP11A1, cytochrome P450 17A1(CYP17A1), cytochrome P450 19A1(CYP19A1, aromatase), 3β-hydroxysteroid dehydrogenase (3β-HSD), and 17β-hydroxysteroid dehydrogenase(17β-HSD). We analyzed elderberry extract and extract-derived FL for changes in ROS scavenging activity and testosterone secretion. Elderberry extract and FL significantly reduced H2O2-induced intracellular ROS levels, improved testosterone secretion, and increased the mRNA and protein expression levels of steroidogenesis-related enzymes (StAR, 3b-HSD, 17b-HSD, CYP11A1, CYp17A1). However, the conversion of testosterone to estradiol was inhibited by elderberry extract and extract-derived FL, which reduced the mRNA and protein expression of CYP19A1. In conclusion, elderberry extract and FL are predicted to have value as novel functional ingredients that may contribute to the prevention of TDS by ameliorating reduced steroidogenesis.

Progress in the Use of Hydrogels for Antioxidant Delivery in Skin Wounds

The skin is the largest organ of the body, and it acts as a protective barrier against external factors. Chronic wounds affect millions of people worldwide and are associated with significant morbidity and reduced quality of life. One of the main factors involved in delayed wound healing is oxidative injury, which is triggered by the overproduction of reactive oxygen species. Oxidative stress has been implicated in the pathogenesis of chronic wounds, where it is known to impair wound healing by causing damage to cellular components, delaying the inflammatory phase of healing, and inhibiting the formation of new blood vessels. Thereby, the treatment of chronic wounds requires a multidisciplinary approach that addresses the underlying causes of the wound, provides optimal wound care, and promotes wound healing. Among the promising approaches to taking care of chronic wounds, antioxidants are gaining interest since they offer multiple benefits related to skin health. Therefore, in this review, we will highlight the latest advances in the use of natural polymers with antioxidants to generate tissue regeneration microenvironments for skin wound healing.

Protective effects of Prussian blue nanozyme against sepsis-induced acute lung injury by activating HO-1

Sepsis is a life-threatening condition involving dysfunctional organ responses stemming from dysregulated host immune reactions to various infections. The lungs are most prone to failure during sepsis, resulting in acute lung injury (ALI). ALI is associated with oxidative stress and inflammation, and current therapeutic strategies are limited. To develop a more specific treatment, this study aimed to synthesise Prussian blue nanozyme (PBzyme), which can reduce oxidative stress and inflammation, to alleviate ALI. PBzyme with good biosafety was synthesised using a modified hydrothermal method. PBzyme was revealed to be an activator of haem oxygenase-1 (HO-1), improving survival rate and ameliorating lung injury in mice. Zinc protoporphyrin, an inhibitor of HO-1, inhibited the prophylactic therapeutic efficacy of PBzyme on ALI, and affected the nuclear factor-κB signaling pathway and activity of HO-1. This study demonstrates that PBzyme can alleviate oxidative stress and inflammation through HO-1 and has a prophylactic therapeutic effect on ALI. This provides a new strategy and direction for the clinical treatment of sepsis-induced ALI.

Anti-inflammatory, antioxidant and photoprotective activity of standardised Gaultheria procumbens L. leaf, stem, and fruit extracts in UVA-irradiated human dermal fibroblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Gaultheria procumbens L. is a polyphenolic-rich medicinal and food plant. Its leaves, stems, and fruits are traditional anti-inflammatory, antipyretic, antioxidant, and antimicrobial herbal medicines used to treat internal and external inflammation-related ailments, including rheumatic diseases, influenza, the common cold, fever, and skin and periodontal problems. Moreover, G. procumbens leaf extract is used for skin care as an anti-ageing and anti-wrinkle ingredient.

AIM OF THE STUDY

Various environmental factors, especially solar ultraviolet radiation, accelerate skin ageing by promoting oxidative stress and inflammation. Despite the dermoprotective and anti-ageing applications, the impact of G. procumbens on human dermal fibroblasts is unknown. Therefore, the study aimed to evaluate the anti-inflammatory, antioxidant, and photoprotective activity of G. procumbens standardised leaf, stem, and fruit extracts in cellular models, including human dermal fibroblasts (Hs68 cells) under UVA-irradiation, the primary pro-ageing skin stressor.

MATERIALS AND METHODS

Hs68 fibroblasts were pre-treated (24h) with G. procumbens extracts (0.5-100 μg/mL) or reference compounds followed by UVA-irradiation (8 J/cm2). Cell viability and metabolic activity were measured by CCK-8 and MTT assays in human Hs68 and mouse L929 fibroblasts, respectively. The ROS level, SOD, and GST activities were estimated by fluorescence and spectrophotometric techniques. The pro-inflammatory potential (NF-κB transcription factor activation) was checked using THP1-Blue™ NF-κB cells, and the anti-inflammatory activity was studied by measuring IL-8, ICAM-1, and NF-κB levels and phosphorylation of Erk kinase in LPS-stimulated Hs68 cells by spectrophotometry and confocal microscopy. The UVA-induced DNA damage and cell migration were evaluated by comet and scratch assays, respectively.

RESULTS

The extracts did not affect the metabolic activity of mouse L929 fibroblasts and the viability of unirradiated human Hs68 cells. Additionally, the extracts noticeably enhanced the viability of UVA-irradiated Hs68 cells up to 115-120% (p < 0.001) for stem and leaf extract at 25 μg/mL. All extracts in a wide concentration range (0.5-100 μg/mL) did not activate monocytes or induce the NF-κB transcription factor in LPS-stimulated Hs68 fibroblasts. On the other hand, the extracts (5-25 μg/mL) restored the activity of endogenous antioxidant enzymes, i.e., SOD and GST, up to 120-140% (p < 0.001) in the UVA-irradiated Hs68 cells. Moreover, a statistically significant reduction of ROS, IL-8, ICAM-1, and NF-κB levels by up to 48%, 88%, 43%, and 39%, respectively (p < 0.001) and strong suppression of Erk kinase activation was observed for the extracts (25-50 μg/mL) in LPS-stimulated human fibroblasts. The total DNA damage (% tail DNA) in irradiated Hs68 cells was also strongly decreased by up to 66-69% (p < 0.001) at 50 μg/mL. However, the treatment with the extracts did not relevantly enhance the cell migration of Hs68 fibroblasts.

CONCLUSIONS

The results suggest that G. procumbens may effectively protect human skin fibroblast from UVA irradiation. The leaf and stem extracts were the most potent antioxidants, while fruit and stem extracts revealed the strongest anti-inflammatory activity. The observed effects support the traditional use of aerial plant parts (leaves, stems, and fruits) in treating inflammation-related skin disorders cross-linked with oxidative stress and the topical application of Gaultheria extracts as anti-ageing agents intended for skin care.

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

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

Anthraquinones from Rhamnus alaternus L.: A Phytocosmetic Ingredient with Photoprotective and Antimelanogenesis Properties

The purpose of the present work was to develop a phytocosmetic sunscreen emulsion with antioxidant activity and an anti-melanogenic effect, containing an anthraquinone-enriched extract of Rhamnus alaternus (A.E.). Our findings demonstrated that A.E. decreased the levels of reactive oxygen species, DNA damage, and malondialdehyde induced by UVA in human keratinocytes and melanocytes. Furthermore, the calculated SPF value in vitro of the cream containing A.E. was 14.26±0.152. Later, it was shown that A.E. extract had an inhibitory effect on the amount of melanin. This extract could also reduce B16F10 intracellular tyrosinase activity. Besides, docking studies were carried out to provide a logical justification for the anti-tyrosinase potential. The findings showed that, A.E. may provide protection against UVA-induced oxidative stress and could be thought of as a viable treatment for hyperpigmentation disorders.

β-Glucan extracts as high-value multifunctional ingredients for skin health: A review

β-Glucans, which are naturally present in cereals, yeast, and mushrooms, have gained attention as a potential natural source for functional foods and pharmaceuticals. Due to the availability of β-glucans from several sources, different extraction methods can be employed to obtain high purity extracts that can be further modified to enhance their solubility or other biological properties. Apart from their known ability to interact with the immune system, β-glucans possess specific properties that could benefit overall skin health and prevent age-related signs, including soothing and antioxidant activities. As a result, the use of β-glucans to mitigate damage caused by environmental stressors or skin-related issues that accelerate skin aging or trigger chronic inflammation may represent a promising, natural, eco-friendly, and cost-effective approach to maintaining skin homeostasis balance. This review outlines β-glucan extraction methodologies, molecular structure, functionalization approaches, and explores skin-related benefits of β-glucans, along with an overview of related products in the market.

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

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

A critical review on the biosynthesis, properties, applications and future outlook of green MnO2 nanoparticles

MnO2 nanoparticles have played a vital role in biomedical, catalysis, electrochemical and energy storage fields, but requiring toxic chemicals in the fabrication intercepts their applications. There is an increasing demand for biosynthesis of MnO2 nanoparticles using green sources such as plant species in accordance with the purposes of environmental mitigation and production cost reduction. Here, we review recent advancements on the use of natural compounds such as polyphenols, reducing sugars, quercetins, etc. Extracted directly from low-cost and available plants for biogenic synthesis of MnO2 nanoparticles. Role of these phytochemicals and formation mechanism of bio-medicated MnO2 nanoparticles are shed light on. MnO2 nanoparticles own small particle size, high crystallinity, diverse morphology, high surface area and stability. Thanks to higher biocompatibility, bio-mediated synthesized MnO2 nanoparticles exhibited better antibacterial, antifungal, and anticancer activity than chemically synthesized ones. In terms of wastewater treatment and energy storage, they also served as efficient adsorbents and catalyst. Moreover, several aspects of limitation and future outlook of bio-mediated MnO2 nanoparticles in the fields are analyzed. It is expected that the present work not only expands systematic understandings of synthesis methods, properties and applications MnO2 nanoparticles but also pave the way for the nanotechnology revolution in combination with green chemistry and sustainable development.

Carryover effects from environmental change in early life: An overlooked driver of the amphibian extinction crisis?

Ecological carryover effects, or delayed effects of the environment on an organism's phenotype, are central predictors of individual fitness and a key issue in conservation biology. Climate change imposes increasingly variable environmental conditions that may be challenging to early life-history stages in animals with complex life histories, leading to detrimental physiological and fitness effects in later life. Yet, the latent nature of carryover effects, combined with the long temporal scales over which they can manifest, means that this phenomenon remains understudied and is often overlooked in short-term studies limited to single life-history stages. Herein, we review evidence for the physiological carryover effects induced by elevated ultraviolet radiation (UVR; 280-400 nm) as a potential contributor to recent amphibian population declines. UVR exposure causes a suite of molecular, cellular and physiological consequences known to underpin carryover effects in other taxa, but there is a lack of research linking embryonic and larval UVR exposures to fitness consequences post-metamorphosis in amphibians. We propose that the key impacts of UVR on disease-related amphibian declines are facilitated through carryover effects that bridge embryonic and larval UVR exposure with potential increased disease susceptibility post-metamorphosis. We conclude by identifying a practical direction for the study of ecological carryover effects in amphibians that could guide future ecological research in the broader field of conservation physiology. Only by addressing carryover effects can many of the mechanistic links between environmental change and population declines be elucidated.

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

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.

Dissolvable Topical Formulations for Burst and Constant Delivery of Vitamin C

Healthy skin has a high vitamin C concentration that protects against ultraviolet (UV)-induced damage, promotes wound healing, and lowers cancer risk. The present contribution describes two drug delivery systems for topical administration of vitamin C. The electrospun poly(vinyl alcohol) (PVA) nanofiber carrier of vitamin C exhibits a burst release profile (66 mg/g/h followed by 6.3 mg/g/h). In comparison, a new composite PVA nanofiber-molecular capsule delivers vitamin C at a constant rate (8.2 mg/g/h) with a zeroth-order release profile for better therapeutic management. Both delivery systems protect vitamin C and afford increased heat stability. The molecular capsules of β-cyclodextrin with the vitamin C inclusion complex are immobilized on cellulose acetate and electrosprayed onto an electrospun PVA nanofiber mat.

Gelatin methacryloyl (GelMA) loaded with concentrated hypoxic pretreated adipose-derived mesenchymal stem cells(ADSCs) conditioned medium promotes wound healing and vascular regeneration in aged skin

BACKGROUND

Aging skin is characterized by a disturbed structure and lack of blood supply, which makes it difficult to heal once injured. ADSCs secrete large amounts of cytokines, which promote wound healing and vascular regeneration through paracrine secretion, and the number of cytokines can be elevated by hypoxic pretreating. However, the components of ADSCs are difficult to retain in wounds. Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel synthesized from gelatin and has recently emerged as a potentially attractive material for tissue engineering applications. GelMA loaded with concentrated hypoxic pretreated ADSCs conditioned medium could provide a new method of treating wounds in aged skin.

METHODS

Primary ADSCs were isolated from human adipose tissue and characterized by flow cytometry and differentiation test. ADSCs in passages 4-6 were pretreated in the hypoxic and normoxic environments to collect conditioned medium, the conditioned medium was then concentrated to prepare concentrated ADSCs conditioned medium(cADSC-CM)(the one collected from ADSCs under hypoxia was called hypo-CM ,and the one from normoxia was called nor-CM). The concentration of cytokines was detected. After treated with cADSC-CM, the abilities of proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs) were assayed, and Akt/mTOR and MAPK signal pathway was detected using western blotting. GelMA+hypo-CM hydrogel was prepared, and a comprehensive evaluation of morphology, protein release efficiency, degradation rate, mechanical properties, and rheology properties were performed. Full-thickness skin wounds were created on the backs of 20-month-old mice. After surgery, GelMA, GelMA+F12, GelMA+hypo-CM, and GelMA+nor-CM were applied to the wound surface respectively. H&E, Masson, and immunohistochemistry staining were performed, and a laser Doppler perfusion imager was used to evaluate the blood perfusion. The student's t-test was used for analysis between two groups and a one-way analysis of variance (ANOVA) was used for analysis among multi groups.

RESULTS

Our results revealed that 1) wounds in aged skin healed more slowly than that in young skin and exhibited poorer perfusion; 2) hypoxic pretreated ADSCs secreted more cytokines including VEGF by activating HIF1α; 3) hypo-CM promoted proliferation and migration of HUVECs through VEGF/Akt/mTOR and MAPK signal pathway; 4) GelMA-hypoCM accelerated wound healing and angiogenesis in aged skin in vivo.

CONCLUSION

GelMA loaded with concentrated hypoxic pretreated adipose-derived mesenchymal stem cells conditioned medium could accelerate wound healing in aged skin by promoting angiogenesis.

Novelty Cosmetic Filters Based on Nanomaterials Composed of Titanium Dioxide Nanoparticles

The following work describes the synthesis of new physical filters based on TiO₂/SiO₂ and TiO₂/Ag nanostructures. Titanium dioxide nanoparticles (TiO₂ NPs) were applied as control material and a popular physical UV filter. The advantage of using materials on the nanometer scale is the elimination of the skin whitening effect that occurs when using photoprotective cosmetics containing titanium dioxide on a macro scale. In addition, the silica coating makes the material less harmful, and the silver coating enriches the material with antibacterial properties. Nanoparticles and nanostructures have been characterized by Energy Dispersive X-Ray Analysis (EDX), the Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Fourier-Transform Infrared Spectroscopy (FT-IR) methods. Due to the use of physical filters in anti-radiation protection cosmetics, water-in-oil (W/O) emulsion has been prepared. All cosmetic formulations have been tested for stability. The sun protection research with the Sun Protection Diagnostic SP37 was carried out. These studies made it possible to determine the natural sun protection time and to compare the synthesized materials. Furthermore, one of the most important parameters when describing this type of cosmetic is water resistance, which has also been measured. The results show that the new type of material of TiO₂/Ag used as a new physical filter in emulsion W/O shows the best sun protection compared with other obtained nanomaterials. It is most likely due to the improved optical properties of the combination of noble metals, for example, silver with TiO₂.

Antioxidants in Sunscreens: Which and What For?

Ultraviolet (UV) radiation promotes the generation of reactive oxygen species (ROS) and nitrogen species (RNS), resulting in skin damage. Cosmetic industries have adopted a strategy to incorporate antioxidants in sunscreen formulations to prevent or minimize UV-induced oxidative damage, boost photoprotection effectiveness, and mitigate skin photoaging. Many antioxidants are naturally derived, mainly from terrestrial plants; however, marine organisms have been increasingly explored as a source of new potent antioxidant molecules. This work aims to characterize the frequency of the use of antioxidants in commercial sunscreens. Photoprotective formulations currently marketed in parapharmacies and pharmacies were analyzed with respect to the composition described on the label. As a result, pure compounds with antioxidant activity were found. The majority of sunscreen formulations contained antioxidants, with vitamin E and its derivatives the most frequent. A more thorough analysis of these antioxidants is also provided, unveiling the top antioxidant ingredients found in sunscreens. A critical appraisal of the scientific evidence regarding their effectiveness is also performed. In conclusion, this work provides an up-to-date overview of the use of antioxidants in commercial sunscreens for a better understanding of the advantages associated with their use in photoprotective formulations.

Process Optimization of Phytoantioxidant and Photoprotective Compounds from Carob Pods (Ceratonia siliqua L.) Using Ultrasonic Assisted Extraction Method

The current study first describes the extraction of phytoantioxidant polyphenols from Carob byproducts (pods) using maceration and heating-assisted extraction as traditional methods and ultrasonic-assisted extraction (UAE) as an innovative method to determine the most efficient extraction process in terms of four targeted responses: total phenolic content (TPC), antioxidant activities (TAC and DPPH), and photoprotective properties as measured by the sun protection factor (SPF). Second, we used response surface methodology (RSM) with a central composite rotatable design (CCDR) approach to investigate the influence of process variables (extraction time, extraction temperature, and solvent concentration) on UAE, which was found to be the most effective extraction technique in our study. Carob byproduct extracts had a TPC ranging from 6.21 to 21.92 mg GAE/g dw, a TAC ranging from 22.00 to 49.30 mg AAE/g dw, DPPH scavenging activity ranging from 56.35 to 90.50%, and SPF values ranging from 8.62 to 22.37. The optimal UAE conditions for maximum TPC, TAC, DPPH, and SPF responses were determined to be 38.90% ethanol, 53.90 °C, and 50.92 min. Using Carob as a source for sustainable and bioactive products in conjunction with optimized UAE is a promising contribution to the cosmetic industry that will help to strengthen the concept of environmentally-friendly "green chemistry". Given that Carob pulp or seeds are considered food byproducts, the research presented here encourages the use of these agri-food waste materials in cosmetics.

The antiaging effects of a product containing collagen and ascorbic acid: In vitro, ex vivo, and pre-post intervention clinical trial

Various substances, including collagen (Naticol®) and ascorbic acid, that inhibit and prevent skin aging have been studied. Collagen prevents skin aging, has anti-inflammatory effects, and assists in normal wound healing. Ascorbic acid is a representative antioxidant that plays a role in collagen synthesis. To achieve a synergistic effect of collagen and ascorbic acid on all skin types, we prepared a product named "TEENIALL." In addition, we used a container to separate ascorbic acid and collagen to prevent the oxidation of ascorbic acid. To confirm the effects of TEENIALL, we first confirmed its penetrability in fibroblasts, keratinocytes, melanocyte, and human skin tissues. Thereafter, we confirmed the collagen synthesis ability in normal human fibroblasts. Based on the results of in vitro tests, we conducted a clinical trial (KCT0006916) on female volunteers, aged 40 to 59 years, with skin wrinkles and hyperpigmentation, to evaluate the effects of the product in improving skin wrinkles, skin lifting, and pigmentation areas before using the product, and after 2 and 4 weeks of using the product. The values of nine wrinkle parameters that were evaluated decreased and those for skin sagging, pigmentation, dermal density, and mechanical imprint (pressure) relief were improved. Skin wrinkle and pigmentation were evaluated to ensure that the improvement effect was maintained even after 1 week of discontinuing the product use. The evaluation confirmed that the effects were sustained compared to those after 4 weeks of using the product. Additionally, skin wrinkles, skin lifting, radiance, and moisture content in the skin improved immediately after using the product once. Based on the results of in vitro and ex vivo experiments and the clinical trial, we show that the product containing ascorbic acid and collagen was effective in alleviating skin aging.

Chemical Permeation Enhancers for Topically-Applied Vitamin C and Its Derivatives: A Systematic Review

This paper reports the permeation-enhancing properties and safety of different chemical permeation enhancers (CPEs) on the topical delivery of vitamin C (VC) and its derivatives. A literature search using search keywords or phrases was done in PubMed®, ScienceDirect, and MEDLINE databases. The calculated Log P (cLog P) values were referenced from PubChem and the dermal LD50 values were referenced from safety data sheets. Thirteen studies described the permeation-enhancing activity of 18 identified CPEs in the topical delivery of VC. Correlation analysis between ER and cLog P values for porcine (r = 0.114) and rabbit (r = 0.471) showed weak and moderate positive correlation, while mouse (r = −0.135), and reconstructed human epidermis (r = −0.438) had a negative correlation. The majority (n = 17) of the CPEs belonged to Category 5 of the Globally Harmonized System of Classification or low toxicity hazard. CPEs alone or in combination enhanced permeation (ER = 0.198–106.57) of VC in topical formulations. The combination of isopropyl myristate, sorbitan monolaurate, and polyoxyethylene 80 as CPEs for VC resulted in the highest permeation enhancement ratio.

New insight into the pigmented rice of northeast India revealed high antioxidant and mineral compositions for better human health

Northeast (NE) India possesses a rich diversity of rice cultivars including pigmented and non pigmented varieties. The pigmented rice is reported to possess a considerable amount of antioxidant compounds, free radical scavengers etc. In this study, eleven (black, red and white) rice cultivars of NE India were analyzed for antioxidant potentials, mineral and protein contents. Total phenolic content ranged from 94.8 (Idaw) to 900.90 mg GAE/100 g (Lumre). Total flavonoid content varied from 3.46 (Idaw) to 286.76 mg QE/100 g (Menil mibabaret). Total anthocyanin content varied from 0.23 (Farel) to 93.52 mg/100 g (Chakhao poireiton). The pigmented rice is also good sources of Catalase (CAT), Ascorbate peroxidase (APX) and Superoxide Dismutase (SOD) that can significantly reduce stress oxidative reactions. Chakhao poireiton possessed the highest Ni and Mn content, Tsulu tsuk had the highest Zn content, while Fazu and Tasung contained the highest Fe and Ca. The highest total protein was found in Chakhao poireiton (11.06%). And all the cultivars were found to be aromatic. Fourier Transformed Infra-Red spectroscopy (FTIR) identified various signature peaks and could discriminate the cultivars into pigmented and non pigmented. Principle Component Analysis (PCA) revealed the grouping of the cultivars based on the functional groups present. The present study could provide a better understanding of choosable rice lines for human consumption and also as germplasm resources for future rice improvement programs.

Ultraviolet Light Protection: Is It Really Enough?

Our current understanding of the pathogenesis of skin aging includes the role of ultraviolet light, visible light, infrared, pollution, cigarette smoke and other environmental exposures. The mechanism of action common to these exposures is the disruption of the cellular redox balance by the directly or indirectly increased formation of reactive oxygen species that overwhelm the intrinsic antioxidant defense system, resulting in an oxidative stress condition. Altered redox homeostasis triggers downstream pathways that contribute to tissue oxinflammation (cross-talk between inflammation and altered redox status) and accelerate skin aging. In addition, both ultraviolet light and pollution increase intracellular free iron that catalyzes reactive oxygen species generation via the Fenton reaction. This disruption of iron homeostasis within the cell further promotes oxidative stress and contributes to extrinsic skin aging. More recent studies have demonstrated that iron chelators can be used topically and can enhance the benefits of topically applied antioxidants. Thus, an updated, more comprehensive approach to environmental or atmospheric aging protection should include sun protective measures, broad spectrum sunscreens, antioxidants, chelating agents, and DNA repair enzymes.

Aryl Hydrocarbon Receptor in Oxidative Stress as a Double Agent and Its Biological and Therapeutic Significance

The aryl hydrocarbon receptor (AhR) has long been implicated in the induction of a battery of genes involved in the metabolism of xenobiotics and endogenous compounds. AhR is a ligand-activated transcription factor necessary for the launch of transcriptional responses important in health and disease. In past decades, evidence has accumulated that AhR is associated with the cellular response to oxidative stress, and this property of AhR must be taken into account during investigations into a mechanism of action of xenobiotics that is able to activate AhR or that is susceptible to metabolic activation by enzymes encoded by the genes that are under the control of AhR. In this review, we examine various mechanisms by which AhR takes part in the oxidative-stress response, including antioxidant and prooxidant enzymes and cytochrome P450. We also show that AhR, as a participant in the redox balance and as a modulator of redox signals, is being increasingly studied as a target for a new class of therapeutic compounds and as an explanation for the pathogenesis of some disorders.

Microbial Interventions in Bioremediation of Heavy Metal Contaminants in Agroecosystem

Soil naturally comprises heavy metals but due to the rapid industrialization and anthropogenic events such as uncontrolled use of agrochemicals their concentration is heightened up to a large extent across the world. Heavy metals are non-biodegradable and persistent in nature thereby disrupting the environment and causing huge health threats to humans. Exploiting microorganisms for the removal of heavy metal is a promising approach to combat these adverse consequences. The microbial remediation is very crucial to prevent the leaching of heavy metal or mobilization into the ecosystem, as well as to make heavy metal extraction simpler. In this scenario, technological breakthroughs in microbes-based heavy metals have pushed bioremediation as a promising alternative to standard approaches. So, to counteract the deleterious effects of these toxic metals, some microorganisms have evolved different mechanisms of detoxification. This review aims to scrutinize the routes that are responsible for the heavy metal(loid)s contamination of agricultural land, provides a vital assessment of microorganism bioremediation capability. We have summarized various processes of heavy metal bioremediation, such as biosorption, bioleaching, biomineralization, biotransformation, and intracellular accumulation, as well as the use of genetically modified microbes and immobilized microbial cells for heavy metal removal.

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.

Development of Stable Tocopherol Succinate-Loaded Ethosomes to Enhance Transdermal Permeation: In-Vitro and In-Vivo Characterizations

BACKGROUND

Tocopherol succinate (TS) represents synthetic derivative of α-tocopherol (vitamin E), it act as anti-aging, moisturizing and antioxidant. Ultraviolet (UV) photo stability of TS is low and it cause skin irritation.

AIM

To develop tocopherol succinate loaded ethosomal gel for topical TS delivery and to evaluate its moisturizing and anti-aging effects.

METHOD

Cold method technique was used to produce ethosomal formulations (N=9) by varying ethanol and lipid concentrations (F1-F9). The most optimized formulation (F5) was selected for further study on the basis of characterization. F5 Formulation was incorporated into gel. Ex vivo permeation study was done by using Franz diffusion cell. Non-invasive in-vivo study was performed by using corneometer for evaluation of skin moisture content and skin mechanical properties by using cutometer, for 12 weeks on human subjects (N=13).

RESULTS

Particle size (PS), zeta potential (ZP) and polydispersity index (PDI), Entrapment efficiency were found to be 179.1 nm, -13.7 mV and 0.345, 99.71% respectively. TEM depicted spherical ethosomal particles. Ethosomal gel and control gel were evaluated for Conductivity and pH. Rheological analysis revealed a non-Newtonian flow. The release profile showed Initial burst and then sustained release, release data followed Korsmeyer-Peppas model. TS loaded ethosomal gel appeared physically stable and showed significant results in terms of skin capacitance and mechanical properties.

CONCLUSION

The prepared ethosomal gel formulation containing TS is more stable with enhanced antioxidant, moisturizing properties and increased TS deposition into the skin layer.

Oxidative Stress and Gut Microbiome in Inflammatory Skin Diseases

Oxidative stress plays a dominant role in inflammatory skin diseases. Emerging evidence has shown that the close interaction occurred between oxidative stress and the gut microbiome. Overall, in this review, we have summarized the impact of oxidative stress and gut microbiome during the progression and treatment for inflammatory skin diseases, the interactions between gut dysbiosis and redox imbalance, and discussed the potential possible role of oxidative stress in the gut-skin axis. In addition, we have also elucidated the promising gut microbiome/redox-targeted therapeutic strategies for inflammatory skin diseases.

Nanocarriers as Active Ingredients Enhancers in the Cosmetic Industry-The European and North America Regulation Challenges

“Flawless skin is the most universally desired human feature” is an iconic statement by Desmond Morris. Skin indicates one´s health and is so important that it affects a person’s emotional and psychological behavior, these facts having propelled the development of the cosmetics industry. It is estimated that in 2023, this industry will achieve more than 800 billion dollars. This boost is due to the development of new cosmetic formulations based on nanotechnology. Nanocarriers have been able to solve problems related to active ingredients regarding their solubility, poor stability, and release. Even though nanocarriers have evident benefits, they also present some problems related to the high cost, low shelf life, and toxicity. Regulation and legislation are two controversial topics regarding the use of nanotechnology in the field of cosmetics. In this area, the U.S. FDA has taken the lead and recommended several biosafety studies and post-market safety evaluations. The lack of a global definition that identifies nanomaterials as a cosmetic ingredient is a hindrance to the development of global legislation. In the EU, the legislation regarding the biosafety of nanomaterials in cosmetics is stricter. “The cost is not the only important issue, safety and the application of alternative testing methods for toxicity are of crucial importance as well”.

Wearable Light Sensors Based on Unique Features of a Natural Biochrome

Overexposure to complete solar radiation (combined ultraviolet, visible, and infrared) is correlated with several harmful biological consequences including hyperpigmentation, skin cancer, eye damage, and immune suppression. With limited effective therapeutic options available for these conditions, significant efforts have been directed toward promoting preventative habits. Recently, wearable solar radiometers have emerged as practical tools for managing personal exposure to sunlight. However, designing simple and inexpensive sensors that can measure energy across multiple spectral regions without incorporating electronic components remains challenging, largely due to inherent spectral limitations of photoresponsive indicators. In this work, we report the design, fabrication, and characterization of wearable radiation sensors that leverage an unexpected feature of a natural biochrome, xanthommatin-its innate sensitivity to both ultraviolet and visible through near-infrared radiation. We found that xanthommatin-based sensors undergo a visible shift from yellow to red in the presence of complete sunlight. This color change is driven by intrinsic photoreduction of the molecule, which we investigated using computational modeling and supplemented by radiation-driven formation of complementary reducing agents. These sensors are responsive to dermatologically relevant doses of erythemally weighted radiation, as well as cumulative doses of high-energy ultraviolet radiation used for germicidal sterilization. We incorporated these miniature sensors into pressure-activated microfluidic systems to illustrate on-demand activation of a wearable and mountable form factor. When taken together, our findings encompass an important advancement toward accessible, quantitative measurements of UVC and complete solar radiation for a variety of use cases.

Plant Secondary Metabolites against Skin Photodamage: Mexican Plants, a Potential Source of UV-Radiation Protectant Molecules

Human skin works as a barrier against the adverse effects of environmental agents, including ultraviolet radiation (UVR). Exposure to UVR is associated with a variety of harmful effects on the skin, and it is one of the most common health concerns. Solar UVR constitutes the major etiological factor in the development of cutaneous malignancy. However, more than 90% of skin cancer cases could be avoided with appropriate preventive measures such as regular sunscreen use. Plants, constantly irradiated by sunlight, are able to synthesize specialized molecules to fight against UVR damage. Phenolic compounds, alkaloids and carotenoids constitute the major plant secondary metabolism compounds with relevant UVR protection activities. Hence, plants are an important source of molecules used to avoid UVR damage, reduce photoaging and prevent skin cancers and related illnesses. Due to its significance, we reviewed the main plant secondary metabolites related to UVR protection and its reported mechanisms. In addition, we summarized the research in Mexican plants related to UV protection. We presented the most studied Mexican plants and the photoprotective molecules found in them. Additionally, we analyzed the studies conducted to elucidate the mechanism of photoprotection of those molecules and their potential use as ingredients in sunscreen formulas.

The Role of Oxidative Stress, Inflammation, and Advanced Glycation End Product in Skin Manifestations of Diabetes Mellitus

Diabetes mellitus is a metabolic disorder caused by an increase in insulin resistance, a decrease in insulin production, or both of them, resulting in a high level of blood glucose or hyperglycemia. An uncontrolled state of DM may cause complications, namely skin disorder. One or more skin disorders are found amongst 74% of T2DM patients, with the highest percentage is dry skin (47%), followed by infection (10%), diabetic hand (5%), hair loss and diabetic dermopathy (each 4%). In DM, the state of hyperglycemia and production of advanced glycaemic end-products (AGEs) profoundly impact skin changes. In the pathological pathway, AGEs induce oxidative stress and inflammation. Nonetheless, AGEs level is higher in T2DM patients compared to non- T2DM people. This is caused by hyperglycemia and oxidative stress. Binding between AGEs and receptor of AGEs (RAGE) promotes pathway of oxidative stress and inflammation cascade via mitogen- activated protein kinases (MAPK), nuclear factor-k-light-chain-enhancer of activated β cells (NF-kβ), interleukin- 6 (IL-6), tumor necrosis factor-α (TNF-α), expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 2 (VCAM-2) pathway which furtherly effectuates DM complication including skin disorders.

Formation, antimicrobial activity, and biomedical performance of plant-based nanoparticles: a review

Because many engineered nanoparticles are toxic, there is a need for methods to fabricate safe nanoparticles such as plant-based nanoparticles. Indeed, plant extracts contain flavonoids, amino acids, proteins, polysaccharides, enzymes, polyphenols, steroids, and reducing sugars that facilitate the reduction, formation, and stabilization of nanoparticles. Moreover, synthesizing nanoparticles from plant extracts is fast, safe, and cost-effective because it does not consume much energy, and non-toxic derivatives are generated. These nanoparticles have diverse and unique properties of interest for applications in many fields. Here, we review the synthesis of metal/metal oxide nanoparticles with plant extracts. These nanoparticles display antibacterial, antifungal, anticancer, and antioxidant properties. Plant-based nanoparticles are also useful for medical diagnosis and drug delivery.

Photoprotective Effect of Artemisia sieversiana Ehrhart Essential Oil Against UVB-induced Photoaging in Mice

Photoaging refers to the extrinsic aging resulting from ultraviolet (UV) irradiation, which impacts skin appearance and is accompanied by the risk of skin carcinoma. Developing natural products as photoprotective agents is of great interest in cosmetic industry nowadays. The present study aimed at investigating the possible use of Artemisia sieversiana Ehrhart essential oil (AEO) for the prevention of photoaging induced by UVB. AEO was characterized by chamazulene, which accounted for 38.92% among total 51 identified compounds. In in vitro assays, AEO was found to be a moderate antioxidant and good UVB filter with photostability. A UVB-induced photoaging mice model was established with three AEO formulations (0.1%, 0.5% and 1.5%, w/w) topically applied prior to UVB irradiation. The activities of catalase, particularly superoxide dismutase of skin increased, while malondialdehyde content decreased in AEO groups as compared with model controls. The production of matrix metalloproteinases (MMP-1 and MMP-3) and depletion of hydroxyproline in skin were inhibited by AEO in a dose-dependent manner. Histological evaluation indicated that AEO decreased epidermal thickness, inflammatory cell infiltration, collagen degradation and elastin aberrance. These findings indicated that AEO could be a promising sunscreen agent in protecting the skin against photoaging.

Carotenoids from Persimmon (Diospyros kaki Thunb.) Byproducts Exert Photoprotective, Antioxidative and Microbial Anti-Adhesive Effects on HaCaT

Persimmon (Diospyros kaki Thunb.) fruits are a remarkable source of carotenoids, which have shown protective effects against UV radiation in bacteria, fungi, algae, and plants. The aim of this study was to analyze the photoprotection provided by an acetone extract, rich in carotenoids and obtained from byproducts derived from the persimmon juice industry, against UV-induced cell death in the keratinocyte HaCaT cell line. For this purpose, the cytotoxicity and phototoxicity of carotenoid extract, as well as its intracellular reactive oxygen species (ROS) scavenging and anti-adhesive activities towards HaCaT cells, were evaluated. The in vitro permeation test provided information about the permeability of the carotenoid extract. Persimmon extracts, rich in carotenoids (PEC), were absorbed by HaCaT keratinocyte cells, which reduced the UV-induced intracellular ROS production in treated cells. Thus, PEC exerted a photoprotective and regenerative effect on UV-irradiated HaCaT cells, and this protection was UV dose-dependent. No cytotoxic effect was observed in HaCaT cultures at the concentration tested. PEC treatment also stimulated the adhesion capacity of skin microbiome to HaCaT cells, while exhibiting a significant anti-adhesive activity against all tested pathogens. In conclusion, PEC showed potential for use as a functional ingredient in skin-care products.

Dermocosmetic applications of microalgal pigments

Among photosynthetic microorganisms, Cyanobacteria and Microalgae species have been highly studied thank to their high value-added compounds for several industrial applications. Thus, their production is increasing in the last decade to produce raw material for cosmetics. In fact, the daily routine includes the use of cosmetics and sunscreens to protect against the environmental changes, mainly the increment of ultraviolet (UV) radiation rate with a consequent skin damage and premature aging due to this overexposure. As it is well discussed, chemical UV filters are extensively incorporated into sunscreens formulas; however, they can induce allergenic reactions as well. For these reasons, some pigments derived from microalgae, such as astaxanthin, lutein, β-carotene as well as other biocompounds are now well described in the literature as well as biotechnologically manufactured as natural ingredients to be incorporated into skin care products with multifunctional benefits even for sunscreen purposes. Hence, this investigation summarizes the recent studies about the main pigments from photosynthetic microorganisms' biomasses as well as their uses in dermocosmetics with novel attributes, such as anti-aging agents, makeups, skin lightening and whitening, among others.

Sunscreens and Photoaging: A Review of Current Literature

Sunscreens have been on the market for many decades as a means of protection against ultraviolet-induced erythema. Over the years, evidence has also shown their efficacy in the prevention of photoaging, dyspigmentation, DNA damage, and photocarcinogenesis. In the USA, most broad-spectrum sunscreens provide protection against ultraviolet B (UVB) radiation and short-wavelength ultraviolet A (UVA) radiation. Evidence suggests that visible light and infrared light may play a role in photoaging and should be considered when choosing a sunscreen. Currently, there is a paucity of US FDA-approved filters that provide protection against long UVA (> 370 nm) and none against visible light. Additionally, various sunscreen additives such as antioxidants and photolyases have also been reported to protect against and possibly reverse signs of photoaging. This literature review evaluates the utility of sunscreen in protecting against photoaging and further explores the requirements for an ideal sunscreen.

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.

Nanostructured lipid carriers for the encapsulation of phloretin: preparation and in vitro characterization studies

Phloretin is a powerful antioxidant with many effects, such as anti-cancer, anti-inflammatory, promoting cell renewal, delaying aging and so on. However, the application of phloretin was limited by its low water solubility, low absorption in vivo and unstable properties. A phloretin-loaded nanostructured lipid carrier was designed with a high-pressure homogenization technique. The mean particle size of phloretin NLC was 137.40 ± 3.27 nm, and the Polydispersity index (PdI) value was 0.237 ± 0.005. The encapsulation efficiency was 96.68% ± 0.06%. Transmission electron microscopy images showed that the phloretin-loaded nanostructured lipid carriers were spherical. Phloretin in NLC showed a sustained release pattern in vitro. The results showed that phloretin NLC is more suitable for absorption than phloretin ethanol solution, and NLC can be a promising carrier for phloretin in the food industry.

Antioxidative Composites Based on Multienzyme Systems Encapsulated in Metal-Organic Frameworks

Skin is exposed to ultraviolet radiation from the sun constantly, which may induce overproduction of reactive oxygen species (ROS) causing oxidative stress to cells and tissues. Enzymes and small molecules work together to maintain the redox homeostasis, among which superoxide dismutase (SOD) and catalase (CAT) are two kinds of most important antioxidants that suffer from the fragile nature of proteins. Moreover, the proportion of two enzymes used in products must be precisely controlled to reduce the damage caused by the toxic intermediate H₂O₂. Metal-organic frameworks (MOFs) are emerging as promising candidates for multiple enzyme encapsulation due to their high porosity, easy synthesis, and good biocompatibility. Herein, we developed enzyme-MOF composites, SC@ZIF-8, which exhibited an excellent antioxidative activity in vitro. Chemically protective cages formed by MOFs endow the encapsulated enzymes the long-term stability under unnatural conditions in cosmetic and biomedical materials. The pH-dependent protein release profile of SC@ZIF-8 facilitated the successful delivery of enzymes into the cytoplasm to scavenge toxic ROS. The nanocomposites protected human cells from paraquat-induced oxidative stress, paving a new path for the stable and efficient application of antioxidative enzymes in cosmetic and dermatological fields.

Protective effects of GLHP from Gracilaria lemaneiformis against UVB-induced photodamage in human immortalized keratinocytes cells and BALB/c mice

Our previous study showed that the water-soluble heteropolysaccharide extracted from Gracilaria lemaneiformis (GLHP) has excellent anti-inflammation and anti-oxidant properties. This study explored the efficacy of GLHP against skin anti-photoaging in human immortalized keratinocytes (HaCaT) cells and BALB/c mice under UVB irradiation. Cell viability, antiapoptotic, reactive oxygen species (ROS) scavenging activity, mitochondrial membrane potential, and cell wound scratch assays were conducted, as well as assessment of inflammation markers and sun protection factors. The in vitro results showed that GLHP pretreatment significantly inhibited UVB-induced apoptosis, reversed the decrease of cell viability via downregulating the expression of apoptosis-related protein caspase-3, accelerated the migration of HaCaT cells, and promoted wound healing. Notably, the protective effect of GLHP may be associated with the scavenging of ROS and the decrease of mitochondrial membrane potential. Moreover, GLHP pretreatment significantly restrained the upregulation of iNOS (UVB-induced inflammation marker), suppressed the expression of P-ERK and NF-κB, and decreased the activity of MMPs, suggesting that it exerts the therapeutic effects by inhibiting the MAPK/NF-κB signal pathway. Results obtained after conducting the in vivo assay confirmed that GLHP could reverse the UVB-induced increase of epidermal thickness in BALB/c mice. In conclusion, this study shows that GLHP can be utilized as a safer resource in the manufacture of anti-aging cosmetics because it exerts excellent anti-photoaging effects.