Skin antioxidants: their role in aging and in oxidative stress--new approaches for their evaluation

Oxidative stress in hair follicle development and hair growth: Signalling pathways, intervening mechanisms and potential of natural antioxidants

Hair follicle development and hair growth are regulated by multiple factors and multiple signalling pathways. The hair follicle, as an important skin appendage, is the basis for hair growth, and it has the functions of safeguarding the body, perceiving the environment and regulating body temperature. Hair growth undergoes a regular hair cycle, including anagen, catagen and telogen. A small amount of physiological shedding of hair occurs under normal conditions, always in a dynamic equilibrium. Hair loss occurs when the skin or hair follicles are stimulated by oxidative stress, inflammation or hormonal disorders that disrupt the homeostasis of the hair follicles. Numerous researches have indicated that oxidative stress is an important factor causing hair loss. Here, we summarize the signalling pathways and intervention mechanisms by which oxidative stress affects hair follicle development and hair growth, discuss existing treatments for hair loss via the antioxidant pathway and provide our own insights. In addition, we collate antioxidant natural products promoting hair growth in recent years and discuss the limitations and perspectives of current hair loss prevention and treatment.

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.

Evidence of the protective effect of anti-pollution products against oxidative stress in skin ex vivo using EPR spectroscopy and autofluorescence measurements

The concentration of air pollution is gradually increasing every year so that daily skin exposure is unavoidable. Dietary supplements and topical formulations currently represent the protective strategies to guard against the effects of air pollution on the body and the skin. Unfortunately, there are not yet enough methods available to measure the effectiveness of anti-pollution products on skin. Here, we present two ex vivo methods for measuring the protective effect against air pollution of different cream formulations on the skin: Electron paramagnetic resonance (EPR) spectroscopy and autofluorescence excited by 785 nm using a confocal Raman microspectrometer (CRM). Smoke from one cigarette was used as a model pollutant. EPR spectroscopy enables the direct measurement of free radicals in excised porcine skin after smoke exposure. The autofluorescence in the skin was measured ex vivo, which is an indicator of oxidative stress. Two antioxidants and a chelating agent in a base formulation and a commercial product containing an antioxidant mixture were investigated. The ex vivo studies show that the antioxidant epigallocatechin-3-gallate (EGCG) in the base cream formulation provided the best protection against oxidative stress from smoke exposure for both methods.

Predicting Chronological Age via the Skin Volatile Profile

Skin volatile emissions offer a noninvasive insight into metabolic activity within the body as well as the skin microbiome and specific volatile compounds have been shown to correlate with age, albeit only in a few small studies. Building on this, here skin volatiles were collected and analyzed in a healthy participant study (n = 60) using a robust headspace-solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) workflow. Following processing, 18 identified compounds were deemed suitable for this study. These were classified according to gender influences and their correlations with age were investigated. Finally, 6 volatiles (of both endogenous and exogenous origin) were identified as significantly changing in abundance with participant age (p < 0.1). The potential origins of these dysregulations are discussed. Multiple linear regression (MLR) analysis was employed to model age based on these significant volatiles as independent variables, along with gender. Our analysis shows that skin volatiles show a strong predictive ability for age (explained variance of 68%), stronger than other biochemical measures collected in this study (skin surface pH, water content) which are understood to vary with chronological age. Overall, this work provides new insights into the impact of aging on the skin volatile profiles which comprises both endogenously and exogenously derived volatile compounds. It goes toward demonstrating the biological significance of skin volatiles and will help pave the way for more rigorous consideration of the healthy "baseline" skin volatile profile in volatilomics-based health diagnostics development going forward.

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.

Antioxidant Biomaterials in Cutaneous Wound Healing and Tissue Regeneration: A Critical Review

Natural-based biomaterials play an important role in developing new products for medical applications, primarily in cutaneous injuries. A large panel of biomaterials with antioxidant properties has revealed an advancement in supporting and expediting tissue regeneration. However, their low bioavailability in preventing cellular oxidative stress through the delivery system limits their therapeutic activity at the injury site. The integration of antioxidant compounds in the implanted biomaterial should be able to maintain their antioxidant activity while facilitating skin tissue recovery. This review summarises the recent literature that reported the role of natural antioxidant-incorporated biomaterials in promoting skin wound healing and tissue regeneration, which is supported by evidence from in vitro, in vivo, and clinical studies. Antioxidant-based therapies for wound healing have shown promising evidence in numerous animal studies, even though clinical studies remain very limited. We also described the underlying mechanism of reactive oxygen species (ROS) generation and provided a comprehensive review of ROS-scavenging biomaterials found in the literature in the last six years.

Ethyl Gallate Isolated from Castanopsis cuspidata var. sieboldii Branches Inhibits Melanogenesis and Promotes Autophagy in B16F10 Cells

The Castanopsis cuspidata var. sieboldii (CCS) plant grows predominantly in temperate regions of Asian countries, such as South Korea. Research on CCS has so far concentrated on the nutritional analysis, antioxidant activity, and anti-inflammation properties of its branches. However, the isolation of compounds and structural elucidation of effective single molecules remain unexplored, necessitating further exploration of CCS branches. Therefore, this study demonstrates the antioxidant and antimelanogenic activity of a single substance of ethyl gallate (EG) isolated from CCS branch extracts. Notably, the antimelanogenic (whitening) activity of EG extracted from CCS branches remains unexplored. Tyrosinase inhibition, kinetic enzyme assays, and molecular docking studies were conducted using mushroom tyrosinase in order to examine the antioxidant mechanism and antimelanin activity of EG in B16F10 melanoma cells. Nontoxic EG concentrations were found to be below 5 µg/mL. While EG significantly reduced the levels of whitening-associated proteins, p-CREB, and p-PKA, it dose-dependently inhibited the expression of TYR, TRP-1, TRP-2, and transcription factor (MITF). In addition, EG downregulated melanogenetic gene expression and activated autophagy signals. Therefore, EG extracted from CCS branches could serve as a novel functional cosmetic material with antimelanogenic and autophagy-enhancing activity.

Elderly-friendly indoor vertical dimensional layout method based on joint mobility

INTRODUCTION

The vertical dimensional arrangement of space is primarily influenced by the reachable range of human fingertips. Currently, this dimensional layout analysis concentrates solely on static body dimensions based on Farley's principle. However, the joint mobility of the elderly population has diminished, necessitating the identification of the factors influencing the age-friendly spatial vertical dimension layout through experimentation.

METHODS

A random sample of 62 adults and 62 elderly individuals were selected to measure the joint mobility of 8 groups with varying comfort levels. The measurement results were analyzed using an independent sample t-test with SPSS software.

RESULTS

The joint mobility of the elderly group exhibited a notable difference from that of the adult group across distinct comfort gradients. A significant reduction in the range of motion of all joints in the elderly was observed. The findings suggest that the reachable range of the upper limbs of the elderly should be considered in conjunction with joint mobility. We propose a vertical dimensional layout method for residential spaces that accommodates the joint mobility of elderly users.

CONCLUSION

The joint mobility of the elderly is significantly deteriorating, and the traditional vertical spatial layout method cannot adequately support the daily life of the elderly. It is essential to integrate the joint mobility factor into the vertical dimensional layout design process. In this paper, we propose an elderly-friendly vertical spatial dimension layout method. It offers a reference for subsequent planning of elderly-friendly vertical dimension layout.

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.

The Role of Preservatives and Multifunctionals on the Oxidation of Cosmetic O/W Emulsions

Preservatives are typically used to protect cosmetic products from microbial spoilage. However, there is evidence that some preservatives can increase oxidation in O/W emulsions. This could have disadvantages for product quality, efficacy, and consumer health and well-being. Therefore, the impact of preservatives or multifunctionals on oxidation should be quantified. For this purpose, five O/W emulsions with different preservatives were prepared and stored. During storage, the oxygen concentration in the headspace of the samples was studied. The samples showed significant differences in their oxygen uptake and daily oxygen consumption rate. Thus, the preservatives used in this study had an influence on oxidation.

Anti-Glycation and Anti-Aging Properties of Resveratrol Derivatives in the in-vitro 3D Models of Human Skin

Purpose

Human skin undergoes modifications affecting its structural properties and barrier functions involved in protection against age-related damage. Glycation is a non-enzymatic reaction between macromolecules and sugars causing alterations to the elastic fibers and premature aging of the skin. Glycation can be prevented by a range of bioactive molecules; however, at present only a few of them are validated for inclusion in cosmetic products. There is also a demand for reproducible in-vitro assays demonstrating the anti-aging effect of compounds on the skin. This study aimed to define the potential targets for screening and validation of anti-glycation activity of novel cosmetic candidates from natural products and to provide a plausible mechanism for their anti-aging potential based on 3D skin models.

Methods

Dermal fibroblasts and 3D skin models were treated with glycation agent and topical applications of Resveratrol derivatives. The samples were analyzed for advanced glycation end products (AGEs) alongside an organization of elastic fibers and expression of proliferative, senescence, and oxidative stress markers by autofluorescence, immunocytochemistry and quantitative assays.

Results

Accumulation of AGEs in the 3D skin model is associated with reduced stratification of the epidermis and re-organization of the collagen in the upper, cell-dense layer of the dermis. Treatment of dermal fibroblasts with Resveratrol, OxyResveratrol, Piceatannol, and Triacetyl Resveratrol ameliorates the effects of glycation consistent with cellular aging. Subsequent topical application of the compounds in skin models results in a reduction in glycation-induced AGEs, an increase in collagen expression and a stratification of the epidermis.

Conclusion

Glycation could result in age-related alterations in the structural and cellular organizations of the superficial layers of the skin, which can be restored by Resveratrol derivatives, pointing to their promising capacities as bioactive ingredients in cosmetic products. Insight into the potential parameters affected by skin glycation could also serve as a reference for screening the bioactive molecules for cosmetic purposes.

Novel amphibian-derived antioxidant peptide protects skin against ultraviolet irradiation damage

Given the adverse impact of ultraviolet irradiation on human skin, as well as currently limited interventions, the discovery of new molecules with anti-photodamage potency remains critical. In this research, we obtained a new bioactive peptide (named OS-LL11, amino acid sequence 'LLPPWLCPRNK') from Odorrana schmackeri. Results showed that OS-LL11 could directly scavenge free radicals and sustain the viability of mouse keratinocytes challenged by ultraviolet B (UVB) irradiation or hydrogen peroxide (H₂O₂) by decreasing the levels of lipid peroxidation, malondialdehyde, and reactive oxygen species while increasing the level of catalase, Keap-1, HO-1, GCLM, and NQO1. Interestingly, topical application of OS-LL11 protected mouse skin against UVB irradiation damage by up-regulating the levels of superoxide dismutase, glutathione, and nitric oxide, but down-regulating the levels of H₂O₂, IL-1α, IL-1β, IL-6, TNF-α, 8-OHdG, Bcl-2, and Bax, as well as the number of apoptotic bodies. Our research demonstrated the anti-photodamage activity of a novel amphibian-derived peptide and the potential underlying mechanisms related to its free radical scavenging ability and antioxidant, anti-inflammatory, and anti-apoptotic activities. This study provides a new molecule for the development of anti-skin photodamage drugs or cosmetics and highlights the prospects of amphibian-derived peptides in photodamaged skin intervention.

The New Challenge of Green Cosmetics: Natural Food Ingredients for Cosmetic Formulations

Nowadays, much attention is paid to issues such as ecology and sustainability. Many consumers choose “green cosmetics”, which are environmentally friendly creams, makeup, and beauty products, hoping that they are not harmful to health and reduce pollution. Moreover, the repeated mini-lock downs during the COVID-19 pandemic have fueled the awareness that body beauty is linked to well-being, both external and internal. As a result, consumer preferences for makeup have declined, while those for skincare products have increased. Nutricosmetics, which combines the benefits derived from food supplementation with the advantages of cosmetic treatments to improve the beauty of our body, respond to the new market demands. Food chemistry and cosmetic chemistry come together to promote both inside and outside well-being. A nutricosmetic optimizes the intake of nutritional microelements to meet the needs of the skin and skin appendages, improving their conditions and delaying aging, thus helping to protect the skin from the aging action of environmental factors. Numerous studies in the literature show a significant correlation between the adequate intake of these supplements, improved skin quality (both aesthetic and histological), and the acceleration of wound-healing. This review revised the main foods and bioactive molecules used in nutricosmetic formulations, their cosmetic effects, and the analytical techniques that allow the dosage of the active ingredients in the food.

The Anti-Inflammatory Effect of Aptamin C on House Dust Mite Extract-Induced Inflammation in Keratinocytes via Regulation of IL-22 and GDNF Production

Atopic dermatitis (AD), a chronic inflammatory skin disease, is characterized by eczemous lesions on the skin that manifest as severe itching and last a long time. AD is thought to be a response to local allergens, including house dust mites (HDMs). Aptamin C is a modified form of vitamin C comprised of aptamers (DNA fragments) that bind specifically to vitamin C and inhibit its oxidation, thereby increasing its stability and antioxidant effects. It is already known that vitamin C shows an anti-inflammatory effect on skin inflammation. Oxidative stress is one of the major causes of inflammatory diseases, including HDM-induced skin inflammation, suggesting that the antioxidant activity of Aptamin C could regulate inflammatory responses to HDMs in the skin keratinocyte cell line HaCaT and primary skin keratinocytes. Aptamin C not only inhibited HDM-induced proliferation of both type of cells, but suppressed HDM-induced increases in interleukin (IL)-1α and IL-6 production by these cells. In addition, Aptamin C suppressed the production of IL-17 and IL-22 by T cells, which are closely associated with AD pathogenesis, as well as HDM-induced IL-22Rα expression. Aptamin C also reduced the production of thymus and activation-regulated chemokine (TARC) by suppressing the interaction between IL-22 and IL-22Rα, as well as reducing T cell migration. Although HDM treatment markedly increased the expression of glial cell line-derived neurotrophic factor (GDNF), which is associated with itching in AD skin lesions, this increase was reduced by Aptamin C treatment. Taken together, these results suggest that Aptamin C can effectively regulate inflammatory lesions, such as AD, by regulating the production of inflammatory cytokines and GDNF induced by HDM.

Estimation of the reducing power and electrochemical behavior of few flavonoids and polyhydroxybenzophenones substantiated by bond dissociation energy: a comparative analysis

Oxidative stress that damages cellular components affects various organs including the brain. It is thus believed to play an active role in neurodegenerative diseases, wherein the intrinsic antioxidant enzymes metabolize toxic intermediates. For therapeutic purpose, instead of antioxidant enzymes, small organic compounds as antioxidants may be more effective. Here, reducing power and electrochemical behavior of some flavanols, flavanonols, flavones, flavonols and O-methylated flavonols have been estimated and confirmed by the calculated bond dissociation energy. Compared to other classes, flavonols exhibited increased reducing power that decreased with methylation of the oxygen atom in the B-ring. Gossypetin emerged as the most effective of these flavonols. Generally, compounds with two hydroxyl groups in two consecutive positions of the phenyl ring and an enolic group in the C-ring with more preference for the hydroxyl group in the ortho position with respect to each other in the catechol moiety showed major activity. 5 position of the A-ring showed the least effect on the activity. The present understanding therefore may be applied for identifying compounds to be used as scaffold for designing potent antioxidants.

Diversified Stimuli-Induced Inflammatory Pathways Cause Skin Pigmentation

The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. This review covers the mechanistic aspects of skin pigmentation caused by inflammation.

Phenolic compounds of blueberries (Vaccinium spp) as a protective strategy against skin cell damage induced by ROS: A review of antioxidant potential and antiproliferative capacity

The skin is a tissue with a high metabolic activity that acts as a protective layer for the internal organs of the body. This tissue is exposed to a variety of damaging agents, including reactive oxygen species (ROS), which can lead to oxidative damage to various macromolecules, disrupting vital cellular processes and increasing mutations. A situation referred to as oxidative stress occurs when a large amount of oxidants exceeds the capacity of the antioxidant defense system. Oxidative stress is considered a contributory factor to the aging process and the pathogenesis of various skin diseases, including cancer. Several current studies seek to identify new natural compounds with properties that mitigate the harmful effects of ROS, thereby acting as blockers or suppressors of the carcinogenesis process. This review briefly presents the relationship between ultraviolet radiation, ROS, and skin damage; and summarizes the in vitro and in vivo experimental evidence of the chemopreventive effect on skin cancer of phenolic compounds from blueberries (Vaccinium spp). Although several studies addressed the topic of bioactive compounds and their activities as possible anticancer agents, none have focused on the antioxidative action and antiproliferative effects on skin cancer of phenolic compounds derived from blueberries.

A novel amphibian-derived peptide alleviated ultraviolet B-induced photodamage in mice

Although the application potential of amphibian skin-derived active peptides in alleviating ultraviolet B (UVB)-induced damage has attracted increasing attention, research remains in its infancy. In this study, a new peptide (OM-GL15, GLLSGHYGRASPVAC) was identified from the skin of the green odorous frog (Odorrana margaretae). Results showed that OM-GL15 scavenged free radicals (2,2'-diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid and 1,1-diphenyl-2-trinitrophenylhydrazine) and reduced Fe³⁺ to Fe²⁺. Moreover, topical administration of OM-GL15 significantly alleviated UVB-induced skin photodamage in mice. Exploration of the underlying mechanisms further showed that OM-GL15 exerted antioxidant potency. Specifically, the peptide reduced the levels of lipid peroxidation and malondialdehyde and protected epidermal cells from UVB-induced apoptosis by inhibiting DNA damage via down-regulation of p53, caspase-3, caspase-9, and Bax and up-regulation of Bcl-2. Our results highlight the potential application of amphibian skin-derived peptides in protection against UVB-induced photodamage and provide a novel peptide candidate for the development of anti-photodamage agents.

The Cutaneous Physiological Redox: Essential to Maintain but Difficult to Define

Skin is a unique tissue, possessing extremely efficient protective and regulative mechanisms, similar only to the gut and lungs. These tissues serve as an interface with the environment and are exposed to stressors from both endogenous and exogenous sources. Interestingly, all these stressors lead downstream to a cellular production of reactive oxygen species (ROS) and other electrophiles, which, in turn could have deleterious outcomes for the living organism. Hence, such tissues should always maintain a “high-alert” condition in order to cope with these various insults. Nevertheless, a moderate production of ROS induced by stressors could actually be beneficial, although it is impossible to predict if and which exposure would lead to which outcome. Consequently, a parameter which would indicate the skin’s readiness to cope with continuously fluctuating conditions is required. It has been proposed that the redox status may serve as a suitable indicator. In this opinion manuscript, we argue that the redox status is a vague parameter that is difficult to characterized and quantify due to its extremely dynamic nature. The common convention that the redox status is composed solely of the balance between oxidants and reductants (ROS and antioxidants) is also thought-provoking. Since this parameter in vivo behaves in a dynamic and complex manner, it better fits the description of a process, rather than an individual parameter. We suggest that the homeostatic modulation of the physiological redox (PR) should be in focus, rather than the redox status parameter itself. It is further suggested that low molecular weight antioxidants (LMWA) are, in fact, rather insignificant concerning the PR maintenance, and that the major contributors to this delicate modulation are regulative, protein-based systems such as the protective phase II antioxidant enzymes. Moreover, we show that skin microbiome and cutaneous advanced lipid peroxidation end-products (ALEs) take part in sustaining the cutaneous PR homoeostasis via activation of the Nrf2–Keap1 protective pathway.

Reductive stress in striated muscle cells

Reductive stress is defined as a condition of sustained increase in cellular glutathione/glutathione disulfide and NADH/NAD+ ratios. Reductive stress is emerging as an important pathophysiological event in several diseased states, being as detrimental as is oxidative stress. Occurrence of reductive stress has been documented in several cardiomyopathies and is an important pathophysiological factor particularly in coronary artery disease and myocardial infarction. Excess activation of the transcription factor, Nrf2-the master regulator of the antioxidant response-, consequent in most cases to defective autophagy, can lead to reductive stress. In addition, hyperglycemia-induced activation of the polyol pathway can lead to increased NADH/NAD+ ratio, which might translate into increased levels of hydrogen sulfide-via enhanced activity of cystathionine β-synthase-that would fuel reductive stress through inhibition of mitochondrial complex I. Reductive stress may be either a potential weapon against cancer priming tumor cells to apoptosis or a cancer's ally promoting tumor cell proliferation and making tumor cells resistant to reactive oxygen species-inducing drugs. In non-cancer pathological states reductive stress is definitely harmful paradoxically leading to reactive oxygen species overproduction via excess NADPH oxidase 4 activity. In face of the documented occurrence of reductive stress in several heart diseases, there is much less information about the occurrence and effects of reductive stress in skeletal muscle tissue. In the present review we describe relevant results emerged from studies of reductive stress in the heart and review skeletal muscle conditions in which reductive stress has been experimentally documented and those in which reductive stress might have an as yet unrecognized pathophysiological role. Establishing whether reductive stress has a (patho)physiological role in skeletal muscle will hopefully contribute to answer the question whether antioxidant supplementation to the general population, athletes, and a large cohort of patients (e.g. heart, sarcopenic, dystrophic, myopathic, cancer, and bronco-pulmonary patients) is harmless or detrimental.

Microalgae as Potential Anti-Inflammatory Natural Product Against Human Inflammatory Skin Diseases

The skin is the first line of defense against pathogen and other environmental pollutant. The body is constantly exposed to reactive oxygen species (ROS) that stimulates inflammatory process in the skin. Many studies have linked ROS to various inflammatory skin diseases. Patients with skin diseases face various challenges with inefficient and inappropriate treatment in managing skin diseases. Overproduction of ROS in the body will result in oxidative stress which will lead to various cellular damage and alter normal cell function. Multiple signaling pathways are seen to have significant effects during ROS-mediated oxidative stress. In this review, microalgae have been selected as a source of natural-derived antioxidant to combat inflammatory skin diseases that are prominent in today’s society. Several studies have demonstrated that bioactive compounds isolated from microalgae have anti-inflammation and anti-oxidative properties that can help remedy various skin diseases. These compounds are able to inhibit production of pro-inflammatory cytokines and reduce the expression of inflammatory genes. Bioactive compounds from microalgae work in action by altering enzyme activities, regulating cellular activities, targeting major signaling pathways related to inflammation.

Saturated and aromatic aldehydes originating from skin and cutaneous bacteria activate the Nrf2-keap1 pathway in human keratinocytes

Skin homeostasis is constantly challenged by environmental factors, affecting its delicate redox balance. The skin is also home to a wide variety of bacterial species, including Staphylococci. The cutaneous redox state is governed by the Nrf2-keap1 pathway, which is responsible for the induction of phase II cytoprotective enzymes, thus sustaining a healthy oxidative state. As part of normal metabolism, both bacteria and cutaneous tissue emit copious amounts of volatile organic compounds (VOCs), one subgroup of which are aldehydes. α,β-unsaturated aldehydes are known activators of Nrf2-keap1 pathway by direct oxidation of the keap1 protein. However, we did not encounter reports of Nrf2 activation by saturated or aromatic aldehydes, neither bacteria nor skin-derived. We hypothesized that non-α,β-unsaturated aldehydes derived from skin or cutaneous bacteria may act as Nrf2-keap1 pathway activators and therefore afford protection against environmental insults. The saturated aldehydes nonanal and decanal (known skin metabolites) and the aromatic aldehyde benzaldehyde (known skin and Staphylococcus epidermidis metabolite) were shown to induce the Nrf2-keap1 pathway in human keratinocytes. We also identified a newly described aromatic aldehyde, 3-furaldehyde (3-FA), emitted from S. aureus and S. epidermidis cultures, which also activated the pathway. Moreover, Nrf2-keap1 induction led to a significant protection against UVB-induced apoptosis. The mechanism involved in this activation has been partially elucidated. This work emphasizes the importance of cutaneous bacteria, as well as healthy skin lipid peroxidation processes in the maintenance and regulation of the cellular antioxidant response, namely with regard to coping with environmental stressors.

Simultaneous nanoencapsulation of lipoic acid and resveratrol with improved antioxidant properties for the skin

Cutaneous aging is intimately related to redox imbalance, which is mainly caused by ultraviolet radiation exposure. The aim of the present investigation was to develop lipid-core nanocapsules for the co-nanoencapsulation of resveratrol and lipoic acid aiming to improve the chemical stability and photostability of the compounds, as well as their antioxidant properties. Lipid-core nanocapsules were developed and characterized according to their mean size, size distribution, zeta potential, pH value, drug content, encapsulation efficiency, release profile, stability under storage, photostability and skin permeation profile. In vitro antioxidant activity was analyzed by lipid peroxidation method and the in vitro cytotoxicity by MTT assay and cellular count, using BALB/c-3T3 fibroblasts. It was possible to co-nanoencapsulate resveratrol and lipoic acid into particles of average diameter close to 200 nm, low polydispersity index and encapsulation efficiencies around 90 %. Nanoencapsulation increased the substances stability under storage and photostability under UVA light exposure, besides controlling substances release. The actives were able to permeate a skin model membrane when nanoencapsulated, with a faster permeation of lipoic acid. The antioxidant activity was potentiated by the co-nanoencapsulation of resveratrol and lipoic acid, without signs of cytotoxicity to fibroblasts. Therefore, the co-nanoencapsulation of resveratrol and lipoic acid is promising for application in topical formulations aiming antioxidant effects.

Composition-Engineered Metal-Organic Framework-Based Microneedles for Glucose-Mediated Transdermal Insulin Delivery

Elaborately designed glucose-responsive insulin-delivery systems are highly desirable for the treatment of diabetes because it can secrete insulin depending on blood glucose levels. Herein, mimic multi-enzyme metal-organic framework (MOF)-based (insulin and glucose oxidase-loaded cobalt-doped ZIF-8, abbreviated as Ins/GOx@Co-ZIF-8) stimuli-responsive microneedles (MNs) were designed for painless glucose-mediated transdermal administration. In this work, GOx and Co²⁺ ions were engineered into MOFs to construct a mimic multi-enzyme vehicle. GOx in the MOF, as the glucose-responsive factor, could catalyze glucose into gluconic acid with the formation of H₂O₂ as the byproduct. The gluconic acid formed decreases the local pH in MOFs, resulting in the degradation of MOFs and thus preloaded insulin would be released. Meanwhile, catalyzed by Co²⁺ ions in the MOF, the byproduct H₂O₂ was decomposed. Possible free Co²⁺ ions would be chelated by EDTA-SiO₂ nanoparticles in MNs and removed by peeling MNs off. The as-obtained mimic multi-enzyme MOF-based MNs showed good dependence on glucose concentration without divulging H₂O₂ and Co²⁺ ions and enough stiffness to penetrate into skin. This study offers a new strategy, using facilely synthesized MOFs as depots to integrate with MNs, for designing stimuli-responsive transdermal drug-delivery systems.

Advances in dermatology using DNA aptamer "Aptamin C" innovation: Oxidative stress prevention and effect maximization of vitamin C through antioxidation

BACKGROUND

Vitamin C (also known as L-ascorbic acid) plays a critical role in reactive oxygen species (ROS) reduction and cell regeneration by protecting cell from oxidative stress. Although vitamin C is widely used in cosmetic and therapeutic markets, there is considerable evidence that vitamin C easily undergoes oxidation by air, pH, temperature, and UV light upon storage. This deficiency of vitamin C decreases its potency as an antioxidant and reduces the shelf-life of products containing vitamin C as its ingredient. To overcome the deficiency of vitamin C, we have developed Aptamin C, an innovative DNA aptamer maximizing the antioxidant efficacy of vitamin C by binding to the reduced form of vitamin C and delaying its oxidation.

METHODS

Binding of Aptamin C with vitamin C was determined using ITC analysis. ITC experiment was performed 0.2 mmol/L vitamin C that was injected 25 times in 2 µL aliquots into the 1.8 mL sample cell containing the Aptamin C at a concentration of 0.02 mmol/L. The data were fitted to a one-site binding isotherm using with origin program for ITC v.5.0.

RESULTS

To investigate the effect of Aptamin C and vitamin C complex in human skins, both in vitro and clinical tests were performed. We observed that the complex of Aptamin C and vitamin C was significantly effective in wrinkle improvement, whitening effect, and hydration increase. In the clinical test, subjects treated with the complex showed dramatic improvement in skin irritation and itching. No adverse reaction was presented by Aptamin C complex in the test.

CONCLUSION

Taken together, these results showed that Aptamin C, an innovative novel compound, should potentially be served as a key cosmeceutical ingredient for a range of skin conditions.

Disposable Potentiometric Sensory System for Skin Antioxidant Activity Evaluation

The skin is a natural barrier between the external and internal environment. Its protective functions and the relationship of its state with the state of health of the organism as a whole are very important. It is known that oxidant stress (OS) is a common indicator of health status. This paper describes a new sensory system for monitoring OS of the skin using antioxidant activity (AOA) as its criteria. The contact hybrid potentiometric method (CHPM) and new electrochemical measuring scheme were used. A new sensory system, including disposable modified screen-printed carbon and silver electrodes covered by membrane impregnated by mediator, was developed. Its informative ability was demonstrated in the evaluation of the impact of fasting, consumption of food and food enriched by vitamins (antioxidants) on skin AOA. This device consisting of a sensory system and potentiometric analyzer can be used in on-site and in situ formats.

Stimulus Sensitive Smart Nanoplatforms: An Emerging Paradigm for the Treatment of Skin Diseases

Background:

Over the past century, the prevalence of skin diseases has substantially increased. These diseases present a significant physical, emotional and socio-economic burden to the society. Such conditions are also associated with a multitude of psychological traumas to the suffering patients. The effective treatment strategy implicates targeting of drugs to the skin. The field of drug targeting has been revolutionized with the advent of nanotechnology. The emergence of stimulus-responsive nanoplatforms has provided remarkable control over fundamental polymer properties for external triggers. This enhanced control has empowered pioneering approaches in the treatment of chronic inflammatory skin diseases.

Objective:

Our aim was to investigate the studies on smart nanoplatforms that exploit the altered skin physiology under diseased conditions and provide site-specific controlled drug delivery.

Method:

All literature search regarding the advances in stimulus sensitive smart nanoplatforms for skin diseases was done using Google Scholar and Pubmed.

Conclusion:

Various stimuli explored lately for such nano platforms are pH, temperature, light and magnet. Although, the scientists have actively taken up this research topic but there are still certain lacunaes associated which have been discussed in this review. Further, an interdisciplinary collaboration between the healthcare providers and pharmacists is a pivotal requirement for such systems to be available for patients.

Identification and Characterization of a Novel Gene-encoded Antioxidant Peptide from Odorous Frog Skin

Background:

Amphibian skin plays an essential role in protecting organisms from harmful external factors such as UV radiation. How amphibians protect themselves from reactive oxygen species following long-term sun exposure is an important and interesting question. Amphibian skins possess a novel antioxidant system composed of various Antioxidant Peptides (AOPs), which maintain redox homeostasis. However, only a few AOPs have been identified so far.

Methods:

Using combinational methods of peptidomics and genomics, we characterized a novel gene-encoded antioxidant peptide (herein named OA-VI12) from Odorrana andersonii skin secretions, which was produced by the post-translational processing of a 59-residue prepropeptide. The amino acid sequence of the OA-V112 was 'VIPFLACRPLGL', with a molecular mass of 1298.6 Da and no observed post-transcriptional modifications. Functional analysis demonstrated that OA-VI12 was capable of scavenging ABTS+, DPPH, NO and decreasing the Fe3+ production.

Results:

We determined that the C7 amino acid was responsible for ABTS+ and Fe3+ scavenging, activities, the F4, C7, and P9 amino acids were crucial for DPPH scavenging activity, and the P9 amino acid was responsible for NO scavenging activity. Unlike several other amphibian peptides, OA-VI12 did not accelerate wound healing in a full-thickness skin-wound mouse model and did not demonstrate direct microbial killing. Here, we identified and named a novel gene-encoded antioxidant peptide from the skin secretions of an odorous frog species, which may assist in the development of potential antioxidant candidates.

Conclusion:

This study may help improve our understanding of the molecular basis of amphibians’ adaptation to environments experiencing long-term UV radiation.

Quantification and characterization of radical production in human, animal and 3D skin models during sun irradiation measured by EPR spectroscopy

Sun radiation is indispensable to our health, however, a long term and high exposure could lead to erythema, premature skin aging and promotion of skin tumors. An underlying pathomechanism is the formation of free radicals. First, reactive oxygen species (*OH, *O₂^-) and then, secondary lipid oxygen species (C centered radicals, CCR) are formed. A high amount of free radicals results in oxidative stress with subsequent cell damage. In dermatological research different skin models are used, however, comparative data about the cutaneous radical formation are missing. In this study, the radical formation in porcine-, (SKH-1) murine-, human- ex vivo skin and reconstructed human skin (RHS) were investigated during simulated sun irradiation (305-2200 nm), with X-band EPR spectroscopy. The amount of radical formation was investigated with the spin probe PCA exposed to a moderate sun dose below one minimal erythema dose (MED, ~25 mJ/cm² UVB) in all skin models. Furthermore, the *OH and *CCR radical concentrations were measured with the spin trap DMPO within 0-4 MED (porcine-, human skin and RHS). The highest amount of radicals was found in RHS followed by murine and porcine, and the lowest amount in human ex vivo skin. In all skin models, more *OH than CCR radicals were found at 0-4 MED. Additionally, this work addresses the limitations in the characterization with the spin trap DMPO. The measurements have shown that the most comparable skin model to in vivo human skin could differ depending on the focus of the investigation. If the amount of radial production is regarded, RHS seems to be in a similar range like in vivo human skin. If the investigation is focused on the radical type, porcine skin is most comparable to ex vivo human skin, at an irradiation dose not exceeding 1 MED. Here, no comparison to in vivo human skin is possible.

Local arginase inhibition does not modulate cutaneous vasodilation or sweating in young and older men during exercise

Age-related impairments in cutaneous vascular conductance (CVC) and sweat rate (SR) during exercise may result from increased arginase activity, which can attenuate endogenous nitric oxide (NO) production. We therefore evaluated whether arginase inhibition modulates these heat-loss responses in young (n = 9, 23 ± 3 yr) and older (n = 9, 66 ± 6 yr) men during two 30-min bouts of moderate-intensity cycling (Ex1 and Ex2) in the heat (35°C). CVC and SR were measured at forearm skin sites perfused with 1) lactated Ringer's (control), 2) N^G-nitro-_L-arginine methyl ester (L-NAME; NO synthase-inhibited), or 3) N^ω-hydroxy-nor-arginine and S-(2-boronoethyl)-l-cysteine (Nor-NOHA + BEC; arginase-inhibited). In both groups, CVC was reduced at L-NAME relative to control and Nor-NOHA + BEC (both P < 0.01). Likewise, SR was attenuated with L-NAME compared with control and Nor-NOHA + BEC during each exercise bout in the young men (all P ≤ 0.05); however, no influence of treatment on SR in the older men was observed (P = 0.14). Based on these findings, we then evaluated responses in 7 older men (64 ± 7 yr) during passively induced elevations in esophageal temperature (∆T_es) equal to those in Ex1 (0.6°C) and Ex2 (0.8°C). L-NAME reduced CVC by 18 ± 20% CVC_max at a ∆T_es of 0.8°C (P = 0.03) compared with control, whereas Nor-NOHA + BEC augmented CVC by 20 ± 18% CVC_max, on average, throughout heating (both P ≤ 0.03). SR was not influenced by either treatment (P = 0.80) Thus, arginase inhibition does not modulate CVC or SR during exercise in the heat but, consistent with previous findings, does augment CVC in older men during passive heating. NEW & NOTEWORTHY In the current study, we demonstrate that local arginase inhibition does not influence forearm cutaneous vasodilatory and sweating responses in young or older men during exercise-heat stress. Consistent with previous findings, however, we observed augmented cutaneous blood flow with arginase inhibition during whole-body passive heat stress. Thus, arginase differentially affects cutaneous vasodilation depending on the mode of heat stress but does not influence sweating during exercise or passive heating.

Mechanisms of and variables affecting UVR photoadaptation in human skin

Humans have been exposed to solar UV radiation since their appearance on Earth and evolution has enabled most individuals to adapt to this exposure, to some degree. UV radiation produces several deleterious effects in human skin and light-skinned individuals are at greatest risk for both acute and long-term negative effects such as DNA damage, sunburn, immune suppression and skin cancer. The benefits of photoadaptation, which leads to a decreased response after acclimatization, are that humans who have skin that is capable of photoadaptation can work and play in the sun with reduced fear of painful sunburn. However, the effects of photoadaptation on DNA damage and development of skin cancer are quite complex and less well-understood. In this article, we have reviewed the current state of knowledge of UVR photoadaptation in human skin. However, more studies are needed to explore the use of UVR photoadaptation to protect against critical endpoints, such as skin cancer.

Can Light Emitted from Smartphone Screens and Taking Selfies Cause Premature Aging and Wrinkles?

Since the early days of human life on the Earth, our skin has been exposed to different levels of light. Recently, due to inevitable consequences of modern life, humans are not exposed to adequate levels of natural light during the day but they are overexposed to relatively high levels of artificial light at night. Skin is a major target of oxidative stress and the link between aging and oxidative stress is well documented. Especially, extrinsic skin aging can be caused by oxidative stress. The widespread use of light emitting diodes (LEDs) and the rapidly increasing use of smartphones, tablets, laptops and desktop computers have led to a significant rise in the exposure of human eyes to short-wavelength visible light. Recent studies show that exposure of human skin cells to light emitted from electronic devices, even for exposures as short as 1 hour, may cause reactive oxygen species (ROS) generation, apoptosis, and necrosis. The biological effects of exposure to short-wavelength visible light in blue region in humans and other living organisms were among our research priorities at the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC). Today, there is a growing concern over the safety of the light sources such as LEDs with peak emissions in the blue light range (400-490 nm). Recent studies aimed at investigating the effect of exposure to light emitted from electronic device on human skin cells, shows that even short exposures can increase the generation of reactive oxygen species. However, the biological effects of either long-term or repeated exposures are not fully known, yet. Furthermore, there are reports indicating that frequent exposure to visible light spectrum of the selfie flashes may cause skin damage and accelerated skin ageing. In this paper we have addressed the different aspects of potential effects of exposure to the light emitted from smartphones' digital screens as well as smartphones' photoflashes on premature aging of the human skin. Specifically, the effects of blue light on eyes and skin are discussed. Based on current knowledge, it can be suggested that changing the spectral output of LED-based smartphones' flashes can be introduced as an effective method to reduce the adverse health effects associated with exposure to blue light.

Identification and characterization of a novel gene-encoded antioxidant peptide obtained from amphibian skin secretions

Amphibian skin is known to secrete gene-encoded antioxidant peptides of small molecular weight, which play important roles in host defense. However, recognition of such peptides is still in its infancy. Here, we discovered a novel gene-encoded antioxidant peptide (named OM-GF17) from skin secretions of amphibian species, Odorrana margaretae. Produced by the post-translational processing of a 61-residue prepropeptide, the amino acid sequence of OM-GF17 was 'GFFKWHPRCGEEHSMWT', with a molecular mass of 2135.7 Da. Functional analysis revealed that OM-GF17 scavenged ABTS⁺, DPPH, NO and decreased iron oxidation. Our results also implied that five amino acid residues, including Cys, Pro, Met, Trp, and Phe, be related to the antioxidant activity of OM-GF17. Furthermore, OM-GF17 did not exhibit direct microbe-killing activity. This novel gene-encoded antioxidant peptide could help in the development of new antioxidant agents and increase our understanding of the biological functions of amphibian skin. [Formula: see text].

Black soybeans protect human keratinocytes from oxidative stress-induced cell death

Black soybeans are functional foods containing a variety of bioactives such as isoflavones, carotenoids, tocopherols, phenolic acid as well as anthocyanins. Here, we examined whether Cheongja#3 black soybean extract has a protective effect on oxidative stress-induced cell death in human keratinocytes HaCaT. First, we identified fat-soluble bioactives in three varieties of soybean extracts (Saedanbaek, Daechan, and Cheongja#3). In particular, black soybean Cheongja#3 had high amounts of lutein than other varieties. We demonstrated that Cheongja#3 extract reduced intracellular reactive oxygen species levels in HaCaT cells. Furthermore, Cheongja#3 protected cells from hydrogen peroxide (H2O2)-induced oxidative stress and triggered cell death determined by cell viabilities and apoptotic caspase activities. Next, we identified the underlying mechanism is due to increased Nrf2 antioxidant system by Cheongja#3, thus increasing the expression of heme oxygenases (HO)-1. These results indicated that Cheongja#3 soybean extract has protective role against oxidative stress by upregulating the Nrf-2 antioxidant system in human keratinocyte HaCaT cells.

Evaluation of Gamma Radiation-Induced Biochemical Changes in Skin for Dose Assesment: A Study on Small Experimental Animals

OBJECTIVE

Researchers have been evaluating several approaches to assess acute radiation injury/toxicity markers owing to radiation exposure. Keeping in mind this background, we assumed that whole-body irradiation in single fraction in graded doses can affect the antioxidant profile in skin that could be used as an acute radiation injury/toxicity marker.

METHODS

Sprague-Dawley rats were treated with CO-60 gamma radiation (dose: 1-5 Gy; dose rate: 0.85 Gy/minute). Skin samples were collected (before and after radiation up to 72 hours) and analyzed for glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (LPx).

RESULTS

Intra-group comparison showed significant differences in GSH, GPx, SOD, and CAT, and they declined in a dose-dependent manner from 1 to 5 Gy (P value0.05).

CONCLUSIONS

This study suggests that skin antioxidants were sensitive toward radiation even at a low radiation dose, which can be used as a predictor of radiation injury and altered in a dose-dependent manner. These biochemical parameters may have wider application in the evaluation of radiation-induced skin injury and dose assessment. (Disaster Med Public Health Preparedness. 2019;13:197-202).

Safety and Antioxidant Efficacy Profiles of Rutin-Loaded Ethosomes for Topical Application

Topical application of dermocosmetics containing antioxidant and/or the intake of antioxidants through diet or supplementation are remarkable tools in an attempt to slow down some of the harmful effects of free radicals. Rutin is a strong antioxidant compound used in food and pharmaceutical industries. It was established that rutin presents a low skin permeation rate, a property that could be considered an inconvenience to the satisfactory action for a dermocosmetic formulation to perform its antioxidant activity onto the skin. Therefore, it is indispensable to improve its delivery, aiming at increasing its antioxidant capacity in deeper layers of the epidermis, being a possibility to associate the rutin to liposomal vesicles, such as ethosomes. Thus, in this work, the pre-clinical safety of rutin-loaded ethosomes was investigated employing an in vitro method, and the clinical safety and efficacy were also assessed. Rutin-loaded ethosomes were efficaciously obtained in a nanoscale dimension with a relevant bioactive compound loading (80.2%) and provided antioxidant in vitro activity in comparison with the blank sample. Pre-clinical and clinical safety assays assured the innocuous profile of the rutin-loaded ethosomes. The ethosomes containing the bioactive compound accomplished a more functional delivery system profile, since in the tape stripping assay, the deeper layers presented higher rutin amounts than the active delivered in its free state. However, the ex vivo antioxidant efficacy test detected no positive antioxidant activity from the rutin-loaded ethosomes, even though the in vitro assay demonstrated an affirmative antioxidant action.

Orthogonal Array composite design to study and optimize antioxidant combinations in the prevention of UVB-induced HSF damage

Excessive exposure to ultraviolet (UV) B radiation may lead to skin damage, photosensitivity, or even tumorigenesis via induction of oxidative stress. Naturally derived antioxidants could play significant roles in cancer therapy due to their multi-targeted actions and lack of substantial toxicity. Drug combinations target at diverse pathway of cells and make cells export meticulous biological outcomes through the multifaceted signaling network. The UVB protective effects of combinations of naturally derived antioxidants- curcumin, resveratrol, proanthocyanidins, baicalein, and beta-nicotinamide adenine dinucleotide (NADH) were investigated. An oxidative cell damage model was established to study the ultraviolet irradiation system. An orthogonal array composite design (OACD) was employed in the optimization of antioxidants combinations. Combination of resveratrol (0.1μM) and baicalein in medium concentration (0.2μM), with NADH in high concentration (0.8μM) was found to be the most efficacious combination among all the 30 runs performed using OACD. The findings suggested that UVB exposure-inflicted cell apoptosis can be significantly reduced by naturally-derived antioxidant combinations. These results provide an insight into the discovery of synergistic antioxidant combinations in skin cancer, using orthogonal array composite design (OACD). The results also have practical implications in the understanding of drug mechanisms in skin cancer, which can assist clinical practice by recommending better drug combinations.

Mechanisms underlying the wound healing potential of propolis based on its in vitro antioxidant activity

BACKGROUND

Propolis is a resinous substance collected by honeybees, Apis mellifera, from various plant sources. Having various pharmacological and biological activities, it has been used in folk medicine and complementary therapies since ancient times.

PURPOSE

To evaluate the effects and underlying mechanism of the protective effects of the ethanol extract of Chinese propolis (EECP) on L929 cells injured by hydrogen peroxide (H₂O₂).

STUDY DESIGN

The wound healing activities of EECP in L929 cells with H₂O₂-induced damage were investigated.

METHODS

The main components of EECP were analyzed by RP-HPLC, and the free radical scavenging capacity and reducing power were also measured. The effects of EECP on the expression of antioxidant-related genes in fibroblast L929 cells were determined using qRT-PCR and western blotting.

RESULTS

EECP had significant protective effects against cell death induced by H₂O₂ and significantly inhibited the decline of collagen mRNA expression caused by H₂O₂ in L929 cells.

CONCLUSION

EECP induced the expression of antioxidant-related genes, such as HO-1, GCLM, and GCLC, which has great implications for the potential of propolis to alleviate oxidative stress in wound tissues. The protective effects of propolis have great implications for using propolis as a wound healing regent.

Can regenerative medicine and nanotechnology combine to heal wounds? The search for the ideal wound dressing

Skin is the outermost covering of the human body and at the same time the largest organ comprising 15% of body weight and 2 m2 surface area. Skin plays a key role as a barrier against the outer environment depending on its thickness, color and structure, which differ from one site to another. The four major types of problematic wounds include ulcers (diabetic, venous, pressure) and burn wounds. Developing novel dressings helps us to improve the wound healing process in difficult patients. Recent advances in regenerative medicine and nanotechnology are revolutionizing the field of wound healing. Antimicrobial activity, exogenous cell therapy, growth factor delivery, biodegradable and biocompatible matrix construction, all play a role in hi-tech dressing design. In the present review, we discuss how the principles of regenerative medicine and nanotechnology can be combined in innovative wound dressings.

Gallic Acid-Loaded Gel Formulation Combats Skin Oxidative Stress: Development, Characterization and Ex Vivo Biological Assays

Oxidative stress, which is a result of overproduction and accumulation of free radicals, is the main cause of several skin degenerative diseases, such as aging. Polyphenols, such as gallic acid, are an important class of naturally occurring antioxidants. They have emerged as strong antioxidants that can be used as active cosmetics. The purpose of this study was to develop a gallic acid-loaded cosmetic gel formulation and characterize it using rheological, mechanical, and bioadhesive tests. Its antioxidant effect in the stratum corneum was evaluated by a non-invasive method. According to the characterization tests, the formulation exhibited skin adhesiveness and pseudoplastic behavior without thixotropy, rendering it suitable for use as a cosmetic formulation. Furthermore, the non-invasive method indicated the antioxidant effect in the stratum corneum, with the global lipid peroxide reduction being 33.97 ± 11.66%. Thus, we were able to develop a promising gallic acid-loaded gel formulation that could reduce lipid peroxides and thus combat skin oxidative stress.