Effective Photoprotection of Human Skin against Infrared A Radiation by Topically Applied Antioxidants: Results from a Vehicle Controlled, Double-Blind, Randomized Study

Evaluation of an advanced antioxidant and double-conjugated retinoid/AHA cream in participants with FST IV-V

BACKGROUND

Topical antioxidants and retinoids are foundational components of an effective skincare regimen. Pyrroloquinoline quinone (PQQ) is a potent free radical scavenger that supports efficient mitochondrial energy creation. An advanced antioxidant combines topical allyl PQQ with existing WEL antioxidant technology (TAP) to comprehensively address extrinsic and intrinsic skin aging. In conjunction with TAP, a double-conjugated retinoid/alpha hydroxy acid (AHA-Ret) designed to minimize irritation and optimize delivery was used over 12 weeks to improve the appearance of photodamaged skin.

PATIENTS/METHODS

Twice-daily application of TAP and nightly application of AHA-Ret was evaluated in female participants aged 40-65 years with FST IV-V and mild (3) to moderate (6) facial photodamage using a 10-point grading scale. Visible improvements from baseline in lines/wrinkles, skin texture, skin tone, skin dullness and erythema were assessed using a six-point grading scale (0 = None to 5 = Severe). Adverse Events (AEs) were captured throughout the study period.

RESULTS

Participants (N = 21; mean age, 56 years) equally represented mild and moderate photodamage, and FST IV and V (41%, Hispanic; 36%, African American; and 32%, Caucasian). Significant mean improvements from baseline occurred in skin dullness, skin texture, and skin tone (all, p < 0.0001), and significant mean reductions from baseline were demonstrated in erythema and melanin at Week 12. Mild, transient AEs were reported. No participant discontinued study participation due to an AE.

CONCLUSIONS

A skincare regimen comprised of an advanced antioxidant and AHA-Ret cream, in conjunction with daily use of a broad-spectrum sunscreen (SPF 56), led to significant improvements at 12 weeks in the appearance of photodamaged skin in females with FST IV and V.

Awareness of sun exposure risks and photoprotection for preventing pigmentary disorders in Asian populations: Survey results from three Asian countries and expert panel recommendations

BACKGROUND

In this article, we review and discuss the photoprotection behavior of Asians based on the literature, along with a subanalysis of an original online survey, and make recommendations to optimize photoprotection for Asian populations to prevent photoaging and pigmentary disorders.

METHODS

An international panel of eight dermatologists from Asia (China, Korea, Japan, Singapore, Indonesia, and Vietnam) met to discuss sunscreen photoprotection for Asian patients. Additionally, a subanalysis of an online survey by 3000 respondents from three Asian countries (China, Indonesia, and Japan) investigated general public awareness and attitudes to sun exposure.

RESULTS

A pre-meeting survey of the eight experts from Asia showed key concerns of Asian patients consulting dermatologists are pigmentary disorders, especially actinic/senile lentigo, post-inflammatory hyperpigmentation, melasma, vitiligo, and Hori's nevus. The survey subanalysis of participants from China, Indonesia, and Japan with predominantly Fitzpatrick skin types (FST) II to IV revealed that they are particularly concerned about sun exposure causing photoaging and pigmentary disorders. Most of the respondents indicated they have limited knowledge on sunlight radiation and appropriate sunscreen protection factors. Only 22%, 13%, and 3% for China, Indonesia, and Japan, respectively, systematically use multiple protective measures (using sunscreen, avoiding midday sun, staying in the shade, wearing a hat, protective clothing, and sunglasses) when exposed to the sun.

CONCLUSIONS

Further education is needed for Asian populations on the importance of comprehensive daily photoprotection, including broad-spectrum sunscreen, with high UVA and visible light protection, to reduce and prevent photoaging and pigmentary disorders.

The effects of infrared radiation on the human skin

BACKGROUND

Infrared radiation (IR) is the portion of the electromagnetic spectrum between visible light (VL) and microwaves, with wavelengths between 700 nm and 1 mm. Humans are mainly exposed to ultraviolet (UV) radiation (UVR) and IR through the sun. Unlike UVR which is well known for its carcinogenic properties, the relationship between IR and skin health has not been as extensively studied; as such, we gather the available published evidence here to better elucidate this relationship.

METHODS

Several databases including Pubmed, Google Scholar, and Embase were searched for articles relating to infrared radiation and the skin. Articles were selected for their relevance and novelty.

RESULTS

Detrimental effects such as thermal burns, photocarcinogenesis, and photoaging have been reported, though evidence suggests that these may be due to the thermal effects produced secondary to IR exposure rather than the isolated effect of IR. There are currently no chemical or physical filters specifically available for protection against IR, and existing compounds are not known to have IR-filtering capacity. Interestingly, IR may have some photoprotective properties against the carcinogenic effects of UVR. Furthermore, IR has been used with encouraging results in skin rejuvenation, wound healing, and hair restoration when given at an appropriate therapeutic dose.

CONCLUSION

A better understanding of the current landscape of research surrounding IR can help illuminate its effects on the skin and highlight areas for further research. Here, we review relevant data on IR to assess its deleterious and beneficial effects on human skin, along with possible means for IR photoprotection.

Environmental Air Pollutants Affecting Skin Functions with Systemic Implications

The increase in air pollution worldwide represents an environmental risk factor that has global implications for the health of humans worldwide. The skin of billions of people is exposed to a mixture of harmful air pollutants, which can affect its physiology and are responsible for cutaneous damage. Some polycyclic aromatic hydrocarbons are photoreactive and could be activated by ultraviolet radiation (UVR). Therefore, such UVR exposure would enhance their deleterious effects on the skin. Air pollution also affects vitamin D synthesis by reducing UVB radiation, which is essential for the production of vitamin D3, tachysterol, and lumisterol derivatives. Ambient air pollutants, photopollution, blue-light pollution, and cigarette smoke compromise cutaneous structural integrity, can interact with human skin microbiota, and trigger or exacerbate a range of skin diseases through various mechanisms. Generally, air pollution elicits an oxidative stress response on the skin that can activate the inflammatory responses. The aryl hydrocarbon receptor (AhR) can act as a sensor for small molecules such as air pollutants and plays a crucial role in responses to (photo)pollution. On the other hand, targeting AhR/Nrf2 is emerging as a novel treatment option for air pollutants that induce or exacerbate inflammatory skin diseases. Therefore, AhR with downstream regulatory pathways would represent a crucial signaling system regulating the skin phenotype in a Yin and Yang fashion defined by the chemical nature of the activating factor and the cellular and tissue context.

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.

New insights and advances on pyomelanin production: from microbial synthesis to applications

Pyomelanin is a brown-black phenolic polymer and results from the oxidation of homogentisic acid (HGA) in the L-tyrosine pathway. As part of the research for natural and active ingredients issued from realistic bioprocesses, this work re-evaluates the HGA pigment and makes an updated inventory of its syntheses, microbial pathways, and properties, with tracks and recent advances for its large-scale production. The mechanism of the HGA polymerization is also well documented. In alkaptonuria, pyomelanin formation leads to connective tissue damages and arthritis, most probably due to the ROS issued from HGA oxidation. While UV radiation on human melanin may generate degradation products, pyomelanin is not photodegradable, is hyperthermostable, and has other properties better than the L-Dopa melanin. This review aims to raise awareness about the potential of this pigment for various applications, not only for skin coloring and protection but also for other cells, materials, and as a promising (semi)conductor for bioelectronics and energy.

[Sunscreens of the future: challenges and opportunities]

Sunscreens provide excellent protection against erythema and against chronic damage such as photoaging and skin cancer. Today's challenges concern safety of the products and improved methods for standardizing the evaluation of their efficacy. Other important topics are the further development of sunscreen products, as well as personalization of use. Personalized sun protection based on the phenotype, the genetic profiles and moreover the skin's microbiome - all linked to the identification of certain consumer susceptibility factors - is an exciting new area of research. In particular, the expansion with innovative topical agents such as DNA repair liposomes in improved galenic formulations with UV filters tailored to the skin phototype and new topical antioxidants could in future provide even more comprehensive sun protection. New antioxidants and other agents such as nicotinamide could increase systemic photoprevention. Sustainability will also be an important aspect to protect consumers, but also the environment (i.e. especially marine wildlife) from toxic effects of sunscreens.

Shedding a New Light on Skin Aging, Iron- and Redox-Homeostasis and Emerging Natural Antioxidants

Reactive oxygen species (ROS) are necessary for normal cell signaling and the antimicrobial defense of the skin. However excess production of ROS can disrupt the cellular redox balance and overwhelm the cellular antioxidant (AO) capacity, leading to oxidative stress. In the skin, oxidative stress plays a key role in driving both extrinsic and intrinsic aging. Sunlight exposure has also been a major contributor to extrinsic photoaging of the skin as its oxidising components disrupt both redox- and iron-homeostasis, promoting oxidative damage to skin cells and tissue constituents. Upon oxidative insults, the interplay between excess accumulation of ROS and redox-active labile iron (LI) and its detrimental consequences to the skin are often overlooked. In this review we have revisited the oxidative mechanisms underlying skin damage and aging by focussing on the concerted action of ROS and redox-active LI in the initiation and progression of intrinsic and extrinsic skin aging processes. Based on these, we propose to redefine the selection criteria for skin antiaging and photoprotective ingredients to include natural antioxidants (AOs) exhibiting robust redox-balancing and/or iron-chelating properties. This would promote the concept of natural-based or bio-inspired bifunctional anti-aging and photoprotective ingredients for skincare and sunscreen formulations with both AO and iron-chelating properties.

Encapsulated Activated Grape Seed Extract: A Novel Formulation with Anti-Aging, Skin-Brightening, and Hydration Properties

Protein phosphatase 2A (PP2A) is a master regulatory protein that plays a critical role in oxidative stress signaling. A novel, proprietary grape seed extract called Activated Grape Seed Extract (AGSE), enriched for PP2A-activating flavonoids, was recently developed and demonstrated to have antioxidant and anti-inflammatory activities. AGSE is a purple-colored powder, with limited solubility restricting its use in a broad range of formulations. Our aim was to develop a formulation that reduced the color and increased the solubility of AGSE, allowing its skin-health-enhancing properties to be utilized in a wider array of products, and to test it clinically. Encapsulation was performed utilizing a liposome and hydroxypropyl-β-cyclodextrin, (HPCD)-based approach to produce Encapsulated AGSE (E-AGSE). Human dermal fibroblasts and epidermal keratinocytes were used to determine expression levels of aging and dermal–epidermal junction (DEJ) markers. EpiDerm™ was UVB-irradiated to measure the effects against cytokine release, DNA damage, apoptosis, and skin barrier. Human melanocytes were used to determine melanin production and mushroom tyrosinase was used for inhibitory activity. A 4-week, 31-subject sensitive-skin clinical was performed with 2% E-AGSE Essence to assess its activity on human skin. We demonstrated that E-AGSE inhibits PP2A demethylation, increases key anti-aging (collagen I, III, elastin) and DEJ markers, protects against UVB-induced DNA damage, reduces inflammation, and promotes filaggrin in vitro. Moreover, E-AGSE reduces melanin production via tyrosinase inhibition. Clinical assessment of E-AGSE showed that it reduces the appearance of wrinkles, brightens the skin, and boosts hydration. E-AGSE is a novel grape seed extract formulation enriched for PP2A-activating flavonoids that is clinically effective in sensitive skin, providing several benefits.

Clinical and biological impact of the exposome on the skin

The skin exposome is defined as the totality of environmental exposures over the life course that can induce or modify various skin conditions. Here, we review the impact on the skin of solar exposure, air pollution, hormones, nutrition and psychological factors. Photoageing, photocarcinogenesis and pigmentary changes are well-established consequences of chronic exposure of the skin to solar radiation. Exposure to traffic-related air pollution contributes to skin ageing. Particulate matter and nitrogen dioxide cause skin pigmentation/lentigines, while ozone causes wrinkles and has an impact on atopic eczema. Human skin is a major target of hormones, and they exhibit a wide range of biological activities on the skin. Hormones decline with advancing age influencing skin ageing. Nutrition has an impact on numerous biochemical processes, including oxidation, inflammation and glycation, which may result in clinical effects, including modification of the course of skin ageing and photoageing. Stress and lack of sleep are known to contribute to a pro-inflammatory state, which, in turn, affects the integrity of extracellular matrix proteins, in particular collagen. Hormone dysregulation, malnutrition and stress may contribute to inflammatory skin disorders, such as atopic dermatitis, psoriasis, acne and rosacea.

Photoprotection according to skin phototype and dermatoses: practical recommendations from an expert panel

Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin phototype and dermatoses, which is now possible due to advances in the filters and formulations of sunscreens. A selective literature search was performed by an international expert panel, focusing on the type of sunscreen to recommend for photoaging, skin cancers, photodermatoses, pigmentary disorders and skin inflammatory disorders. Protection against ultraviolet (UV)B is especially important for light skin as there is a high risk of sunburn, DNA damage and skin cancers. Darker skin may be naturally better protected against UVB but is more prone to hyperpigmentation induced by visible light (VL) and UVA. Protection against UVA, VL and infrared A can be helpful for all skin phototypes as they penetrate deeply and cause photoaging. Long‐wave UVA1 plays a critical role in pigmentation, photoaging, skin cancer, DNA damage and photodermatoses. Adapting the formulation and texture of the sunscreen to the type of skin and dermatoses is also essential. Practical recommendations on the type of sunscreen to prescribe are provided to support the clinician in daily practice.

Developments and challenges in dermatology: an update from the Interactive Derma Academy (IDeA) 2019

The 2019 Interactive Derma Academy (IDeA) meeting was held in Lisbon, Portugal, 10-12 May, bringing together leading dermatology experts from across Europe, the Middle East and Asia. Over three days, the latest developments and challenges in relation to the pathophysiology, diagnosis, evaluation and management of dermatological conditions were presented, with a particular focus on acne, atopic dermatitis (AD) and actinic keratosis (AK). Interesting clinical case studies relating to these key topics were discussed with attendees to establish current evidence-based best practices. Presentations reviewed current treatments, potential therapeutic approaches and key considerations in the management of acne, AK and AD, and discussed the importance of the microbiome in these conditions, as well as the provision of patient education/support. It was highlighted that active treatment is not always required for AK, depending on patient preferences and clinical circumstances. In addition to presentations, two interactive workshops on the diagnosis and treatment of sexually transmitted infections/diseases (STIs/STDs) presenting to the dermatology clinic, and current and future dermocosmetics were conducted. The potential for misdiagnosis of STIs/STDs was discussed, with dermoscopy and/or reflectance confocal microscopy suggested as useful diagnostic techniques. In addition, botulinum toxin was introduced as a potential dermocosmetic, and the possibility of microbiome alteration in the treatment of dermatological conditions emphasized. Furthermore, several challenges in dermatology, including the use of lasers, the complexity of atopic dermatitis, wound care, use of biosimilars and application of non-invasive techniques in skin cancer diagnosis were reviewed. In this supplement, we provide an overview of the presentations and discussions from the fourth successful IDeA meeting, summarizing the key insights shared by dermatologists from across the globe.

Daily photoprotection to prevent photoaging

BACKGROUND

Extrinsic skin aging or photoaging was previously thought to be almost exclusively due to solar ultraviolet (UV) radiation. However, recent literature has described other contributing factors and clarification is thus required as to what extent and what type of daily photoprotection is needed to mitigate extrinsic skin aging.

METHODS

We reviewed the existing scientific evidence on daily photoprotection, and specific requirements at the product level, to prevent extrinsic skin aging. We critically reviewed the existing evidence on potential ecological and toxicological risks which might be associated with daily photoprotection.

RESULTS

Evidence shows that broad protection against the entire solar range of UVB, UVA, UVA1, visible light, and short infrared (IRA) is required to prevent extrinsic aging. Other exposome factors, such as air pollution and smoking, also contribute to skin aging. Daily broad-spectrum sunscreen photoprotection should thus contain antioxidant ingredients for additional benefits against UV, IRA, and pollution-induced oxidative stress as well as anti-aging active ingredients to provide clinical benefits against skin aging signs, such as wrinkles and dark spots. Broad-spectrum sunscreen containing pigments, such as iron oxide, may be required for melasma prevention. There is no conclusive clinical evidence that daily sunscreen use is unsafe or that it compromises vitamin D synthesis.

CONCLUSION

Daily use of broad-spectrum sunscreen containing antioxidant and anti-aging active ingredients can effectively reduce extrinsic aging.

[Sun-damaged skin (photoaging): what is new?]

Skin aging results from the interaction of genetic and nongenetic so-called exposomal, factors. Among the exposomal factors, chronic, life-long exposure to sunlight is of eminent importance for the development of skin aging characteristics. Importantly, photoaging of human skin is not only caused by ultraviolet (UV) B and A radiation, but is also the consequence of exposure to wavelengths beyond the UV spectrum. These include visible, i.e. blue light (400-440 nm) as well as the short part of infrared radiation, i.e. IRA (760-1200 nm). Here we summarize the scientific evidence supporting these conclusions and emphasize the resulting consequences for daily photoprotection of human skin. We also explain the clinical significance of the concept that is offered by the skin aging exposome, which e.g. takes into account the fact that sunlight interacts with other exposomal factors and that this interaction is important for photoaging of the skin.

[Effects of solar radiation and an update on photoprotection]

Sunburn, immunodepression, photoaging, and photocarcinogenesis, are some of the most significant adverse effects of solar radiation in humans. Children are population group of special vulnerability, due to the fact that exposure to the sun has more pronounced biological effects compared to adults. Furthermore, childhood is a critical period for promoting the development of photo damage and photocarcinogenesis in the later stages of life if adequate measures at not put into place. This is because it is estimated that between 18 and 20 years of age is when 40% to 50% of the accumulative exposure to ultraviolet radiation up to 60 years of age is received. The most important strategy for the photoprotection of children is changes in behaviour and habits associated with exposure to the sun at all levels (school, society, family, etc.). Resorting to the shade, reduction in overall time of exposure to the sun, and physical protection (clothes, hats, and sunglasses) are the best and least costly photoprotection strategies. The photoprotectors must be incorporated into the daily routine of children in the same way as adults, and must complete a series of requirements in order to make them effective, safe, and in line with the environment.

Protective effects of a comprehensive topical antioxidant against ozone-induced damage in a reconstructed human skin model

Tropospheric ozone (O₃) is a source of oxidative stress. This study examined the ability of a topical antioxidant (WEL-DS) to inhibit O₃-mediated damage in a human epidermal skin model. Four groups of tissues (N = 24) were compared: Group 1 (control) were untreated and unexposed; Group 2 were untreated and exposed to O₃ (0.4 ppm, 4 h); Group 3 were pretreated with WEL-DS and unexposed; Group 4 were pretreated with WEL-DS and exposed to O₃ (0.4 ppm, 4 h). Pretreated tissues were topically treated with 20 uL of WEL-DS and incubated for up to 20 h at 37 °C [humidified, 5% carbon dioxide (CO₂)]. After 24 h, tissues were re-treated with WEL-DS and exposed to O_3. Tissues were evaluated for Reactive Oxygen Species (ROS), hydrogen peroxide (H₂O₂), 4-hydroxynonenal (4-HNE) protein adducts, NF-κB p65 response and histology. In O₃-exposed groups, WEL-DS significantly inhibited ROS formation vs. untreated tissues (p < 0.05). Pretreatment with WEL-DS inhibited H₂O₂ production vs. untreated tissues (p < 0.05), and decreased NF-κB p65 transcription factor signal. Oxidative stress induction in O₃-exposed tissues was confirmed by increased levels of 4-HNE protein adducts (marker of lipid peroxidation); WEL-DS application reduced this effect. WEL-DS inhibited damage in tissues exposed to O₃ with no significant changes in epidermal structure. A comprehensive topical antioxidant significantly diminished O₃-induced oxidative damage in a human epidermal skin model.

Balance between Health Risks and Benefits for Outdoor Workers Exposed to Solar Radiation: An Overview on the Role of Near Infrared Radiation Alone and in Combination with Other Solar Spectral Bands

Near infrared or infrared A (IRA) accounts for over 40% of the solar spectrum (SS) and is able to reach subcutaneous tissue as well as the retina. Outdoor workers are occupationally exposed to solar radiation (SR), but the level of exposure may differ widely depending on the job performed, time spent outdoors, latitude, altitude, season, personal protection, etc. Until now, risk assessment and management for outdoor workers has focused on the prevention of both acute and long-term effects on the eye and the skin due to solar ultraviolet radiation (UVR) with little consideration of the other components of the SS (a possible exception is represented by visible radiation with reference to the eye). A growing body of evidence coming from in vitro studies indicates that IRA is involved in cellular reactive oxygen species (ROS) production and may interfere with the respiratory chain in the mitochondria. Moreover, it can modulate gene expression and some metabolic pathways. The biological action of IRA is only partly attributable to a thermal mechanism, should it be also involved in photochemical ones. The cellular and molecular pathways affected by IRA are partly similar and partly different with respect to those involved in the case of visible ultraviolet A (UVA) and ultraviolet B (UVB) radiation. Consequently, the net effect of the SS is very difficult to predict at different levels of the biological organization, making more difficult the final balance of health risk and benefits (for the skin, eye, immune system, blood pressure, etc.) in a given exposure situation. Moreover, few in vivo studies and no epidemiological data are presently available in this regard. Investigating this topic may contribute to better defining the individual exposome. More practically, it is expected to bring benefits to the risk assessment and management for outdoor workers exposed to SS, contributing to: (1) better definition of the individual profiles of susceptibility, (2) more focused preventive and protective measures, (3) better implementation of the health surveillance and (4) a more effective information and training.

Photoprotection of the future: challenges and opportunities

The use of sunscreens is an important and essential component of photoprotection. Since their introduction during the first half of the last century, sunscreens have benefited enormously from major technological advances such as the development of novel UV filters; as a result, their efficacy in preventing UV-induced erythema is unequivocal. More recently, however, new challenges have appeared, which have prompted a robust discussion about the safety of sunscreens. These include topics directly related to photoprotection of human skin such as improved/alternative methods for standardization of assessment of the efficacy of sunscreens, but also many others such as photoprotection beyond UV, concerns about human toxicity and ecological safety, the potential of oral photoprotective measures, consequences of innovative galenic formulations. On a first glance, some of these might raise questions and doubts among dermatologists, physicians and the general public about the use sunscreens as a means of photoprotection. This situation has prompted us to critically review such challenges, but also opportunities, based on existing scientific evidence. We conclude by providing our vision about how such challenges can be met best in the future in an attempt to create the ideal sunscreen, which should provide adequate and balanced protection and be easy and safe to use.

Application of an Easy-to-Perform High-Energy and Low-End Visible Light Transmittance Method and the Influence of Tinted Sunscreens on High-Energy/Low-End Visible Light Transmittance and Infrared Protection

BACKGROUND

About 50% of the sun's radiation arriving on earth is visible light (VIS). For a long time, its effects on human health have not been fully investigated. But recently, the influence of VIS has gained more attention, especially regarding skin physiology. Studies showed various effects, many of them harmful, comparable to UV radiation. As a result, there are now a few sunscreens commercially available which claim protection against VIS. The question of whether protection is necessary is still much discussed.

AIMS

The objective of this study was to develop an easy-to-perform high-energy visible (HEV) and low-end visible (LEV) light transmittance method to determine the direct VIS protection of sunscreens and other cosmetic samples. Furthermore, the influence of the brightness of the tested products on the HEV, LEV, and infrared A protection was investigated.

METHODS

An experimental setup consisting of a light source, a VIS-transmissible filter system, and a sensor unit was built to measure the direct VIS protection of sunscreens and other daily skin care products in two ranges of the VIS area. For a closer look, the brightness of the samples was evaluated by photometric assessment.

RESULTS/CONCLUSION

The experimental setup could be validated. It could be demonstrated for the first time that there is a strong positive linear correlation between transmittance and brightness of tinted sunscreen and daily skin care products with sunscreen properties in the HEV, LEV, and infrared A range. However, tinted samples worked best in the blue light region, and the higher the wavelength range, the lower the protection.

Tomato Phytonutrients Balance UV Response: Results from a Double-Blind, Randomized, Placebo-Controlled Study

BACKGROUND

Our previous double-blinded, placebo-controlled cross-over study indicated that a nutritional supplement named lycopene-rich tomato nutrient complex (TNC) can protect from UVA1-induced (340-400 nm) and UVA- (320-400 nm)/UVB-induced (280-320 nm) upregulation of molecular markers associated with oxidative stress, inflammation, and ageing.

OBJECTIVES

in the current double-blind, randomized, placebo-controlled multicenter study, we analyze whether a similar, synergistic carotenoid-rich TNC can protect from broadband UVB-induced threshold erythema formation assessed as increase in minimal erythemal dose (MED) reading, the intensity of erythema formation, and the upregulation of molecular markers associated with inflammation and immunosuppression, and whether this correlates with carotenoid blood levels.

METHODS

One hundred and forty-nine healthy volunteers were randomized to two groups and subjected to a 5-week washout phase, followed by a 12-week treatment phase receiving either 15 mg lycopene, 5.8 mg phytoene and phytofluene, 0.8 mg β-carotene, 5.6 mg tocopherols from tomato extract, and 4 mg carnosic acid from rosemary extract per day or placebo made from medium-chain triglycerides. At the end of each phase, MED determination, UVB irradiation, chromametry, biopsies, and blood samples were undertaken.

RESULTS

The active supplement was well tolerated. Interestingly, no significant difference was seen in the MED between the active-supplement and placebo groups, as determined by visual grading by expert assessors. Of note, the carotenoid-containing supplement significantly protected against UVB-induced erythema formation measured as Δa* after the intervention minus Δa* after the washout phase as compared to the placebo. Moreover, intake of the active supplement significantly protected against UVB-induced upregulation of IL6 and TNFα as compared with the intake of placebo. Lastly, carotenoid plasma levels were significantly increased.

CONCLUSION

This well-tolerated carotenoid-containing supplement significantly protected against UVB-induced erythema formation and upregulation of proinflammatory cytokines in healthy volunteers.

What's New in Photoprotection: A Review of New Concepts and Controversies

Cumulative ultraviolet exposure plays a critical role in photodamage. Recent advancements in photomedicine have resulted in a more thorough understanding of these mechanisms. Despite this, the adoption of routine sun protective practices is commonly not undertaken regularly by a large proportion of the public. Various obstacles exist that contribute to the public's nonadherence to these practices. Sunscreens, which are an integral component in all photoprotective regimens, have been questioned recently in terms of their safety. The aim of this article is to provide an overview of new concepts in photoprotection and also address current controversies pertaining to sunscreens.

Antioxidants from Plants Protect against Skin Photoaging

Exposure to UV light triggers the rapid generation and accumulation of reactive oxygen species (ROS) in skin cells, with consequent increase in oxidative stress and thus in photoaging. Exogenous supplementation with dietary antioxidants and/or skin pretreatment with antioxidant-based lotions before sun exposure might be a winning strategy against age-related skin pathologies. In this context, plants produce many secondary metabolites to protect themselves from UV radiations and these compounds can also protect the skin from photoaging. Phenolic compounds, ascorbic acid and carotenoids, derived from different plant species, are able to protect the skin by preventing UV penetration, reducing inflammation and oxidative stress, and influencing several survival signalling pathways. In this review, we focus our attention on the double role of oxidants in cell metabolism and on environmental and xenobiotic agents involved in skin photoaging. Moreover, we discuss the protective role of dietary antioxidants from fruits and vegetables and report their antiaging properties related to the reduction of oxidative stress pathways.

Antioxidants in dermatology

The skin cells continuously produce, through cellular respiration, metabolic processes or under external aggressions, highly reactive molecules oxidation products, generally called free radicals. These molecules are immediately neutralized by enzymatic and non-enzymatic systems in a physiological and dynamic balance. In situations where this balance is broken, various cellular structures, such as the cell membrane, nuclear or mitochondrial DNA may suffer structural modifications, triggering or worsening skin diseases. several substances with alleged antioxidant effects has been offered for topical or oral use, but little is known about their safety, possible associations and especially their mechanism of action. The management of topical and oral antioxidants can help dermatologist to intervene in the oxidative processes safely and effectively, since they know the mechanisms, limitations and potential risks of using these molecules as well as the potential benefits of available associations.

Sunscreens: An Update

Sunscreens have been widely used by the general public for their photoprotective properties, including prevention of photocarcinogenesis and photoaging and management of photodermatoses. It is important to emphasize to consumers the necessity of broad-spectrum protection, with coverage of both ultraviolet A (320-400 nm) and ultraviolet B (290-320 nm) radiation. This review discusses the benefits of sunscreen, different ultraviolet filters, sunscreen regulations and controversies, the importance of broad-spectrum protection, issues of photostability and formulation, and patient education and compliance.

The Roles of Vitamin C in Skin Health

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.

Development of an in vitro Test Procedure to Determine the Direct Infrared A Protection of Sunscreens and Non-Cosmetic Samples

BACKGROUND

Every day human skin is exposed to infrared A (IRA) radiation as part of the natural sun rays. As IRA radiation accounts for around one third of the solar radiation, it has gained great attention concerning its effects on the human body and skin. In the past few years it has been discussed controversially whether IRA radiation (of solar origin) is harmful or not. Nonetheless, there are several sunscreens on the German market that claim IRA protection for themselves.

AIMS

The present study seeks to find an experimental set-up and a test procedure for the determination and quantification of direct IRA protection (realized via reflection or absorption of the IRA radiation), since to our knowledge these do not yet exist.

METHODS

In this study we proved the usability of a set-up consisting of a light source, an IRA-transmissible filter system and a sensor unit, for the determination and quantification of the IRA protection of cosmetic and non-cosmetic samples.

RESULTS/CONCLUSION

The applicability of the IRA emission of the light source, the spectral detector, transmissivity of the filter systems and the sample carriers could be validated. This experimental set-up can be used as an in vitro test procedure for the determination of direct IRA protection.

The Use of Directional Reflectance Measurement for in vivo Assessment of Protective Properties of Cosmetics in the Infrared Radiation Range

Photoprotection of skin is now focused on UV radiation. The aim of this study was to evaluate in vivo cosmetic products in terms of protection against infrared radiation (IR) and propose a methodology for conducting such measurements. The directional reflectance (DR) of 12 UV filters, six care creams and two preparations containing fumed silica applied on the forearm of 36 volunteers was examined in six spectral bands for two angles of incidence. SOC-410 Directional Hemispherical Reflectometer was used to measure DR. There is very little change in DR for all spectral bands for both incident angles for both UV filters, care creams and preparations containing fumed silica. For example, for 15% of fumed silica in glycerin for the spectral band of 0.9-1.1 μm and the incident angle of 20°, skin DR prior to application was 0.543; 5 min after application was 0.533 and 30 min after application was 0.559. Both UV filters, care creams and fumed silica do not protect skin against IR. The proposed method of in vivo measurements is superior to in vitro studies which have been conducted so far because it takes into account both the refractive index at the tissue/air interface and the absorption of IR by adipose tissue.

Current challenges in photoprotection

Electromagnetic radiation in the ultraviolet, visible, and infrared ranges all produce biologic effects. Ultraviolet filters are the most well-studied photoprotective measure for the adverse effects of ultraviolet radiation. Because of the reported endocrinologic effects of oxybenzone in animal studies, its effects on coral reefs, and its photocontact allergy potential, its use has been minimized in many countries worldwide. New developments in topical antioxidants and oral and subcutaneous agents (eg, Polypodium leucotomos extract, afamelanotide, nicotinamide) with photoprotective and antiphotocarcinogenic properties could potentially provide addition modalities for protection against the effects of visible light and infrared radiation.

[Environmentally induced (extrinsic) skin aging]

Chronic exposure to ultraviolet light, particularly as a component of natural sunlight, is a major cause of environmentally induced aging of the skin. In addition, other environmental factors for premature skin aging include longer wavelength radiation in the visible light region and in particular in the shortwave infrared radiation region. Furthermore, particulate and gaseous components of air pollution significantly contribute to the aging process.

The skin aging exposome

The term "exposome" describes the totality of exposures to which an individual is subjected from conception to death. It includes both external and internal factors as well as the human body's response to these factors. Current exposome research aims to understand the effects all factors have on specific organs, yet today, the exposome of human skin has not received major attention and a corresponding definition is lacking. This review was compiled with the collaboration of European scientists, specialized in either environmental medicine or skin biology. A comprehensive review of the existing literature was performed using PubMed. The search was restricted to exposome factors and skin aging. Key review papers and all relevant, epidemiological, in vitro, ex vivo and clinical studies were analyzed to determine the key elements of the exposome influencing skin aging. Here we propose a definition of the skin aging exposome. It is based on a summary of the existing scientific evidence for the role of exposome factors in skin aging. We also identify future research needs which concern knowledge about the interaction of distinct exposomal factors with each other and the resulting net effects on skin aging and suggest some protective measures.

Current application of phytocompound-based nanocosmeceuticals for beauty and skin therapy

Phytocompounds have been used in cosmeceuticals for decades and have shown potential for beauty applications, including sunscreen, moisturizing and antiaging, and skin-based therapy. The major concerns in the usage of phyto-based cosmeceuticals are lower penetration and high compound instability of various cosmetic products for sustained and enhanced compound delivery to the beauty-based skin therapy. To overcome these disadvantages, nanosized delivery technologies are currently in use for sustained and enhanced delivery of phyto-derived bioactive compounds in cosmeceutical sectors and products. Nanosizing of phytocompounds enhances the aseptic feel in various cosmeceutical products with sustained delivery and enhanced skin protecting activities. Solid lipid nanoparticles, transfersomes, ethosomes, nanostructured lipid carriers, fullerenes, and carbon nanotubes are some of the emerging nanotechnologies currently in use for their enhanced delivery of phytocompounds in skin care. Aloe vera, curcumin, resveratrol, quercetin, vitamins C and E, genistein, and green tea catechins were successfully nanosized using various delivery technologies and incorporated in various gels, lotions, and creams for skin, lip, and hair care for their sustained effects. However, certain delivery agents such as carbon nanotubes need to be studied for their roles in toxicity. This review broadly focuses on the usage of phytocompounds in various cosmeceutical products, nanodelivery technologies used in the delivery of phytocompounds to various cosmeceuticals, and various nanosized phytocompounds used in the development of novel nanocosmeceuticals to enhance skin-based therapy.