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Understanding the biothermal response of skin tissue exposed to electromagnetic (EM) radiation and variable thermal fields is crucial for mitigating risks associated with such exposures. This knowledge can empower the development of safe and efficacious evidence‐based treatments for various skin conditions within the medical field. This study employs the fourth‐order Moore–Gibson–Thomson (MGT) concept to establish a theoretical framework for biothermal analysis. This investigation aims to elucidate the biothermal response of skin tissues to EM radiation. The developed model facilitates the prediction of thermal reactions within human skin and the subsequent evaluation of bioheat transfer efficiency in biological tissues. The proposed model is implemented on a one‐dimensional representation of a skin layer and incorporates the effects of an induced electric field and a time‐harmonic heat source. Additionally, a linear dependence of metabolic heat generation on tissue temperature is considered. By employing Laplace transforms, the analytical solutions for tissue temperature are presented. The derived analytical solutions are compared with established theories to assess the accuracy of the proposed model. The results reveal that the modified MGT bioheat transfer model predicts lower temperatures compared to the conventional Pennes model, attributable to the incorporation of the thermal relaxation time constant. [ABSTRACT FROM AUTHOR]

Solar radiation can cause damage to the skin, and the use of sunscreens is one of the main protective measures. However, photounstable ultraviolet (UV) filters can generate photoproducts and reactive oxygen species (ROS). Adding antioxidants, such as resveratrol, to enhance the action of UV filters in sunscreens is an interesting strategy for reducing the damage caused by UV radiation exposure. However, new compounds must have their stability, safety and efficacy guaranteed. Avobenzone, a commonly used UV filter, stands out as a promising candidate for structural modification to enhance its stability. Its molecular hybridization with other UV filters and antioxidants can lead to safer and more effective compounds. In this study, the photoprotective and antioxidant potential of a derivative of avobenzone, hybridized with resveratrol's molecule, was evaluated using in vitro models of cells in monolayer and reconstructed human skin (RHS). Phototoxic potential was assessed using fibroblasts, while the antioxidant activity was measured using the DCFH2-DA probe in HaCaT keratinocytes and in-house RHS. The derivative exhibited UV absorption and demonstrated photostability. It did not exhibit any phototoxic nor photoreactivity potential. Additionally, it was able to photo stabilize a combination of photounstable UV filters, avobenzone and octyl methoxycinnamate, and to reduce their phototoxic potential. In terms of antioxidant activity, the derivative successfully protected against UVA-induced ROS production in the HaCaT keratinocytes model, showing statistical equivalence to the antioxidant control, quercetin (10 μg/mL). Furthermore, experiments conducted in the RHS model demonstrated a significant reduction of 30.7% in ROS generation compared to the irradiated control. This study demonstrated that structural modifications of avobenzone can lead to the development of a broad spectrum (absorbing UVB and UVA II radiation, as well as a portion of the UVA I radiation), non-phototoxic, non-photoreactive and photostable derivative for sunscreen and anti-aging formulations. This derivative enhances protection against oxidative stress induced by UV radiation and improves the effectiveness of sun protection. In addition to the monolayer model, the use of a standardized in-house RHS model was highly relevant for evaluating the effects of UV radiation and skin aging. This model closely mimics human physiological conditions and enables the testing of new compounds and the investigation of protective mechanisms against skin damage. [ABSTRACT FROM AUTHOR]

Sunlight, despite its benefits, can pose a threat to the skin, which is a natural protective barrier. Phototoxicity caused by overexposure, especially to ultraviolet radiation (UVR), results in burns, accelerates photoaging, and causes skin cancer formation. Natural substances of plant origin, i.e., polyphenols, flavonoids, and photosynthetic pigments, can protect the skin against the effects of radiation, acting not only as photoprotectors like natural filters but as antioxidant and anti-inflammatory remedies, alleviating the effects of photodamage to the skin. Plant-based formulations are gaining popularity as an attractive alternative to synthetic filters. Over the past 20 years, a large number of studies have been published to assess the photoprotective effects of natural plant products, primarily through their antioxidant, antimutagenic, and anti-immunosuppressive activities. This review selects the most important data on skin photodamage and photoprotective efficacy of selected plant carotenoid representatives from in vivo studies on animal models and humans, as well as in vitro experiments performed on fibroblast and keratinocyte cell lines. Recent research on carotenoids associated with lipid nanoparticles, nanoemulsions, liposomes, and micelles is reviewed. The focus was on collecting those nanomaterials that serve to improve the bioavailability and stability of carotenoids as natural antioxidants with photoprotective activity. [ABSTRACT FROM AUTHOR]

Ultraviolet-A (UVA) radiation comprises more than 90% of the solar ultraviolet (UV) radiation reaching the earth. Exposure to UVA has been associated with dermatological disorders including skin cancer. Despite their preponderance amongst the UV range received on earth, the biological impacts of long wave UVA rays (340-400 nm) upon human skin have not been investigated so thoroughly. Nevertheless, recent studies have proven their harmful effects and involvement in carcinogenesis and immunosuppression. The aim of this study was to investigate the effect of the UVA radiation on the skin tissue of a living organism. Among this study the trace elements concentration using the Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) technique, blood counts have been deduced. Forty male wistar albino rats (180-200) gm. are included in the study and divided into four groups, each containing ten rats. Group I was formed to be the control group, which was not exposed to UV radiation. Other groups were formed to observe the effects of UVA with different exposure doses on the skin. For all studied groups the trace elements and Complete blood counts after 17, 27 and 59 days exposure in continue form (24 hr./dy) were examined. Statistical analyzed using IBM SPSS software package version 20.0 was used, (Armonk, NY: IBM Corp). The Kolmogorov-Smirnov test was used to verify the normality of distribution Quantitative data was described using mean and standard deviation. Significance of the obtained results was judged at the 5% level. All groups exposed to UVA radiation showed a statistically sig-nificant variation in trace elements concentration and complete blood counts. However, a comparison between the control groups and the different other groups, shows the effects of UV exposure on the skin and blood. [ABSTRACT FROM AUTHOR]

Solar radiation can cause damage to the skin, leading to various adverse effects such as sunburn, reactive oxygen species production, inflammation, DNA damage, and photoaging. To study the potential of photoprotective agents, full-thickness skin models are increasingly being used as in vitro tools. One promising approach to photoprotection involves targeting the redox-sensitive transcription factor Nrf2, which is responsible for regulating various cellular defense mechanisms, including the antioxidant response, inflammatory signaling, and DNA repair. Obacunone, a natural triterpenoid, has been identified as a potent Nrf2 agonist. The present study aims to evaluate the relevance of full-thickness (FT) skin models in photoprotection studies and to explore the potential photoprotective effects of obacunone on those models and in human keratinocytes. Phenion® full-thickness skin models and keratinocytes were incubated with increasing concentrations of obacunone and irradiated with solar-simulated radiation (SSR). Various photodamage markers were evaluated, including histological integrity, oxidative stress, apoptosis, inflammation, photoaging-related dermal markers, and photocarcinogenesis markers. Increasing doses of SSR were found to modulate various biomarkers related to sun damage in the FT skin models. However, obacunone attenuated cytotoxicity, inflammation, oxidative stress, sunburn reaction, photoaging, and photocarcinogenesis in both keratinocytes and full thickness skin models exposed to SSR. These results suggest that obacunone may have potential as a photoprotective agent for preventing the harmful effects of solar radiation on the skin. [ABSTRACT FROM AUTHOR]

The progressive depletion of the ozone layer poses a significant threat to both human health and the environment. Prolonged exposure to ultraviolet radiation increases the risk of developing skin cancer, particularly melanoma. Early diagnosis and vigilant monitoring play a crucial role in the successful treatment of melanoma. Effective diagnostic strategies need to be implemented to curb the rising incidence of this disease worldwide. In this work, we propose an artificial intelligence-based detection model that employs deep learning techniques to accurately monitor nevi with characteristics that may indicate the presence of melanoma. A comprehensive dataset comprising 8598 images was utilized for the model development. The dataset underwent training, validation, and testing processes, employing the algorithms such as AlexNet, MobileNet, ResNet, VGG16, and VGG19, as documented in current literature. Among these algorithms, the MobileNet model demonstrated superior performance, achieving an accuracy of 84.94% after completing the training and testing phases. Future plans involve integrating this model with a desktop program compatible with various operating systems, thereby establishing a practical detection system. The proposed model has the potential to aid qualified healthcare professionals in the diagnosis of melanoma. Furthermore, we envision the development of a mobile application to facilitate melanoma detection in home environments, providing added convenience and accessibility. [ABSTRACT FROM AUTHOR]

The study of inclined magnetohydrodynamics (MHD) mixed convective incompressible flow of a fluid with hybrid nanoparticles containing a colloidal combination of nanofluids and base fluid is presented in the current research. Al2O3-Cu/H2O hybrid nanofluid is utilized in the current analysis to enhance the heat transfer analysis. The impact of radiation is also placed at energy equation. The main research methodology includes that the problem provided equations are first transformed into non-dimensional form, and then they are obtained in ordinary differential equations (ODEs) form. Then using the solutions of momentum and transfers equations to solve the given ODEs to get the root of the equation. The main purpose includes the resulting equations are then analytically resolved with the aid of suitable boundary conditions. The results can be discussed with various physical parameters viz., stretched/shrinked-Rayleigh number, stretching/shrinking parameter, Prandtl number, etc. Besides, skin friction and heat transfer coefficient can be examined with suitable similarity transformations. The main significance of the present work is to explain the mixed convective fluid flow on the basis of analytical method. Main findings at the end we found that the transverse and tangential velocities are more for more values of stretched/shrinked-Rayleigh number and mass transpiration for both suction and injection cases. This is the special method it includes stretched/shrinked-Rayleigh number, it contributes major role in this analysis. The purpose of finding the present work is to understand the analytical solution on the basis of mixed convective method. [ABSTRACT FROM AUTHOR]

Exposure to ultraviolet (UV) radiation causes harmful effects on the skin, such as inflammatory states and photoaging, which depend strictly on the form, amount, and intensity of UV radiation and the type of individual exposed. Fortunately, the skin is endowed with a number of endogenous antioxidants and enzymes crucial in its response to UV radiation damage. However, the aging process and environmental stress can deprive the epidermis of its endogenous antioxidants. Therefore, natural exogenous antioxidants may be able to reduce the severity of UV-induced skin damage and aging. Several plant foods constitute a natural source of various antioxidants. These include gallic acid and phloretin, used in this work. Specifically, polymeric microspheres, useful for the delivery of phloretin, were made from gallic acid, a molecule that has a singular chemical structure with two different functional groups, carboxylic and hydroxyl, capable of providing polymerizable derivatives after esterification. Phloretin is a dihydrochalcone that possesses many biological and pharmacological properties, such as potent antioxidant activity in free radical removal, inhibition of lipid peroxidation, and antiproliferative effects. The obtained particles were characterized by Fourier transform infrared spectroscopy. Antioxidant activity, swelling behavior, phloretin loading efficiency, and transdermal release were also evaluated. The results obtained indicate that the micrometer-sized particles effectively swell, and release the phloretin encapsulated in them within 24 h, and possess antioxidant efficacy comparable to that of free phloretin solution. Therefore, such microspheres could be a viable strategy for the transdermal release of phloretin and subsequent protection from UV-induced skin damage. [ABSTRACT FROM AUTHOR]

This work investigated effects of plant polyphenolic compounds (PPs) on responses of cultured human HaCaT keratinocytes to ultraviolet radiation in the C range (UV-C). The experimental data obtained indicate a cytoprotective effect of PPs added immediately after UV-C exposure. The efficiency of PPs was lowered in the following order: acacetin ≥ silybin > quercetin. The influence of PPs on phosphorylation of histone H2AX and the number of single-strand DNA breaks in the nuclei of keratinocytes were also studied. Using the comet assay and γH2AX staining, followed by fluorescence microscopy, it has been established that PPs can reduce DNA damage in the nuclei of keratinocytes exposed to UV-C. It is concluded that PPs can diminish the destructive effect of UV radiation on skin cells, activating the process of repairing genetic damage. [ABSTRACT FROM AUTHOR]

The effects of UV radiation on the skin and its damage mechanisms are well known. New modalities of exogenous photoprotection have been studied. It was demonstrated that Polypodium leucotomos extract acts as an antioxidant, photoprotectant, antimutagenic, anti-inflammatory, and immunoregulator. It is effective when taken orally and/or applied topically to support the prevention of skin cancers. It also has an important role in preventing photoaging. This review aims to report the mechanisms through which Polypodium leucotomos acts and to analyze its uses in oncodermatology with references to in vitro and in vivo studies. Additionally, alternative uses in non-neoplastic diseases, such as pigmentary disorders, photosensitivity, and atopic dermatitis, have been considered. [ABSTRACT FROM AUTHOR]

Actinic Reticuloid (AR) is a rare, severe, chronic photodermatosis that generally occurs in older males. Belonging to the group of cutaneous pseudolymphomas identified as benign reactive lymphocytic proliferations. It is characterized by being photosensitive, specifically to UV (ultraviolet) rays and visible light. It manifests in patients with a characteristic clinical picture of erythematous, edematous, pruritic, lichenified and scaly papules and plaques, which later develop as residual pigmented macules and progressively worsen with sun exposure; It mainly occurs in exposed areas such as the face, arms, hands, neck, among others. Actinic Reticuloid is a strange, poorly documented pathology and as a consequence of not knowing about it, patients do not go to the clinic until the disease is in an advanced stage and with a severe clinical picture of the disease; here lies the importance of the exposition of this bibliographic review where, in addition to presenting the case of a 58-year-old man, the clinical assessment is evidenced from the symptomatology and the main treatment for the patient is determined, as well as different alternatives for relieve symptoms and as a support for effective recovery. [ABSTRACT FROM AUTHOR]

The document titled "Comment on Vishalakshi et al. MHD Hybrid Nanofluid Flow over a Stretching/Shrinking Sheet with Skin Friction: Effects of Radiation and Mass Transpiration" criticizes two errors in a previous publication. The first error is related to an incorrect gravity term in an equation, which violates the known physics principle that gravity acts in the vertical direction. The second error involves a dimensional inconsistency in an equation, where some parameters are dimensionless while one parameter is dimensional. The document concludes by stating that the authors have no conflicts of interest. [Extracted from the article]

Nowadays, skin cancer is a worldwide panic. It is related to ultraviolet radiation. In this paper, we have formulated a SIRS type mathematical model to show the effects of ultraviolet radiation on skin cancer. At first, we have showed the boundedness and positivity of the model solutions to verify the model's existence and uniqueness. The boundedness and positivity gave the solutions of our model bounded and positive, which was very important for real-world situation because in real world, population cannot be negative. Then, we have popped out all the equilibrium points of our model and verified the stability of the equilibrium points. This stability test expressed some physical situation of our model. The disease-free equilibrium point is locally asymptotically stable if R 0 < 1 and if R 0 > 1 , then it is unstable. Again, the endemic equilibrium point is stable, if R 0 > 1 and unstable if R 0 < 1. In order to understand the dynamical behavior of the model's equilibrium points, we examined the phase portrait. We also have observed the sensitivity of the model parameters. After this, we have investigated the different scenarios of bifurcations of the model's parameters. At the set of Hopf bifurcation parameters when infection rate due to UV rays is less than α 1 = 0.01 , proper control may eradicate the existence of disease. From transcritical bifurcation, we can say when recovery rate greater than 1.9, then the disease of skin cancer can be eliminated and when recovery rate less than 1.9 then the disease of skin cancer cannot be eradicated. Finally, numerical analysis is done to justify our analytical findings. [ABSTRACT FROM AUTHOR]

Acute scalp edema is very rare, and diseases such as subgaleal hemorrhage, solar urticaria, and angioedema may present with acute generalized or localized scalp edema. Sunburn is common, but the acute sunburn occurred on the head may present very differently to other parts of the body due to the unique anatomical structure of the head and gravitational effect on fluids. [Extracted from the article]

Keywords: Lilium plant; polyphenols; polysaccharides; cosmetic application; antiaging; ultraviolet blocker; skin whitening; moisturizing; freckle removal; acne treatment EN Lilium plant polyphenols polysaccharides cosmetic application antiaging ultraviolet blocker skin whitening moisturizing freckle removal acne treatment N.PAG N.PAG 17 08/29/22 20220801 NES 220801 1. [Extracted from the article]

Here, we examined the skin microbiome of two groups of healthy volunteers living on the Mediterranean coast with different exposures to sun radiation. One group, exposed to the sun in the summer, was compared with a group covered with clothing throughout the year. The seasonal effects on the skin microbiome of three body sites were determined before and after summer. Surprisingly, at the phyla level, there were no significant differences in microbiome diversity between the groups. Furthermore, within each group, there were no significant seasonal differences in high-abundance species at any of the sampling sites. These results suggest that the skin microbiome, developed over years, remains stable even after several months of exposure to summer weather, direct sunlight and humidity. However, in the group exposed to the sun during the summer months, there were significant differences in low-abundance species in sun-exposed areas of the skin (the inner and outer arm). These subtle changes in low-abundance species are interesting, and their effect on skin physiology should be studied further. [ABSTRACT FROM AUTHOR]

The medicinal mushroom Ganoderma lucidum is traditionally used for treating multiple diseases, including cancer. This study examined skin cancer preventive activity of a commercial product containing spore and fruiting body in 30:8 ratio (GLSF). Extracts of GLSF and spore component (GLS) were prepared using artificial gastrointestinal juice and examined on JB6 cells. GLSF and GLS dose-dependently inhibited epidermal growth factor-induced JB6 transformation at non-toxic concentrations. SKH-1 mice which were fed with diets containing GLSF (1.25%), GLS (0.99%) or the fruiting body (GLF) (0.26%) were exposed to chronic low-dose ultraviolet (UV) radiation to assess their effects on skin carcinogenesis. GLSF, but not GLS or GLF, reduced skin tumor incidence and multiplicity. In non-tumor skin tissues of mice, GLSF attenuated UV-induced epidermal thickening, expression of Ki-67, COX-2 and NF-κB, while in tumor tissues, GLSF increased expression of CD8 and Granzyme B. To examine the effects of GLSF on UV-induced immunosuppression, mice which were fed with GLSF were evaluated for the contact hypersensitivity (CHS) response to dinitrofluorobenzene (DNFB). GLSF significantly reversed UV-mediated suppression of DNFB-induced CHS by increasing CD8+ and decreasing CD4+ and FoxP3+ T-cells in mouse ears. Therefore, GLSF prevents skin cancer probably via attenuating UV-induced immunosuppression. [ABSTRACT FROM AUTHOR]

Skin cancer is one of the most common types of cancer and UV radiation is one of the main risk factors. Therefore, sun protection, especially in childhood, is strongly recommended. We examined the effectiveness of the 'Clever in Sun and Shade for Preschools' program (CLEVER) in promoting sun protection behavior among preschool staff (trial registration: DRKS00023468) and describe its dissemination. Within a cluster randomized trial with 24 preschools (n = 273 staff members) stating a high need for sun protection measures, an educational workshop for preschool staff and a project kit with materials applicable in preschool groups was provided. Staff members of preschools taking part in CLEVER report significantly stronger sun protection behavior to avoid the sun (effect size [ES] 0.70, 95% confidence interval [CI] 0.04 0.71, p < 0.05) and less perceived impediments to avoid the sun (ES -0.56, CI -0.82 -0.17, p < 0.01) after 12 months as well as higher self-efficacy to avoid the sun (ES 1.09, CI 0.39 1.07, p < 0.001) and to use sunscreen (ES 0.71, CI 0.03 0.88, p < 0.05) after 1 month. Compared to the control group, there was no significant effect on sunscreen use and further psychosocial outcomes. The effectiveness of CLEVER may be underrated due to a high drop-out rate. Within three years, an enhanced free-of-charge program kit, including a media-based workshop and materials, had reached over 4000 preschools, i.e., 7.1% of all daycare centers in Germany. The results show that CLEVER can strengthen sun protection, offer high-quality information at low cost, and is easily disseminable. [ABSTRACT FROM AUTHOR]

Excessive sun exposure can have serious consequences on the body in general and on the skin in particular. Due to the reduction of the ozone layer and to the global warming, solar radiation is increasingly harmful, as a result, the negative effects of the sun are closely monitored by specialists, and the use of photoprotection products has become increasingly necessary. This paper presents the effects on the skin of the UV radiation and aspects related to photoprotection with the help of cosmetics which, through the active substances they contain, provide adequate protection to a large extent. [ABSTRACT FROM AUTHOR]

The 3,4-Dimethoxychalcone (3,4-DC) is a derivative chalcone compound considered to have potency as a protection agent against ultraviolet exposure. Ultraviolet A (UV-A) is one of the UV ray components that could damage the skin and has a more destructive effect than Ultraviolet B (UV-B). The purpose of this research was to evaluate the activity of 3,4-DC as a protection agent in protecting the skin from UV-A exposure. The parameters are percent transmission of erythema (%TE) and percent transmission of pigmentation (%TP), UVA Protection Factor (UVA-PF) in vitro, and also to know photostability phenomena due to UV-A exposure. All determinations in this research were conducted based on UV-Vis spectrophotometry. Determination of %TE and %TP were conducted using Cumpelik's method. Determination of UV-A PF in vitro value was done by the Diffey-Robson method, while UV-A exposure was done with ultraviolet radiation (UVR) simulator. Photostability of 3,4-DC was observed based on spectra UV before and after UVA exposure. Results showed that %TE and %TP HPMC gel preparation has the least %TP value (23,64%) which signifies the best protection, then subsequently microemulgel HPMC (26,00%), gel CMC-Na (31,89%), and microemulgel CMC-Na (44,12%). In vitro UV-A exposure tests obtained the highest UVA-PF values was HPMC microemulgel (2,72), then subsequently HPMC gel (2,33), CMC-Na microemulgel (1,17), and CMC-Na gel (1,10). Meanwhile, UV spectra shift occurred in all preparations due to exposure to UV-A rays. [ABSTRACT FROM AUTHOR]

Background: With the global sunscreen market expected to reach $24.4 billion worldwide by 2029, this demonstrates the increasing awareness of the damaging effects of sunlight. Sunscreen has been gradually evolving, and new photoprotective ingredients are continuing to be produced in response to growing scientific evidence on the effect of solar radiation on the skin. Aims: This literature review aims to provide an updated view of the history of sunscreens. Methods: A literature search was conducted with the keywords "Sunscreen, history, regulation, ultraviolet A, ultraviolet B, visible light" from PubMed, Medline, and online search engines. Results: Humankind has always found ways to provide photoprotection since 4000BC. Only in the last century, evidence‐based sunscreens have existed. The first ultraviolet B filters were produced in 1928, its evidence of efficacy and safety discovered in 1956 and development of sun protection factor in 1974. Similarly, sunscreen containing ultraviolet A filters was released in 1980 and the ultraviolet A star rating system developed in 1992. Regulatory bodies for sunscreen were introduced in the 1970s and have sought to review the safety and efficacy of ingredients. With the rising number of researches on the effects of visible light on hyperpigmentation over the past decade, the need for photoprotection beyond ultraviolet has been increasing. Conclusion: To provide consumers with evidence‐based sunscreen, challenges remain in acquiring further evidence, regulation, and rating systems. [ABSTRACT FROM AUTHOR]

Pigmentation, a process controlled by melanogenesis, plays a vital role in protecting the skin against harmful ultraviolet rays. The level of protection is compromised in case of hypopigmentation. This study aimed to evaluate an Aspalathus linearis extract, fractions and phytoconstituents, for their efficacy on melanogenesis stimulation. Fifteen compounds were kinetically assessed against tyrosinase; the rate-limiting enzyme of melanogenesis. Aspalathin and catechin significantly (p value < 0.001) increased the enzymatic rate, showing 50% stimulatory effects at 119.70 ± 2.06 µg/mL and 143.30 ± 2.74 µg/mL, respectively, by acting as subversive substrates. Five compounds inhibited the enzyme's activity, of which four exhibited competitive inhibition. To investigate the molecular interactions between the compounds and the active site, molecular docking was done, using tyrosinase (PBD: 2Y9X) and tyrosinase related protein 1 (PBD: 5M8P). All the compounds docked successfully with acceptable docking scores. Further quantitative structure–activity relationship analysis identified potential functional groups, linked to the specific activity. The crude extract, its fractions, and compounds exhibited low antiproliferative activity with 50% cell viability at concentrations higher than 100 µg/mL. Finally, both aspalathin and catechin exhibited a significant increase (4.5%) in melanin production at 119.82 µg/mL and 76.92 µg/mL, respectively. This is the first report of A. linearis' compounds on skin re-pigmentation. [ABSTRACT FROM AUTHOR]

Exposure to moderate doses of ionizing radiation (IR), which is sufficient for causing skin injury, can occur during radiation therapy as well as in radiation accidents. Radiation-induced skin injury occasionally recovers, although its underlying mechanism remains unclear. Moderate-dose IR is frequently utilized for bone marrow transplantation in mice; therefore, this mouse model can help understand the mechanism. We had previously reported that bone marrow-derived cells (BMDCs) migrate to the epidermis-dermis junction in response to IR, although their role remains unknown. Here, we investigated the role of BMDCs in radiation-induced skin injury in BMT mice and observed that BMDCs contributed to skin recovery after IR-induced barrier dysfunction. One of the important mechanisms involved the action of CCL17 secreted by BMDCs on irradiated basal cells, leading to accelerated proliferation and recovery of apoptosis caused by IR. Our findings suggest that BMDCs are key players in IR-induced skin injury recovery. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) is the predominant gas molecule emitted during aerobic respiration. Although CO2 can improve blood circulation in the skin via its vasodilatory effects, its effects on skin inflammation remain unclear. The present study aimed to examine the anti-inflammatory effects of CO2 in human keratinocytes and skin. Keratinocytes were cultured under 15% CO2, irradiated with ultraviolet B (UVB), and their inflammatory cytokine production was analyzed. Using multiphoton laser microscopy, the effect of CO2 on pH was observed by loading a three-dimensional (3D)-cultured epidermis with a high-CO2 concentration formulation. Finally, the effect of CO2 on UVB-induced erythema was confirmed. CO2 suppressed the UVB-induced production of tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) in keratinocytes and the 3D epidermis. Correcting medium acidification with NaOH inhibited the CO2-induced suppression of TNFα and IL-6 expression in keratinocytes. Moreover, the knockdown of H+-sensing G protein-coupled receptor 65 inhibited the CO2-induced suppression of inflammatory cytokine expression and NF-κB activation and reduced CO2-induced cyclic adenosine monophosphate production. Furthermore, the high-CO2 concentration formulation suppressed UVB-induced erythema in human skin. Hence, CO2 suppresses skin inflammation and can be employed as a potential therapeutic agent in restoring skin immune homeostasis. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Thermal processes are the essence of living organisms and are necessary for understanding life. The study of Transfer of heat in tissues is known as Bioheat transfer. Many techniques are developed for the thermal treatment of skin and other disease such as skin cancer, skin burns and injured skin tissue with laser. The tissue is inhomogeneous and at times anisotropic with complex thermal properties. Moreover, there may be skin tissue damage when irradiated with a laser beam. OBJECTIVES: In this research a novel one-dimensional (1-D) bioheat model has been used with memory-dependent derivative (MDD) in Pennes' bioheat transfer equation due to laser radiation and the thermal damage in tissue caused due to laser heating has been examined. METHODS: Bioheat transfer model has been used with memory-dependent derivative (MDD) in Pennes' bioheat transfer equation. The problem is solved using Laplace transform technique. RESULTS: The temperature and thermal damage in the skin exposed to heating with laser radiation is calculated and obtained in physical form. The thermal reaction of skin tissues during laser radiation is studied under memory-dependent derivative (MDD) in Pennes' bioheat transfer equation. CONCLUSION: Analyzed a novel bioheat mathematical model on the basis of MDD involving time-delay parameter 𝜒𝜒 for the Pennes' bioheat transfer equation and applied to examine the thermal properties of the skin tissue for burns caused due to laser radiations. The thermal damages can be measured in a better way with the MDD model. The blood perfusion prevent the tissue damage by developing the cooling function. Effect of memory dependent derivatives and time delay parameter are represented graphically and analysed. [ABSTRACT FROM AUTHOR]

The article presents the study in assessing smartphone use and skin changes associated with smartphone use. Topics include with the increase in use and overuse of smartphones, many aspects of society and health being likely affected; discussing the changes in the dermatologic health secondary to the increased use of smartphones; and investigating the positive and negative effects of smartphone use on various musculoskeletal conditions of the upper extremities.

Lifeguards working at outdoor pools typically receive high amounts of sun exposure, increasing their risk for developing skin cancer. This study evaluates the effectiveness of a targeted, peer-driven intervention for skin cancer prevention among lifeguards. Nine pools received the targeted intervention, Pool Cool Plus, and five received the standard Pool Cool prevention program. Lifeguards completed surveys at the beginning and end of the summer. Lifeguards in both the targeted intervention and standard program groups increased their sun safety practices and reported more sun-safe pool policies and environments. Sunburn rates decreased among lifeguards participating in Pool Cool Plus. Future research should test the feasibility and effectiveness of disseminating the Pool Cool Plus program. [ABSTRACT FROM AUTHOR]

Radiologic accidents or terrorist acts involving radioactive material, as well as radiation exposure in medical or industrial procedures are potential sources of risk for human health. All these risks share a common element, exposure to ionizing radiation. The extent of ionizing radiation injury will depend on a number of independent variables such as dose, type of radiation and tissue, etc. As a result of ionizing radiation exposure, biological effects can take place in acute or long-term manner. As in the case of other self-renewing tissues (e.g. hematopoietic system and intestinal epithelium), skin is also extremely sensitive to ionizing radiation. In this way, appropriate management of radiation skin effects might improve the therapeutic benefit of medical radiation therapy, as well as reduce the mortality associated with any radiological incident (e.g. accident or terrorist attack). For this reason, current and potential future treatment approaches for skin radiation injury are reviewed in this work. Unfortunately, there is no sufficient evidence for establishing a standard treatment to prevent or mitigate radiation-induced cutaneous injury. Thus, continued research is necessary to achieve effective therapies to address this important health problem. [ABSTRACT FROM AUTHOR]

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Abstract The objective of this study was to investigate the effect of Mycosporine-like amino acids (MAAs) extracted from Porphyra tenera skin against UV irradiation-induced photoaging using an ICR mouse model of skin photoaging and to explore the curative effects of the compounds in MAAs. The skin damage and collagenous tissue impairments induced by ultraviolet radiation were observed by histopathological analysis, and the effects of MAAs on protecting against skin damage and maintaining an intact structure of collagenous tissue were studied. The expression of NF-κB and the MAPK signaling pathway and nuclear transcription factors MMP-1, MMP-3 and TNF-α was analyzed used quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and ELISA assays. The results showed that the MAAs extracted from Porphyra tenera contained Porphyra-334 and shinorine, which could prevent skin photoaging induced by ultraviolet irradiation and reduce the damage to collagen and elastin. Meanwhile, MAAs significantly inhibited the decrease in hydroxyproline and collagen content and protected against pathological damage to collagen fibers in photoaging skin. MAAs resulted in a reduction in the expression of interstitial collagenase (MMP-1), matrix metalloproteinases (MMP-3) and tumor necrosis factor-α (TNF-α) and a reduction in the content of tissue matrix metalloproteinase (MMPs). Furthermore, MAAs may promote procollagen synthesis by downregulating the expression of TNF-α and downregulating the levels of MMPs, which demonstrates that MAAs are involved in matrix collagen synthesis by activating the NF-kB pathway in photoaging skin. Based on these results, we concluded that MAAs protect skin from UV irradiation-induced photodamage, and therefore, MAAs may be a potentially effective agent for the prevention of photoaging. Graphical Abstract Unlabelled Image Highlights • Mycosporine-like amino acids (MAAs) from Porphyra tenera against skin photoaging. • MAAs extracted from Porphyra tenera were separated: Porphyra-334 andshinorine. • MAAs may promote procollagen synthesis by down-regulate expression of TNF-α and MMPs level. • MAAs could suppressed inflammation by activating the NF-kB and MAPK signaling pathway. [ABSTRACT FROM AUTHOR]

Skin pigmentation is believed to contribute to the generally low serum 25-hydroxyvitamin D (25(OH)D) concentrations observed in darker-skinned persons. The influence of measured skin pigmentation on UVB-induced 25(OH)D increase was investigated together with 9 demographic and 13 genetic parameters (pigment SNPs). Forty participants representing a wide range in measured skin pigmentation were exposed to identical UVB doses on identical body areas over nine weeks with weekly measurements of serum 25(OH)D. This study took place in Denmark during winter, a period with negligible ambient UVB, so variation in 25(OH)D synthesis was not influenced by latitude, season, sun and clothing habits. The increase in 25(OH)D concentration displayed considerable variation (range: 2.9 to 139 nmol L−1). Constitutive and facultative skin pigmentation exerted separate influence on the variation of the UVB-induced linear 25(OH)D increase. However, this influence was statistically non-significant in the presence of separate significant pigment SNPs. The variation in the 25(OH)D increase in the combined linear model was not explained by measured skin pigmentation but by sex, height, age and seven SNPs located in the ASIP, MTAP, MIR196A29 and Solute Carrier Family genes. This linear model including individual intercepts and the 10 parameters influencing the slope explained 77.4% of the variation. This study confirmed the influence of sex, age and height on 25(OH)D increase and found that pigment genes provided a better relation to UVB-induced 25(OH)D increase compared to the actual measured skin pigmentation. Therefore, only investigating skin pigmentation obscures other causal parameters for low 25(OH)D. [ABSTRACT FROM AUTHOR]

Abstract Natured botanical extract has attracted considerable attention recently in the field of skin anti-ultraviolet (UV) radiation. As a medicinal herb, Sophora japonica flower buds contained several components such as flavonoids, isoflavonoids, triterpenes, alkaloids and polysaccharides, which have multiple pharmacological properties except hemostatic agents which have been used in China and Korea for centuries. The purpose of our study was to investigate whether polysaccharide extracted from Sophora japonica L. flower buds (PS) was able to attenuate UVB-induced damage using a human keratinocyte cell line (HaCaT cells). HaCaT cells were pretreated with PS in a serum-free medium for 2 h and then irradiated with different doses of UVB rays. The results showed that the PS attenuated UVB-induced cytotoxicity which was verified by MTT method and morphology feature assay. UVB exposure (30–120 mJ/cm2) reduced HaCaT cells viability significantly following with the increased irradiation dose 24 h later, while pretreatment with PS (0.25–2.0 mg/mL) attenuated UVB-induced cytotoxicity significantly and increased cell viability in a dose-dependent manner except 30 mJ/cm2 group. The PS reduced the ROS generation, down-regulated the expression of phosphor-JNK and phosphor-p38 MAPK proteins significantly through MAPK pathway in UVB-irradiated HaCaT cells. It also decreased the apoptosis rate at low dose of UVB ray and protected the cells from apoptosis which had been identified by the down-regulated level of active-caspase3 in UVB-irradiated HaCaT cells. In conclusion, PS pretreatment protected HaCaT keratinocytes from UVB irradiation-induced skin injuries effectively, and the underlying mechanism may involve MAPK signaling pathway which contribute to apoptotic cell death. However, further studies especially whose using human systems are needed to determine efficacy of PS in vivo. Graphical Abstract Unlabelled Image Highlights • Polysaccharide from Sophora japonica flower buds decreases UVB-induced cytotoxicity. • The polysaccharide significantly reduces UVB-induced ROS generation. • The Polysaccharide decreases UVB-induced apoptosis rate. [ABSTRACT FROM AUTHOR]

Excessive exposure to ultraviolet (UV) radiation can chemically alter biological molecules and is one of the major environmental health risks with potential to damage the structure and function of the skin. Numerous dietary supplements are known to optimize the skin's defenses against radiation exposure. Several studies in which the beneficial roles of functional food components, that can protect against UV‐induced skin damage, have been demonstrated. Supplemental dietary sphingomyelin maintains covalently bound ω‐hydroxy ceramides to avert skin barrier defects after UVB irradiation. The oral administration of collagen hydrolysates has been shown to limit decreases in skin elasticity via increases in the dermal hyaluronic acid content. Milk fermented with lactic acid bacteria has been shown to augment DNA repair mechanisms and improve skin immunity in the aftermath of UVB damage. Furthermore, long‐term ingestion of fermented milk containing lactic acid bacteria, collagen hydrolysates and sphingomyelin increases the minimal erythema dose (MED) in human subjects with moderate sunburn or redness and tanned skin after exposure to UV solar radiation. Thus, products containing these functional food components are one means by which the adverse effects of UV radiation on the skin can be mitigated. [ABSTRACT FROM AUTHOR]

Summary: Background: Novel drug delivery systems have gained popularity since last two decades because of its advantages over conventional dosage forms. Effect of UV radiation on skin can cause either acute or chronic damage to our skin. Solid lipid nanoparticles (SLNs) were developed as novel carrier over the conventional carrier systems like liposomes and emulsions. The SLNs were selected as a carrier for the formulation because of its ability to protect the labile drug particles, the ability to make the drug release in a controlled manner, and occlusive property of the SLNs. Objective: The current review is an attempt to focus on the characteristics of solid lipid nanoparticles, methods for the preparations, and their cosmetic applications along with some future perspectives of the nanodrug delivery systems. Methods: A review of the current literature of solid lipid nanoparticles (SLNs) as novel carrier showed better photoprotection in sunscreens. Results and conclusions: The disadvantages of conventional sunscreens can be overcome by incorporation of solid lipid nanoparticles. On comparing the lipid nanobased systems with traditional cosmetic products, the occlusion can be achieved without the use of paraffin and other greasy oils. The film formed by lipid nanoparticles will be smooth as compared to the inflexible films formed by the paraffin. Newer approaches may lead to even better results. They also possess excellent UV‐blocking activity and showed better photoprotection. [ABSTRACT FROM AUTHOR]

Abstract The primary cause of non-melanoma skin cancer (NMSC) is ultraviolet B (UVB) radiation. We have shown previously that mTORC2 inhibition sensitizes keratinocytes to UVB-induced apoptosis mediated by the transcription factor FOXO3a. FOXO3a is a key regulator of apoptosis and a tumor suppressor in several cancer types. Activation of FOXO3a promotes apoptosis through the coordinated expression of a variety of target genes, including TRAIL and NOXA. We hypothesized that in the setting of mTORC2 inhibition, the UVB-induced expression of these factors would lead to apoptosis in a FOXO3a-dependent manner. Using spontaneously immortalized human keratinocytes (HaCaT cells), we observed that both TRAIL and NOXA expression increased in cells exposed to UVB and the TOR kinase inhibitor Torin 2. Similar to knockdown of FOXO3a, NOXA knockdown reversed the sensitization to UVB-induced apoptosis caused by mTORC2 inhibition. In contrast, loss of TRAIL by either knockdown or knockout actually enhanced expression of nuclear FOXO3a, which maintained apoptosis. These surprising results are not due to faulty death receptor signaling in HaCaT cells, as we found that the cells undergo extrinsic apoptosis in response to treatment with recombinant TRAIL. Even more striking, TRAIL knockout cells were sensitized to recombinant TRAIL-induced apoptosis compared to wild-type HaCaT cells, with the largest increase occurring in the presence of mTORC2 inhibition. Taken together, these studies provide strong evidence that mTORC2 controls UVB-induced apoptosis by regulating NOXA expression downstream of FOXO3a. Moreover, FOXO3a transcriptional activation by mTORC2 inhibitors may be a valuable target for prevention or therapy of NMSC, especially in cases with low endogenous TRAIL. Graphical abstract Unlabelled Image Highlights • Regulation of TRAIL and NOXA is dependent on mTOR/FOXO3a signaling following UVB. • TRAIL loss has no effect on UVB-induced apoptosis in cells with mTORC2 inhibition. • Knockout of TRAIL sensitizes cells to recombinant TRAIL-induced cell death. • Increased NOXA drives UVB-induced apoptosis following inhibition of mTORC2. [ABSTRACT FROM AUTHOR]

Benzophenone-4 (BP4) is UV-filter that is widely in sunscreens and cosmetics to prevent skin damage from sunlight exposure. Washing off of BP4 from the human body in swimming pools represents a direct source of BP4 in the environment. In this study, we investigated the transformation of BP4 by free chlorine, chloramine, and UV/chlorine, which can be found in swimming pool water. It was found that BP4 can be rapidly removed by both chlorine and chloramine treatment, but only chlorination led to appreciable formation of chlorinated disinfection by-products (DBPs), such as dichloroacetic acid and trichloroacetic acid. However, chloramination of BP4 resulted in higher levels of chlorinated intermediates, which were relatively recalcitrant to further chlorination. The UV/chlorine process was significantly more efficient than the chlorine treatment alone for BP4 removal and resulted in trace chlorinated intermediates and formation of DBPs. Radical scavenger tests revealed that the removal of BP4 in the UV/chlorine process was mostly ascribed to reactions with the Cl and OH generated from HClO photolysis. The presence of methanol as a radical scavenger resulted in incomplete removal of BP4 in the UV/chlorine process and enhanced the formation of DBPs. The increase in DBP formation was because the residual BP4 can be exited to a triplet state ( 3 BP4 ∗ ) upon UV irradiation. 3 BP4 ∗ subsequently reacted with O 2 to form 1 O 2 , a reactive oxygen species that generated DBPs by reacting with chlorinated intermediates in water. All benzophenone-type UV-filters may have similar photochemical activity and thus influence the transformation of other organics in sunlit surface water environments. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) is a common and abundant environmental factor that affects daily life. Although the effects of UV radiation on the skin have been extensively reported, studies on the influence of UV radiation on internal organs are still limited. This study aimed to evaluate the influence of UVB exposure on the kidney of mice and to investigate the possible mechanism. In the present study, histopathology changes, oxidative stress, and inflammatory response were used to evaluate the kidney and colon injury induced by UVB exposure. The results showed that the 14-week chronic skin exposure to UVB triggers a kidney injury response characterized by macrophage infiltration, elevated oxidative stress as well as inflammatory and injury markers. The RNA sequencing demonstrated that chronic UVB exposure could alter the kidney transcriptomic profile distinguished by the regulation of genes involved in the Notch signaling pathway, JAK-STAT signaling pathway, and ECM-receptor interaction. Besides, chronic UVB exposure also resulted in gut dysbiosis, manifested as colon macrophage infiltration, stimulated inflammatory responses, impaired barrier integrity, and microbiota structural and functional disorders. The Spearman analysis results further revealed a strong correlation between gut microbiota and kidney injury. In conclusion, skin chronic exposure to UVB causes nephritis and gut microbiota dysbiosis in mice, and these findings provide new insight into the underlying risks of chronic UVB exposure to human wellness. [Display omitted] • Mice chronic exposure to UVB induced renal inflammation and colonic injury. • More than 1700 DEGs were identified by RNA-seq in kidneys of UVB-irradiated mice. • Chronic UVB exposure upregulated Notch, JAK-STAT, and ECM pathways in the kidneys. • Chronic UVB exposure altered the gut microbiota structure and function in mice. [ABSTRACT FROM AUTHOR]

Studies assessing the impact of extrinsic factors on skin aging have increased during the last with the increase in life expectancy. Although most of the studies are about the sun radiation impact, many factors should be considered in elderly people, beyond environmental conditions. Lifestyle factors, like diet, sleeping, smoking, should be analyzed carefully, as common age-related conditions (menopause, diabetes, pulmonary diseases, etc.). All these factors could accelerate the natural decline of skin structure and functions, possibly affecting the responses to treatments and drugs. This review demonstrates that growing evidence regarding environmental factors that are associated with lifestyle and comorbidities deserve greater attention from researchers and dermatologists and may require new approaches in the management of skin aging. [ABSTRACT FROM AUTHOR]

Adult wild-type mice are not supposed to be proper models for ultraviolet radiation (UVR)-induced melanoma since melanocytes are confined to hair follicles and cannot be sufficiently reached by UVR. On the other hand, in mutated mouse models used for melanoma research limitations, including an altered immune system and selection of affected pathways, lead to tumors phenotypically quite different from naturally occurring melanomas. We compared the distribution of epidermal melanocytes in UVR and not-UVR-exposed wild-type C57BL/6 mice. Starting at the age of 8 weeks, mice were exposed to physiologic doses of UVR three times weekly over 16 weeks. Back skin biopsies were taken 4, 8, 12 and 16 weeks after initiation of exposure, and stained for Melan-A, representing a highly selective marker for melanocytes. Surprisingly, after exposure to UVR, Melan-A positive cells were detected also in the interfollicular epidermis of C57BL/6 mice. We conclude that UVR is capable of inducing interfollicular epidermal melanocytes in wild-type mice. [ABSTRACT FROM AUTHOR]

Background. To assess effectiveness of NPE, a proprietary Camellia sinensis nonfermentatum (CSNF) extract, in prevention and recovery of acute radiation-induced skin reaction (ARSR) and skin care during postoperative whole breast radiotherapy (RT). Methods. Twenty patients were enrolled in this single centre, prospective, open-label pilot study. The outcomes of 20 prospective data sets were compared with 100 retrospectively collected matched data sets derived from hospital records. The preventive CSNF gel (2.5%) was administered 1 to 2 hours before each session on the irradiated fields. The care CSNF lotion (0.4%) was administered as 7-day pretreatment after each RT session, twice daily between RT sessions, and 4 to 8 weeks thereafter. The control group was treated according to the hospital care guidelines. The primary endpoint was time to ARSR ≥ Grade 2 (CTCAE v4.03); secondary endpoints were frequencies of ARSR grades 1, 2, 3, and 4, recovery of ARSR, frequencies of interruption and RT stop, complications and required rescue interventions, and tolerability of CSNF. Results. Time to ARSR ≥ G2 (censoring) was significantly longer (p = 0.014) in the CSNF group. The hazard ratio was 2.33 (95% CI: 1.15–4.72), demonstrating a 50% decrease in the risk of developing ARSR ≥ G2. There was a trend to faster recovery from ARSR G2 in the CSNF group (100% versus 47%; p = 0.078). The proportion of patients requiring rescue treatment during RT and follow-up was markedly higher in the control compared to the CSNF group (1% to 51% versus 0% to 15%). CSNF gel and lotion were well tolerated both during and after RT. Conclusions. This pilot study provides the first evidence on the potential pharmacological effectiveness of CSNF extract in prevention of RT-induced ARSR and recovery of skin irritation in patients undergoing postoperative whole breast RT and may reflect a novel concept for prevention of RT-induced ARSR and care of irritated skin. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted to explore the therapeutic potential of human adipose‐derived stem cells (ADSCs) irradiated with a low‐level laser (LLL). Cultured ADSCs were treated with 650‐nm GaAlAs laser irradiation at 2, 4 and 8 J cm−2. Cell proliferation was quantified by MTT assays, cytokine secretion was determined by enzyme‐linked immunosorbent assays, and adipogenic differentiation was examined by oil red O staining. Additionally, the expression profiles of putative ADSC surface markers were analyzed by quantitative real‐time PCR. In addition, a mouse photoaged skin model was established by UVB irradiation. Effects of GaAlAs laser–treated ADSCs on the thicknesses of the epidermis and dermis were analyzed by hematoxylin and eosin staining. The results showed that GaAlAs laser treatment of cells at a radiant exposure of 4 J cm−2 enhanced ADSC proliferation and adipogenic differentiation and increased secretion of growth factors. Furthermore, GaAlAs laser irradiation upregulated the expression of putative ADSC surface markers. In the mouse model of photoaged skin, ADSCs treated with GaAlAs laser irradiation had markedly decreased the epidermal thickness and increased the dermal thickness of photoaged mouse skin. Our data indicate that LLL irradiation is an effective biostimulator of ADSCs and might enhance the therapeutic potential of ADSCs for clinical use. [ABSTRACT FROM AUTHOR]