Linoleic Acid Induces Metabolic Reprogramming and Inhibits Oxidative and Inflammatory Effects in Keratinocytes Exposed to UVB Radiation.

Linoleic acid (LA), the primary ω-6 polyunsaturated fatty acid (PUFA) found in the epidermis, plays a crucial role in preserving the integrity of the skin's water permeability barrier. Additionally, vegetable oils rich in LA have been shown to notably mitigate ultraviolet (UV) radiation-induced effects, including the production of reactive oxygen species (ROS), cellular damage, and skin photoaging. These beneficial effects are primarily ascribed to the LA in these oils. Nonetheless, the precise mechanisms through which LA confers protection against damage induced by exposure to UVB radiation remain unclear. This study aimed to examine whether LA can restore redox and metabolic equilibria and to assess its influence on the inflammatory response triggered by UVB radiation in keratinocytes. Flow cytometry analysis unveiled the capacity of LA to diminish UVB-induced ROS levels in HaCaT cells. GC/MS-based metabolomics highlighted significant metabolic changes, especially in carbohydrate, amino acid, and glutathione (GSH) metabolism, with LA restoring depleted GSH levels post-UVB exposure. LA also upregulated PI3K/Akt-dependent GCLC and GSS expression while downregulating COX-2 expression. These results suggest that LA induces metabolic reprogramming, protecting against UVB-induced oxidative damage by enhancing GSH biosynthesis via PI3K/Akt signaling. Moreover, it suppresses UVB-induced COX-2 expression in HaCaT cells, making LA treatment a promising strategy against UVB-induced oxidative and inflammatory damage.

Sunproofing from within: A deep dive into oral photoprotection strategies in dermatology.

BACKGROUND: Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others. METHODS: A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health. RESULTS: Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection. CONCLUSION: Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.

Spatially modulated ablation driven by chaotic attractors in human lung epithelial cancer cells.

A significant modification in photoinduced energy transfer in cancer cells is reported by the assistance of a dynamic modulation of the beam size of laser irradiation. Human lung epithelial cancer cells in monolayer form were studied. In contrast to the quantum and thermal ablation effect promoted by a standard focused Gaussian beam, a spatially modulated beam can caused around 15% of decrease in the ablation threshold and formation of a ring-shaped distribution of the photothermal transfer effect. Optical irradiation was conducted in A549 cells by a 532 nm single-beam emerging from a Nd:YVO4 system. Ablation effects derived from spatially modulated convergent waves were controlled by an electrically focus-tunable lens. The proposed chaotic behavior of the spatial modulation followed an Arneodo chaotic oscillator. Fractional dynamic thermal transport was analyzed in order to describe photoenergy in propagation through the samples. Immediate applications of chaos theory for developing phototechnology devices driving biological functions or phototherapy treatments can be considered.

Recombinant production of a highly efficient photolyase from Thermus thermophilus.

Ultraviolet (UV) radiation from sunlight can damage DNA, inducing mutagenesis and eventually leading to skin cancer. Topical sunscreens are used to avoid the effect of UV irradiation, but the topical application of DNA repair enzymes, such as photolyase, can provide active photoprotection by DNA recovery. Here we produced a recombinant Thermus thermophilus photolyase expressed in Escherichia coli, evaluated the kinetic parameters of bacterial growth and the kinetics and stability of the enzyme. The maximum biomass (𝑋𝑚𝑎𝑥 ) of 2.0 g L-1 was reached after 5 h of cultivation, corresponding to 𝑃X  = 0.4 g L-1 h. The µð‘šð‘Žð‘¥ corresponded to 1.0 h-1 . Photolyase was purified by affinity chromatography and high amounts of pure enzyme were obtained (3.25 mg L-1 of cultivation). Two different methods demonstrated the enzyme activity on DNA samples and very low enzyme concentrations, such as 15 µg mL-1 , already resulted in 90% of CPD photodamage removal. We also determined photolyase kM of 9.5 nM, confirming the potential of the enzyme at very low concentrations, and demonstrated conservation of enzyme activity after freezing (-20°C) and lyophilization. Therefore, we demonstrate T. thermophilus photolyase capacity of CPD damage repair and its potential as an active ingredient to be incorporated in dermatological products.

Caracterización del fotoenvejecimiento en consulta de Dermatología

Introducción: El fotoenvejecimiento es una entidad creciente en la consulta de Dermatología, y su comportamiento aparece en edades tempranas de la vida. Esto trae como consecuencia el surgimiento del cáncer cutáneo de forma precoz. Esta afección resulta de la combinación de los efectos del envejecimiento biológico y las consecuencias a largo plazo de la exposición a la radiación ultravioleta, fenómeno que afecta las zonas de la piel expuestas con numerosos cambios morfofisiológicos. Objetivo: Caracterizar el fotoenvejecimiento en pacientes asistidos en consulta de Dermatología. Materiales y métodos: Se realizó un estudio descriptivo, prospectivo en consulta de Dermatología. El universo quedó constituido por 35 pacientes con diagnóstico de fotoenvejecimiento. Se recolectaron las variables en un modelo para este fin. Los resultados se procesaron en tablas para el análisis y discusión de los mismos. Resultados: La mayor frecuencia estuvo entre los 20-30 años y 31-40, con un 37,14 %. El sexo femenino presentó el 91,43 %. Se mostró prevalencia del fotoenvejecimiento grado II, con un 62,86 %, y fotoexposición todo el año, con un 68,57 %. El 74,28 % de los casos fueron trabajadores. Los pacientes con fototipo grados II y III con fotoenvejecimiento grado II, fueron los de mayor porcentaje, con 61,5 % y 56,2 % respectivamente. El 77,3 % tuvo entre 11 y 20 lesiones, y el melasma fue la de mayor incidencia, con 61,54 %. Conclusiones: Las féminas de edad media con fototipo grado III, fotoenvejecimiento grado II, y fotoexpuestas todo el año, mostraron un promedio entre 11 y 20 lesiones, siendo el melasma la más identificada.

Introduction: Photoaging is a growing entity in the Dermatology consultation, and its behavior appears in early ages of life. This results in the onset of precocious skin cancer. This affection results from the combination of the effects of biological aging and the long-term consequences of exposure to ultraviolet radiation, a phenomenon that affects exposed skin areas with numerous morphophysiological changes. Objective: To characterize photoaging in patients treated in Dermatology consultation. Materials and methods: A descriptive, prospective study was carried out in a Dermatology consultation. The universe consisted of 35 patients with diagnosis of photoaging. The variables were collected in a form for this purpose. The results were processed in tables, for their analysis and discussion. Results: The highest frequency was between 20-30 and 31-40 years, with 37.14%. Female sex accounted for 91.43%. It was shown the prevalence of grade II photoaging, with 62.86%, and photo-exposure throughout the year, with 68.75%. 74.28% of cases were workers. The patients with grade II and III phototypes, with grade II photoaging, were the ones with highest percentage, with 61.5% and 56.2% respectively. 77.3% had between 11 and 20 lesions, and melasma had the highest incidence, with 61.54%. Conclusions: Middle-aged women, with grade III photo-type, grade II photoaging, and photoexposure throughout the year, showed an average of between 11 to 20 lesions, melasma being the most identified.

Pirfenidone Protects from UVB-Induced Photodamage in Hairless Mice.

BACKGROUND: Ultraviolet radiation (UV) is the main environmental factor that causes histological degenerative changes of the skin giving rise to a chronic process called photodamage. Non-melanoma skin cancer induced by UVB radiation is a result of a cascade of molecular events caused by DNA damage in epidermis cells, including persistent inflammation, oxidative stress, and suppression of T cell-mediated immunity. Retinoids such as tretinoin have been widely used in skin to treat photoaging and photodamage, though its secondary adverse effects have been recognized. Pirfenidone (PFD) has emerged as an antifibrogenic, anti-inflammatory and antioxidant agent, and in this work its efficacy was evaluated in a model of UVB-induced photodamage. METHODS: Epidermal, dermal, and inflammatory changes were measured by histomorphometric parameters. In addition, gene, and protein expression of key molecules in these processes were evaluated. RESULTS: Our results revealed an anti-photodamage effect of topical PFD with absence of inflammatory skin lesions determined by dermoscopy. In addition, PFD reduced elastosis, improved organization, arrangement, and deposition of dermal collagens, downregulated several pro-inflammatory markers such as NF-kB, IL-1, IL-6 and TNFα, and decreased keratinocyte damage. CONCLUSION: Topical pirfenidone represents a promising agent for the treatment of cell photodamage in humans. Clinical trials need to be carried out to explore this premise.

Inflammatory stimulus worsens the effects of UV-A exposure on J774 cells.

UV-A radiation affects skin homeostasis by promoting oxidative distress. Endogenous photosensitizers in the dermis and epidermis of human skin absorb UV-A radiation forming excited states (singlet and triplet) and reactive oxygen species (ROS) producing oxidized compounds that trigger biological responses. The activation of NF-kB induces the expression of pro-inflammatory cytokines and can intensify the generation of ROS. However, there is no studies evaluating the cross talks between inflammatory stimulus and UV-A exposure on the levels of redox misbalance and inflammation. In here, we evaluated the effects of UV-A exposure on J774 macrophage cells previously challenged with LPS in terms of oxidative distress, release of pro-inflammatory cytokines, and activation of regulated cell death pathways. Our results showed that LPS potentiates the dose-dependent UV-A-induced oxidative distress and cytokine release, in addition to amplifying the regulated (autophagy and apoptosis) and non-regulated (necrosis) mechanisms of cell death, indicating that a previous inflammatory stimulus potentiates UV-A-induced cell damage. We discuss these results in terms of the current-available skin care strategies.

Caracterización clínico-epidemiológica de pacientes con daño actínico crónico. Cochabamba, Bolivia / Clinical-epidemiological characterization of patients with chronic actinic damage. Cochabamba, Bolivia

RESUMEN Introducción: el daño actínico crónico es un grupo de alteraciones en la estructura, función y apariencia de la piel como resultado de la exposición no controlada a las radiaciones ultravioletas. Puede provocar el cáncer de piel. Objetivo: caracterizar a los pacientes con daño actínico crónico, atendidos en la consulta de Dermatología del Hospital Comunitario Valle Hermoso, en el departamento de Cochabamba, Bolivia. Materiales y métodos: se realizó un estudio clínico descriptivo, prospectivo, en un universo de 1 833 pacientes diagnosticados con daño actínico crónico, atendidos en la consulta de Dermatología del Hospital Comunitario Valle Hermoso, en Cochabamba, entre septiembre de 2017 y septiembre de 2018. Se evaluaron las variables edad, sexo, color y fototipo de piel, ocupación, uso de medios de protección solar, exposición a otro tipo de radiaciones, manifestaciones clínicas de fotodaño y altitud del lugar de residencia. Resultados: predominaron el grupo de edad de 25 a 59 años, el sexo femenino, el color de piel mestizo (77,08 %), el fototipo de piel IV (76,98 %) y la ocupación comerciante (72,56 %). La mayoría de los pacientes (82,7 %) no utilizaron medios de protección solar, y el 99,8 % no tuvieron exposición a otro tipo de radiaciones. Las lesiones por fotodaño que prevalecieron fueron melasma (83,03 %) y lentigos (12,22 %). El 99,29 % vivían en zonas de gran altitud. Conclusiones: se caracterizaron los pacientes con daño actínico crónico, obteniendo en algunas variables estudiadas resultados similares a los mencionados por otros investigadores (AU).

ABSTRACT Introduction: chronic actinic damage is a group of alterations in the structure, function, and appearance of the skin as a result of uncontrolled exposure to ultraviolet radiation. It can cause skin cancer. Objective: to characterize the patients with chronic actinic damage, treated at the Dermatology consultation of Valle Hermoso Community Hospital, in the department of Cochabamba, Bolivia. Materials and methods: a descriptive, prospective clinical study was conducted in a universe of 1,833 patients diagnosed with chronic actinic damage, treated at the Dermatology clinic of the Valle Hermoso Community Hospital, Cochabamba, between September 2017 and September 2018. The variables age, sex, skin color, skin phototype, occupation, use of sun protectors, exposure to other types of radiation, clinical manifestations of photodamage and altitude of the place of residence were evaluated. Results: the age group from 25 to 59 years, the female sex, mestizo skin color (77.08 %), the IV skin phototype (76.98 %) and merchant occupation (72.56 %) predominated. Most patients (82.7 %) did not use sun protection means, and 99.8 % had no other radiation exposure. The prevailing photodamage lesions were melasma (83.03 %) and lentigo (12.22 %). 99.29 % lived in high altitude areas. Conclusions: the patients with chronic actinic damage were characterized, obtaining in some variables studied results similar to those mentioned by other researchers (AU).

Lycium barbarum polysaccharide fraction associated with photobiomodulation protects from epithelium thickness and collagen fragmentation in a model of cutaneous photodamage.

Ultraviolet radiation (UVR) is the major etiologic agent of cutaneous photoaging, and different strategies are used to prevent and treat this condition. The polysaccharide fraction (LBPF) isolated from Lycium Barbarum fruits (goji berry) contains several active ingredients with antioxidant, immune system modulation, and antitumor effects. In addition, the photobiomodulation (PBM) is widely applied in photoaging treatment. This study investigated the effects of LBPF and PBM against the UVR-induced photodamage in the skin of hairless mice. The mice were photoaged for 6 weeks in a chronic and cumulative exposure regimen using a 300-W incandescent lamp that simulates the UVR effects. From the third to the sixth week of photoaging induction, the animals received topical applications of LBPF and PBM, singly or combined, in different orders (first LBPF and then PBM and inversely), three times per week after each session of photoaging. After completion of experiments, the dorsal region skin was collected for the analysis of thickness, collagen content, and metalloproteinases (MMP) levels. A photoprotective potential against the increase of the epithelium thickness and the fragmentation of the collagen fibers was achieved in the skin of mice treated with LBPF or PBM singly, as well as their combination. All treatments maintained the skin collagen composition, except when PBM was applied after the LBPF. However, no treatment protected against the UVR-induced MMP increase. Taken together, we have shown that the LBPF and PBM promote a photoprotective effect in hairless mice skin against epidermal thickening and low collagen density. Both strategies, singly and combined, can be used to reduce the UVR-induced cutaneous photoaging.

Histopathological features of photodamage and mast cell infiltrate in actinic cheilitis with different grades of epithelial dysplasia.

BACKGROUND: Actinic cheilitis is induced by chronic exposure to ultraviolet radiation and shows solar elastosis, a feature that has been associated with mast cell infiltrates. This study aimed to investigate the area of solar elastosis, collagen loss, and mast cell infiltrates in a series of actinic cheilitis. METHODS: We evaluated the epithelial dysplasia in 52 cases of actinic cheilitis and the solar elastosis with Weigert's resorcin-fuchsin. Collagen loss was evaluated with Picrosirius red, analyzed under polarized microscopy, and scored from 1 to 3. Elastosis proportionate area (EPA) was calculated with image software. Mast cells were highlighted with toluidine blue stain. RESULTS: EPA varied from 2% to 45%, with a mean of 17.1% in the cases, with no differences among epithelial dysplasia degrees. Most cases presented collagen loss scores of 2 or 3, and higher loss of type I collagen was associated with older age. Mast cell density was higher in severe epithelial dysplasia (P = 0.002) and in high-risk cases (P = 0.01). CONCLUSION: Actinic cheilitis presented variable EPA and marked loss of type I collagen; however, these features were not associated with the degrees of epithelial dysplasia. Besides, mast cell density increased with epithelial dysplasia worsening and this was not associated with elastosis area or collagen loss.

Identifying Specific Subcellular Organelle Damage by Photosensitized Oxidations.

The search for conditions that maximize the outcome of Photodynamic Therapy (PDT) continues. Recent data indicate that PDT-induced cell death depends more on the specific intracellular location of the photosensitizer (PS) than on any other parameter. Indeed, knowledge of the PS intracellular location allows the establishment of clear relationships between the mechanism of cell death and the PDT efficacy. In order to determine the intracellular localization sites of a given PS, classical co-localization protocols, which are based in the comparison of the emissive profiles of organelle-specific probes to those of the PS, are usually performed. Since PSs are usually not efficient fluorophores, co-localization protocols require relatively high PS concentrations (micromolar range), distorting the whole proposal of the experiment, as high PS concentration means accumulation in many low-affinity sites. To overcome this difficulty, herein we describe a method that identifies PS intracellular localization by recognizing and quantifying the photodamage at intracellular organelles. We propose that irradiation protocols and characterization of major sites of photodamage results from many cycles of photosensitized oxidations, furnishing an integrated picture of the PS location. By comparing the results of protocols based in either method, we showed that the analysis of the damaged organelles can be conducted at optimal conditions (low PS concentrations), providing clear correlations with cell death mechanisms, which is not the case for the results obtained with co-localization protocols. Experiments using PSs that target either mitochondria or lysosomes were described and investigated in detail, showing that evaluating organelle damage is as simple as performing co-localization protocols.

Fotoprotección y fotodaño en la niñez y la adolescencia / Photoprotection and photodamage in the childhood and adolescence

Durante las últimas décadas se ha incrementado la incidencia del cáncer de piel, debido fundamentalmente a la exposición a las radiaciones solares, por lo cual es importante la protección desde las edades tempranas. Teniendo en cuenta lo anterior, se realizó una revisión bibliográfica con el objetivo de describir los efectos que estas ocasionan en los seres humanos y las formas de protección adecuadas. Se concluyó que el conocimiento y la implementación de las recomendaciones para la fotoprotección, son necesarias para prevenir los efectos causados por dichas radiaciones.

During the last decades the incidence of the skin cancer has been increased, due fundamentally to the exposure to the sun radiations, reason why it is important the protection since early ages. Keeping this in mind, a literature review was carried out with the objective of describing the effects that they cause in the human beings and the appropriate protection forms. It was concluded that the knowledge and the implementation of the recommendations for photoprotection, are necessary to prevent the effects caused by these radiations.

Elastosis en la queilitis actínica. Revisión de literatura / Elastosis in Actinic Cheilitis. Literature Review

Resumen La matriz extracelular (MEC) juega un papel importante en la regulación de los eventos biológicos, tales como, el desarrollo de la migración celular, proliferación y diferenciación. La exposición crónica a la luz ultravioleta (UV) provoca elastosis (en distintos grados), que corresponde a una degeneración basófila de la MEC. La queilitis actínica (QA) es una lesión potencialmente maligna del labio inducida por la exposición regular y prolongada a la luz UV, que afecta principalmente al bermellón del labio inferior. Las lesiones de QA tienen un estroma complejo, se observa siempre la presencia de elastosis, infiltrado inflamatorio crónico de distinta intensidad y la aparición de vasos sanguíneos telangiectásicos. Dentro de este infiltrado inflamatorio se ha descrito un aumento significativo de mastocitos (MCs), localizados especialmente alrededor de las zonas de elastosis y en la zona subepitelial. Se ha propuesto que la elastosis actínica se produce tanto por procesos degenerativos como de síntesis anormal de fibras elásticas por parte de fibroblastos con daño solar, lo que va acompañado de cambios morfológicos del colágeno. A pesar de que el fibroblasto tendría un rol preponderante en la formación de la elastosis actínica, diversos estudios sugieren que otros tipos celulares como el MC también contribuirían en forma significativa al daño actínico de la MEC. El propósito de esta revisión es analizar las características de la elastosis en la QA.

Abstract The extracellular matrix (ECM) plays an important role in the regulation of biological events, such as cell migration, proliferation and differentiation. Chronic exposure to ultraviolet (UV) light causes elastosis (to varying degrees), which corresponds to a basophilic degeneration of the ECM. Actinic cheilitis (AC) is a potentially malignant lip lesion induced by regular and prolonged exposure to UV light, which mainly affects the vermilion. AC lesions have a complex stroma characterized by the presence of elastosis, chronic inflammatory infiltrate of different intensity and the appearance of telangiectatic blood vessels. Within this inflammatory infiltrate a significant increase of mast cells (MCs) has been described, located especially around areas of elastosis and at the subepithelial zone. It has been proposed that actinic elastosis is produced both, by degenerative processes and by abnormal synthesis of elastic fibers by photodamaged fibroblasts, which is accompanied by morphological changes in collagen. Although the fibroblast would play a major role in actinic elastosis formation, several studies suggest that other cell types such as MCs also contribute significantly to actinic ECM damage. The purpose of this review is to discuss the characteristics of elastosis in AC.

Conocimientos, hábitos y actitudes de fotoprotección en adolescentes / Knowledge, habits, and attitudes of photoprotection in teenagers

Introducción: el cáncer de piel es una neoplasia frecuente en el ser humano a nivel mundial, su incidencia se ha incrementado durante las últimas décadas, considerado como una expresión de hábitos de mayor exposición a radiaciones ultravioletas. Entre el 60% y 80 % de la exposición solar a lo largo de la vida tiene lugar antes de la edad de 18 años. Los niños y adolescentes son los más vulnerables a la radiación, debido a que el daño solar es máximo y acumulativo. Objetivo: describir los conocimientos, hábitos y actitudes de fotoprotección en escolares del nivel secundario. Material y métodos: se realizó un estudio descriptivo, transversal en adolescentes de la Escuela Secundaria Básica Cándido González, ubicada en la localidad ¨La Playa¨, municipio Matanzas, en el periodo de febrero a marzo del 2017. El universo quedó constituido por la totalidad de los estudiantes que cursan el séptimo y octavo grado (259). Resultados: se encontró un predominio del fototipo cutáneo III en la población de estudio. En cuanto a los conocimientos sobre fotoprotección y fotodaño, 195 estudiantes (75,3%) fueron evaluados de mal. El 65,6% de los adolescentes refirieron usar cremas de protección solar. En relación con la actitud ante el bronceado, se observó que fue adecuada en 240 alumnos (92,7%). Conclusiones: los malos conocimientos sobre fotoprotección y fotodaño de los alumnos encuestados pueden estar relacionados a hábitos inadecuados e historias de quemadura solar encontrados (AU).

Introduction: skin cancer is a frequent neoplasia in the human being all around the world; its incidence has increased during the last decades, fact that is considered as an expression of habits of more exposition to ultraviolet radiations. Between 60 % and 80 % of the exposition to sunlight throughout the live occurs before the age of 18 years. Children and teenagers are the most vulnerable to radiation due to the fact that sun damage is maximal and accumulative. Objective: to describe knowledge, habits and attitudes of photoprotection in students of the secondary level. Materials and methods: a descriptive, cro0ss-sectional study was carried out in teenagers of the Secondary School ¨Candido González¨, located in La Playa, municipality of Matanzas, in the period from January to March 2017. The universe was formed by all the students attending the 7th and 8th grade (259). Results: the skin phototype III predominated in the studied population. According to knowledge on photoprotection and photodamage, 195 students (75.3 %) were evaluated as bad. 65.6 % of teenagers referred the usage of sun protective creams. In relation with the attitude toward sun tanning, it was adequate in 240 students (92.7 %). Conclusions: the erroneous knowledge on photoprotection and photodamage of the questioned students could be related to inadequate habits and histories of sunburn they listened (AU).

Conocimientos, hábitos y actitudes de fotoprotección en adolescentes / Knowledge, habits, and attitudes of photoprotection in teenagers

Introducción: el cáncer de piel es una neoplasia frecuente en el ser humano a nivel mundial, su incidencia se ha incrementado durante las últimas décadas, considerado como una expresión de hábitos de mayor exposición a radiaciones ultravioletas. Entre el 60% y 80 % de la exposición solar a lo largo de la vida tiene lugar antes de la edad de 18 años. Los niños y adolescentes son los más vulnerables a la radiación, debido a que el daño solar es máximo y acumulativo. Objetivo: describir los conocimientos, hábitos y actitudes de fotoprotección en escolares del nivel secundario. Material y métodos: se realizó un estudio descriptivo, transversal en adolescentes de la Escuela Secundaria Básica Cándido González, ubicada en la localidad ¨La Playa¨, municipio Matanzas, en el periodo de febrero a marzo del 2017. El universo quedó constituido por la totalidad de los estudiantes que cursan el séptimo y octavo grado (259). Resultados: se encontró un predominio del fototipo cutáneo III en la población de estudio. En cuanto a los conocimientos sobre fotoprotección y fotodaño, 195 estudiantes (75,3%) fueron evaluados de mal. El 65,6% de los adolescentes refirieron usar cremas de protección solar. En relación con la actitud ante el bronceado, se observó que fue adecuada en 240 alumnos (92,7%). Conclusiones: los malos conocimientos sobre fotoprotección y fotodaño de los alumnos encuestados pueden estar relacionados a hábitos inadecuados e historias de quemadura solar encontrados (AU).

Introduction: skin cancer is a frequent neoplasia in the human being all around the world; its incidence has increased during the last decades, fact that is considered as an expression of habits of more exposition to ultraviolet radiations. Between 60 % and 80 % of the exposition to sunlight throughout the live occurs before the age of 18 years. Children and teenagers are the most vulnerable to radiation due to the fact that sun damage is maximal and accumulative. Objective: to describe knowledge, habits and attitudes of photoprotection in students of the secondary level. Materials and methods: a descriptive, cro0ss-sectional study was carried out in teenagers of the Secondary School ¨Candido González¨, located in La Playa, municipality of Matanzas, in the period from January to March 2017. The universe was formed by all the students attending the 7th and 8th grade (259). Results: the skin phototype III predominated in the studied population. According to knowledge on photoprotection and photodamage, 195 students (75.3 %) were evaluated as bad. 65.6 % of teenagers referred the usage of sun protective creams. In relation with the attitude toward sun tanning, it was adequate in 240 students (92.7 %). Conclusions: the erroneous knowledge on photoprotection and photodamage of the questioned students could be related to inadequate habits and histories of sunburn they listened (AU).

Estudio morfométrico de la mitosis y altura del epitelio, en piel facial expuesta al foto - daño / Morphometric study of mitosis and epithelial height, in facial skin exposed to photo damage

Introducción: El envejecimiento facial es una consecuencia de factores causales genéticos, exposición al sol, tabaquismo, el efecto de la fuerza de gravedad y la pérdida del trofismo muscular. Existen dos tipos: intrínseco y extrínseco. Objetivo: Profundizar en el conocimiento del efecto del foto- daño en la población holguinera. Método: Se realizó un estudio longitudinal prospectivo en el hospital Vladimir Ilich Lenin, en el periodo de 1ro de septiembre del 2012 al 1ro de septiembre del 2015. Se aplicó una caracterización clínica de edad, sexo, tipo y color de la piel, grado de envejecimiento, así como toma de biopsia para evaluación morfométrica de la altura epitelial y el índice de mitosis. Resultados:Los grupos de edad que predominaron en el estudio fueron los de 40 - 49 y 50 - 59 años, para un 43,3% y 50%, respectivamente. El cutis seco y la piel blanca se encuentran en el mayor número de pacientes con envejecimiento grado III. Los cambios morfométricos fueron significativos en la zona pre- auricular, en relación con la post- auricular en la altura epitelial, no así en el índice de mitosis, donde no hubo diferencias significativas para los mismos. Conclusiones:Se demostró que el envejecimiento facial estuvo condicionado por la edad, el color de la piel, y tipo de cutis. La edad influyó, de igual manera, en la mitosis de ambos grupos y en la altura epitelial, la cual también se vio afectada por el foto- daño en la zona pre- auricular.

Introduction: Facial cutaneous aging is a result of the factors that cause it. Sun exposure, smoking, genetic factors, gravity effects and muscle trophy lost. They are divided in two groups: intrinsically and extrinsically. Objective: to widen the knowledge about the photo- damage in Holguin´s population. Methods: a longitudinal prospective study at Vladimir Ilich Lenin Hospital, within September 2012 and September 2015. Characterization of patient according to age, sex, skin type and skin colour. Biopsies of morphometrical study of epithelial height and mitosis number. Results: most present age groups were: 40 - 49, for 43.3% y and 50 - 59 years old, pointing a 50%. A higher number of dry cutis and white skin patients were found in group III, and the morphometric changes of epithelial level was significant in the pre- auricular region, in relation to post- auricular region. The change in pre- auricular and post- auricular region, was not significant in relation to the number of mitosis. Conclusions: In present studies, facial cutaneous aging is a condition of age, sense and colour skin. Number of mitosis was influenced by age in pre and post- auricular region. Epithelial height was affected in pre- auricular region by photo- damage too.

Daylight Photodynamic Therapy Versus 5-Fluorouracil for the Treatment of Actinic Keratosis: A Case Series.

INTRODUCTION: The incidence of actinic keratosis (AK) continues to increase worldwide. Currently available options for the treatment of AK include topical 5-fluorouracil (5-FU) and daylight-mediated photodynamic therapy (DL-PDT). This split-face pilot study compared DL-PDT using 16% methyl aminolevulinate (MAL) cream versus 5-FU cream in patients with AK on the face/scalp. METHODS: Five male subjects (mean age 70 years) with grade I-III AK on the face/scalp were enrolled. Subjects received a single session of DL-PDT with 16% MAL on one side and topical 5% 5-FU for 21 days on the other side. Evaluations of efficacy, safety, and subject satisfaction were conducted 48 h, 7 days, 14 days, 1 month, and 3 months after treatment. RESULTS: At 3 months, the lesion complete response rate was 80% and 93% for DL-PDT and 5-FU, respectively. Lesion partial response was 20% and 7%, respectively. Fewer treatment-related adverse events (AEs) were reported with DL-PDT than with 5-FU, and they resolved spontaneously in 5-7 and 27-30 days, respectively. Subjects preferred DL-PDT because of the lower incidence of AEs and rapid recovery compared with 5-FU. CONCLUSION: DL-PDT is a convenient alternative to 5-FU with good efficacy and a favorable safety profile, allowing patients to effectively treat their AK without compromising their social life. FUNDING: Galderma.

Histological observation of hairless mice skin after exposure to Simulated Solar Light: Comparison between the histological findings with different methodologies and 3R principle correlations.

BACKGROUND: Albino hairless mouse (AHM) has been used as a biological model in photodermatology. However, the experimental landscape is diverse to follow and need particular attention. PURPOSE: Irradiation parameters were investigated for the development of a protocol to assess alterations in the AHM skin using Simulated Solar Light (SSL). The present study was compared with published articles (last 15 years) according to irradiation protocols, morphological findings to minimize animal suffering and UV exposure. MATERIALS AND METHODS: Three groups: Control (G1), experimental - sunburn (G2) and skin photodamage assay (G3). G2 were immobilized and exposed to SSL once for 15, 30 and 45min. G3 were exposed to SSL, without immobilization, for 15min once a day for one week. The dorsal skin was analyzed using hematoxylin and eosin technique. RESULTS: G2 displayed different sunburn degrees. Based on the profile of the observed morphological alterations, a 15min irradiation was chosen as the exposure time to expose G3, without immobilization, for 5 consecutive days. CONCLUSION: These conditions produced the same morphological changes in the AHM with a shorter solar exposure time, without immobilizing the animals but using environmental exposure fluences, conforming to 3R (reduction - refinement - replacement) recommendations.

Hydrogel containing silibinin-loaded pomegranate oil based nanocapsules exhibits anti-inflammatory effects on skin damage UVB radiation-induced in mice.

The present study shows the development of a topical formulation (hydrogel) containing silibinin-loaded pomegranate oil based nanocapsules suspension and its evaluation as an alternative for the treatment of cutaneous UVB radiation-induced damages. For this, an animal model of skin injury induced by UVB radiation was employed. Gellan gum was used as gel forming agent by its direct addition to nanocapsules suspension. The hydrogels showed adequate pH values (5.6-5.9) and a silibinin content close to the theoretical value (1mg/g). Through vertical Franz diffusion cells it was demonstrated that nanocapsules decreased the silibinin retention in the semisolid formulation. All formulations were effective in reducing mice ear edema and leukocyte infiltration induced by UVB radiation 24h after the treatments. After 48h, only the hydrogels containing nanocapsules or silibinin associated with pomegranate oil demonstrated anti-edematogenic effect, as well as the positive control (hydrogel containing silver sulfadiazine 1%). After 72h, the hydrogel containing unloaded pomegranate oil based nanocapsules still presented a small activity. In conclusion, the results of this investigation demonstrated the feasibility to prepare a semisolid formulation presenting performance comparable to the traditional therapeutic option for skin burns (silver sulfadiazine) and with prolonged in vivo anti-inflammatory activity compared to the non-nanoencapsulated compounds.

Morphological degradation of human hair cuticle due to simulated sunlight irradiation and washing.

Morphological changes in hair surface are undesirable, since they cause shine loss, roughness increase and split ends. These effects occur more frequently in the cuticle, which is the outermost layer of the hair strand, and thus the most exposed to the environmental damages. Sunlight irradiation contributes significantly to these morphological alterations, which motivates the investigation of this effect on hair degradation. In this work, the influence of irradiation and hand-washing steps on the morphology of pigmented and non-pigmented hair cuticle was investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). To simulate daily conditions, where hair is hand-washed and light exposed, samples of dark brown and gray hair underwent three different conditions: 1) irradiation with a mercury lamp for up to 600h; 2) irradiation with the mercury lamp combined with washes with a sodium lauryl sulphate solution; and 3) only washing. A new preparation procedure was applied for TEM samples to minimize natural variations among different hair strands: a single hair strand was cut into two neighbouring halves and only one of them underwent irradiation and washing. The non-exposed half was used as a control, so that the real effects caused by the controlled irradiation and washing procedures could be highlighted in samples that had very similar morphologies initially. More than 25images/sample were analysed using FESEM (total of 300 images) and ca. 150images/sample were obtained with TEM (total of 900 images). The results presented herein show that the endocuticle and the cell membrane complex (CMC) are the cuticle structures more degraded by irradiation. Photodegradation alone results in fracturing, cavities (Ø≈20-200nm) and cuticle cell lifting, while the washing steps were able to remove cuticle cells (≈1-2 cells removed after 60 washes). Finally, the combined action of irradiation and washing caused the most severe damages, resulting in a more pronounced cuticle extraction (≈1-4 cuticle cells after a 600h irradiation and a 60 times washing). This irradiation dose corresponds to ca. 2months of sunlight exposure (considering 5h/day) in Campinas-SP, Brazil, during the day period of maximum irradiation intensity. The combined action of irradiation and washing can be explained by the creation of fragile photodegraded spots in the endocuticle and in the CMC, where the mechanical stress associated to the washing steps are more prone to induce rupture.