Avaliação do potencial fotoprotetor de extratos de musgos e investigação de seus riscos toxicológicos

A radiação ultravioleta (UV) induz diversos efeitos nocivos nos organismos e a quantidade desta radiação que atinge a biosfera é afetada pela concentração de ozônio, latitude, altitude, clima e reflexão especular. As respostas de briófitas em relação aos efeitos da radiação UV e a presença de compostos que absorvem esta radiação têm sido estudadas. Sanionia uncinata, Holomitriopsis laevifolia e Leucobryum laevifolium são espécies de musgos encontrados em locais expostos a alta incidência de radiação UV e com habitats distintos. Considerando que as respostas de musgos contra os efeitos da radiação UV e seus mecanismos de proteção ainda são pouco caracterizados, o objetivo deste estudo foi investigar o potencial fotoprotetor e possíveis riscos toxicológicos associados aos extratos dos musgos S. uncinata, proveniente da Antártica e H. laevifolia e L. laevifolium, proveniente do Amazonas. Seus extratos metanólico (EM), aquoso (EA), hidroalcoólico (EH) e etanólico (EE) foram estudados com a caracterização química por absorção ao UV e visível e pela cromatografia líquida de alta eficiência; quantificação do índice total de compostos fenólicos; determinação da capacidade captadora do radical 2,2-difenil-1-picril-hidrazila a fim de avaliar as atividades antioxidantes; avaliação do potencial de fotoproteção cutânea pela determinação do fator de proteção solar; avaliações do potencial mutagênico e citototóxico, através do ensaio de Salmonella/microssoma, utilizando as cepas TA97, TA98, TA100, TA102 e TA104; do potencial fotomutagênico através do ensaio de fotomutagenicidade, usando as cepas TA102 e TA104; e investigação dos efeitos genotóxicos e fotogenotóxicos, pelo ensaio de micronúcleo e fotomicronúcleo, respectivamente, usando diferentes linhagens celulares estabelecidas. Foram encontradas atividades fotoprotetoras e antioxidantes e observou-se que os extratos se apresentaram singulares devido a sua composição química. Os resultados fotoprotetores, além dos mutagênicos/fotomutagênicos, genotóxicos/fotogenotóxicos e suas respectivas avaliações citotóxicas também permitiram selecionar extratos e suas concentrações, como promissores candidatos em fotoproteção Assim, os EA e EH de H. laevifolia e L. laevifolium apresentam, no geral, os resultados mais significativos, tornando-se potenciais para avaliações refinadas em fotoproteção e na separação de componentes que possam levar a futuras aplicações como antioxidantes e protetores solares ou como adjuvantes.

Development and characterization of novel vehicles for topical drug delivery

Tese de doutoramento, Farmácia (Tecnologia Farmacêutica), Universidade de Lisboa, Faculdade de Farmácia, 2016

Estabilidade e eficácia de fotoprotetores contendo filtros inorgânicos e quercetina

A exposição ao sol traz benefícios à saúde, no entanto, o excesso pode ocasionar danos cutâneos dentre os quais se destacam as neoplasias. A fotoproteção é um método para a prevenção dos efeitos danosos da radiação ultravioleta (UV) e a biodiversidade Brasileira é campo fértil para pesquisas nesta área. Dessa forma, os objetivos deste estudo envolveram o desenvolvimento de formulações fotoprotetoras contendo quercetina (composto bioativo) e filtros solares físicos (dióxido de titânio e óxido de zinco), com posterior caracterização das formulações e avaliação da sua estabilidade. As formulações contendo o composto bioativo, isolado ou em associação com os filtros físicos, possuíram valores de pH biocompatíveis com a pele,intervalo de viscosidade aparente entre 10550 e 23600 cP; fator de proteção solar (FPS) estimado entre 2.1 e 22.5; e amplo espectro de proteção, com comprimentos de onda crítico acima de 379 nm. Constatou-se que não foi adequado utilizar a quercetina associada aos filtros solares físicos devido às interações negativas que ocorreram entre o composto e os metais, somente identificadas ao longo do estudo de estabilidade. No entanto, em função da eficácia estimada in vitro apresentada pelo flavonoide, seu uso ainda pode ser explorado como substituto alternativo aos filtros solares clássicos.

Avaliação das propriedades sensoriais de uma formulação cosmética contendo óleo de café verde

O óleo de café verde (OCV) é um ingrediente bastante conhecido com propriedades cosméticas como: manter a hidratação da pele, melhorar o fator de proteção solar e manter a função barreira da pele. Assim, o objectivo deste estudo foi avaliar a influência da adição de uma quantidade considerável de OCV (15%) nas propriedades sensoriais de uma formulação cosmética. O painel sensorial consistiu de 19 voluntários com idades entre 19 e 43 anos. Os atributos sensoriais foram avaliadas em uma região definida de 25 cm2 na parte interna do antebraço. Os voluntários foram instruídos a avaliar as propriedades sensoriais que eles sentiam para cada formulação imediatamente e 5 minutos após a aplicação. As formulações mostraram quase a mesma percepção entre os voluntários. A maioria dos voluntários percebeu a pele suave e hidratada após a aplicação das formulações. No entanto, a percepção de um resíduo oleoso sobre a pele foi o principal efeito da formulação contendo OCV. Assim, podemos concluir que a quantidade total de OCV utilizado mostrou propriedades interessantes para aplicação em peles secas ou cremes noturnos, uma vez que foi capaz de deixar uma película oleosa sobre a pele.

Desenvolvimento de filtros solares a partir de complexos metálicos de Zn2+ e/ou Ce3+ com quercetina para protetores solares

Pós-graduação em Química - IQ

Synergistic effect of green coffee oil and synthetic sunscreen for health care application

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da eficácia e citotoxicidade de filme e sistema emulsionado contendo ácido cafeico

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do potencial antioxidante, citotóxico e fotoprotetor de extratos de Hymenaea courbaril L. e Hymenaea stigonocarpa Mart. ex Hayne

Pós-graduação em Biociências - FCLAS

Avaliação do perfil químico de fenólicos, do potencial antioxidante e fotoprotetor da torta de semente de Coffea arabica L. (Rubiaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Brazilian consensus on photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

DNA Dosimetry Assessment for Sunscreen Genotoxic Photoprotection

Background: Due to the increase of solar ultraviolet radiation (UV) incidence over the last few decades, the use of sunscreen has been widely adopted for skin protection. However, considering the high efficiency of sunlight-induced DNA lesions, it is critical to improve upon the current approaches that are used to evaluate protection factors. An alternative approach to evaluate the photoprotection provided by sunscreens against daily UV radiation-induced DNA damage is provided by the systematic use of a DNA dosimeter. Methodology/Principal Findings: The Sun Protection Factor for DNA (DNA-SPF) is calculated by using specific DNA repair enzymes, and it is defined as the capacity for inhibiting the generation of cyclobutane pyrimidine dimers (CPD) and oxidised DNA bases compared with unprotected control samples. Five different commercial brands of sunscreen were initially evaluated, and further studies extended the analysis to include 17 other products representing various formulations and Sun Protection Factors (SPF). Overall, all of the commercial brands of SPF 30 sunscreens provided sufficient protection against simulated sunlight genotoxicity. In addition, this DNA biosensor was useful for rapidly screening the biological protection properties of the various sunscreen formulations. Conclusions/Significance: The application of the DNA dosimeter is demonstrated as an alternative, complementary, and reliable method for the quantification of sunscreen photoprotection at the level of DNA damage.

Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial

Background The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings. Methods In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat. Findings 1383 participants underwent full shin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new shin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100 000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100 000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100 000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100 000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100 000; 0.61 [0.46-0.81]). Interpretation There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.

Desenvolvimento de emulsões o/a contendo extrato glicólico de açai e avaliação da atividade fotoprotetora

Sunscreen use is the most common photoprotection alternative used by the population, and so these products should offer improved protection with broad - spectrum, UVA and UVB protection . Vegetal substances have recently been considered as resources for sunscreen formulations due to their UV spectrum absorption and antioxidant properties. The Euterpe oleracea Mart., popularly known as açai, in its che mical composition contain polyphenols compounds, such as anthocyanins and flavonoids , to which antioxidant properties have been attributed . The aim of this work was to develop O/W sunscreens emulsions con taining açai glycolic extract ( AGE) and to evaluate both their physical stability , safety and photoprotective efficacy. The safety of the extract was evaluated by in vitro phototoxicity and cytotoxicity tests. Emulsions containing AGE and sunscreens were formulated using different types and concentrations o f polymeric surfactant (Acrylates/C 10 - 30 Alkyl Acrylate Crosspolymer and Sodium Polyacrylate). The influence of two rheology modifiers (Polyacrylamide (and) C13 - 14/Isoparaffin (and) Laureth - 7 and Carbomer) on the stability was also investigated. Physical stability was evaluated by preliminary and accelerated studies. The macroscopic analyses, pH value and electrical conductivity determinations and rheological behavior were evaluated at different time intervals . The in vivo Sun Protect Factor ( SPF ) was determined according to the International Sun Protection Factor Test Method – 2006 and UVA Protection Factor (FPUVA), wavelength critical and reason SPF/FPUVA were performed according to the method Colipa 2011. The extract did not present cytotoxic ity and phototoxic ity . The stable emulsion containing 5% glycolic extract of açai and 1.0% of sodium poliyacrylate showed pseudoplastic and thixotropic behavior . The sunscreen emulsion containing açai glycolic extract showed a SPF 25.3 and PF - UVA = 14.97. Whe n açai glycolic extract was added in the emulsion sunscreen, no significant increase in the in vivo SPF and FPUVA values were observed. This emulsion showed 1.69 of the SPF/PF - UVA ratio and a critical wavelength value of 378 nm, so may therefore be conside red a sunscreen with UVA and UVB protection.

The influence of yarn parameters on the ultraviolet protection of yarns

 Improving ultraviolet (UV) protection of textiles is essential to protect wearers against UV radiation induced risks. In addition to fabric parameters, yarn parameters are important factors affecting UV protection of textiles. This work is to examine the influence of yarn parameters on UV protection in order to set up a statistical model for predicting the UV protection of yarns. Wool yarns with different variables were used to test the ultraviolet protection factor (UPF) values for data analysis and the model verification. The model provides the optimized parameters for the UV protective fabric design. This work is helpful as a pre-cursor to the development of a more advanced optical model, which will look at understanding the penetration of UV light through fibres, yarns and fabrics.

Re-think, Re-generate, Re-envisage fashionable sun-safe apparel

Design is a way of thinking and working that systematically can create immense societal change. In particular, fashion design is one of the most progressively forward-looking creative and commercial generators that can envisage and initiate meaningful visual and social transformation. If we look back in time at the authority of fashion, many trends have significantly induced visual norms aligning glamour and health with tanned skin - numerous examples exist, including Vogue magazine proclaiming (front-cover) that ‘The 1929 girl must be tanned’. Indeed, in a contemporary landscape, fashion trends continue to re-generate apparel that, in-the-main, has limited design resolution connected to sun safety, and surprisingly many designers elect to ignore this vital and potentially lucrative market segment. In a context with soaring skin cancer rates, how can this powerful design medium of fashion make a positive difference to sun protection; what is the untapped potential for young design talent to connect with the health sector for skin cancer prevention; and, how can fashion designers be swayed to design and produce fashionable sun-safe apparel, that address pertinent issues including heat build up, comfort and transformability? Through a case study approach, examining emergent fashion designers, this paper will propose that astute and novel avenues exist for fashion to re-think sun protective apparel, including: generation of crucial design standards for sun-safe apparel, exploration of co-branding opportunities, advancement of fashion forecasting to connect modesty of body coverage to fashion trends and alignment of the market segment to re-envisage a critical mass for fashionable sun-safe apparel.