Quinolines derivatives as novel sunscreening agents.

Currently, the research and development of sunscreens play an important role on the synthesis of actives that are stable in various kinds of formulations-in addition to their efficiency and broad spectrum of protection against ultraviolet radiation. Our objective here was to synthesize new sunscreening chemical agents using quinoline as a base molecule. Twelve quinoline derivatives were synthesized, four of them novel molecules, and their photoprotective activity was determined in vitro using diffuse transmittance spectrophotometry. We determined their SPF, UVAPF, UVA/UVB ratio, critical wavelength and Boots Star Rating. The quinolines derivatives presented a varied profile of photoprotection, their SPF ranging from 2 to 11 and their UVAPF from 2 to 7. In terms of the critical wavelength, all molecules were considered of broad-spectrum by different classifications. Regarding the Boots Star Rating, one compound received no rating, seven of them received a three stars rating, three received a four stars rating and three were given a five stars rating. The molecules showed in the present work have a wide range of possibilities for creating new sunscreen products, once they have good SPF or UVAPF for single molecules, and they also possess other different qualities that can act synergistically.

Biological activities of Solanum sessiliflorum Dunal / Atividades biológicas de Solanum sessiliflorum dunal

This study evaluated the antioxidant, antimicrobial and wound healing activities from the aqueous extract of cubiu (AEC - Solanum sessiliflorum Dunal). The antioxidant activity was evaluated by the scavenging method with 2.2-diphenyl-1.2-picrylhydrazyl radical (DPPH) and, the antimicrobial activity, by the turbidimetric method. The dermal ulcers induced model in rabbits was used in order to study the wound healing activity. Creams containing 5% and 10% AEC and 5% AEC associated with 1% copaiba oil and 1% rosemary oil were tested. The wounds were macroscopically (ulcer aspect and ulcer area contraction) and microscopically examined. The histological study considered the number of inflammatory cells, fibroblasts, blood vessels, collagen and extracellular matrix areas. Analysis of variance (ANOVA) followed by Tukey's post hoc test was performed. The AEC showed IC50=65.12 µg/mL and no antimicrobial activity against all of the strains tested was verified. The formulation containing 5% AEC associated with 1% copaiba oil exhibited the greatest pharmacological potentiality in dermal wound healing due to the increased number of blood vessels (p <0.001) and the largest extracellular matrix area (p <0.001) presented. The results justify further studies about biological activities of cubiu in the search for bioactive compounds.

O presente estudo avaliou as atividades antioxidante, antimicrobiana e cicatrizante do extrato aquoso do cubiu (EAC - Solanum sessiliflorum Dunal). A atividade antioxidante foi avaliada pelo método sequestrante de radicais 2,2-difenil-1,2-picrilhidrazil (DPPH) e, a atividade antimicrobiana, por método turbidimétrico. Para o estudo da atividade cicatrizante foi utilizado o modelo de indução de úlceras dérmicas em coelhos, sendo testados cremes contendo 5% e 10% de EAC e cremes contendo 5% de EAC associado à 1% de óleo de copaíba e à 1% de óleo de alecrim. As lesões foram analisadas macro (aspecto da lesão e contração da área ferida) e microscopicamente. O estudo histológico considerou o número de células inflamatórias, fibroblastos, vasos sanguíneos, e as áreas de colágeno e de matriz extracelular. Foi realizada análise de variância (ANOVA) seguida do teste post hoc de Tukey. O EAC apresentou IC50=65,12 µg/mL e não apresentou atividade antimicrobiana frente a nenhuma das cepas testadas. A formulação contendo 5% de EAC associado a 1% de óleo de copaíba foi a que exibiu maior potencialidade farmacológica na cicatrização de lesões dérmicas, devido ao maior número de vasos sanguíneos (p<0,001) e a maior área de matriz extracelular (p<0,001) apresentados. Os resultados encontrados justificam novos estudos sobre as atividades biológicas do cubiu na busca de compostos bioativos.

Photoprotective activity of resveratrol analogues.

Resveratrol is a promising agent for protecting human skin from UV radiation and to reduce the occurrence of cutaneous malignancies. We describe the photoprotective activity of six resveratrol analogues using the diffuse transmittance technique to determine the SPF and the protection against UVA radiation. The analogues presented a varied profile of photoprotection, the SPF ranging from 2 to 10 and the UVAPF from 0 to 9. Among the six compounds tested, the protection against UVB sunrays provided by compound B was more significant than the protection provided by resveratrol; compounds C, D, E and F show photoprotection similar to resveratrol.