New Approaches to Clarify Antinociceptive and Anti-Inflammatory Effects of the Ethanol Extract from Vernonia condensata Leaves

The present study was aimed at evaluating the antinociceptive and anti-inflammatory effects of the ethanol extract from Vernonia condensata leaves in animal models, in order to afford a better understanding of these properties. The extract reduced the number of abdominal contortions at doses of 100 (51.00 ± 3.00), 200 (42.00 ± 2.98) and 400 mg/kg (39.00 ± 4.00). In formalin tests, a significant reduction in the licking time (p < 0.01) was observed in the first phase by 25.14 (200 mg/kg = 51.50 ± 4.44) and 31.15% (400 mg/kg = 48.00 ± 4.37). The doses of 100 (43.37 ± 5.15), 200 (34.62 ± 4.16) and 400 mg/kg (28.37 ± 3.98) inhibited (p < 0.001) the second phase. After 60 and 90 min of treatment, a dose of 400 mg/kg (10.13 ± 0.39 and 11.14 ± 1.33, respectively) increased the latency time. Doses of 200 and 400 mg/kg potentiated the sleeping time induced by diazepam, pentobarbital and meprobamate. The extracts (100, 200 and 400 mg/kg) showed anti-inflammatory effects by a decrease in paw edema. The extracts also reduced the exudate volume at the doses of 200 and 400 mg/kg. The leukocyte migration had significant effect (p < 0.001) at doses of 100, 200 and 400 mg/kg. The completion of additional experiments in the investigation of the antinociceptive and anti-inflammatory activities of V. condensata allowed a better understanding of the central and peripheral mechanisms involved

Evaluation of the photoprotector and photochemoprotector effect of the topical formulations containing Cecropia obtusa extract

Cecropia obtusa é popularmente utilizada na Amazônia para vários fins medicinais, e possui atividade antioxidante comprovada por diferentes metodologias. Neste trabalho objetivou-se caracterizar o extrato; avaliar o potencial fotoquimioprotetor; separar os constituintes por CLAE; identificar os constituintes majoritários e desenvolver formulações tópicas. O conteúdo de polifenóis e flavonoides totais foi de 371,5 mg EGA/g e 66,68 mg EQ/g, respectivamente, e os IC50 para os radicais DPPHo, O2 o- e 1O2 foram, respectivamente1,83, 0,34 e 0,55 ?g/mL, respectivamente. Para o radical OHo, 125 ?g/mL de extrato foi capaz de inibir a formação do radical em 35,48%. O extrato demonstrou fotoestabilidade e capacidade de absorver a radiação UVB e UVA-II. O FPS calculado pela metodologia de Mansur e estimado pelo experimento de fotoproteção em cultura de células foi de 16. O método analítico cromatográfico apresentou boa resolução e separação, sendo linear para o intervalo de 5 a 125 ?g/mL e apresentando coeficientes de variação que variaram de 3,12% a 4,51%. Através da espectrometria de massas foi possível sugerir a presença do ácido clorogênico e três flavonas-C-heterosídicas (duas luteolinas-C-heterosídicas e uma apigenina-C-heterosídicas). Em cultura de células HaCaT submetidas à radiação UVA, o extrato diminuiu a produção de espécies reativas do oxigênio, protegeu contra o processo de peroxidação lipídica e contra a depleção da glutationa reduzida induzidos pela radiação, além de proteger contra a diminuição da atividade das enzimas catalase e superóxido dismutase. Em cultura de fibroblastos humanos submetidos à radiação UVA/UVB, o tratamento com o extrato forneceu maior proteção do que o ácido clorogênico contra o aumento da proteína carbonilada. O extrato foi capaz de retornar o conteúdo de ácido hialurônico ao nível basal enquanto o tratamento com ácido clorogênico foi capaz de aumentar acima do nível basal. Em relação ao conteúdo de colágeno, tanto o extrato quanto o ácido clorogênico foram capazes de retornar os valores ao nível basal da célula. O extrato também foi capaz de diminuir a atividade da enzima metaloproteinase enquanto o ácido clorogênico não exibiu efeito. Em relação às formulações desenvolvidas, as mudanças mais significativas nos parâmetros de estabilidade avaliados foram para as formulações incubadas a 40?C: o decréscimo da atividade antioxidante em aproximadamente 40% entre 0 e 2 meses, a diminuição do pH abaixo do limite de estabilidade do agente de viscosidade e, para a reologia, o aumento da área de histerese entre 4 e 6 meses. A formulação com oleato de isodecila dobrou a quantidade de extrato penetrada na pele em 12 e 6 horas, em comparação com as outras duas formulações, além de ter mantido a atividade de absorção da radiação. O extrato apresentou atividade fotoquimioprotetora e a formulação promoveu a penetração do extrato e manteve a atividade de absorção da radiação, sugerindo a incorporação do extrato de C. obtusa em formulações contendo filtros, visando aumentar o espectro de absorção e promover um efeito atenuador do estresse oxidativo na pele.Cecropia obtusa is commonly used in Amazon with different medicinal purposes and the antioxidant activity of this specie has been proved by different methodologies. The aim of this work was: to characterize the purified extract of C. obtusa; to evaluate the photochemoprotective effect in cell culture; develop an HPLC methodology to separate the extract\'s compounds; suggest the identification of the major compounds, and develop a stable formulation that would be able to penetrate on the skin to exert the antioxidant effect, besides absorbing the radiation. The contents of total polyphenols and flavonoids were 371.5 mg GAE/g and 66.68 mg QE/g, respectively, and the IC50 for the radicals DPPHo, O2 o- and 1O2 were respectively 1.83, 0.34 and 0.55 ?g/mL. For the OHo radical, 125 ?g/mL of extract was able to inhibit the radical formation by 35.48%. The extract was photo stable and exhibited the ability to absorb UVB and UVA-II radiation. The SPF calculated by the Mansur methodology and confirmed by the photoprotection experiment in cell culture was 16. The HPLC method exhibited good resolution and separation, being linear from 5 to 125 ?g/mL and presenting coefficients of variation ranging from 3.12% to 4.51%. By employing mass spectrometry, it was possible to suggest the presence of chlorogenic acid and three C-heterosidic flavones (two Cheterosidic luteolins and one C-heterosidic apigenin). In HaCaT culture exposed to UVA radiation, the extract decreased the production of reactive oxygen species, protected against the lipid peroxidation process and against the depletion of the reduced glutathione. In addition, extract also protected against the decrease in the activity of the enzymes catalase and superoxide dismutase. In human fibroblasts exposed to UVA/UVB radiation, the treatment with the extract provided higher protection than chlorogenic acid against the increase in the production of carbonyl protein. The extract was able to return the content of hyaluronic acid to the basal level while the treatment with chlorogenic acid was able to increase above the basal level. Regarding the collagen content, both the extract and the chlorogenic acid were able to return the values to the basal level of the cell. The extract was also able to decrease metalloproteinase activity, while chlorogenic acid had no effect. Regarding the developed formulations, the most significant changes in the stability parameters were for the formulations incubated at 40°C: the decrease in the antioxidant activity, which was, approximately, 40% between 0 and 2 months, and the increase of hysteresis area and decrease of the pH below the limit for the viscosity agent, between 4 and 6 months. The formulation with isodecyl oleate doubled the amount of extract penetrated into the skin in 12 and 6 hours compared with the other two formulations. The extract exhibited photochemoprotective effect, and the formulation penetrated on the skin, besides absorbing the UV radiation, which suggests the incorporation of C. obtusa extract in formulations containing filters, aiming to increase the absorption spectrum and to attenuate the oxidative stress in the skin

Development of Topical Formulations Containing 20% of Coated and Uncoated Zinc Oxide Nanoparticles: Stability Assessment and Penetration Evaluation by Reflectance Confocal Laser Microscopy

The introduction of zinc oxide nanoparticles (ZnOn) in sunscreens solved the issue of poor spreadability of these formulations, which often left a white film on the skin. However, safety concerns have arisen regarding the topical application of ZnOn. Some studies employed commercial sunscreens to address the safety issues of the topical application of ZnOn; however, commercial formulations are often complex and contain a wide range of ingredients that could attenuate the potential damage caused by the ZnOn. Therefore, in this study we aimed to develop a simple stable formulation containing 20% of coated and uncoated ZnOn, characterize the formulations and the nanoparticles, and assess the skin penetration in a Franz diffusion cell. The Feret’s diameter for the uncoated and coated ZnOn was 137 nm and 134 nm, respectively. For the uncoated ZnOn the hydrodynamic size in water was 368 nm and for the coated ZnOn, the average hydrodynamic size in ethyl acetate was 135 nm. The incorporation of ZnOn led to formulations more consistent and easier to spread, as suggested by the lower work of shear and higher values of firmness, cohesiveness, consistency and index of viscosity compared with the vehicle. The stability assessment at 45 °C suggested that the formulations containing the ZnOn were stable for 30 days and the vehicle was stable for 90 days. The assessment of the skin penetration by reflectance confocal laser microscopy indicated that the ZnOn did not permeate into the deepest layers of the skin, but accumulated on the skin furrows, hair and hair follicles

Seminário de Dissertação (2024)

Página da disciplina de Seminário de Dissertação (MPPP, UFPE, 2022) Lista de participantes == https://docs.google.com/spreadsheets/d/1mrULe1y04yPxHUBaF50jhaM1OY8QYJ3zva4N4yvm198/edit#gid=