Navegando por Assunto "Quercetina"

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Acesso aberto (Open Access)
Avaliação in vitro da atividade antifúngica da Malpighia glabra linn. em agentes da cromoblastomicose
(Universidade Federal do Pará, 2017-08-29) CRUZ, Naila Ferreira da; SILVA, Moises Batista da; http://lattes.cnpq.br/5525661855611118; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Chromoblastomycosis (CBM) is a mycosis by implantation, chronic, with a cosmopolitan distribution, caused by melanized fungi. After transcutaneous implantation, the propagules of the CBM agents present a unique cellular and morphological plasticity. The cellular differentiation results in the appearance of muriform cells. The treatment of this mycosis is a challenge due to the absence of a standard antifungal, resulting in several therapy methods (physical and pharmacological), used isolated or associated, with little clinical cure success. Amazon region has a vast biodiversity of vegetables that need to be better characterized as to their chemical composition and applicability in the treatment of different diseases. In this variety of plants, the fruit of Malpighia glabra Linn. (acerola) has a high content of vitamin C, also presenting vitamins of the complex B, A, anthocyanins and flavonoids, which stand out for having different biological and therapeutic actions already demonstrated both in vitro and in vivo. A major interest is currently focused on the biological activities of quercetin, belonging to the class of flavonoids, as it exerts multiple pharmacological activities, presenting unique biological properties that can improve mental and/or physical performance and reduce the risk of different infections. This study aims to evaluate the in vitro antifungal activity of M. glabra extract in conidia and muriform cells of Fonsecaea spp. The extract of M. glabra presented antifungal activity in both, conidia and muriform cells, of the evaluated strains. Much interest is now centered on biological activities of the flavonoid quercetin. In addition to the crude extract, the conidia of different strains were also sensitive to different dilutions of the extract. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were evaluated. The geometric mean of the quercetin MIC for the conidia was 4.75 μg/mL and the geometric mean of the CFM was 11.31 μg/mL. Further study is needed so that M. glabra or quercetin, isolated or associated with another isolated component of the extract, may be used for the treatment of CBM in the future.
Acesso aberto (Open Access)
Maturação in vitro de oócitos bovinos em meios suplementados com quercetina e seu efeito sobre o desenvolvimento embrionário
(2013-12) GUEMRA, Samuel; MONZANI, Paulo Sérgio; SANTOS, Ériko da Silva; ZANIN, Renato; OHASHI, Otávio Mitio; MIRANDA, Moysés dos Santos; ADONA, Paulo Roberto
Quercetin is a flavonoid widely found in fruit, vegetables, grains and flowers, with a high concentration in red wine, and has been functionally characterized by its antioxidant activity. For assessment of nuclear maturation and bovine embryo, oocytes were matured for 22h in the presence of quercetin (0.4, 2, 10 and 50µM), cysteamine (100µM) and in the absence of antioxidants. The matured oocytes were stained with Hoechst to evaluate the in vitro maturation. To assess embryonic development, oocytes were fertilized and cultured in vitro and rates of embryo development were obtained in the seventh day of culture and the percentage of hatching and the number of cells on eighth day embryos. The levels of glutathione (GSH) of the oocytes were measured by fluorescence emission with CMF2HC. The percentage of nuclear maturation (±89%) did not differ between groups. Embryonic development varied between treatments, the percentage of blastocyst was higher (P<0.05) in the groups treated with 0.4, 2, 10 and 50∝M of quercetin (56.9, 59.5, 53.6 and 49.6%, respectively) and 100 ∝M cysteamine (50.4%) compared to the control group (42.3%). Comparing the two antioxidants, quercetin (0.4 to 2µM) was superior in embryo production (56.9 and 59.5% respectively) compared with cysteamine (50.4%). The rates of hatched embryos were similar (P>0.05) between groups (±63.0%). The average number of embryo cells was also similar in both groups (±233). The intracellular GSH levels were higher in oocytes matured with cysteamine, but similar between the oocytes treated with quercetin and control. The supplementation of matured in vitro with antioxidants improves blastocyst rates. Quercetin was greater than cysteamine, which in turn was superior to the control. However, GSH levels were higher in oocytes treated only with cysteamine.