Navegando por Autor "Telles, Cinthia Beatrice Silva"
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Artigo Heterofucan from Sargassum filipendula induces apoptosis in HeLa cells(MDPI, 2011-04-14) Costa, Leandro Silva; Telles, Cinthia Beatrice Silva; Oliveira, Ruth Medeiros; Nobre, Leonardo Thiago Duarte Barreto; Dantas-Santos, Nednaldo; Câmara, Rafael Barros Gomes da; Costa, Mariana Santana Santos Pereira; Almeida-Lima, Jailma; Melo-Silveira, Raniere Fagundes; Albuquerque, Ivan Rui Lopes; Leite, Edda Lisboa; Rocha, Hugo Alexandre de OliveiraFucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated L-fucose. Heterofucan SF-1.5v was extracted from the brown seaweed Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. This fucan showed antiproliferative activity on Hela cells and induced apoptosis. However, SF-1.5v was not able to activate caspases. Moreover, SF-1.5v induced glycogen synthase kinase (GSK) activation, but this protein is not involved in the heterofucan SF-1.5v induced apoptosis mechanism. In addition, ERK, p38, p53, pAKT and NFκB were not affected by the presence of SF-1.5v. We determined that SF-1.5v induces apoptosis in HeLa mainly by mitochondrial release of apoptosis-inducing factor (AIF) into cytosol. In addition, SF-1.5v decreases the expression of anti-apoptotic protein Bcl-2 and increased expression of apoptogenic protein Bax. These results are significant in that they provide a mechanistic framework for further exploring the use of SF-1.5v as a novel chemotherapeutics against human cervical cancerArtigo Immunomodulatory effects and antimicrobial activity of heterofucans from Sargassum filipendula(Springer, 2017-07-18) Telles, Cinthia Beatrice Silva; Mendes-Aguiar, Carolina; Fidelis, Gabriel Pereira; Frasson, Amanda Piccoli; Pereira, Wogelsanger Oliveira; Scortecci, Katia Castanho; Camara, Rafael Barros Gomes; Nobre, Leonardo Thiago Duarte Barreto; Costa, Leandro Silva; Tasca, Tiana; Rocha, Hugo Alexandre de OliveiraParasitic diseases are a human health problem mainly in low-income areas. The drugs available for the treatment of these diseases are far from satisfactory due to high costs, toxicity, and drug resistance. Sulfated polysaccharides are a complex group of bioactive polymers and can be obtained from seaweeds. The heterofucans from Sargassum filipendula (SF) present strong antiproliferative and antioxidant activities. However, their immunomodulatory and antimicrobial capacity have not been evaluated until now. In this study, five sulfated fucose-rich fractions were isolated (named SF0.5V, SF0.7V, SF1.0V, SF1.5V, and SF2.0V). The chemical composition showed slight differences among polysaccharides and, consequently, biological activity of these polymers. Three fractions (SF0.5V, SF0.7V, and SF1.0V) showed a strong immunomodulatory activity enhancing the release of nitric oxide (NO) by murine macrophages (RAW 264.7), though only SF0.5V was able to induce interleukin-6 (IL-6) and TNF-α release from RAW cells. The sugar to sulfate ratio was not correlated with these activities. Meanwhile, the contents of xylose (P = 0.98 for NO; P = 0.98 for IL-6; P = 0.96 for TNF-α) and glucuronic acid (P = 0.91 for NO; P = 0.9190 for IL-6; P = 0.79 for TNF-α) were strongly positively correlated. SF0.7V and SF1.0V inhibited biofilm formation by Klebsiella pneumoniae (4.2 and 6.8%, respectively), whereas SF0.5V showed inhibitory effect (~50%) on biofilm formation by Staphylococcus epidermidis. Furthermore, SF0.7V and SF1.0V showed high inhibition capacity on the survival of the protozoan Trichomonas vaginalis. The sugar to sulfate ratio was positively correlated (P = 0.60) with this activity. The results demonstrate the spectrum of action of these sulfated polysaccharides obtained from SF and show their potential as immunomodulatory and microbicidal agents