Navegando por Autor "Queiroz, Moacir Fernandes"
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Artigo Antioxidant sulfated polysaccharide from edible red seaweed Gracilaria birdiae is an inhibitor of calcium oxalate crystal formation(MDPI, 2020-04-28) Oliveira, Leticia Castelo Branco Peroba; Queiroz, Moacir Fernandes; Fidelis, Gabriel Pereira; Melo, Karoline Rachel Teodosio; Câmara, Rafael Barros Gomes da; Alves, Monique Gabriela das Chagas Faustino; Costa, Leandro Silva; Teixeira, Dárlio Inácio Alves; Melo-Silveira, Raniere Fagundes; Rocha, Hugo Alexandre de OliveiraThe genus Gracilaria synthesizes sulfated polysaccharides (SPs). Many of these SPs, including those synthesized by the edible seaweed Gracilaria birdiae, have not yet been adequately investigated for their use as potential pharmaceutical compounds. Previous studies have demonstrated the immunomodulatory effects of sulfated galactans from G. birdiae. In this study, a galactan (GB) was extracted from G. birdiae and evaluated by cell proliferation and antioxidant tests. GB showed no radical hydroxyl (OH) and superoxide (O2−) scavenging ability. However, GB was able to donate electrons in two further different assays and presented iron- and copper-chelating activity. Urolithiasis affects approximately 10% of the world’s population and is strongly associated with calcium oxalate (CaOx) crystals. No efficient compound is currently available for the treatment of this disease. GB appeared to interact with and stabilize calcium oxalate dihydrate crystals, leading to the modification of their morphology, size, and surface charge. These crystals then acquired the same characteristics as those found in healthy individuals. In addition, GB showed no cytotoxic effect against human kidney cells (HEK-293). Taken together, our current findings highlight the potential application of GB as an antiurolithic agentArtigo Commercial fucoidans from Fucus vesiculosus can be grouped into antiadipogenic and adipogenic agents(MDPI, 2018-06-04) Oliveira, Ruth Medeiros; Câmara, Rafael Barros Gomes da; Monte, Jessyka Fernanda Santiago; Viana, Rony Lucas Silva; Melo, Karoline Rachel Teodosio; Queiroz, Moacir Fernandes; Filgueira, Luciana Guimarães Alves; Oyama, Lila Missae; Rocha, Hugo Alexandre de OliveiraFucus vesiculosus is a brown seaweed used in the treatment of obesity. This seaweed synthesizes various bioactive molecules, one of them being a sulfated polysaccharide known as fucoidan (FF). This polymer can easily be found commercially, and has antiadipogenic and lipolytic activity. Using differential precipitation with acetone, we obtained four fucoidan-rich fractions (F0.5/F0.9/F1.1/F2.0) from FF. These fractions contain different proportions of fucose:glucuronic acid:galactose:xylose:sulfate, and also showed different electrophoretic mobility and antioxidant activity. Using 3T3-L1 adipocytes, we found that all samples had lipolytic action, especially F2.0, which tripled the amount of glycerol in the cellular medium. Moreover, we observed that FF, F1.0, and F2.0 have antiadipogenic activity, as they inhibited the oil red staining by cells at 40%, 40%, and 50%, respectively. In addition, they decreased the expression of key proteins of adipogenic differentiation (C/EBPα, C/EBPβ, and PPARγ). However, F0.5 and F0.9 stimulated the oil red staining at 80% and increased the expression of these proteins. Therefore, these fucoidan fractions have an adipogenic effect. Overall, the data show that F2.0 has great potential to be used as an agent against obesity as it displays better antioxidant, lipolytic and antiadipogenic activities than the other fucoidan fractions that we testedArtigo In vitro studies reveal antiurolithic effect of antioxidant sulfated polysaccharides from the green seaweed Caulerpa cupressoides var flabellata(MDPI, 2019-06-01) Gomes, Dayanne Lopes; Melo, Karoline Rachel Teodosio; Queiroz, Moacir Fernandes; Batista, Lucas Alighieri Neves Costa; Santos, Pablo Castro; Costa, Mariana Santana Santos Pereira; Almeida-Lima, Jailma; Câmara, Rafael Barros Gomes da; Costa, Leandro Silva; Rocha, Hugo Alexandre de OliveiraUrolithiasis affects approximately 10% of the world population and is strongly associated with calcium oxalate (CaOx) crystals. Currently, there is no efficient compound that can be used to prevent this disease. However, seaweeds’ sulfated polysaccharides (SPs) can change the CaOx crystals surface’s charge and thus modify the crystallization dynamics, due to the interaction of the negative charges of these polymers with the crystal surface during their synthesis. We observed that the SPs of Caulerpa cupressoides modified the morphology, size and surface charge of CaOx crystals. Thus, these crystals became similar to those found in healthy persons. In the presence of SPs, dihydrate CaOx crystals showed rounded or dumbbell morphology. Infrared analysis, fluorescence microscopy, flow cytometry (FITC-conjugated SPs) and atomic composition analysis (EDS) allowed us to propose the mode of action between the Caulerpa’s SPs and the CaOx crystals. This study is the first step in understanding the interactions between SPs, which are promising molecules for the treatment of urolithiasis, and CaOx crystals, which are the main cause of kidney stonesArtigo Proteolysis, NaOH and ultrasound-enhanced extraction of anticoagulant and antioxidant sulfated polysaccharides from the edible seaweed, Gracilaria birdiae(MDPI, 2014-11-13) Fidelis, Gabriel Pereira; Câmara, Rafael Barros Gomes da; Queiroz, Moacir Fernandes; Costa, Mariana Santana Santos Pereira; Santos, Pablo Castro; Rocha, Hugo Alexandre de Oliveira; Costa, Leandro SilvaThe sulfated polysaccharides (SP) from the edible red seaweed, Gracilaria birdiae, were obtained using five different extraction conditions: Gracilaria birdiae 1 (GB1)-water; GB1s-water/sonication; GB1sp-water/sonication/proteolysis; GB2s-NaOH/sonication; and GB2sp-NaOH/sonication/proteolysis. The yield (g) increased in the following order: GB2sp > GB1sp > GB2s > GB1s > GB1. However, the amount of SP extracted increased in a different way: GB2sp > GB1 > GB1sp > GB1s > GB2s. Infrared and electrophoresis analysis showed that all conditions extracted the same SP. In addition, monosaccharide composition showed that ultrasound promotes the extraction of polysaccharides other than SP. In the prothrombin time (PT) test, which evaluates the extrinsic coagulation pathway, none of the samples showed anticoagulant activity. While in the activated partial thromboplastin time (aPTT) test, which evaluates the intrinsic coagulation pathway, all samples showed anticoagulant activity, except GB2s. The aPTT activity decreased in the order of GB1sp > GB2sp > GB1 > GB1s > GB2s. The total capacity antioxidant (TCA) of the SP was also affected by extraction condition, since GB2s and GB1 showed lower activity in comparison to the other conditions. In conclusion, the conditions of SP extraction influence their biological activities and chemical composition. The data revealed that NaOH/sonication/proteolysis was the best condition to extract anticoagulant and antioxidant SPs from Gracilaria birdiae