Moreira, Susana Margarida GomesFarias, Pablo Felipe Ferreira2024-11-112024-09-25FARIAS, Pablo Felipe Ferreira. Polissacarídeos sulfatados da alga Caulerpa cupressoides var. flabellata: estudo das propriedades antioxidantes e da biocompatibilidade. Orientadora: Dra. Susana Margarida Gomes Moreira. 2024. 73f. Dissertação (Mestrado em Bioquímica e Biologia Molecular) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2024.https://repositorio.ufrn.br/handle/123456789/60619Neurodegenerative diseases (NDs), such as Alzheimer's and Parkinson's, are global health issues affecting millions of people. Oxidative stress is believed to be a key factor in the cause and/or progression of NDs, damaging neuronal cells and leading to symptoms such as memory loss and motor problems. Therefore, searching for new antioxidant agents to mitigate those damages is crucial. Among the potential antioxidant agents, sulfated polysaccharides (SPs) obtained from seaweeds stand out. Beyond their antioxidant properties, SPs also exhibit various bioactivity properties, including anticoagulant, antiproliferative, and anti-inflammatory effects. Thus, this study aimed to evaluate the antioxidant potential of SP-rich samples obtained from the green seaweed Caulerpa cupressoides var. flabellata against hydrogen peroxide (H2O2) in murine neuroblastoma cells (Neuro-2A) . Four SP-rich samples (CCB-F0.3, CCB-F0.5, CCBF1.0, and CCB-F2.0) were obtained from polysaccharide-crude extract of Caulerpa cupressoides (PCE). The cytotoxicity and protective effect of the samples against H2O2 in Neuro-2A cells were evaluated, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method. No cytotoxic effects were observed, except for the PCE and CCB-F0.5 samples at higher concentrations. The CCB-F2.0 sample presented antioxidant potential and protective effects against H2O2 under the tested conditions. Additionally, the CCB-F2.0 sample reduced the reactive oxygen species (ROS), evaluated by the 2,7- dichlorofluorescein diacetate (DCFH-DA) fluorescent probe. The biosafety profile of the CCBF2.0 sample was then evaluated using different models. This sample did not exhibit genotoxicity or mutagenicity, as determined by single-cell gel electrophoresis assays (comet assay) and the Salmonella microsuspension reversion assay (Kado test), respectively. Furthermore, embryotoxicity and optomotor response were evaluated using the zebrafish model. Thus, CCB-F2.0 sample showed no embryotoxic or neurotoxic effects in the zebrafish embryos at different concentrations, since no changes in mortality, malformations, and optomotor response were observed in the larvae. Therefore, it is expected that the results of this study may contribute to the development of an alternative treatment for NDs.Acesso EmbargadoAlgas verdesBiomoléculasNeuroproteçãoGenotoxicidademasterThesisCNPQ::CIENCIAS BIOLOGICAS