Dissertações em Farmacologia e Bioquímica (Mestrado) - FARMABIO/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/13299
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Navegando Dissertações em Farmacologia e Bioquímica (Mestrado) - FARMABIO/ICB por Orientadores "MONTEIRO, Marta Chagas"
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Item Acesso aberto (Open Access) Efeito da temperatura e molaridade na avaliação das atividades antimicrobiana, citotóxica e antioxidante do bio-óleo da semente do açaí (Euterpe oleracea, Mart.)(Universidade Federal do Pará, 2024-08) SILVA, Iago Castro da; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/0000-0002-3328-5650Açaí, a fruit from the Amazon, is valuable both economically and nutritionally. Its seeds, which are typically discarded, can be converted into bio-oil through pyrolysis (a process of thermochemical degradation of residual biomass), offering a sustainable alternative to fossil fuels. This study explores how temperature and molarity with Potassium Hydroxide (KOH) and Hydrochloric Acid (HCl), which are chemical impregnation reagents in the process, affect the antimicrobial, antioxidant, and cytotoxic activities of the produced bio-oil. Tests were conducted using Gas Chromatography coupled with Mass Spectrometry (GC-MS) and assays to evaluate antimicrobial, antioxidant, and cytotoxic activities at different temperatures (350, 400, and 450 °C) and molarities (0.5 M, 1.0 M, and 2.0 M). Phenolic compounds were the most abundant in the bio-oil (55.70%), followed by cyclic and aromatic hydrocarbons (11.89%) and linear hydrocarbons (9.64%). Despite a reduction in oxygenated compounds, the bio-oil retained bacteriostatic activity against Escherichia coli and Staphylococcus aureus across various temperature ranges, with notable effectiveness at 350 °C. Antioxidant activity was highest at 350 °C and at lower molarities. Furthermore, lower concentrations of acidic impregnation exhibited cytotoxic effects at high temperatures. Thus, bio-oil from açaí seeds generated through pyrolysis shows potential for antioxidant and antimicrobial activities, suggesting feasibility for further testing in dilutions with lower cytotoxicity.Item Acesso aberto (Open Access) Evaluation of the acute toxicity and antioxidant activity of Justicia secunda methanolic extract in a murine sepsis model(Universidade Federal do Pará, 2024-09) DAVIS, Kelly; LIMA, Kely Campos Navegantes; http://lattes.cnpq.br/7998567135164137; HTTPS://ORCID.ORG/0000-0001-8613-3223; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/0000-0002-3328-5650Sepsis is a clinical condition that involves a dysregulated immune response to an infection, leading to complications such as organ dysfunction. The condition begins with hyperinflammation, followed by an increase in oxidative stress and depletion of antioxidant defenses. The rates of sepsis and septic shock have increased markedly in the last couple of decades. Therefore, the search for new therapies to aid in sepsis treatment is important. Justicia secunda Vahl is a widely used specie in traditional medicine. It has anti-inflammatory, antinociceptive, antioxidant, antianemic, antidiabetic, and antimicrobial properties due to secondary metabolites such as flavonoids, polyphenols, alkaloids, and terpenes. We evaluated a J. secunda methanolic extract (JSLS) in an acute oral toxicity test and as a pretreatment in a murine cecal ligation and perforation (CLP) sepsis model. In the acute oral toxicity test, we evaluated clinical parameters for 14 days after a single dose of 2000 mg JSLS/kg body weight, as well as oxidative stress parameter in organ samples. Subsequently, we evaluated the survival and antioxidant parameters of septic mice pretreated with 400 mg JSLS/kg body weight. In the acute oral toxicity test, there were no signs of toxicity, suggesting that JSLS has a median lethal dose greater than 2000 mg/kg body weight. JSLS pretreatment improved the survival rate, clinical parameters, antioxidant levels, and hematological profile of septic mice. We conclude that JSLS could be applied as a coadjutant agent to manage oxidative stress-related diseases. Additional studies are needed to better elucidate the mechanisms, as well as the effective dose of the chemical compounds present in JSLS.Item Acesso aberto (Open Access) A sinalização adenosinérgica na regulação da gravidade da sepse e da liberação de armadilhas extracelulares de neutrófilos (NETs)(Universidade Federal do Pará, 2024-09) PAMPOLHA, Ana Flavia Oliveira; CUNHA, Fernando de Queiroz; http://lattes.cnpq.br/2869737621338203; HTTPS://ORCID.ORG/0000-0003-4755-1670; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/0000-0002-3328-5650Neutrophils express different purinergic receptors, including four adenosine-ligand P1 receptors, which regulate their primary functions, such as migration and production of inflammatory mediators, including neutrophil extracellular traps (NETs). In sepsis, NETs exhibit a dual role: microbicidal properties but also contribute to organ damage, leading to multiple organ failure and worsening the clinical condition. In this study, we investigated the role of adenosine in NETs release and the progression of experimental sepsis induced by the Cecum Ligation and Puncture (CLP) or endotoxemia models. We observed that treatment of mice subjected to both models with adenosine deaminase (ADA), which metabolizes adenosine to inosine, aggravates organ damage and reduces the survival rate of septic animals. Supporting these findings, we demonstrated that NET production in vitro by neutrophils stimulated with PMA was enhanced by ADA treatment and reduced by NECA, a molecule that mimics adenosine's actions. The modulation of NET production by adenosine was attributed to the activation of A2AAR receptors. In conclusion, our results suggest that during sepsis, adenosine is released and decrease NET production via A2AAR activation.