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 Assunto "Antioxidantes"
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Item Acesso aberto (Open Access) Apocinina reverte fibrose e disfunção elétrica cardíaca induzida pelo aumento sistêmico de MMP-2 em camundongos adultos(Universidade Federal do Pará, 2024-09) PONTES, Maria Helena Barbosa Pontes; RODRIGUES, Keuri Eleutério; http://lattes.cnpq.br/0030683756521893; PRADO, Alejandro Ferraz do; http://lattes.cnpq.br/7016475842644161; https://orcid.org/0000-0001-7495-9837Heart failure (HF) is characterized by the heart's inability to maintain adequate tissue blood flow, associated with deficits in contraction and relaxation, due to either an acute or chronic injurious event. Matrix metalloproteinase 2 (MMP-2) is linked to the pathogenesis and pathophysiology of HF, promoting proteolysis of contractile proteins and oxidative stress. Rescue therapies that directly or indirectly modulate MMP-2 activity could help improve cardiac remodeling and dysfunction. Apocynin inhibits NADPH oxidase, thereby attenuating oxidative stress. This study hypothesizes that apocynin can reverse cardiac remodeling and electrical dysfunction induced by MMP-2 by preventing oxidative imbalance. The aim of this study is to evaluate the effect of apocynin on oxidative imbalance and cardiac remodeling induced by systemic MMP-2 increase in adult mice. Adult male C57BL/6 mice were subjected to two experimental protocols. First, the animals underwent a time course protocol and were divided into two groups: the vehicle group received 0.9% saline via intraperitoneal (ip) injection, and the MMP-2 group received MMP-2 (150 ng/g body weight) via ip injection, for up to 4 weeks. Subsequently, a treatment protocol with apocynin was performed, starting 4 weeks after the cessation of MMP-2 administration. During this period, the animals were divided into four experimental groups: 1) vehicle (received water via gavage); 2) apocynin (50 mg/kg via gavage); 3) MMP-2 (received water via gavage); and 4) MMP-2 + apocynin (50 mg/kg via gavage). At the end of the protocols, all animals underwent electrocardiography, and then their hearts were collected for morphological and biochemical evaluation. During the time course, the MMP-2 group showed increased gelatinolytic activity, oxidative imbalance, fibrosis, decreased heart rate, along with increased RR, PQ, QT, and QTc intervals from the first week of administration, effects that persisted over the four weeks, even without MMP-2 administration. Treatment with apocynin reversed the increase in MMP-2 activity and expression in the heart, as well as oxidative imbalance, lipid peroxidation, hypertrophy, cardiac fibrosis, and electrical dysfunction. We conclude that systemic MMP-2 increase can promote cardiac remodeling through increased MMP-2 activity and expression in cardiac tissue, leading to redox imbalance and electrical dysfunction, and that apocynin treatment was able to reverse the effects induced by MMP-2, suggesting that these effects are dependent on oxidative imbalance and NADPH oxidase.Item Acesso aberto (Open Access) Efeito citoprotetor e cicatrizante gástrico do extrato padronizado de Euterpe oleracea Mart.(Universidade Federal do Pará, 2024-05) SOUZA, Keyla Rodrigues de; MELLO, Vanessa Jóia de; http://lattes.cnpq.br/9437589201689717A gastric ulcer is an acidic peptic lesion of the digestive tract resulting from an imbalance between the factors that damage the mucosa and those that protect it. It is a prevalent disease throughout the world and the medications used to treat it, although efficient, have side effects. Among these, açaí (Euterpe oleracea Mart.), has high antioxidant and anti-inflammatory capacity due to its composition of bioactive phytochemicals that include the class of anthocyanins, proanthocyanidins, and other flavonoids with promising health effects. The present work investigated the cytoprotective and gastric healing activity of the standardized extract of Euterpe oleracea Mart. (EO). Initially, the ability of EO to promote increased cell migration of epithelial-type cells (Vero) in the in vitro healing model was evaluated. In the spectrum of evaluation of in vivo antiulcer activity, initially, the cytoprotective activity of EO was determined in gastric ulcer models induced by ethanol and indomethacin. Furthermore, the action of EO on gastric secretion was investigated. The in vivo healing effect was evaluated in a gastric ulcer model induced by acetic acid. Treatment with EO at a concentration of (1 μg/mL) promoted a significant increase in cell migration after 48 hours. Pre-treatment with EO at doses of (2.5 μL/g and 10 μL/g) reduced the area of gastric lesions in ulcer models induced by ethanol and indomethacin. EO was not able to increase pH and reduce acidity or volume of gastric secretion to levels similar to animals treated with omeprazole (20 mg/kg) in a pylorus ligation model. In the gastric ulcer model induced by acetic acid, treatment with EO at doses of (2.5 μL/g and 10 μL/g) for eight days reduced the area of the acid-induced gastric ulcer, increasing the healing rate when compared to animals without treatment (one way ANOVA, post-Tukey test p < 0.0001). EO treatment in the acetic acid model also increased catalase activity, increased total glutathione levels, and reduced malondialdehyde and nitrite levels compared to untreated animals. According to the results, the standardized extract of Euterpe oleracea Mart. (EO) showed a healing effect in both in vitro and in vivo studies. It presented a cytoprotective effect that is probably not related to a capacity to modulate gastric secretion, but possibly related to the reduction of oxidative stress and its healing effects.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.