Navegando por Assunto "Antioxidantes"

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Acesso aberto (Open Access)
Adsorção e dessorção supercrítica de carotenos e antioxidantes do óleo de buriti (Mauritia flexuosa, Mart) em leito de γ- Alumina
(Universidade Federal do Pará, 2012-03) CUNHA, Marcos Augusto Eger da; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work we investigated the enrichment of antioxidants buriti oil (Mauritiaflexuosa Mart) adsorption process by supercritical. The adsorption was carried out experimentally by the method of frontal analysis in columns packed with y-alumina and 15, 20 e 25 MPa, 333 K, and flow of solvent QCO2 = 10,6 L/min, using an assembly of double columns of 81 cm3, tested and approved for use as a cell adsorption. The oil was buriti physic-chemically characterized according to the AOCS official methods and found to comply with the data reported in the literature. The composition of methyl esters was determined by gas chromatography (CG) and antioxidant activity by the method of capture of free radicals (DPPH). The adsorbent was characterized by fluorescence and x-ray diffraction, determining the particle size distribution, porosity and surface area by BET in each experiment, a material balance was performed in the adsorption column to calculate the mass of the adsorbed species in y-alumina in the process of supercritical adsorption. The influence of pressure on supercritical adsorption was investigated by examining the behavior of the isotherms. The Langmuir isotherm was used to model the experimental data of adsorption. The experimental results show an increased capacity adsorbent with higher pressures, showing a maximum of 90,9 ± 8,6 mg oil/g y-alumina, at 25 MPa. The adsorption supercritical buriti oil on γ-alumina using carbon dioxide as solvent appears to be an alternative method for extracting antioxidants from the includ carotenes.
Acesso aberto (Open Access)
Alterações oxidativas em portadores de doença de Parkinson: correlação com critérios clínicos e estágios da doença
(Universidade Federal do Pará, 2012-08-31) DOMINGUES, Mariângela Moreno; KIETZER, Kátia Simone; http://lattes.cnpq.br/7986644672973004; LIMA, Patrícia Danielle Lima de; http://lattes.cnpq.br/3411620003450812
Parkinson's disease (PD) is a neurologic disease of the most prevalent. In this disease, have neurodegeneration in the nigrostriatal system with altered neuronal circuitry of the basal ganglia leading to motor impairment characteristic of the disease. The classic symptoms are resting tremor, rigidity, akinesia or bradykinesia and postural instability. The pathogenesis of PD remains unclear. However, it is estimated that the mitochondrial and the development of oxidative stress in the substantia nigra have an important role in this process. The diagnosis of PD is clinical and usually occurs late, when most neurons nigrais is degenerate. Some studies have shown the neuroprotective effect of antiparkinsonian medications, and the earlier introduction of treatment better the long-term prognosis of the disease. Therefore, the peripheral development of markers to assist in early diagnosis is important for to start the treatment time delay the progress of neuronal death. The aim of this study was to verify the existence of alterations in oxidant and antioxidant parameters in blood of PD patients and its relationship with disease stage and clinical criteria. We evaluated 30 patients with PD and 30 individuals without the disease. To evaluate the stage of disease and clinical character were applied Hoehn & Yahr and UPDRS (unified scale for Parkinson's disease) scales in parkinsonian patients. To evaluate the oxidative activity in plasma of individuals, was analyzed by measuring lipid peroxidation products from the action of Reactive Oxygen and Nitrogen (Eron, TBARS) and to evaluate the antioxidant response was made to evaluate the Total Antioxidant Capacity (TEAC). In groups mild DP and moderate DP was found higher TBARS value and lower TEAC value compared to controls and impairment PD (p <0.05), confirming the presence of oxidative stress in the early stages of PD. In this study these parameters proved to be good peripheral markers of oxidative stress, contributing to an early diagnosis of PD.
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/0000-0001-7495-9837
Heart 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.
Acesso aberto (Open Access)
Atividade antimicrobiana, antioxidante e imunomoduladora de Agaricus brasiliensis e Ilex paraguariensis in vitro e em modelo de sepse murino
(Universidade Federal do Pará, 2016-09-15) NAVEGANTES, Kely Campos; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Sepsis is an organ dysfunction caused by a dysregulated immune response to an infection, the initial therapeutic approach to sepsis are broad spectrum antimicrobials, which is not sufficient for control of infection, requiring association with other therapies. Thus, Ilex paraguariensis where to be a potent antimicrobial, antioxidant and Agaricus brasiliensis has immunomodulatory properties could be a new source of therapy. Thus, this study aimed to evaluate the antimicrobial effect, antioxidant and immunomodulatory in vitro and in vivo of the extracts. Therefore, in this study, we evaluated the in vitro antimicrobial activity of aqueous extracts from A.brasiliensis and I. paraguariensis against Staphylococcus aureus and Escherichia coli by the method of microdilution and by spectophotometry for determination of minimum inhibitory concentration and cultivation technique on petri dish for minimum bactericidal concentration, cytotoxicity in macrophages was evaluated, nitric oxide (NO) production, proliferation, phagocytosis, equivalent antioxidant capacity to Trolox (TEAC) and determination of the total antioxidant activity by capturing the free radical and reactive species production oxygen (ROS). In the swiss mice with induced sepsis were pretreated with aqueous extracts of A.brasiliensis and I. paraguariensis, after 12 and 24 hours collected their samples and evaluated the survival, leukocyte migration, hemogram, bacterial load, NO production, malondialdehyde (MDA), TEAC and ex vivo we evaluated phagocytic capacity and release of ROS. The A.brasiliensis showed no antimicrobial activity in vitro, remained viable cells reduced the phagocytic capacity, increased NO, but in the presence of LPS reduced, showed proliferative effect, but in the presence of mitogen had antiproliferative effect and has a strong antioxidant activity and capacity to sequester radicals in vitro. I.paraguariensis presented antimicrobial activity as well as cytotoxic effect induced phagocytic capacity increased NO, but in the presence of LPS reduced, had proliferative effect, antioxidant activity and capacity to sequester radicals in vitro. In vivo model of sepsis, both increased the survival of animals, A.brasiliensis reduced leukocyte influx while Ilex increased, only A.brasiliensis had hemogram similar to sham, both extracts reduced bacterial load and levels decreased NO, MDA and increased antioxidant levels in the tissues, in addition, both reduced the production of both extracts present ERO. Although excellent in vitro results, the aqueous extract from A.brasiliensis was found to be most promising as an adjuvant therapy in sepsis that I. paraguariensis due to its high antimicrobial activity, antioxidant and anti-inflammatory in vivo.
Acesso aberto (Open Access)
Atividade imunomoduladora e antioxidante da saliva do Aedes aegypti em modelo de sepse
(Universidade Federal do Pará, 2017-07-04) GOMES, Rafaelli de Souza; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Sepsis is an organ dysfunction caused by a dysregulated immune response to an infection, the initial therapeutic approach to sepsis are broad spectrum antimicrobials, which is not sufficient for control of infection, requiring association with other therapies focused in the interruption of the inflammatory response chain, provided by the pathogens. In this way, the Aedes Aegypti’s saliva presents immunomodulary features, with a potential pro inflammatory cytokine inhibition, as well as the presence of nitric oxide peptides activators. Therefore, it would be a great interest to search the saliva’s immunomodulator effect in animal model sepses. In this regards, mices were pre treated with Aedes aegypti saliva, and sepsis was induced by the cecal ligation and puncture. After 12 and 24 hours, the samples were collected, and evaluated the survival rate, bacteria level, leukocyte migration, and oxidative parameters (NO, EROs, MDA e TEAC). The saliva improved the animal prognostic, increasing the survival rate and weight. Furthermore, decreased the bacterial levels and increased the influx of monocytes. The saliva, in addition, presented antioxidant effects by reducing production of the reatives species, and increasing the antioxidant capacity, other than decrease the lipid peroxidation. Thus, the saliva was capable to inhibit damages caused by sepsis in animals in vivo, improving its prognostic.
Acesso aberto (Open Access)
Avaliação do efeito da fração lipídica extraída de Agaricus brasiliensis antioxidante e imunomoduladora in vitro e em modelo de sepse letal em murino
(Universidade Federal do Pará, 2021-01) LIMA, Kely Campos Navegantes; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/0000-0002-3328-5650
Sepsis is defined as a potentially fatal organ dysfunction caused by a dysregulated host immune response to an infection. During sepsis, dysregulation of the host response occurs with the excessive release of pro-inflammatory mediators, generation of reactive species with depletion of antioxidant defenses and cellular damage. As a result, the patient develops organ dysfunction. In this context, our group proposes the A.brasiliensis Lipid Fraction (FLAb) as a possible therapy for sepsis considering its immunomodulatory and systemic antioxidant activity in a murine sepsis model. Thus, the present study aimed to evaluate the activity of FLAb isolated in vitro and to evaluate the effect of treatment with FLAb alone or associated with the antibiotic ertapenem (F-Erta) on coagulation, antioxidant and immunomodulatory parameters in the lethal sepsis model in murine. For this, FLAb was kindly provided by Dr. Herta Dalla- Santa from UNICENTRO. In the present study, the antioxidant capacity of different concentrations of FLAb (1.25 and 5 μg/mL) was evaluated and in a RAW 264.7-Luc macrophage cell line, cytotoxicity, phagocytic capacity, nitric oxide, NF-κB activity and cytokines TNF-α and IL-6 were evaluated.The survival rates were analyzed 7 days in a model of CLP sepsis in swiss albino mice (Mus musculus), and treated with CLP+Salt (0.9%), CLP+FLAb (0.2mg/Kg), CLP+F-erta (0.2mg) /Kg; 30mg/Kg). For evaluation of on coagulation, antioxidant and immunomodulatory parameters, the mice were treated by 6 and/or 24h after CLP. In vitro, FLAb show antioxidant and anti-inflammatory activity in both concentrations. In vivo, all CLP+Salt animals died within a maximum of 48 hours while the FLAb and F-Erta treated groups survived the 7 days. During this period, clinical parameters of these animals were evaluated, the septic animals treated with saline showed piloerection, with little active level of consciousness and most of the time they were stopped in the cage, some of them had ocular secretion. In addition, animals treated with saline showed significant weight loss, reduced water and feed consumption resulting in death. The FLAb and F-Erta groups were active, with normal appearance, with normal breathing and heart rate, in addition to consuming water and food within normal limits. In the inflammatory site, peritoneal cavity, the treatment with FLAb showed an anti-inflammatory effect, decreased reactive oxygen species (ROS) and increased GSH antioxidant activity and protected from cell damage, maintaining neutrophil recruitment and nitric oxide levels (NO), reducing the bacterial load. Regarding coagulation parameters (platelet count, tp and ttpa), treatment with FLAb and F-Erta eliminated the bacterial load and protected the animals from tissue damage. In the liver, 6 hours after CLP the treatment with FLAb and F-ERTA was observed in the biochemical parameters protective effect, in addition, it presented immunomodulatory, antimicrobial and antioxidant activity preventing liver damage. In the parameters evaluated in the heart, the treatment with FLAb and F-ERTA after CLP protected the animals from cardiac damage through immunomodulatory, antimicrobial and antioxidant activity. In this sense, FLAb alone showed promise as a treatment and/or adjunct in sepsis, in addition to preventing organic dysfunction in septic animals.
Acesso aberto (Open Access)
Dihydroflavonols from the leaves of Derris urucu (Leguminosae): structural elucidation and DPPH radical-scavenging activity
(2009) LÔBO, Lívia Trindade; SILVA, Geilson Alcantara da; FERREIRA, Malisson; SILVA, Milton Nascimento da; SANTOS, Alberdan Silva; ARRUDA, Alberto Cardoso; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Lourivaldo da Silva; BORGES, Rosivaldo dos Santos; ARRUDA, Mara Silvia Pinheiro
Derris urucu is an Amazonian plant with insecticide and ichthyotoxic properties. Studies with this species show the presence of flavonoids, mainly rotenoids, as well as stilbenes. The ethanol extract of the leaves of Derris urucu (Leguminosae) afforded three new dihydroflavonols named urucuol A (1), B (2) and C (3), and the dihydroflavonol isotirumalin (4). Their structures were elucidated by extensive analysis of 1D and 2D NMR, UV and IR spectra and MS data and comparison with literature data. The isolated compounds (1-4) were evaluated for DPPH• radical scavenging activity and showed a relatively lower antioxidant ability compared to the commercial antioxidant trans-resveratrol.
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/9437589201689717
A 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.
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/0000-0002-3328-5650
Açaí, 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.
Acesso aberto (Open Access)
O efeito in vitro dos compostos ácido alfa-lipoico e resveratrol em parâmetros do estresse oxidativo durante o uso da poliquimioterapia para hanseníase
(Universidade Federal do Pará, 2014-10-20) PESSÔA, Mariely Cristine Amador; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
The leprosy is an infectious disease that represents a major preoccupation in global public health in 21st century. The treatment with Multi Drug Therapy (MDT) approved by the World Health Organization (WHO) is the best treatment to Mycobacterim leprae infection; however, is one of the factors of increasing Reactive Oxygen Species (ROS) production and the development of methemoglobinemia and hemolytic anemia in these patients. The aim of this study was to verify the oxidative damage in leprosy patients receiving MDT, by evaluation of hematological and oxidative stress biomarkers, and identify the effects of in vitro treatment with antioxidants alpha-lipoic acid (ALA) and resveratrol (RSV) in antioxidant enzymes activity and prevention of methemoglobinemia. The results revealed a decrease in RBC count and reticulocytosis in patients receiving MDT during the 4th and 7th month of treatment. The percentual of methemoglobin increased since the fifth month of treatment with MDT, and the treatment with 100 μM RSV-treated and ALA-treated preserved the values similar to control group only in 4th to 6th month of MDT samples. The leprosy patients presented values of SOD activity similar to the control group and a decreased CAT activity, leading to an inbalance in the ratio of both enzymes and possibly resulting in an over-producing of H2O2. The treatment with RSV and ALA in 100 μM and 500 μM concentrations increases twice the SOD activity in 4th month patient samples; however, these concentrations did not change CAT and SOD activities found in leprosy patients. Such results demonstrate that RSV and ALA did not show antioxidant activity in installed oxidative stress, and subsequent studies are necessary to evaluate dose-dependent and time-dependent concentrations of RSV and ALA to prevent oxidative damage in chronic infectious diseases.
Acesso aberto (Open Access)
Efeito protetor de antioxidantes na formação de metemoglobina induzida pelo metabólito dapsona-hidroxilamina in vitro
(Universidade Federal do Pará, 2017-07-11) VARELA, Everton Luiz Pompeu; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Dapsone used in leprosy therapy its metabolite dapsone-hydroxylamine are potent pro-oxidant agents that cause acquired methemoglobinemia. For the treatment of this disease is used as antidote the Methylene Blue, however in high doses this antidote becomes pro-oxidant. In this sense, antioxidant substances may be potential alternatives to methylene blue for the treatment of methemoglobinemia. In this study we investigated the effect of antioxidants Ebselen, N-acetylcysteine, R-lipoic acid and L-lipoic acid on oxidative damage induced by dapsone-hydroxylamine in human erythrocytes, in vitro. Our results demonstrated that pre-treatment with antioxidants Ebselen, N-acetylcysteine, R-lipoic acid and S-lipoic acid prevented the formation of methemoglobin, reduction of glutathione and lipid peroxidation induced by the metabolite dapsone-hydroxylamine in human erythrocytes, In vitro. These substances were able to increase the antioxidant capacity of the erythrocyte associated with increased concentration of glutathione. Thus, antioxidants acted to reduce the oxidation of hemoglobin and / or directly or indirectly impeded the action of the metabolite dapsone-hydroxylamine. Our results indicate that the antioxidants tested can protect erythrocytes against oxidative damage under experimental conditions, suggesting that antioxidants may serve as the most effective and safe antidote in the treatment of methemoglobinemia.
Acesso aberto (Open Access)
Efeito protetor de antioxidantes na metemoglobina e no dano em dna induzidos pela dapsona-hidroxilamina in vitro
(Universidade Federal do Pará, 2016-06-21) GOMES, Antonio Rafael Quadros; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Dapsone (DDS) is one of the drugs used in polychemotherapy of leprosy associated with rifampicin and clofazimine. Of these drugs, DDS is primarily responsible for adverse reactions, such as methemoglobinemia and hemolytic anemia. These reactions are related to the DDS metabolite, dapsone hydroxylamine (DDS-NOH). In an attempt to promote the reduction of toxic effects are studied alternative therapies with antioxidants. This work aimed to evaluate the protective effect of N-acetylcysteine (NAC), A. brasiliensis and Glutathione ethyl ester (GSH-EE) in methemoglobin (MetHb) and DNA damage induced by DDS-NOH in vitro , correlating to oxidative stress parameters. For this, suspensions of human erythrocytes to 50% were pre- and post-treated with NAC, A. brasiliensis and GSH-EE in different concentrations, being exposed groups DDS-NOH to induce the formation MetHb. It also assessed whether the activity of enzymes-SOD and CAT and GSH levels, TEAC and MDA. In leukocytes evaluated the induction of ROS intracellularly using DCFH-DA and the damage to DNA by comet assay. The results showed that the DDS-NOH metabolite was capable of inducing MetHb in vitro, this dose-dependent effect. Regarding the pre-treatment, all the antioxidants prevented MetHb formation induced by DDS-NOH, as well as post-treatment. For SOD, only the pre-treatment with NAC and A. brasiliensis reduced SOD activity. In the post-treatment, there was increased when treated with antioxidants. Pre-treatment with NAC and GSH-EE increased CAT activity, moreover A. brasiliensis reduced, as after treatment with antioxidants. As for GSH levels, pre-treatment with NAC and GSH increased A. brasiliensis, on the other hand, did not alter after treatment. Regarding TEAC did not change. With respect to oxidative damage in the pre-treatment A. brasiliensis and GSH-EE reduced MDA. In the post-treatment, there was an increase in group A. brasiliensis and reduced GSH-EE group. Only the NAC was shown to be effective in removing the intracellular ROS induced by DDS-NOH in leukocytes. While in erythrocytes, a NAC and A. brasiliensis were able to reduce this effect. In the study of the comet assay, the DDS-NOH was able to induce DNA damage in peripheral blood leukocytes, however this damage was reduced when treated with NAC and A. brasiliensis. It can be concluded from our data that the evaluated antioxidants have therapeutic potential in the prevention of MetHb and DNA damage induced by DDS-NOH in vitro, more effective NAC against these effects.
Acesso aberto (Open Access)
Efeitos da suplementação com açaí clarificado (Euterpe oleracea Mart.) sobre marcadores de estresse oxidativo em pacientes com doença renal crônica em hemodiálise
(Universidade Federal do Pará, 2019-06) MARTINS, Isabelle Christine Vieira da Silva; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978; https://orcid.org/0000-0003-3647-9124
Acesso aberto (Open Access)
Efeitos da suplementação com antioxidantes sobre as alterações oxidativas cerebrais e pulmonares em malária murina
(Universidade Federal do Pará, 2011) GOMES, Bruno Alexandre Quadros; PERCÁRIO, Sandro; http://lattes.cnpq.br/3018367879063988
During malaria infection, Plasmodium may provoke high oxidative stress, resulting in oxidative damage, and may lead to the development of severe malaria, such as cerebral and pulmonary malaria. Furthermore, the involvement of reactive oxygen species and antioxidant defenses in the physiopathological phenomena of disease has been discussed, as well as the potential benefit of antioxidant supplements. Hence, from the antioxidant sources that would be suitable, two are particularly interesting: N-acetylcysteine (NAC) and mushroom Agaricus sylvaticus. Thus, the aim of this study was to investigate the potential benefit NAC and Agaricus sylvaticus supplementation against oxidative changes in murine malaria caused by Plasmodium berghei. Two-hundred male mice (Mus musculus) were randomly divided into 20 groups, as following: Groups I-V (positive control); Groups VI-X (negative control); Groups XI-XV: (infected and treated with N-acetylcysteine animals); Groups XVI-XX: (infected and treated with Agaricus sylvaticus animals). Them, brain, lung, and blood samples were collected after 1, 3, 5, 7, or 10 days after infection for malondialdehyde (MDA), trolox equivalente antioxidant capacity (TEAC), nitrites and nitrates (NO) measurement, and parasitemia rate evaluation. Results show that parasitemia increased progressively with evolution of disease, and that was a significant decrease from 7th to 10 th day of infection in both antioxidant supplemented groups. Total antioxidant capacity was higher in supplemented animal’s groups, in that Agaricus sylvaticus treated animals presented a most pronuncied effect in lung samples, with progressive increase along with the days of infection. At the same time, pulmonary MDA levels in the Agaricus sylvaticus and NAC groups showed similar between themselves and with positive control. On the other hand, the cerebral MDA in antioxidants supplemented groups increased during infection, but not in a progressive way. Besides, in the Agaricus sylvaticus groups, MDA levels were lower than NAC, particularly in 5th day of infection. Thus, oxidative damage were most pronounced in pulmonary tissue than brain and related to lipid peroxidation. However, Agaricus sylvaticus was found to be more effective in preventing lipid peroxidation in brain and lung. In addition, pulmonary NO levels were increased in Nacetylcysteine supplemented animals in relationship to Agaricus sylvaticus from 3rd to 10th days of study, progressively increasing, and Agaricus sylvaticus supplemented animals presented similar NO levels to negative control groups. NAC also induced cerebral NO synthesis, but not in a progressive way. In addition, positive and negative control groups show similar cerebral NO levels. Probabily Agaricus sylvaticus and NAC act in two distinct mechanisms in attempt to defeat infection, and can be helpful in the adjuvant therapy of malaria.
Acesso aberto (Open Access)
Efeitos do exercício físico sore parâmetros cognitivos e bioquímicos em ratos expostos ao etanol de forma intensa e episódica (Binge Drinking)
(Universidade Federal do Pará, 2018-12-21) TEMBRA, Dinair Pamplona dos Santos; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468
The consumption pattern of heavy and episodic ethanol, weekend consumption, characterizes the pattern of excessive alcohol consumption or binge drinking that promotes an imbalance of brain metabolic functions, contributing to neurodegeneration and cerebral dysfunction. And because it is a legal drug, it has global relevance in public and social health. In this way, we aimed to investigate the effects of physical training of moderate intensity, in treadmill, on the deleterious effects of ethanol on hippocampus functions related to memory and learning. For this, 80 Wistar rats were divided into four groups: Control group; Trained group (animals trained and treated with distilled water); Ethanol group (animals not trained and treated with doses of 3 g / kg / day of ethanol, 20% w / v); and ethanol + trained group (animals trained and exposed to ethanol). Physical exercise was performed on a treadmill for 5 days a week for 4 weeks and all doses of ethanol and distilled water were administered by intragastric gavage (three days a week) in four repeated cycles. After the experimental period, the animals were submitted to the task of object recognition and Morris aquatic labyrinth test, and after euthanasia, blood and hippocampus were collected to measure levels of antioxidant capacity equivalent to trolox (TEAC), content of reduced glutathione (GSH), nitrite and lipid peroxidation. (LPO). Our results showed that EtOH caused marked oxidative stress and mnemonic damage, and physical exercise promoted neuroprotective effects, including modulation of oxidative plasma biochemistry (by restoration of GSH levels) and hippocampus (reducing levels of LPO and increasing antioxidant parameters) and improving cognitive function. Therefore, physical exercise may be an important prophylactic and therapeutic tool to improve and even prevent the deleterious effects of ethanol on cognitive functions.
Acesso aberto (Open Access)
Estresse oxidativo de aves em clareiras naturais e sub-bosque na região Amazônica
(Universidade Federal do Pará, 2013) GOMES, Andreza de Lourdes Souza; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Background: (Oxidative stress of birds in natural gaps and understory sites in the Amazon region). Studies that provide information about the distribution of birds in different phases of forest mosaic are essential for understanding the maintenance of biodiversity, since natural gaps play a central role on the structure and dynamics of tropical forest. Objectives: (a) to determine and compare the abundance and richness of frugivorous birds between the natural gap and understory habitats; (b) verify and associate the abundance of frugivorous birds with the availability of fruits in both areas; (c) to investigate the echophysiological interactions between the oxidative stress and the distribution of specimens of Dixiphia pipra and Willisornis poecilinotus, to determine which factors account for the variance of biomarkers of oxidative stress in these species. Methods: This study was carried out from November 2010 to October 2011 in terra firme forest sites at the National Forest of Caxiuanã, Melgaço, Pará, Brazil. Two different understory forest habitats were selected for sampling on the basis of physiognomies: natural tree fall gap and undisturbed forest. Twelve (12) sites were selected (6 natural gaps and 6 undisturbed continuous forests). In each site, groups of 10 mist nets were set at ground level which remained open from 6:00am to 2:00pm for two consecutive days, totaling six days each month. This procedure lasted for 12 months and the sampling effort totaled 23,040 mist net hours. All specimens captured were identified, marked with metal rings and kept in cotton bags. We collected blood, feces and regurgitation samples to determine the biomarkers of oxidative stress and the composition of the diet. The relationship between thiobarbituric acid reactive substances and the total antioxidant capacity was used as an index of oxidative stress. The vegetation structure was determined based on transects along the mist nets; the plants bearing fruits were identified and the total antioxidant capacity was determined in each plant. Results: During the period of the study 347 specimens of 21 species were sampled. The assemblage of frugivorous birds in natural gap is distinct from that of undisturbed forest sites. The species responsible for dissimilarity were Dixiphia pipra, Pipra rubrocapilla and Turdus albicollis. The richness of birds was similar in both sites, but the availability of fruits and the total capture index were higher in natural gaps. The primary frugivores (those whose feces or regurgitation always showed fruit pulp or seeds) occurred mainly in natural gaps, where the most abundant species was Dixiphia pipra. In addition, Pipra rubrocapilla was the most abundant species in undisturbed sites. Thirty-six (36) species of plants bearing fruits were recorded, and the abundance of frugivorous birds was significantly correlated with the number of plants bearing fruits in natural gaps, where the most common species of plants were: Psychotria colorata and Psychotria iodotricha. On the other hand, Faramea anisocalyx and Virola surinamensis were the most common species in undisturbed sites. The variation of biomarkers of oxidative stress in specimens presenting lek behavior varied with gender and to the site of sampling. In natural gaps, the adult males of Dixiphia pipra showed higher levels of oxidative stress. The high metabolic rate resulting of flight effort to avoid predators, courtship behavior to the female and territory defense, can increase the production of pro-oxidant compounds. However, the ingestion of fruits with high content of antioxidant compounds by male can minimize the deleterious effects of oxidative stress. The variance of oxidative stress of species that do not have organization in leks was associated only with the site of sampling. The specimens sampling in natural gaps showed higher levels of oxidative stress. This can be due to the increase in metabolic rate to avoid predators as well as new flight strategies for foraging.
Acesso aberto (Open Access)
Expressão gênica e viabilidade de folículos pré-antrais submetidos à vitrificação do córtex ovariano de Sapajus apella (macacas-prego)
(Universidade Federal do Pará, 2012-05-25) SANTANA, Luana de Nazaré da Silva; DOMINGUES, Sheyla Farhayldes Souza; http://lattes.cnpq.br/2794753357251149; SANTOS, Regiane Rodrigues dos; http://lattes.cnpq.br/0500967766886604
Vitrification is a biotech that has been increasingly showing promise in several species, among them domestic ruminants (such as sheep, goats and cows) and in nonhuman primates (NHP) (as cynomologus and rhesus), and consists in reducing ultra-rapid temperature by the presence of high concentrations of cryoprotective agents (PCA's) in liquid nitrogen. Thus the aim of this study was to develop a methodology for cryopreservation by vitrification of preantral follicles (PF's) in Sapajus apella. For this purpose, we used females (n = 9) adult Sapajus apella squad belonging to the National Primate Center (CENP). Samples were taken from the ovarian cortex by laparotomy so as not to destabilize the animals reproducibly. The fragments exposed to 8 different treatments: Ethylene glycol (EG) + 40% Sucrose (Sac) dissolved in 0.5 M TCM-199, added to Selenium (2,5, 5 or 10 ng / ml) or Trolox (25, 50 or 100 mM). Following exposure to cryoprotective agents was analyzed follicular viability before and after vitrification, from the follicular morphology, expression of Hsp70 genes, Erp29, Erp60 SOD1 and through the analysis by Polymerase Chain Reaction (PCR), in addition to performing measurement of oxidative stress thru the TEAC (English Total Equivalent Antioxidant Activity). The analyzes showed that vitrification allowed the maintenance of follicular viability by previous exposure to concentrations of ACP's alevadas, especially when supplemented with 50 mM trolox (which resulted in high follicular survival rates) and increased expression of the antioxidant enzyme SOD1. While in the absence of it was observed an increase in rates of follicles degenerate and vacuolated, and reduced expression of the antioxidant enzyme SOD1 and increased expression of chaperone Erp29.
Acesso aberto (Open Access)
Geoprópolis produzida por diferentes espécies de abelhas: atividades antimicrobiana e antioxidante e determinação do teor de compostos fenólicos
(Universidade Federal do Pará, 2015-05-15) LIMA, Marcus Vinicius Dias de; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Among meliponineos or stingless bees the most important are Melipona quadrifasciata (Mandaçaia), Melipona marginata (Manduri) and Tetragonisca angustula (Jataí). One of their product is geopropolis, a balsamic and resinous substance with complex chemical composition, collected from shoots, seepage and other parts of the plant tissue by these bees, which transformed it through enzymatic process by adding secretions and earth or clay, alone or in combination. Among the chemicals components, highlights the presence of phenolic compounds, diterpenes, triterpenes, essential oils and many other. The most studied propolis activity are antibacterial and antifungal, in addition to antiviral, immunomodulatory, anti-tumor, anti-inflammatory and antioxidant. Therefore this work aim to evaluate the antimicrobial activity, through determination of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Trolox equivalent antioxidant capacity assay (TEAC), beyond the determination of the levels of flavonoids and phenolics compounds (Folin-Cioucalteu method and complexation with aluminum chloride, respectively) using geopropolis samples from different bees species (Melipona quadrifasciata, Melipona marginata and Tetragonisca angustula). All the geopropolis samples exhibit antimicrobial activity against gram-positive bacteria, wherein the Manduri Bee showed the lowest MIC and MBC; only Mandaçaia species showed moderate activity against gram-negative bacteria. The Manduri's geopropolis showed higher content of phenolics compounds and flavonoids, followed by Mandaçaia's geopropolis and both were in accordance with the parameters established by current legislation, wherein the Manduri's geopropolis also present high total antioxidant levels compared with other bees. It was noted that the antimicrobial activity of geopropolis extracts were not directly associated with high levels of phenolic compounds, including flavonoids.
Acesso aberto (Open Access)
A indução do comportamento tipo ansiedade e estresse oxidativo pela indometacina no cérebro do Danio rerio (Zebrafish) é prevenida pelo alfa-tocoferol
(Universidade Federal do Pará, 2021-01) PINHEIRO, Jéssica Souza; OLIVEIRA, Karen Renata Herculano Matos; http://lattes.cnpq.br/3032008039259369; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247
The non-steroidal anti-inflammatory drugs are among the most used and prescribed in the world, however this type of drug has several side effects at the neural level. Studies related to neurobehavioral and neurochemical damage of this class of drug are still necessary for a better understanding of all the possible damages that they can cause. As a result, indomethacin, which is an NSAID, has been widely used to treat pathologies such as rheumatoid arthritis, musculoskeletal injuries, osteoarthritis and postoperative pain. Indomethacin non-selectively blocks the enzymes COX-1 and COX-2, acting to decrease the production of prostaglandins. Therefore, this study proposed that the indomethacin could be generated anxiogenic effects and oxidative stress in the brain, and whether the antioxidant α-tocopherol exercised protection against the possible damage caused by indomethacin in zebrafish. The animals used were fish of the species Danio rerio (n=160), subdivided into the following groups: Control - Saline 0.9%; Indomethacin - INDO 0.5 mg/kg; INDO 0.75 mg/kg; INDO 1.0 mg/kg; INDO 2.0 mg/kg; INDO 3.0 mg/kg; α-Tocopherol - TF; TF + INDO 1 mg/kg; TF + INDO 2 mg/kg and were subjected novel tank diving test, the parameters time on top, freezing, erratic swimming and crossed quadrants were analyzed. The statistical analysis of the results was performed using one-way ANOVA with a post-test bonferroni or tukey for comparison between groups, with values with p <0.05 being considered significant. The results regarding the behavioral parameters and oxidative stress were expressed as mean ± standard error or standard deviation. The parameters that showed statistical differences were the time at the top and freezing, where the animals of the groups INDO 0.5 mg/kg, INDO 0.75 mg/kg, INDO 1 mg/kg and INDO 2 mg/kg explored for less the top of the apparatus compared to the CTRL group. In the freezing parameter the groups treated with indomethacin INDO 0.5 mg/kg, 0.75 mg/kg and 2 mg/kg did not show statistical differences with the CTRL group, however there was a difference between the CTRL and INDO groups 1 mg/kg. In the freezing parameter, the animals in the INDO 1 mg/kg group showed a longer time without movement compared to the CTRL group. In the other parameters, there were no significant differences between the groups treated with the control group. The analysis of lipid peroxidation, the INDO 1 mg/kg and INDO 2 mg/kg groups showed an increase in MDA production compared to the CTRL group, thus inferring that there was an increase in oxidative stress when animals were treated with indomethacin. The α-tocopherol exercised protection when animals were previously treated in both the TF + INDO 1 mg/kg group and the TF + INDO 2 mg/kg group compared to the INDO 1 mg/kg and INDO 2 mg/kg groups, respectively. Therefore, indomethacin is involved in inducing anxiety-like behavior and oxidative stress in zebrafish brains.
Acesso aberto (Open Access)
Investigação de metabólitos secundários de folhas de Derris urucu (Killip et Smith) Macbr. com atividades biológicas
(Universidade Federal do Pará, 2009-06-30) LÔBO, Lívia Trindade; SILVA, Milton Nascimento da; http://lattes.cnpq.br/6742390457977989; ARRUDA, Mara Silvia Pinheiro; http://lattes.cnpq.br/8047078292358267
Derris urucu, belonging to the family Leguminosae / Fabaceae, is popularly known as “timbó”. The roots of this species are commonly used as pesticides and poison to fish. From Derris genus many phytochemical studies have been reported, the roots being of the most studied part from the plants of this genus. The name “timbó” is most general for the species Derris urucu and Derris nicou, which are the species that produce, in their roots, rotenoids such as rotenone and deguelin, from which derives the importance of these plants. The extracts, and the substances isolated from this genus are responsible for a wide range of biological activities, mainly the insecticidal activity. From the ethanolic extract of leaves of D. urucu, twelve compounds were isolated and purified by High Performance Liquid Chromatography: five stilbenes, six dihydroflavonols and one flavanone. The structural identification was based on the mass, 1H and 13C NMR spectrometric analysis and two dimensional NMR, beyond comparison with literature data . The ethanolic extract of leaves of D. urucu was submitted to bioassays to avaluate the allelophatic potential, presenting relevant percentage of inhibition of seed germination and development of weeds in pastures. Aiming to detect the substances responsible for allelophatic activity, three stilbenes and three dihydroflavonols were selected and submitted to bioassays of inhibition of germination and development of the radicle and hypocotyl of weeds. The allelophatic tests were performed with the substances isolated and with the combination of them, aiming to assess the synergism between them, but the magnitude of inhibition observed was very low. By other side, when the substances were tested in mixtures there was a significant increase in the percentage of inhibition, so these substances in mixtures, can be considered promising for future studies involving allelophatic activity. An other test was carried out with the isolated compounds. Three stilbenes and five dihydroflavonols were evaluated for DPPH radical scavenging activity (antioxidant activity). In this bioassay, was not observed a significant antioxidant activity, justified by the analysis in the structures of the substances tested.