Consulta: subjectFacets:"Free radicals"
Registros recuperados: 33
Data/hora: 13/06/2024 18:07:06

LNO3 AND L3 Are Associated With Antiproliferative And Pro-Apoptotic Action In Hepatoma Cells
Provedor de dados: 74
Autores: Zanelatto,Leonardo Campos; Silva,Patrícia Benites Gonçalves da; Sartori,Daniele; Panis,Carolina; Lepri,Sandra; Fátima,Ângelo de; Mantovani,Mário Sérgio.
Abstract The identification of antitumoral substances is the focus of intense biomedical research. Two structural analogues of thalidomide, LNO3 and L3, are two synthetic compounds that might possess such antitumor properties. We evaluated the toxicological effects of these substances, including cytotoxicity, genotoxicity and induction of apoptosis in HTC cells. Additionally, the production of free radicals (nitric oxide and superoxide) was investigated, and the expression of caspases genes 3, 8, and 9 were determined by RT-qPCR. The compounds exhibited cytotoxic effects that resulted in inhibited cell proliferation. LNO3 showed to be more effective and toxic than L3 in all assays. LNO3 stimulated the release of NO and superoxide, which was accompanied by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Thalidomide analogues; Antiproliferative activity; Cytotoxicity; Free radicals; Apoptosis.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572016000200270

Determinação quantitativa da atividade antioxidante de extratos brutos de microrganismos pelo método de captura de radical livre DPPH.
Provedor de dados: 14
Autores: SANTOS, S. N.; CASTANHA, R. F.; HABER, L. L.; MARQUES, M. O. M.; SCRAMIN, S.; MELO, I. S. de.
O escopo deste trabalho é a disponibilização da metodologia científica utilizada na determinação quantitativa da atividade antioxidante de extratos livres DPPH, baseadas nas adaptações realizadas no Laboratório de Microbiologia Ambiental em parceria com o Laboratório de Produtos Naturais, ambos da Embrapa Meio Ambiente.
Tipo: Comunicado Técnico (INFOTECA-E)
Palavras-chave: Radical livre; Microrganismo; Análise microbiológica; Análise bacteriológica; Análise de laboratório; Método; Laboratory techniques; Free radicals.
Ano: 2011
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/898412

Osmoregulation, bioenergetics and oxidative stress in coastal marine invertebrates: raising the questions for future research
Provedor de dados: 5
Autores: Rivera-ingraham, Georgina A.; Lignot, Jehan-herve.
Osmoregulation is by no means an energetically cheap process, and its costs have been extensively quantified in terms of respiration and aerobic metabolism. Common products of mitochondrial activity are reactive oxygen and nitrogen species, which may cause oxidative stress by degrading key cell components, while playing essential roles in cell homeostasis. Given the delicate equilibrium between pro- and antioxidants in fueling acclimation responses, the need for a thorough understanding of the relationship between salinity-induced oxidative stress and osmoregulation arises as an important issue, especially in the context of global changes and anthropogenic impacts on coastal habitats. This is especially urgent for intertidal/estuarine organisms, which may...
Tipo: Text
Palavras-chave: Hyper-/hypo-osmoregulator; Hyper-/iso-osmoregulators; Osmoconformers; Antioxidants; Free radicals; Hypometabolism; Mitochondria.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00625/73717/74820.pdf

Free radical scavenging capacity and cytotoxic and antiproliferative effects of Vaccinium meridionale Sw. agains colon cancer cell lines
Provedor de dados: 98
Autores: Maldonado-Celis,Maria E; Arango-Varela,Sandra Sulay; Rojano,Benjamín Alberto.
Introduction: Vaccinium meridionale Swartz, of the family Ericaceae, is commonly known as mortiño or agraz. The plant is considered a functional food, with a content of anthocyanins and antioxidants similar to or greater than that reported for other Vaccinium species. However, little is known about its nutraceutical and medicinal properties. Objectives: determine the antioxidant activity and cytotoxic and antiproliferative effect of mortiño fruit aqueous extract against colon adenocarcinoma cells (SW480) and their derived metastatic cells (SW620). Methods: total phenols and anthocyanins were determined by the Folin-Ciocalteu method. Caffeoyl derivatives were determined by HPLC-DAD. Antioxidant activity was analyzed as the ability to scavenge reactive...
Tipo: Journal article
Palavras-chave: Cytotoxic; Antiproliferative; Free radicals; Vaccinium meridionale; Colon cancer.
Ano: 2014
URL: http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S1028-47962014000200006

Effect of fermentation time on phenolic content and antioxidant potential in Cupuassu (Theobroma grandiflorum (Willd. ex Spreng.) K.Schum.) beans
Provedor de dados: 109
Autores: Cuellar-Álvarez,Laura; Cuellar-Álvarez,Natalia; Galeano-García,Paula; Suárez-Salazar,Juan Carlos.
Abstract Cupuassu (Theobroma grandiflorum (Willd. ex Spreng.) K.Schum.) is an evergreen tree in the family Malvaceae, with nutritional qualities of interest in the food and cosmetic industry. It is necessary for its processing, in addition to other processes, to perform a fermentation, affecting its chemical composition. Therefore, the effect of fermentation time on the phenolic content and antioxidant activity of Cupuassu (T. grandiflorum) beans, was determined. During this process, the chemical properties of the beans and the phenolic content were evaluated every two days; also quantifying the secondary metabolites Catechin, Epicatechin, Theobromine and Caffeine by high performance liquid chromatography (HPLC). The antioxidant activity was analyzed using...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bromatological analysis; Phenols; Fermentation; Free radicals; Análisis bromatológico; Fenoles; Fermentación; Radicales libres.
Ano: 2017
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122017000400473

Evaluation of the antioxidant potential of Copaifera multijuga in Ehrlich tumor-bearing mice
Provedor de dados: 36
Autores: CUNHA,Ana Paula Simões da; BALDISSERA,Luana; PEREIRA,Débora Linsbinski; ALBIERO,Lucineia Reuse; CASTOLDI,Lindsey; SINHORIN,Adilson Paulo; SINHORIN,Valéria Dornelles Gindri.
ABSTRACT Copaifera multijuga, commonly known as copaiba, is popularly used in the form of tea for various conditions due to the presence of antioxidant substances in its composition, which protect cells against damage caused by free radicals. Its oleoresin is also used as an anti-inflammatory and antitumoral agent. The present study investigated the antioxidant effect of the ethanolic extract of copaiba stem bark on Swiss mice inoculated with solid Ehrlich tumors. Mice were inoculated subcutaneously with 1x106 Ehrlich’s tumor cells and treated via gavage with ethanolic extract of copaiba for thirty days, with doses varying between 100 and 200 mg kg-1. Biochemical analyses of enzymatic antioxidants [superoxide dismutase (SOD), catalase (CAT),...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Solid tumor; Oxidative stress; Free radicals; Copaiba; Antineoplasic.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672019000100041

Antioxidant activity and total phenol content of blackberries cultivated in a highland tropical climate
Provedor de dados: 1
Autores: Guedes, Mayara Neves Santos; Pio, Rafael; Maro, Luana Aparecida Castilho; Lage, Fabíola Fonseca; Abreu, Celeste Maria Patto de; Saczk, Adelir Aparecida.
Blackberries are an important option for the diversification of fruit crops. However, there is currently no literature regarding plant cultivation in high-altitude tropical climates. Knowledge of the phenolic composition of blackberries is essential because variations in the levels of these components may exist between cultivars and may depend on environmental conditions. High performance liquid chromatography (HPLC) was used to evaluate the total phenol content of different blackberry cultivars (Arapaho, Brazos, Cainguangue, Cherokee, Choctaw, Comanche, Ébano, Guarani, Tupy and Xavante). Free radical scavenging activity in these cultivars was assayed using a DPPH test. The HPLC-UV chromatogram of blackberry fruit extracts at 280 nm revealed the presence...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 5.01.03.00-8 total phenols; Free radicals; HPLC; Rubus spp. Fitotecnia.
Ano: 2017
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/28413

Qualidade do sêmen em tilápia do Nilo (Oreochromis niloticus), alimentadas com dietas contendo diferentes níveis de vitamina C - doi: 10.4025/actascianimsci.v32i3.7836
Provedor de dados: 2
Autores: Mataveli, Marcela; UEM; Moraes, Gentil Vanini de; UEM; Streit Junior, Danilo Pedro; Universidade Federal do Rio Grande do Sul; Ribeiro, Ricardo Pereira; UEM; Gasparino, Eliane; UEM.
A vitamina C atua na proteção de danos celulares provocados pelos radicais livres, sendo a suplementação considerada essencial para a maioria das espécies de peixes, uma vez que não a sintetizam em função da ausência da enzima L-gulonolactona oxidase. Assim, avaliou-se o efeito da suplementação de 0, 75, 150 e 225 mg de vitamina C kg-1 de ração na qualidade do sêmen em tilápias do Nilo (Oreochromis niloticus). Os parâmetros quali-quantitativos do sêmen não foram influenciados pela suplementação de vitamina C, exceto a motilidade progressiva que aumentou linearmente com adição de vitamina C. Conclui-se que os reprodutores de tilápias do Nilo devem ser suplementados com 225 mg de vitamina   C kg-1 de ração.
Tipo: Pesquisa de campo e análise laboratorial
Palavras-chave: 5.00.00.00-4; 5.05.00.00-7 Antioxidante; Radicais livres; Reprodução; Suplementação 5.05.04.00-2 Antioxidant; Free radicals; Reproduction; Supplementation.
Ano: 2010
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/7836

High susceptibility of activated lymphocytes to oxidative stress-induced cell death
Provedor de dados: 42
Autores: Degasperi,Giovanna R.; Castilho,Roger F.; Vercesi,Anibal E.
The present study provides evidence that activated spleen lymphocytes from Walker 256 tumor bearing rats are more susceptible than controls to tert-butyl hydroperoxide (t-BOOH)-induced necrotic cell death in vitro. The iron chelator and antioxidant deferoxamine, the intracellular Ca2+ chelator BAPTA, the L-type Ca2+ channel antagonist nifedipine or the mitochondrial permeability transition inhibitor cyclosporin A, but not the calcineurin inhibitor FK-506, render control and activated lymphocytes equally resistant to the toxic effects of t-BOOH. Incubation of activated lymphocytes in the presence of t-BOOH resulted in a cyclosporin A-sensitive decrease in mitochondrial membrane potential. These results indicate that the higher cytosolic Ca2+ level in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cell death; Free radicals; Immune response; Lymphopenia; Mitochondrial permeability transition; Spleen lymphocyte.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000100009

Lipid peroxidation in rats treated with vincristine sulphate and nandrolone decanoate
Provedor de dados: 45
Autores: Martins,D.B; Lopes,S.T.A; Mazzanti,C.M; Spanevello,R; Schmatz,R; Corrêa,M; Stefanello,N; Schetinger,M.R; Morsch,V; Veiga,A.P.M.
Brain and serum lipid peroxidation was studied in rats treated with vincristine sulphate and different doses of nandrolone decanoate. Thirty rats were distributed into six groups (n=5). The treatments were applied once a week for two weeks. Sample collection was performed in the third week. Treatments during the first week were: G1 (control) - physiologic solution, G2 - vincristine sulphate (4mg/m²), G3 - physiologic solution, G4 - physiologic solution, G5- vincristine sulphate (4mg/m²), and G6 - vincristine sulphate (4mg/m²). In the second week, they were: G1 (control) - physiologic solution, G2- physiologic solution, G3 - nandrolone decanoate (1.8mg/kg-1), G4 - nandrolone decanoate (10mg/kg-1), G5 - nandrolone decanoate (1.8mg/kg-1), and G6 - nandrolone...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rat; Anabolic androgenic steroid; Chemotherapeutic; Free radicals; Brain; Blood serum.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352011000100017

Zinc in the prevention of Fe2initiated lipid and protein oxidation
Provedor de dados: 48
Autores: ZAGO,M. PAOLA; VERSTRAETEN,SANDRA V.; OTEIZA,PATRICIA I.
In the present study we characterized the capacity of zinc to protect lipids and proteins from Fe2+-initiated oxidative damage. The effects of zinc on lipid oxidation were investigated in liposomes composed of brain phosphatidylcholine (PC) and phosphatidylserine (PS) at a molar relationship of 60:40 (PC:PS, 60:40). Lipid oxidation was evaluated as the oxidation of cis-parinaric acid or as the formation of 2-thiobarbituric acid-reactive substances (TBARS). Zinc protected liposomes from Fe2+ (2.5-50 muM)-supported lipid oxidation. However, zinc (50 muM) did not prevent the oxidative inactivation of glutamine synthelase and glucose 6-phosphate dehydrogenase when rat brain superntants were oxidized in the presence of 5 muM Fe2+ and 0.5 mM H2O2 .We also...
Tipo: Journal article
Palavras-chave: Aluminum; Catechins; Free radicals; Iron; Lipid peroxidation; Zinc.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200014

Nitric Oxide: Oxygen Radical Interactions in Atherosclerosis
Provedor de dados: 48
Autores: RUBBO,HOMERO; BATTHYANY,CARLOS; RADI,RAFAEL.
Atherosclerosis is one of the most common diseases and the principal cause of death in western civilization. The pathogenesis of this disease can be explained on the basis of the ‘oxidative-modification hypothesis,’ which proposes that low-density lipoprotein (LDL) oxidation represents a key early event. Nitric oxide (.NO) regulates critical lipid membrane and lipoprotein oxidation events by a) contributing to the formation of more potent secondary oxidants from superoxide (i.e.: peroxynitrite), and b) its antioxidant properties through termination reactions with lipid radicals to possibly less reactive secondary nitrogen-containing products (LONO, LOONO). Relative rates of production and steady state concentrations of superoxide and .NO and cellular sites...
Tipo: Journal article
Palavras-chave: Antioxidants; Free radicals; Lipid oxidation; Low density lipoprotein oxidation; Nitric oxide; Peroxynitrite.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200017

Superoxide dismutase and catalase: tissue activities and relation with age in the long-lived species Margaritifera margaritifera
Provedor de dados: 48
Autores: FERNÁNDEZ,CARLOS; SAN MIGUEL,EDUARDO; FERNÁNDEZ-BRIERA,ALMUDENA.
Free radicals are extremely reactive and produce damage and modify cell functions. Furthermore, superoxide dismutase and catalase are believed to play a key role in the enzymatic defence of the cells. Indeed, some authors have argued that reduced free-radical damage could explain increased longevity. Margaritifera margaritifera is one of the longest-lived animals in the world (up to 100-200 years). Furthermore, this organism may serve as a useful model for gerontologists interested in exploring the mechanisms that promote long life and the slowing of senescence. The present study estimated for the first time individual enzymatic activity for superoxide dismutase isozymes (Cu,Zn-SOD and Mn-SOD) and catalase in tissue preparations of gills, digestive glands...
Tipo: Journal article
Palavras-chave: Margaritifera margaritifera; Free radicals; Aging; Superoxide dismutase; Catalase.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602009000100006

In vivo and in vitro anti-inflammatory activity of Cryptostegia grandiflora Roxb. ex R. Br. leaves
Provedor de dados: 48
Autores: Castro,Jenny P; Ocampo,Yanet C; Franco,Luis A.
BACKGROUND: Despite Cryptostegia grandiflora Roxb. ex R. Br. (Apocynaceae) leaves are widely used in folk Caribbean Colombian medicine for their anti-inflammatory effects, there are no studies that support this traditional use. Therefore, this work aimed to evaluate the effect of the total extract and primary fractions obtained from Cryptostegia grandiflora leaves, using in vivo and in vitromodels of inflammation, and further get new insights on the mechanisms involved in this activity. RESULTS: Ethanolic extract of Cryptostegia grandiflora leaves, and its corresponding ether and dichloromethane fractions, significantly reduced inflammation and myeloperoxidase activity (MPO) in ear tissue of mice treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA)....
Tipo: Journal article
Palavras-chave: Ear edema; Free radicals; Inflammation; MPO; PGE2; RAW 264; 7 macrophages.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602014000100032

Antioxidant, Antibacterial activity and Brine shrimp toxicity test of some Mountainous Lichens from Nepal
Provedor de dados: 48
Autores: Paudel,Babita; Datta Bhattarai,Hari; Prasad Pandey,Durga; Seoun Hur,Jae; Gyu Hong,Soon; Kim,Il-Chan; Han Yim,Joung.
A total of twenty four lichen species belonging to six families were collected from mountainous region of Nepal. The methanol extracts of each species were tested for antimicrobial and antioxidant activitiesin vitro. It was found that extracts of twenty one lichen species were active againstB. subtilis and seven species were active againstS. aureus. Similarly, in DPPH assay, three speciesPeltigera sp.,Cladonia sp., andCanoparmelia sp. showed comparable activity with commercial standard, BHA. In ABTS+ assay, extracts ofParmoterma sp.,Ramalina sp.,Peltigera sp. andCladonia sp. showed stronger activity than ascorbic acid. The observed data after comparison with previously published reports indicated that the high altitude lichens contain stronger antioxidant...
Tipo: Journal article
Palavras-chave: Antibacterial; Antioxidant; Nepal lichens; Free radicals.
Ano: 2012
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602012000400010

Ascorbate protects (+)-catechin from oxidation both in a pure chemical system and human plasma
Provedor de dados: 48
Autores: LOTITO,SILVINA B; FRAGA,CESAR G.
We evaluated the interaction between ascorbic acid (AA) and (+)-catechin (CTCH) in potassium phosphate solution, pH 7.4 (PPS) and in human plasma. In both systems, the oxidation was started by adding 2,2’-azobis-(2-amidinopropane) clorhidrate (AAPH). The concentrations of AA and CTCH were determined by HPLC using electrochemical detection. In PPS, CTCH was oxidized by AAPH (50 muM), in either the absence or presence of different initial concentrations of AA (25-200 muM). In the presence of AA, CTCH depletion was delayed, an effect that was dependent upon the initial concentration of AA. When 100 muM AA was added after the oxidation had begun, CTCH depletion was arrested for 30 min. The kinetics of AA oxidation by AAPH was also characterized in PPS. AA (100...
Tipo: Journal article
Palavras-chave: Catechins; Antioxidants; Free radicals; Procyanidins.
Ano: 2000
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200015

Membrane effects of Cocoa Procyanidins in Liposomes and Jurkat T Cells
Provedor de dados: 48
Autores: VERSTRAETEN,SANDRA V.; OTEIZA,PATRICIA I.; FRAGA,CÉSAR G.
We investigated the effects of the interaction between flavanols and related procyanidins (dimer to hexamer) with both cell and synthetic membranes, on bilayer fluidity and susceptibility to oxidation. Cocoa derived dimers (0.05 to 1 µg/ml) protected Jurkat T cells from AMVN-mediated oxidation and increased plasma membrane fluidity. These effects occurred in a concentration- and chain length-dependent manner. In liposomes, procyanidins prevented the Fe2+-induced permeabilization of the membrane. Together, these results support the hypothesis that procyanidins could interact with the polar headgroup of lipids, increasing membrane fluidity and also, preventing the access of molecules that could affect membrane integrity
Tipo: Journal article
Palavras-chave: Epicatechin; Free radicals; Lipid oxidation; Membrane fluidity; Membrane permeability; Procyanidins.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000200016

Biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli AB1157 cultures submitted to the action of stannous chloride
Provedor de dados: 48
Autores: SOUZA,RAPHAEL S S; ALMEIDA,MARCELA C; MANOEL,CRISTIANO V; SANTOS-FILHO,SEBASTIÃO D; FONSECA,ADENILSON S; FILHO,MARIO BERNARDO.
Stannous chloride (SnC12) is used in nuclear medicine as a reducing agent to obtain technetium-99m-radiopharmaceuticals. It have been reported that natural products might reduce the genotoxic and cytotoxic effects related to SnC12. This work evaluated the biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli (E. coli) AB1157 (wild type) cultures submitted to the action of SnC12. E. coli AB1157 cultures (exponential growth phase) were collected by centrifugation, washed and resuspended in 0.9%NaCl. Samples were incubated in water bath shaker with: (a) SnC12 (25mg/ml), (b)Salix alba extract(11.6mg/ml) and (c)SnC12(25mg/ml) + Salix alba extract (11.6mg/ml). Incubation with 0.9% NaCl was also carried out (control). At 60...
Tipo: Journal article
Palavras-chave: Escherichia coli; Free radicals; Salix alba; Stannous chloride.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602009000200008

Antioxidant activity of extract from Polygonum cuspidatum
Provedor de dados: 48
Autores: HSU,CHIN-YUAN; CHAN,YU-PEI; CHANG,JELI.
Numerous diseases are induced by free radicals via lipid peroxidation, protein peroxidation and DNA damage. It has been known that a variety of plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum cuspidatum Sieb. et Zuce has antioxidant activity is unknown. In this study, dried roots of Polygonum cuspidatum were extracted by ethanol and the extract was lyophilized. Free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays were employed to study antioxidant activities. The results indicate that the IC50 value oí Polygonum cuspidatum extract is 110 µg/ml in free radical scavenging assays, 3.2 µg/ml in superoxide radical scavenging...
Tipo: Journal article
Palavras-chave: Antioxidant activity; Free radicals; Phenolics; Lipid peroxidation; DNA damage Polygonum cuspidatum.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602007000100002

Effect of freezing and processing technologies on the antioxidant capacity of fruit pulp and jelly
Provedor de dados: 52
Autores: Bof,Cristine Maso Jeusti; Fontana,Roselei Claudete; Piemolini-Barreto,Luciani Tatsch; Sandri,Ivana Greice.
The effect of freezing and processing technology on the antioxidant capacity of grape (Vitis vinifera), apple (Malus domestica), strawberry (Fragaria x Anassa), pear (Pyrus communis L.), guava (Psidium guajava L.), and fig (Ficus carica L.) was evaluated for 90 days. Under a storage temperature of -15 º C, there was no significant difference in the antioxidant capacity of grape and fig pulp, and a higher antioxidant capacity was found for guava pulp (27 µmol/g). While the technological processing did not affect the antioxidant capacity of pear and apple jellies, all other jellies studied showed a reduced antioxidant capacity. The processing reduced the antioxidant capacity of grapes in 45%. Among the fruit products, the highest antioxidant activities were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Functional foods; Pulps; Jellies; Free radicals; Storage.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000100014

Enhanced response of the fricke solution doped with hematoporphyrin under X-rays irradiation
Provedor de dados: 52
Autores: Austerlitz,Carlos; Souza,Vivianne Lúcia Bormann de; Campos,Diana Maria Tavares; Kurachi,Cristina; Bagnato,Vanderley; Sibata,Cláudio.
The vials filled with Fricke solutions were doped with increasing concentrations of Photogem®, used in photodynamic therapy. These vials were then irradiated with low-energy X-rays with doses ranging from 5 to 20 Gy. The conventional Fricke solution was also irradiated with the same doses. The concentration of ferric ions for the Fricke and doped-Fricke irradiated solutions were measured in a spectrophotometer at 220 to 340 nm. The results showed that there was an enhancement in the response of the doped-Fricke solution, which was proportional to the concentration of the photosensitizer. The use of such procedure for studying the radiosensitizing property of photosensitizers based on the production of free radicals is also discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Hematoporphyrin; Fricke dosimeter; Free radicals.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000200006

Nonspecific blockade of vascular free radical signals by methylated arginine analogues
Provedor de dados: 56
Autores: Pedro,M.A.; Augusto,O.; Barbeiro,H.V.; Carvalho,M.H.C.; da-Luz,P.L.; Laurindo,F.R.M.
Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA) on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol/l, P&amp;lt;0.001) in response to papaverine-induced flow increases of 121 ± 12%. In contrast, after similar papaverine-induced flow increases simultaneously with L-NMMA infusions, ascorbyl levels were not significantly changed compared to baseline. Similar results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Free radicals; Arginine analogues; NG-methyl-L-arginine; NG-methyl-D-arginine; NG-nitro-L-arginine methyl ester.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000600004

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity
Provedor de dados: 56
Autores: Romão,P.R.T.; Tovar,J.; Fonseca,S.G.; Moraes,R.H.; Cruz,A.K.; Hothersall,J.S.; Noronha-Dutra,A.A.; Ferreira,S.H.; Cunha,F.Q.
Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leishmania; Glutathione; Trypanothione; Trypanothione reductase; Nitric oxide; Free radicals.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300006

Antioxidant properties of natural compounds used in popular medicine for gastric ulcers
Provedor de dados: 56
Autores: Repetto,M.G.; Llesuy,S.F.
There is evidence concerning the participation of reactive oxygen species in the etiology and physiopathology of human diseases, such as neurodegenerative disorders, inflammation, viral infections, autoimmune pathologies, and digestive system disorders such as gastrointestinal inflammation and gastric ulcer. The role of these reactive oxygen species in several diseases and the potential antioxidant protective effect of natural compounds on affected tissues are topics of high current interest. To consider a natural compound or a drug as an antioxidant substance it is necessary to investigate its antioxidant properties in vitro and then to evaluate its antioxidant functions in biological systems. In this review article, we shall consider the role of natural...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Antioxidant; Free radicals; Natural antioxidants; Gastric ulcers; Artemisia douglasiana Besser; Dehydroleucodine.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000500003

Alternative mitochondrial functions in cell physiopathology: beyond ATP production
Provedor de dados: 56
Autores: Kowaltowski,A.J.
It is well known that mitochondria are the main site for ATP generation within most tissues. However, mitochondria also participate in a surprising number of alternative activities, including intracellular Ca2+ regulation, thermogenesis and the control of apoptosis. In addition, mitochondria are the main cellular generators of reactive oxygen species, and may trigger necrotic cell death under conditions of oxidative stress. This review concentrates on these alternative mitochondrial functions, and their role in cell physiopathology.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mitochondrial permeability transition; Uncoupling proteins; Alternative oxidase; Cardioprotection; Free radicals; Aging.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000200014

Mitochondrial K+ transport and cardiac protection during ischemia/reperfusion
Provedor de dados: 56
Autores: Carreira,R.S.; Facundo,H.T.F.; Kowaltowski,A.J.
Mitochondrial ion transport, oxidative phosphorylation, redox balance, and physical integrity are key factors in tissue survival following potentially damaging conditions such as ischemia/reperfusion. Recent research has demonstrated that pharmacologically activated inner mitochondrial membrane ATP-sensitive K+ channels (mitoK ATP) are strongly cardioprotective under these conditions. Furthermore, mitoK ATP are physiologically activated during ischemic preconditioning, a procedure which protects against ischemic damage. In this review, we discuss mechanisms by which mitoK ATP may be activated during preconditioning and the mitochondrial and cellular consequences of this activation, focusing on end-effects which may promote ischemic protection. These...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mitochondria; Potassium; Calcium; Free radicals; Heart; Ischemia.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000300004

Protein 3-nitrotyrosine formation during Trypanosoma cruzi infection in mice
Provedor de dados: 56
Autores: Naviliat,M.; Gualco,G.; Cayota,A.; Radi,R.
Nitric oxide (·NO) is a diffusible messenger implicated in Trypanosoma cruzi resistance. Excess production of ·NO and oxidants leads to the generation of nitrogen dioxide (·NO2), a strong nitrating agent. Tyrosine nitration is a post-translational modification resulting from the addition of a nitro (-NO2) group to the ortho-position of tyrosine residues. Detection of protein 3-nitrotyrosine is regarded as a marker of nitro-oxidative stress and is observed in inflammatory processes. The formation and role of nitrating species in the control and myocardiopathy of T. cruzi infection remain to be studied. We investigated the levels of ·NO and protein 3-nitrotyrosine in the plasma of C3H and BALB/c mice and pharmacologically modulated their production during...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Peroxynitrite; Nitric oxide; Nitrotyrosine; Free radicals; Trypanosoma cruzi; Chagas' disease.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005001200011

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress
Provedor de dados: 56
Autores: Torres,R.L.; Torres,I.L.S.; Gamaro,G.D.; Fontella,F.U.; Silveira,P.P.; Moreira,J.S.R.; Lacerda,M.; Amoretti,J.R.; Rech,D.; Dalmaz,C.; Belló,A.A.
Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Stress; TBARS; TRAP; Free radicals; Lungs; Oxidative stress.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200004

Ginseng administration protects skeletal muscle from oxidative stress induced by acute exercise in rats
Provedor de dados: 56
Autores: Voces,J.; Cabral de Oliveira,A.C.; Prieto,J.G.; Vila,L.; Perez,A.C.; Duarte,I.D.G.; Alvarez,A.I.
Enzymatic activity was analyzed in the soleus, gastrocnemius (red and white) and plantaris muscles of acutely exercised rats after long-term administration of Panax ginseng extract in order to evaluate the protective role of ginseng against skeletal muscle oxidation. Ginseng extract (3, 10, 100, or 500 mg/kg) was administered orally for three months to male Wistar rats weighing 200 ± 50 g before exercise and to non-exercised rats (N = 8/group). The results showed a membrane stabilizing capacity of the extract since mitochondrial function measured on the basis of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities was reduced, on average, by 20% (P &lt; 0.05) after exercise but the activities remained unchanged in animals treated with a ginseng...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Panax ginseng; Exercise; Free radicals; Lipid peroxidation; Glutathione status; Mitochondria.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001200012

Effect of trolox C on cardiac contracture induced by hydrogen peroxide
Provedor de dados: 56
Autores: Belló-Klein,A.; Oliveira,A.R.; Miranda,M.F.S.; Irigoyen,M.C.; Homem-de-Bittencourt Jr.,P.I.; Llesuy,S.; Belló,A.A.
Hydrogen peroxide (H2O2) perfused into the aorta of the isolated rat heart induces a positive inotropic effect, with cardiac arrhythmia such as extrasystolic potentiation or cardiac contractures, depending on the dose. The last effect is similar to the "stone heart" observed in reperfusion injury and may be ascribed to lipoperoxidation (LPO) of the membrane lipids, to protein damage, to reduction of the ATP level, to enzymatic alterations and to cardioactive compounds liberated by LPO. These effects may result in calcium overload of the cardiac fibers and contracture ("stone heart"). Hearts from male Wistar rats (300-350 g) were perfused at 31oC with Tyrode, 0.2 mM trolox C, 256 mM H2O2 or trolox C + H2O2. Cardiac contractures (baseline elevation of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trolox C; "stone heart"; Free radicals; Hydrogen peroxide.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100013

Application of various antioxidants in the treatment of influenza
Provedor de dados: 56
Autores: Dolganova,A.; Sharonov,B.P.
We determined the effect of the antioxidants superoxide dismutase, desferrioxamine and allopurinol on the survival of male CBA mice infected intranasally with 2-5 LD50 lung influenza virus A/Aichi/2/68. Survival for at least 20 days was observed for 45% of the mice that received 1000 U/day superoxide dismutase prepared from red blood cells on days 5, 6, 7 and 8 after infection, and 75% survival was observed for mice that received the same dose on days 4, 5, 6, 7 and 8. Desferrioxamine, 25 mg/kg per day and 100 mg/kg per day injected subcutaneously, resulted in survival rates of 5 and 0%, respectively, compared to 10% survival observed for saline-injected controls. Allopurinol at doses of 5 to 50 mg/kg per day had no effect on mouse survival. These data...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Free radicals; Influenza; Antioxidant; Desferrioxamine; Superoxide dismutase; Allopurinol.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100012

Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile
Provedor de dados: 60
Autores: Vellosa,José Carlos Rebuglio; Khalil,Najeh Maissar; Gutierres,Vânia Ortega; Santos,Vânia Aparecida de Freitas Formenton Macedo dos; Furlan,Maysa; Brunetti,Iguatemy Lourenço; Oliveira,Olga Maria Mascarenhas de Faria.
Reactive oxygen species (ROS) and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae) root bark ethanol extract (ScEtOH) was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salacia campestris Walp/antioxidant properties; Hippocrateaceae; Myeloperoxidase; Reactive oxygen species; Antioxidants; Free radicals.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502009000100012

Total carotenoids and antioxidant activity of fillets and shells (in natura or cooked) of “Vila Franca” shrimp (Litopenaeus Schmitti) in different intervals of storage under freezing
Provedor de dados: 64
Autores: Lira,Giselda Macena; Lopez,Ana Maria Queijeiro; Firmino,Guilherme Oliveira; Santos,Suzan Diniz; Bezerra,Ranilson de Souza.
ABSTRACT Shrimps are sources of carotenoids, astaxanthin is the predominant, responsible for their special and desirable properties, as well as for their instability under heat treatment during the domestic preparation, industrial processing or storage under freezing. These can cause discoloration and reduce the beneficial health properties. This study aimed to evaluate the effect of heat treatment and storage under freezing (0, 45 and 90 days) on the levels of total carotenoids and stability of the antioxidant activity of ethanolic extracts of fillets and shells, raw and cooked, of the white shrimp (“Vila Franca”) Litopenaeus schmitti (Burkenroad, 1938). The antioxidant ability of the extracts was evaluated using the radicals DPPH•...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Free radicals; Functional food; Biomolecules oxidation.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000100094