SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Endothelial cell oxidative stress and signal transduction

PEREZ,DRUSO D; LEIGHTON,FEDERICO; ASPEE,ALEXIS; ALIAGA,CAROLINA; LISSI,EDUARDO.

Thrce ditferent methodologies frequently employed to evaluate the indexes that report the antioxidant capabilities of pure compounds and/or complex mixtures of antioxidants are applied to a series of mono- and polyphenols, as well as to two wine (red and white) samples. These methodologies are based on the bleaching of a stable radical, the effect of the additive upon luminol chemiluminescence induced by peroxyl radicals, and the effect of the additive upon the bleaching of the fluorescence from a dye molecule. Widely ditferent responses are obtained from the different methodologies. These differences are interpreted in terms of the different factors (stoichiametric factors and/or reactivities) that determines the indexes evaluated by these different...

Tipo: Journal article

Palavras-chave: ABTS radical bleaching; Antioxidants; C-phycocyanin bleaching; Total antioxidant reactivity; Total reactive antioxidant potential.

Ano: 2000

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200006

Nitric Oxide: Oxygen Radical Interactions in Atherosclerosis

FONCEA,ROCIO; CARVAJAL,CRISTIAN; ALMARZA,CAROLINA; LEIGHTON,FEDERICO.

Endothelial dysfunction (ED) is an early event in atherosclerotic disease, preceding clinical manifestations and complications. Increased reactive oxygen species (ROS) have been implicated as important mechanisms that contribute to ED, and ROSs may function as intracellular messengers that modulate signaling pathways. Several intracellular signal events stimulated by ROS have been defined, including the identification of two members of the mitogen activated protein kinase family (ERK1/2 and big MAP kinase, BMK1), tyrosine kinases (Src and Syk) and different isoenzymes of PKC as redox-sensitive kinases. ROS regulation of signal transduction components include the modification in the activity of transcriptional factors such as NFkB and others that result in...

Tipo: Journal article

Palavras-chave: Oxidative stress; Signal transduction; Gene expression; Endothelial cell; Atherosclerosis; Antioxidants.

Ano: 2000

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200008

Lipid peroxidation and antioxidants in hyperlipidemia and hypertension

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

MORIEL,PATRICIA; PLAVNIK,FRIDA L; ZANELLA,MARIA T; BERTOLAMI,MARCELO C; ABDALLA,DULCINEIA SP.

Lipid peroxidation and lipid-derived oxidized products have been implicated in the pathogenesis of a variety of human diseases. To clarify the role of oxidative stress in essential hypertension and hypercholesterolemia the in vitro oxidative susceptibility of LDL, the antioxidant status and the lipid peroxide content of blood plasma were examined in hypercholesterolemic (HC), hypertensive (H), hypercholesterolemic/hypertensive (HH) and normolipidemic/normotensive subjects (N). Plasma ascorbate and lipid-soluble antioxidants were lower, while LDL oxidizability, CE-OOH and TL-OOH were higher in H, HC, and HH groups than in the N group. No difference was observed among groups for PL-OOH and isoprostanes. In summary, the results show that: 1) lipid- and...

Tipo: Journal article

Palavras-chave: Lipoprotein oxidation; Lipid peroxides; Isoprostanes; Antioxidants; Atherosclerosis; Oxidative stress.

Ano: 2000

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200010

Ascorbate protects (+)-catechin from oxidation both in a pure chemical system and human plasma

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

Effect of nitric oxide and plant antioxidants on microsomal content of lipid radicals

BOVERIS,ALEJANDRO D; GALATRO,ANDREA; PUNTARULO,SUSANA.

The antioxidant ability of nitric oxide (NO) generated by a chemical donor and of commercially available antioxidant preparations was assayed. SNAP (S-Nitroso-N-acetylpenicilamine) was used as the NO donor, and Ginkgo biloba, wheat and alfalfa preparations were tested. Lipid peroxidation was assayed by EPR employing a reaction system consisting of rat liver microsomes, ADP, FeCl3, NADPH and POBN in phosphate buffer, pH=7.4. In vitro NO exposure decreased microsomal lipid peroxidation in a dose-dependent manner. The dose responsible for inhibiting the microsomal content of lipid radical adducts by 50% (LD50) for SNAP was 550 mu M (NO generation rate 0.1 mu M/min). The addition of 50 mM hemoglobin to the incubation media prevented NO effect on lipid...

Tipo: Journal article

Palavras-chave: Antioxidants; Nitric oxide; Plants extracts; Lipid radicals.

Ano: 2000

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000200016

Influences of alpha-tocopherol on cholesterol metabolism and fatty streak development in apolipoprotein E-deficient mice fed an atherogenic diet

Peluzio,M.C.G.; Homem,A.P.P.; Cesar,G.C.; Azevedo,G.S.; Amorim,R.; Cara,D.C.; Saliba,H.; Vieira,E.C.; Arantes,R.E.; Alvarez-Leite,J..

Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion) in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E)-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich...

¿Poseen algunas algas de las costas cubanas propiedades antiinflamatorias analgésicas y antioxidantes?

Palavras-chave: Antioxidants; Atherosclerosis; Apo E; Mice; Alpha-tocopherol; Cholesterol.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001200005

OceanDocs

Llanio, M. D.; Fernández, M. D.; Mata, A.; Cabrera, B.; Valdés-Iglesias, O.; Díaz, C.; Cabranes, Y..

Marine organisms represent a new source for the discovery of anti-inflammatory agents (Grace et al., 1994), mainly obtained starting from sponges, coelenterates and algae. A representative compound from algae, due to its great number of properties, is the epitaondiol that inhibits the phospholipase A2 and the formation and/or release of prostaglandins and leukotrienes. Taking into account these antecedents, we decided to evaluate extracts from four Rhodophyte algae species of the genera Laurencia, Acantophora and Gracilaria in the models of mouse ear oedema induced by croton oil, writhing induced by acetic acid in mouse, and the assay of the tiobarbituric acid (TBA). The objective was to detect antiinflammatory, analgesic and antioxidant properties of the...

Tipo: Journal Contribution

Palavras-chave: Algae; Antioxidants; Algae; Antioxidants; Http://aims.fao.org/aos/agrovoc/c_258; Http://aims.fao.org/aos/agrovoc/c_511.

Ano: 2003

URL: http://hdl.handle.net/1834/3343

Red Wine administration to Apolipoprotein E-deficient Mice reduces their Macrophage-derived Extracellular Matrix Atherogenic Properties

KAPLAN,MARIELLE; AVIRAM,MICHAEL.

Proteoglycans (PGs) from the arterial extracellular matrix (ECM) contribute to the trapping of LDL and oxidized LDL (Ox-LDL) in the arterial wall, a phenomenon called "lipoprotein retention". Moreover, we have shown that subsequent to their binding to the matrix, LDL and Ox-LDL are taken up by macrophages. Oxidative stress significantly increases macrophage secretion of ECM-PGs, lipoprotein binding to the ECM and the uptake of ECM-retained lipoproteins by macrophages. The aim of the present study was to determine whether red wine administration to atherosclerotic mice would affect their peritoneal macrophage-derived extracellular matrix properties, such as the glycosaminoglycan content and the ability to bind LDL. In addition, we questioned the ability of...

Tipo: Journal article

Palavras-chave: Antioxidants; Atherosclerosis; Extracellular matrix; Macrophages; Polyphenols; Proteoglycans; Red wine.

Ano: 2004

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000200010

Omega-3 Fatty Acids and Antioxidants in Edible Wild Plants

Tomato and garlic by gavage modulate 7,12-dimethylbenz[a]anthracene-induced genotoxicity and oxidative stress in mice

SIMOPOULOS,ARTEMIS P.

Human beings evolved on a diet that was balanced in the omega-6 and omega-3 polyunsaturated fatty acids (PUFA), and was high in antioxidants. Edible wild plants provide alpha-linolenic acid (ALA) and higher amounts of vitamin E and vitamin C than cultivated plants. In addition to the antioxidant vitamins, edible wild plants are rich in phenols and other compounds that increase their antioxidant capacity. It is therefore important to systematically analyze the total antioxidant capacity of wild plants and promote their commercialization in both developed and developing countries. The diets of Western countries have contained increasingly larger amounts of linoleic acid (LA), which has been promoted for its cholesterol-lowering effect. It is now recognized...

Tipo: Journal article

Palavras-chave: Alpha-linolenic acid; Antioxidants; Chronic diseases; Edible wild plants; Evolutionary aspects of diet; Omega-3 fatty acids.

Ano: 2004

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000200013

Ten Myths about Tannins in Sorghums

Bhuvaneswari,V.; Velmurugan,B.; Abraham,S.K.; Nagini,S..

Chemoprotection by dietary agents is a promising strategy for cancer prevention. The aim of the present study was to evaluate the combined effect of tomato and garlic against 7,12-dimethylbenz- [a]anthracene (DMBA)-induced genetic damage and oxidative stress in 12-14-week-old male Swiss albino mice. The animals were randomized into experimental and control groups and divided into eight groups of five animals each. Group 1 animals were injected intraperitoneally with 35 mg/kg body weight DMBA suspended in peanut oil as a single dose. Groups 2-4 animals received tomato (500 mg/kg body weight), garlic (125 mg/kg body weight) and a combination of tomato and garlic for 5 days by gavage, respectively, followed by DMBA 1.5 h after the final feeding. The doses of...

Tipo: Info:eu-repo/semantics/other

Palavras-chave: Antioxidants; DMBA; Garlic; Lipid peroxidation; Micronuclei; Tomato; Lycopene.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700012

Open Agri

Rooney, L.

Palavras-chave: Organic acids; Sorghum; Antioxidants; Pigments; Phenols; Linseed; Aromatic compounds; HPLC; Bakery products; Polymers.

Ano: 2005

URL: http://agropedia.iitk.ac.in/openaccess/?q=node/3264

Changes in nitrate reductase activity and oxidative stress response in the moss Polytrichum commune subjected to chromium, copper and zinc phytotoxicity

Braz. J. Plant Physiol.

Panda,Sanjib Kumar; Choudhury,Shuvasish.

The main aim of this paper was to investigate the effect of chromium (Cr), copper (Cu) and zinc (Zn) on nitrate reductase (NR) activity and oxidative stress responses in the moss Polytrichum commune. Cr, Cu and Zn resulted in the inhibition of NR activity. A decline in total chlorophyll content was observed after 24 and 48 h of metal treatment. Accumulation of the metals showed a dose and time dependent increase. High accumulation of Cu, Cr and Zn were seen in moss shoots after 24 and 48 h of treatment. Treatment of Cr, Cu and Zn for 24 or 48 h resulted in the increase of malondialdehyde (MDA) content in moss shoots. The highest increase was observed in shoots under Cu treatment followed by Cr and Zn. The MDA content was significantly higher after 48h....

Chromium stress in plants

Palavras-chave: Antioxidants; Chromium; Copper; Malondialdehyde; Nitrate reductase; Oxidative stress; Polytrichum commune; Zinc.

Ano: 2005

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200001

Braz. J. Plant Physiol.

Panda,S.K.; Choudhury,S..

The article presents an overview of the mechanism of chromium stress in plants. Chromium is known to be a toxic metal that can cause severe damage to plants and animals. Chromium-induced oxidative stress involves induction of lipid peroxidation in plants that causes severe damage to cell membranes. Oxidative stress induced by chromium initiates the degradation of photosynthetic pigments causing decline in growth. High chromium concentration can disturb the chloroplast ultrastructure thereby disturbing the photosynthetic process. Like copper and iron, chromium is also a redox metal and its redox behaviour exceeds that of other metals like Co, Fe, Zn, Ni, etc. The redox behaviour can thus be attributed to the direct involvement of chromium in inducing...

Oxidative stress is closely related to clinical severity of pre-eclampsia

Palavras-chave: Antioxidants; Chromium; Fenton reactions; Metallothioneins; Oxidative stress.

Ano: 2005

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000100008

Actividad antioxidante en extractos de algas marinas

CHAMY,VERÓNICA M; LEPE,JAIME; CATALÁN,ÁLVARO; RETAMAL,DAVID; ESCOBAR,JORGE A; MADRID,EVA M.

Pre-eclampsia is a hypertensive disorder of pregnancy in which enzymatic antioxidant defenses fail and tissues are injured. This prospective case-control study evaluated whether pre-eclamptic women and their newborns show higher degrees of oxidative stress than normal pregnancies and sought to determine if this stress is related to clinical severity. Forty-four pre-eclamptic and thirty healthy pregnant women attending two hospitals in Valparaíso, Chile, were studied. The following plasmatic variables of antioxidant capacity were evaluated: glutathione peroxidase activity (GPx), total antioxidant capacity measured by oxidation of ABTS substrate (2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), and superoxide dismutase activity (SOD). malondialdehide...

Tipo: Journal article

Palavras-chave: Pre-eclampsia; MDA; SOD; GPx; ABTS; Lipoperoxidation; Antioxidants.

Ano: 2006

URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000200005

OceanDocs

Fernández, M.D.; Hernández, I.; Aneiros, A.; Tello, J..

Entre otras múltiples reacciones, los radicales libres pueden interactuar con ácidos grasos de las membranas celulares y causar la destrucción oxidativa de las mismas; a este proceso es al que se le denomina lipoperoxidación (Echeverry, 1998). Como defensas frente a las agresiones de los radicales libres se presentan una serie de sistemas enzimáticos entre los que destacan la superóxido dismutasa y la catalasa. En los organismos marinos se han encontrado compuestos con actividad antioxidantes fundamentalmente en algunas especies de algas. En este trabajo se realizó la evaluación del efecto antioxidante de los extractos de 6 algas mediante los métodos de inhibición de la peroxidación lipídica, determinación de la actividad mimética superóxido dismutasa...

Tipo: Other

Palavras-chave: Antioxidants; Algae; Experimental research; Antioxidants; Algae; Http://aims.fao.org/aos/agrovoc/c_511; Http://aims.fao.org/aos/agrovoc/c_258.

Ano: 2007

URL: http://hdl.handle.net/1834/2604

Functional Foods in the Marketplace: Willingness to Pay for Apples Enriched with Antioxidants

AgEcon

Markosyan, Armenak; Wahl, Thomas I.; McCluskey, Jill J..

The attention on so-called functional foods has been growing as consumers become more concerned with diet and nutrition. This article aims to measure consumers response to apples with naturally enriched antioxidant coatings. Surveys were conducted in grocery stores in Seattle, Washington and Spokane, Washington. The results suggest that consumers have a somewhat positive attitude towards functional foods in general and with apples enriched with antioxidants in particular. A contingent valuation technique was used to assess factors affecting consumers willingness to pay for the apples with antioxidant coatings. Consumers in the Spokane grocery stores are more likely to pay a premium for the new type of apples than consumers in Seattle. Consumers who...

Tipo: Conference Paper or Presentation

Palavras-chave: Functional food; Willingness to pay; Antioxidants; Demand and Price Analysis; Health Economics and Policy.

Ano: 2007

URL: http://purl.umn.edu/9787

Protection against cephalosporin-induced lipid peroxidation and nephrotoxicity by (+)-cyanidanol-3 and vitamin E

Cojocel,C.; Tolle,K.-L.; El-Hajj,H.; Baumann,K..

The ability of the clinically used cephalosporins: cephalothin, cefotaxime and cefotiam to induce lipid peroxidation (LPO) and renal damage was compared to that of nephrotoxic cephaloridine under in vivo conditions. Glutathione was measured in rat liver or in renal cortex as non-protein sulfhydryls. LPO was measured in plasma, renal cortex and liver by the generation of malondialdehyde or as the increase in renal cortical concentration of conjugated dienes. Impairment of renal function was measured as the decrease in renal cortical accumulation of the organic anion p-aminohippurate (PAH). Administration of cephalosporins to rats as a single dose (2000 mg/kg, ip) induced a significant glutathione-depletion in the renal cortex with cephaloridine, and in the...

Pharmacology and toxicology of diphenyl diselenide in several biological models

Palavras-chave: Cephalosporins; Glutathione depletion; Lipid peroxidation; Nephrotoxicity; Antioxidants; Vitamin E.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000600017

Rosa,R.M.; Roesler,R.; Braga,A.L.; Saffi,J.; Henriques,J.A.P..

The pharmacology of synthetic organoselenium compounds indicates that they can be used as antioxidants, enzyme inhibitors, neuroprotectors, anti-tumor and anti-infectious agents, and immunomodulators. In this review, we focus on the effects of diphenyl diselenide (DPDS) in various biological model organisms. DPDS possesses antioxidant activity, confirmed in several in vitro and in vivo systems, and thus has a protective effect against hepatic, renal and gastric injuries, in addition to its neuroprotective activity. The activity of the compound on the central nervous system has been studied since DPDS has lipophilic characteristics, increasing adenylyl cyclase activity and inhibiting glutamate and MK-801 binding to rat synaptic membranes. Systemic...