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Registros recuperados: 66 | |
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Langaro,Ana Claudia; Agostinetto,Dirceu; Ruchel,Queli; Garcia,Jessica Rodrigues; Perboni,Lais Tessari. |
ABSTRACT Among the methods of weed control, stands out chemical control. However, even selective, herbicides can trigger the production of reactive species of oxygen and cause oxidative stress. The aim of the study was to evaluate changes in photosynthetic parameters, oxidative damage, antioxidant enzyme activity and altered metabolism of rice plants after applying pre-emergent herbicides. The experiment was conducted in a greenhouse and herbicides used were oxadiazon, pendimethalin and oxyfluorfen, beyond the control without herbicide. There was a reduction of photosynthetic rate and efficiency of carboxylation, compared to the control, when applied herbicides oxyfluorfen and pendimethalin. The major lipid peroxidation and proline accumulation was... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidant system; Chemical control; Reactive oxygen species; Selectivity. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902017000200358 |
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Sunlight is part of our everyday life and most people accept it as beneficial to our health. With the advance of our knowledge in cutaneous photochemistry, photobiology and photomedicine over the past four decades, the terrestrial solar radiation has become a concern of dermatologists and is considered to be a major damaging environmental factor for our skin. Most photobiological effects (e.g., sunburn, suntanning, local and systemic immunosuppression, photoaging or dermatoheliosis, skin cancer and precancer, etc.) are attributed to ultraviolet radiation (UVR) and more particularly to UVB radiation (290-320 nm). UVA radiation (320-400 nm) also plays an important role in the induction of erythema by the photosensitized generation of reactive oxygen species... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Sunburn; Antioxidant; DNA photodamage; Reactive oxygen species; UV radiation. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000500002 |
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Caverzan,Andréia; Passaia,Gisele; Rosa,Silvia Barcellos; Ribeiro,Carolina Werner; Lazzarotto,Fernanda; Margis-Pinheiro,Márcia. |
When plants are exposed to stressful environmental conditions, the production of Reactive Oxygen Species (ROS) increases and can cause significant damage to the cells. Antioxidant defenses, which can detoxify ROS, are present in plants. A major hydrogen peroxide detoxifying system in plant cells is the ascorbate-glutathione cycle, in which, ascorbate peroxidase (APX) enzymes play a key role catalyzing the conversion of H2O2 into H2O, using ascorbate as a specific electron donor. Different APX isoforms are present in distinct subcellular compartments, such as chloroplasts, mitochondria, peroxisome, and cytosol. The expression of APX genes is regulated in response to biotic and abiotic stresses as well as during plant development. The APX responses are... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ascorbate peroxidase; Antioxidant system; Reactive oxygen species; Abiotic stress; Mutant plants. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572012000600016 |
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Silva,C.B.; Simionatto,E.; Gebara,S.S.; Poppi,N.R.; Cândido,A.C.S.; Lima,C.P.; Dias,J.F.G.; Zanin,S.M.W.; Peres,M.T.L.P.; Moreira,T.F.; Miguel,O.G.; Miguel,M.D.. |
The volatile oils extracted from the roots of Polygala extraaxillaris were analyzed to assess whether they increase oxidative stress in Brachiaria decumbens var. Piatã, as well as to assess their effect on cellular division and cytotoxicity in laboratory. Six concentrations were used (0%, 0.35%, 0.65%, 1.25%, 0.65%, and 5.0%) with four repetitions of 25 seeds. The substance 1-(2-hydroxyphenyl) - ethanone was identified as the major constituent of the volatile oils. The results showed that the highest concentrations of the oils resulted in an increase in the oxidative stress in B. decumbens, as well as alteration in germination and growth, with a consequent reduction in the process of cellular division, causing changes in the growth standard and antioxidant... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Reactive oxygen species; Antioxidant enzymes; Plant defense; Signal grass. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000400005 |
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Touyz,R.M.. |
Diseases such as hypertension, atherosclerosis, hyperlipidemia, and diabetes are associated with vascular functional and structural changes including endothelial dysfunction, altered contractility and vascular remodeling. Cellular events underlying these processes involve changes in vascular smooth muscle cell (VSMC) growth, apoptosis/anoikis, cell migration, inflammation, and fibrosis. Many factors influence cellular changes, of which angiotensin II (Ang II) appears to be amongst the most important. The physiological and pathophysiological actions of Ang II are mediated primarily via the Ang II type 1 receptor. Growing evidence indicates that Ang II induces its pleiotropic vascular effects through NADPH-driven generation of reactive oxygen species (ROS).... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vascular smooth muscle cells; Remodeling; Inflammation; Signal transduction; Reactive oxygen species. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000800018 |
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Touyz,R.M.; Berry,C.. |
Angiotensin II (Ang II)* is a multifunctional hormone that influences the function of cardiovascular cells through a complex series of intracellular signaling events initiated by the interaction of Ang II with AT1 and AT2 receptors. AT1 receptor activation leads to cell growth, vascular contraction, inflammatory responses and salt and water retention, whereas AT2 receptors induce apoptosis, vasodilation and natriuresis. These effects are mediated via complex, interacting signaling pathways involving stimulation of PLC and Ca2+ mobilization; activation of PLD, PLA2, PKC, MAP kinases and NAD(P)H oxidase, and stimulation of gene transcription. In addition, Ang II activates many intracellular tyrosine kinases that play a role in growth signaling and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Angiotensin receptors; Second messengers; Phospholipase; Protein kinase; Reactive oxygen species. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000900001 |
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Han, Kyu-Ho; Hashimoto, Naoto; Fukushima, Michihiro. |
Excessive consumption of alcoholic beverages is a serious cause of liver disease worldwide. The meta-bolism of ethanol generates reactive oxygen species, which play a significant role in the deterioration of alcoholic liver disease (ALD). Antioxidant phytochemicals, such as polyphenols, regulate the expression of ALD-associated proteins and peptides, namely, catalase, superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase. These plant antioxidants have electrophilic activity and may induce antioxidant enzymes via the Kelchlike ECH-associated protein 1-NF-E2-related factor-2 pathway and antioxidant responsive elements. Furthermore, these antioxidants are reported to alleviate cell injury caused by oxidants or inflammatory... |
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Palavras-chave: Electrophile; Mitogen-activating protein kinase; Plant antioxidants; Reactive oxygen species; Preconditioning. |
Ano: 2016 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4425 |
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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 |
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Gomes,A.J.; Lunardi,C.N.; Gonzalez,S.; Tedesco,A.C.. |
Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (·OH, ·O2-, H2O2, ¹O2) in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10(9) M-1 s-1 for KA and 1.0 x 10(9) M-1 s-1 for PL, similar to that of ethanol (1.4 x 10(9) M-1 s-1). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited ·O2-dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of ¹O2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. The present study demonstrates that PL showed an... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Polypodium leucotomos extract; Kojic acid; Antioxidant; Reactive oxygen species. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001100018 |
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Registros recuperados: 66 | |
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