Oxidative stress

Storz, Gisela; Imlayt, James A

doi:10.1016/s1369-5274(99)80033-2

Cited by 1,018 publications

(864 citation statements)

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“…Two key protective responses have been described in E. coli -one controlled by soxRS genes and the other by oxyR (Tsaneva and Weiss, 1990;Storz and Imlay, 1999;Gonzalez-Flecha and Demple, 2000).…”

Section: Sos Responsementioning

confidence: 99%

“…When activated by the univalent oxidation of the 2Fe-2S clusters of the protein through a not yet explained mechanism (Storz and Imlay, 1999) SoxR induces transcription of soxS, a positive regulator that stimulates transcription of more than 16 other superoxide responsive genes (Wu and Weiss, 1992;Hidalgo et al, 1995). Although this system responds to oxidative stress when cells are exposed to superoxide radical-generating agents, it is not induced by H 2 O 2 (Chan and Tsaneva and Weiss, 1990;Hidalgo et al, 1997).…”

Section: The Soxrsmentioning

confidence: 99%

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Several pathways of hydrogen peroxide action that damage the E. coli genome

Asad

Almeida

et al. 2004

Genet. Mol. Biol.

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Hydrogen peroxide is an important reactive oxygen species (ROS) that arises either during the aerobic respiration process or as a by-product of water radiolysis after exposure to ionizing radiation. The reaction of hydrogen peroxide with transition metals imposes on cells an oxidative stress condition that can result in damage to cell components such as proteins, lipids and principally to DNA, leading to mutagenesis and cell death. Escherichia coli cells are able to deal with these adverse events via DNA repair mechanisms, which enable them to recover their genome integrity. These include base excision repair (BER), nucleotide excision repair (NER) and recombinational repair. Other important defense mechanisms present in Escherichia coli are OxyR and SosRS anti-oxidant inducible pathways, which are elicited by cells to avoid the introduction of oxidative lesions by hydrogen peroxide. This review summarizes the phenomena of lethal synergism between UV irradiation (254 nm) and H 2 O 2 , the cross-adaptive response between different classes of genotoxic agents and hydrogen peroxide, and the role of copper ions in the lethal response to H 2 O 2 under low-iron conditions. Key words: hydrogen peroxide, cross-adaptive response, lethal synergism, copper and iron. General AspectsThe appearance of aerobic forms of life was an important step in the evolutionary process, since oxygen consumption leads to the production of ten-fold more energy from glucose than does anaerobic metabolism (Meneghini, 1987). However, this process imposes constraints on cell viability, because of the generation of reactive oxygen species during respiration.The consecutive univalent reduction of molecular oxygen to water produces three active intermediates: superoxide anion (O 2 -• ), hydrogen peroxide (H 2 O 2 ) and hydroxyl radical (OH • ). These intermediates, collectively referred to as reactive oxygen species (ROS) are potent oxidants of lipids, proteins, and nucleic acids (Halliwell and Gutteridge, 1984;Mello-Filho and Meneghini, 1985;Meneghini, 1988). Among the oxidative DNA lesions, one of the major classes of DNA damage leads to modification in purine and pyrimidine bases, together with oligonucleotide strand breaks, DNA-protein cross-links and abasic sites. Increasing evidence suggests that the cumulative damage caused by ROS contributes to numerous degenerative diseases associated with aging, such as atherosclerosis, rheumatoid arthritis and cancer (Ames et al., 1993;Halliwell and Gutteridge, 1999).Living organisms have developed specific mechanisms to prevent the production and effects of ROS. The reduction of O 2 by cytochrome oxidase without yielding ROS, the superoxide dismutase catalysis of O 2 -• into H 2 O 2 through a dismutation reaction, the decomposition of H 2 O 2 by catalase and peroxidases, and the scavenging of ROS by some vitamins comprise part of the set of cellular antioxidant defenses (Halliwell and Gutteridge, 1999). Synthesis of the enzymes that catalyze these reactions is a part of the adaptive response tr...

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Section: Sos Responsementioning

confidence: 99%

Section: The Soxrsmentioning

confidence: 99%

Several pathways of hydrogen peroxide action that damage the E. coli genome

Asad

Almeida

et al. 2004

Genet. Mol. Biol.

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“…The susceptibility of a cell or a tissue to oxidative stress depends on a number of factors including the availability of antioxidants and the ability for inactivation or elimination of formed oxidized products (Storz and Imlay, 1999;Lobo et al, 2010). Free radicals and other reactive oxygen species (ROS) are generated by exogenous chemicals or endogenous metabolic processes in food systems or the human body.…”

Section: Introductionmentioning

confidence: 99%

“…The radicals may cause oxidative damage by oxidizing biomolecules leading to tissue damage and cell death. Atherosclerosis, cancer, emphysema, cirrhosis, and arthritis have been correlated with oxidative damage (Storz and Imlay, 1999;Kapila et al, 2006;Halliwell, 2006;Lobo et al, 2010). Therefore, oxidative damage plays a significant pathological role in human disease.…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

et al. 2015

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Lactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faecium species. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS •+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.Keywords: antimicrobial activity, antioxidant, Enterococcus, lactic acid bacteria, molecular characterization.Atividade antimicrobiana e antioxidante de espécies de Enterococcus isoladas de carne e produtos lácteos ResumoAs bactérias ácido láticas (BAL) têm um papel importante em uma grande variedade de alimentos fermentados. Em adição à sua contribuição para as características sensoriais, estes microorganismos melhoram a conservação de alimentos e podem ser utilizados como probióticos. Neste estudo, as atividades antimicrobiana e antioxidante do sobrenadante e dos extratos livres de células de 16 isolados de LAB de carne e produtos lácteos foram investigadas. Os isolados foram identificados pelo sequenciamento da região 16S do rRNA. Após a comparação das sequências obtidas com aquelas disponíveis na base de dados GenBank, observou-e que todos os isolados foram pertencentes à espécie Enterococcus faecium. A atividade antimicrobiana contra o microrganismo indicador (Listeria monocytogenes) foi observada no sobrenadante das culturas em 11 isolados, e nos extratos livres de células por 4 isolados. A sensibilidade da cultura sobrenadante foi avaliada pela proteinase K e tripsina e observou-se que a atividade da substância antimicrobiana foi completamente perdida após o tratamento com as enzimas proteolíticas. Todos os isolados apresentaram atividade antioxidante, como determinado pelo método do ácido tiobarbitúrico de substâncias reativas (TBARS) com ambos os tipos de extratos. Quando a capacidade antioxidante foi investigada usando o método do ABTS (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) e o método de DPPH (2,2-di...

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“…Small amounts of ROS are indispensable in several biochemical processes. High doses and/or inadequate removal of ROS result in oxidative stress, which can damage nucleic acids, proteins, lipids, carbohydrates, and cell membranes, leading to cell death and tissue injury (15,16). Measurement of ROS is extremely difficult because of the short lifetime of these species, and the methods currently in use are complicated and of poor sensitivity (17).…”

Section: Discussionmentioning

confidence: 99%

Modification to the Lampariello approach to evaluate reactive oxygen species production by flow cytometry

Brescia

Sarti

2007

Cytometry Pt A

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The aim of this article is to perform a statistical analysis of reactive oxygen species (ROS) cytometric data. It is demonstrated that the classical parametric and nonparametric statistical tests are not suitable to examine these data; the Kolmogorov-Smirnov test and the modification proposed by Lampariello are shown to be too sensitive with respect to the experimental bias (due to procedure or to the instrument) and variability in the ROS production within the repeated samples. Several approaches are examined and discussed. Modifications of the Lampariello's procedure are proposed to include the variability within samples. The validity of the proposed approach is verified by analyzing repeated measurements of ROS formation in cultured human lymphocytes untreated or treated with ferrous sulfate. The proposed approach is successful in considering the ''intersample'' variability in the ROS data analysis and keeps a good level of validity. Nevertheless, this procedure is not user-friendly and needs to be handled by an expert operator. ' 2007 International Society for Analytical Cytology Key terms flow cytometry; histogram comparison; Kolmogorov-Smirnov test; ROS production FLOW cytometry is a useful tool for the selective, fast, and accurate analysis of cells or particles (1), and although it is widely used in several application fields ranging from environmental monitoring (2) to cell biology, medicine, and toxicology, the comparison of cytometric data distributions remains an open question.In most cases, a single parameter is considered to characterize data sets. Untreated and treated samples are frequently compared by using the two-sample t test to asses the differences between two means. This test assumes that both samples came from normally distributed populations with equal variances (3), but this condition is often not fulfilled when flow cytometric (FC) data sets are considered.Evaluation of the results by the comparison of medians with a nonparametric test (i.e., paired Wilcoxon test) is free of the methodological inaccuracies, but provides insufficient information on the individual assays and their differences.In 1977, Young (4) introduced the nonparametric Kolmogorov-Smirnov (KS) statistical test (5) to FC data analysis, and now this test is commonly provided by most FC data-analysis programs.However, it is seldom used because the results are too sensitive to systematic shifts, making results statistically different when there is no biological difference.Lampariello (6) emphasized that an effective test should be able to identify the true differences resulting from the underlying biological phenomenon, while ignoring those caused by noise, sample-to-sample variability, and measurements effects. He proposed a modified KS test to evaluate cell ''positivity'' and to distinguish between statistical and biological differences.In this work, the FC frequency distributions of reactive oxygen species (ROS) production in human T leukemia cells (Jurkat) have been analyzed. Spontaneous and

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Oxidative stress

Cited by 1,018 publications

References 59 publications

Several pathways of hydrogen peroxide action that damage the E. coli genome

Several pathways of hydrogen peroxide action that damage the E. coli genome

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products

Modification to the Lampariello approach to evaluate reactive oxygen species production by flow cytometry

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