Therapeutic strategies to protect the immature newborn myocardium during resuscitation following asphyxia

2012 ◽  
Vol 90 (6) ◽  
pp. 689-695 ◽  
Author(s):  
Richdeep S. Gill ◽  
Jean-Sébastien Pelletier ◽  
Joseph LaBossiere ◽  
David L. Bigam ◽  
Po-Yin Cheung
Keyword(s):  
Reperfusion Injury ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Perinatal Asphyxia ◽  
Multiorgan Failure ◽  
Myocardial Damage ◽  
Antioxidant Defenses ◽  
Cellular Injury ◽  
Oxygen Species ◽  
Protective Strategies

Perinatal asphyxia contributes to over one million newborn deaths worldwide annually, and may progress to multiorgan failure. Cardiac dysfunction, of varying severity, is seen in 50%–70% of asphyxiated newborns. Resuscitation is necessary to restore oxygenation to deprived tissues, including the heart. However, reoxygenation of asphyxiated newborns may lead to generation of reactive oxygen species (ROS) and further myocardial damage, termed reperfusion injury. The newborn heart is especially vulnerable to oxidative stress and reperfusion injury due to immature antioxidant defense mechanisms and increased vulnerability to apoptosis. Currently, newborn myocardial protective strategies are aimed at reducing the generation of ROS through controlled reoxygenation, boosting antioxidant defenses, and attenuating cellular injury via mitochondrial stabilization.

scholarly journals Redox Regulation in Diazotrophic Bacteria in Interaction with Plants

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 880
Author(s):  
Karine Mandon ◽  
Fanny Nazaret ◽  
Davoud Farajzadeh ◽  
Geneviève Alloing ◽  
Pierre Frendo
Keyword(s):  
Defense Mechanisms ◽  
Host Plants ◽  
Redox Regulation ◽  
Antioxidant Defense ◽  
Plant Growth Promoting Bacteria ◽  
Oxygen Species ◽  
Diazotrophic Bacteria ◽  
Number Of Microorganisms ◽  
Plant Growth Promoting ◽  
Growth Promoting

Plants interact with a large number of microorganisms that greatly influence their growth and health. Among the beneficial microorganisms, rhizosphere bacteria known as Plant Growth Promoting Bacteria increase plant fitness by producing compounds such as phytohormones or by carrying out symbioses that enhance nutrient acquisition. Nitrogen-fixing bacteria, either as endophytes or as endosymbionts, specifically improve the growth and development of plants by supplying them with nitrogen, a key macro-element. Survival and proliferation of these bacteria require their adaptation to the rhizosphere and host plant, which are particular ecological environments. This adaptation highly depends on bacteria response to the Reactive Oxygen Species (ROS), associated to abiotic stresses or produced by host plants, which determine the outcome of the plant-bacteria interaction. This paper reviews the different antioxidant defense mechanisms identified in diazotrophic bacteria, focusing on their involvement in coping with the changing conditions encountered during interaction with plant partners.

scholarly journals Antioxidant defense in centenarians (a preliminary study).

2000 ◽  
Vol 47 (2) ◽  
pp. 281-292 ◽  
Author(s):  
B Kłapcińska ◽  
J Derejczyk ◽  
K Wieczorowska-Tobis ◽  
A Sobczak ◽  
E Sadowska-Krepa ◽  
...  
Keyword(s):  
Vitamin E ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Potential Role ◽  
Serum Vitamin ◽  
Antioxidant Defenses ◽  
Human Longevity ◽  
Healthy Female ◽  
Preliminary Study

The study was designed to assess the antioxidant defense mechanisms, either enzymatic or non-enzymatic, in a group of sixteen centenarians (one male and fifteen female subjects aged 101 to 105 years) living in the Upper Silesia district (Poland) in order to evaluate the potential role of antioxidant defenses in human longevity. The results of our preliminary study showed that in comparison with young healthy female adults the centenarians had significantly higher red blood cell glutathione reductase and catalase activities and higher, although insignificantly, serum vitamin E level.

Antioxidant defenses and metabolic depression in a pulmonate land snail

1995 ◽  
Vol 268 (6) ◽  
pp. R1386-R1393 ◽  
Author(s):  
M. Hermes-Lima ◽  
K. B. Storey
Keyword(s):  
Oxidative Stress ◽  
Glutathione Peroxidase ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Thiobarbituric Acid ◽  
Land Snail ◽  
Land Snails ◽  
Antioxidant Defenses ◽  
Glutathione S Transferase ◽  
Hypometabolic State

During arousal from estivation oxygen consumption by land snails (Otala lactea) increases severalfold. To determine whether snails prepared for an accompanying rise in the rates of oxyradical generation by altering their antioxidant defense mechanisms, changes in the activities of antioxidant enzymes and lipid peroxidation products were quantified in foot and hepatopancreas of control, 30-day estivating, and aroused snails. Compared with controls, estivating O. lactea showed significant increases in the activities of foot muscle superoxide dismutase (SOD) (increasing by 56-67%), catalase (51-72%), and glutathione S-transferase (79-108%), whereas, in hepatopancreas, SOD (57-78%) and glutathione peroxidase (93-144%) increased. Within 40 min after arousal began, hepatopancreas glutathione peroxidase activity had returned to control values, but SOD showed a further 70% increase in activity but then returned to control levels by 80 min. Estivation had no effect on total glutathione (GSH + 2 GSSG) concentrations in tissues, but GSSG content had increased about twofold in both organs of 30-day dormant snails. Lipid peoxidation (quantified as thiobarbituric acid reactive substances) was significantly enhanced at the onset of arousal from dormancy, indicating that oxidative stress and tissue damage occurred at this time. The data suggest that antioxidant defenses in snail organs are increased while snails are in the hypometabolic state as a preparation for oxidative stress during arousal.

scholarly journals Esculetin as a Bifunctional Antioxidant Prevents and Counteracts the Oxidative Stress and Neuronal Death Induced by Amyloid Protein in SH-SY5Y Cells

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 551 ◽  
Author(s):  
Letizia Pruccoli ◽  
Fabiana Morroni ◽  
Giulia Sita ◽  
Patrizia Hrelia ◽  
Andrea Tarozzi
Keyword(s):  
Oxidative Stress ◽  
Neuronal Death ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Important Determinant ◽  
Related Factor ◽  
Oxygen Species ◽  
Experimental Conditions ◽  
Antioxidant Genes ◽  
Ros Formation

Oxidative stress (OS) appears to be an important determinant during the different stages of progression of Alzheimer’s Disease (AD). In particular, impaired antioxidant defense mechanisms, such as the decrease of glutathione (GSH) and nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), a master regulator of antioxidant genes, including those for GSH, are associated with OS in the human AD brain. Among the neuropathological hallmarks of AD, the soluble oligomers of amyloid beta (A) peptides seem to promote neuronal death through mitochondrial dysfunction and OS. In this regard, bifunctional antioxidants can exert a dual neuroprotective role by scavenging reactive oxygen species (ROS) directly and concomitant induction of antioxidant genes. In this study, among natural coumarins (esculetin, scopoletin, fraxetin and daphnetin), we demonstrated the ability of esculetin (ESC) to prevent and counteract ROS formation in neuronal SH-SY5Y cells, suggesting its profile as a bifunctional antioxidant. In particular, ESC increased the resistance of the SH-SY5Y cells against OS through the activation of Nrf2 and increase of GSH. In similar experimental conditions, ESC could also protect the SH-SY5Y cells from the OS and neuronal death evoked by oligomers of A1–42 peptides. Further, the use of the inhibitors PD98059 and LY294002 also showed that Erk1/2 and Akt signaling pathways were involved in the neuroprotection mediated by ESC. These results encourage further research in AD models to explore the efficacy and safety profile of ESC as a novel neuroprotective agent.

scholarly journals Severe Glutathione Deficiency, Oxidative Stress and Oxidant Damage in Adults Hospitalized with COVID-19: Implications for GlyNAC (Glycine and N-Acetylcysteine) Supplementation

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Premranjan Kumar ◽  
Ob Osahon ◽  
David B. Vides ◽  
Nicola Hanania ◽  
Charles G. Minard ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Age Groups ◽  
Healthcare Systems ◽  
Antioxidant Defenses ◽  
Oxygen Species ◽  
Younger Age ◽  
Oxidant Damage ◽  
Protective Strategies ◽  
Glutathione Deficiency ◽  
Health Deterioration

Humanity is battling a respiratory pandemic pneumonia named COVID-19 which has resulted in millions of hospitalizations and deaths. COVID-19 exacerbations occur in waves that continually challenge healthcare systems globally. Therefore, there is an urgent need to understand all mechanisms by which COVID-19 results in health deterioration to facilitate the development of protective strategies. Oxidative stress (OxS) is a harmful condition caused by excess reactive-oxygen species (ROS) and is normally neutralized by antioxidants among which Glutathione (GSH) is the most abundant. GSH deficiency results in amplified OxS due to compromised antioxidant defenses. Because little is known about GSH or OxS in COVID-19 infection, we measured GSH, TBARS (a marker of OxS) and F2-isoprostane (marker of oxidant damage) concentrations in 60 adult patients hospitalized with COVID-19. Compared to uninfected controls, COVID-19 patients of all age groups had severe GSH deficiency, increased OxS and elevated oxidant damage which worsened with advancing age. These defects were also present in younger age groups, where they do not normally occur. Because GlyNAC (combination of glycine and N-acetylcysteine) supplementation has been shown in clinical trials to rapidly improve GSH deficiency, OxS and oxidant damage, GlyNAC supplementation has implications for combating these defects in COVID-19 infected patients and warrants urgent investigation.

scholarly journals Isolation of a Psychrotolerant and UV-C-Resistant Bacterium from Elephant Island, Antarctica with a Highly Thermoactive and Thermostable Catalase

2020 ◽  
Vol 8 (1) ◽  
pp. 95
Author(s):  
María T. Monsalves ◽  
Gabriela P. Ollivet-Besson ◽  
Maximiliano J. Amenabar ◽  
Jenny M. Blamey
Keyword(s):  
Reactive Oxygen Species ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Reactive Oxygen ◽  
Antioxidant Defense System ◽  
Oxygen Species ◽  
Cold Temperatures ◽  
Wide Range ◽  
Antioxidant Defense Systems ◽  
Uv C

Microorganisms present in Antarctica have to deal not only with cold temperatures but also with other environmental conditions, such as high UV radiation, that trigger the generation of reactive oxygen species. Therefore, Antarctic microorganisms must have an important antioxidant defense system to prevent oxidative damage. One of these defenses are antioxidant enzymes, such as catalase, which is involved in the detoxification of hydrogen peroxide produced under oxidative conditions. Here, we reported the isolation and partial characterization of an Antarctic bacterium belonging to the Serratia genus that was resistant to UV-C radiation and well-adapted to cold temperatures. This microorganism, denominated strain I1P, was efficient at decreasing reactive oxygen species levels produced after UV-C irradiation. Genomic and activity assays suggested that the enzymatic antioxidant defense mechanisms of strain I1P, especially its catalase enzyme, may confer UV resistance. This catalase was active in a wide range of temperatures (20–70 °C), showing optimal activity at 50 °C (at pH 7.0), a remarkable finding considering its psychrotolerant origin. In addition, this enzyme was thermostable, retaining around 60% of its activity after 6 h of incubation at 50 °C. The antioxidant defense systems of strain I1P, including its surprisingly thermoactive and thermostable catalase enzyme, make this microorganism a good source of biocompounds with potential biotechnological applications.

scholarly journals The type and source of reactive oxygen species influences the outcome of oxidative stress in cultured cells

2021 ◽  
Author(s):  
Steffi Goffart ◽  
Petra Tikkanen ◽  
Craig Michell ◽  
Trevor Wilson ◽  
Jaakko L.O. Pohjoismäki
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Defense Mechanisms ◽  
Antioxidant Defense ◽  
Cultured Cells ◽  
Oxygen Species ◽  
Different Types ◽  
Measured Effect ◽  
Experimental Approaches ◽  
Different Sources

AbstractOxidative stress can be modeled using various different experimental approaches, such as exposing the cells or organisms to oxidative chemicals. However, the actual effects of these chemicals, outside of the immediate measured effect, have attracted relatively little attention. We show here that three commonly used oxidants, menadione, potassium bromate and hydrogen peroxide, while known to function differently, also elicit different types of responses in cultured cells. While cells response to menadione and bromate exposure mainly by an integrated stress response, hydrogen peroxide has more indirect effects. Primary oxidative stress does not induce DNA repair or antioxidant defense mechanisms. However, cells with previous experience of oxidative stress show adaptive changes when the stress is renewed. Our results urge caution when comparing studies using different sources of oxidative stress or generalizing the findings of these studies to different tissue or oxidant types.

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