scholarly journals Non-Functionalized Fullerenes and Endofullerenes in Aqueous Dispersions as Superoxide Scavengers

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2506
Author(s):  
Ivan V. Mikheev ◽  
Madina M. Sozarukova ◽  
Elena V. Proskurnina ◽  
Ivan E. Kareev ◽  
Mikhail A. Proskurnin
Keyword(s):  
Superoxide Anion ◽  
Anion Radical ◽  
Cell Model ◽  
Nonuniform Distribution ◽  
Fullerene Cage ◽  
Lipid Phase ◽  
Oxygen Species ◽  
Aqueous Dispersions ◽  
Ros Homeostasis ◽  
Functionalized Fullerenes

Endohedral metal fullerene are potential nanopharmaceuticals for MRI; thus, it is important to study their effect on reactive oxygen species (ROS) homeostasis. Superoxide anion radical is one of the key ROS. The reactivity of aqueous dispersions of pristine (non-functionalized) fullerenes and Gd@C82 endofullerene have been studied with respect to superoxide in the xanthine/xanthine oxidase chemiluminescence system. It was found that C60 and C70 in aqueous dispersions react with superoxide as scavengers by a similar mechanism; differences in activity are determined by cluster parameters, primarily the concentration of available, acting molecules at the surface. Gd endofullerene is characterized by a significantly (one-and-a-half to two orders of magnitude) higher reactivity with respect to C60 and C70 and is likely to exhibit nanozyme (SOD-mimic) properties, which can be accounted for by the nonuniform distribution of electron density of the fullerene cage due to the presence of the endohedral atom; however, in the cell model, Gd@C82 showed the lowest activity compared to C60 and C70, which can be accounted for by its higher affinity for the lipid phase.

Research of corrosion fracture of D16t and AMg6 aluminum alloys exposed to microscopic fungi

2021 ◽  
pp. 163-183
Author(s):  
D. V. Belov ◽  
S. N. Belyaev ◽  
M. V. Maksimov ◽  
G. A. Gevorgyan
Keyword(s):  
Hydrogen Peroxide ◽  
Aluminum Alloys ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Corrosion Damage ◽  
Oxygen Species ◽  
Microscopic Fungi ◽  
Reductive Activation ◽  
Activation Of Oxygen

This paper presents an experimental study of biocorrosion of D16T and AMg6 aluminum alloys. The determining role of reactive oxygen species in aluminum biocorrosion by a consortium of molds has been shown. A model is proposed, according to which the initiators of corrosion damage to the metal surface are superoxide anion radical and hydrogen peroxide released during the life of micromycetes. It is assumed that the initiation and development of biocorrosion occurs, among other things, as a result of the process of reductive activation of oxygen and the Fenton decomposition of hydrogen peroxide. A conclusion is made about the mechanism of the occurrence of intergranular and pitting corrosion of aluminum alloys interacting with microscopic fungi.

Activated oxygen species do not mediate hypercapnia-induced cerebral vasodilation in newborn pigs

1991 ◽  
Vol 261 (2) ◽  
pp. H335-H342 ◽  
Author(s):  
C. W. Leffler ◽  
R. Mirro ◽  
C. Thompson ◽  
M. Shibata ◽  
W. M. Armstead ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Xanthine Oxidase ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Superoxide Anion Radical ◽  
Radical Scavenger ◽  
Oxygen Species ◽  
Pial Arteries ◽  
Activated Oxygen ◽  
Newborn Pigs

In newborn pigs, vasodilation in response to hypercapnia is dependent on prostaglandin (PG) H synthase. We investigated the contribution of activated oxygen by-products to hypercapnia-induced PGH synthase-dependent dilation of pial arteries and arterioles in anesthetized newborn pigs. Activated oxygen species were generated on the cerebral surface using xanthine oxidase and hypoxanthine. Catalase, H2O2, and iron or N-(2-mercaptopropionyl)-glycine (MPG) were used to separate effects of superoxide anion and hydroxyl radical. All the activated oxygen species tested caused vasodilation of both arteries and arterioles. Vasodilation to all activated oxygen species was largely reversible with only the hydroxyl radical encouraging combination of xanthine oxidase, hypoxanthine, H2O2, and FeCl3, causing significant dilation 20 min after removal of treatment. Cotreatment with MPG blocked this residual dilation. Neither pretreatment with the extracellular superoxide anion radical scavenger, superoxide dismutase (SOD), the intracellular superoxide anion radical scavenger, Tiron, the H2O2 scavenger, catalase, nor hydroxyl radical scavengers, dimethyl sulfoxide (DMSO) and MPG, altered vasodilation of pial arteries or arterioles in response to hypercapnia. Furthermore, the increase in cerebral prostanoid synthesis in response to hypercapnia was not affected by pretreatment with SOD, Tiron, catalase, DMSO, or MPG. We conclude that the progressively reduced forms of oxygen that would be produced during PGH synthase metabolism of arachidonic acid can dilate pial arteries and arterioles of newborn pigs. However, these activated oxygen species are not responsible for the vasodilation to hypercapnia in the newborn pig, suggesting that eicosanoids cause the dilation.

ROS generation by reduced graphene oxide (rGO) induced by visible light showing antibacterial activity: comparison with graphene oxide (GO)

RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80192-80195 ◽  
Author(s):  
Taposhree Dutta ◽  
Rudra Sarkar ◽  
Bholanath Pakhira ◽  
Subrata Ghosh ◽  
Ripon Sarkar ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Ros Generation ◽  
Oxygen Species ◽  
Reduced Graphene ◽  
Activity Comparison

Reduced graphene oxide (rGO) generates reactive oxygen species (ROS) under visible light in air via a singlet oxygen–superoxide anion radical pathway that readily kills Enterobacter sp.

Superoxide Anion Radical: Generation and Detection in Cellular and Non-Cellular Systems

2015 ◽  
Vol 22 (37) ◽  
pp. 4234-4256 ◽  
Author(s):  
Renan Chiste ◽  
Marisa Freitas ◽  
Adriana Mercadante ◽  
Eduarda Fernandes
Keyword(s):  
Superoxide Anion ◽  
Anion Radical ◽  
Cellular Systems ◽  
Superoxide Anion Radical ◽  
Radical Generation

scholarly journals A Study of Catechin Photostability Using Photolytic Processing

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 293
Author(s):  
Jeu-Ming P. Yuann ◽  
Shwu-Yuan Lee ◽  
Meei-Ju Yang ◽  
Shiuh-Tsuen Huang ◽  
Chien-Wei Cheng ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Alkaline Solutions ◽  
Light Illumination ◽  
Drug Resistant ◽  
Alkaline Ph ◽  
Radical Species ◽  
Alkaline Conditions ◽  
Photolytic Reaction

Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (O2•−) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less O2•− are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl3 is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl3, and AlCl3 acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates O2•− via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.

scholarly journals PRDX1 is essential for the viability and maintenance of reactive oxygen species in chicken DT40

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Takahito Moriwaki ◽  
Akari Yoshimura ◽  
Yuki Tamari ◽  
Hiroyuki Sasanuma ◽  
Shunichi Takeda ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Intracellular Signaling ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Oxygen Species ◽  
Ros Homeostasis ◽  
Intracellular Ros ◽  
Chromosomal Breaks ◽  
Dt40 Cells

Abstract Background Peroxiredoxin 1 (PRDX1) is a member of a ubiquitous family of thiol peroxidases that catalyze the reduction of peroxides, including hydrogen peroxide. It functions as an antioxidant enzyme, similar to catalase and glutathione peroxidase. PRDX1 was recently shown act as a sensor of reactive oxygen species (ROS) and play a role in ROS-dependent intracellular signaling pathways. To investigate its physiological functions, PRDX1 was conditionally disrupted in chicken DT40 cells in the present study. Results The depletion of PRDX1 resulted in cell death with increased levels of intracellular ROS. PRDX1-depleted cells did not show the accumulation of chromosomal breaks or sister chromatid exchange (SCE). These results suggest that cell death in PRDX1-depleted cells was not due to DNA damage. 2-Mercaptoethanol protected against cell death in PRDX1-depleted cells and also suppressed elevations in ROS. Conclusions PRDX1 is essential in chicken DT40 cells and plays an important role in maintaining intracellular ROS homeostasis (or in the fine-tuning of cellular ROS levels). Cells deficient in PRDX1 may be used as an endogenously deregulated ROS model to elucidate the physiological roles of ROS in maintaining proper cell growth.

scholarly journals A Novel Tetrapeptide Derivative Exhibits In Vitro Inhibition of Neutrophil-Derived Reactive Oxygen Species and Lysosomal Enzymes Release

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sumitra Miriyala ◽  
Manikandan Panchatcharam ◽  
Meera Ramanujam ◽  
Rengarajulu Puvanakrishnan
Keyword(s):  
Reactive Oxygen Species ◽  
Superoxide Anion ◽  
Lysosomal Enzymes ◽  
Reactive Oxygen ◽  
Peptide Sequence ◽  
Ros Generation ◽  
Oxygen Species ◽  
Complement Factors

Neutrophil infiltration plays a major role in the pathogenesis of myocardial injury. Oxidative injury is suggested to be a central mechanism of the cellular damage after acute myocardial infarction. This study is pertained to the prognostic role of a tetrapeptide derivative PEP1261 (BOC-Lys(BOC)-Arg-Asp-Ser(tBu)-OtBU), a peptide sequence (39–42) of lactoferrin, studied in the modulation of neutrophil functions in vitro by measuring the reactive oxygen species (ROS) generation, lysosomal enzymes release, and enhanced expression of C proteins. The groundwork experimentation was concerned with the isolation of neutrophils from the normal and acute myocardial infarct rats to find out the efficacy of PEP1261 in the presence of a powerful neutrophil stimulant, phorbol 12-myristate 13 acetate (PMA). Stimulation of neutrophils with PMA resulted in an oxidative burst of superoxide anion and enhanced release of lysosomal enzymes and expression of complement proteins. The present study further demonstrated that the free radicals increase the complement factors in the neutrophils confirming the role of ROS. PEP1261 treatment significantly reduced the levels of superoxide anion and inhibited the release of lysosomal enzymes in the stimulated control and infarct rat neutrophils. This study demonstrated that PEP1261 significantly inhibited the effect on the ROS generation as well as the mRNA synthesis and expression of the complement factors in neutrophils isolated from infarct heart.

scholarly journals Effect of extraction conditions of paprika oleoresins on their free radical scavenging and anticancer activity

2014 ◽  
Vol 12 (3) ◽  
pp. 377-385 ◽  
Author(s):  
Vesna Šaponjac ◽  
Dragana Četojević-Simin ◽  
Gordana Ćetković ◽  
Jasna Čanadanović-Brunet ◽  
Sonja Djilas ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Cell Line ◽  
Antiproliferative Activity ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Radical Scavenging ◽  
Superoxide Anion Radical ◽  
Food Ingredients ◽  
Supercritical Carbon

AbstractGround spice paprika was extracted with hexane, by conventional Soxhlet procedure (SX oleoresin), and with supercritical carbon dioxide at three different pressures — 20, 30 and 40 MPa (SF20, SF30 and SF40 oleoresins). The effect of extraction method and conditions on the colour intesity of paprika oleoresins, content of α-tocopherol, as well as antioxidant and antiproliferative activity was examined. Hexane showed highest selectivity for paprika pigments (886.02 ASTA), while α-tocopherol showed highest solubility (3846.9 mg kg−1) in supercritical carbon dioxide at 20 MPa. All paprika oleoresins exhibited good superoxide anion radical scavenging activity SF30 being the best superoxide anion radical scavenger. Cell growth activity was evaluated in vitro in human cell lines:cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT-29). The highest antiproliferative activity was exhibited by SX in MCF7 cell line (IC50=14.28 mg mL−1). Extract SF40 produced significant and selective antiproliferative action towards HeLa cell line. These results suggest that paprika oleoresins, due to high antiradical and tumor cell-inhibiting activity, can be regarded as functional food ingredients.

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