scholarly journals Hydroxyl Radical and Its Scavengers in Health and Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Boguslaw Lipinski
Keyword(s):  
Oxidative Stress ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Disulfide Bonds ◽  
Radical Scavenging ◽  
Beneficial Effects ◽  
Binding Agents ◽  
Spatial Configurations ◽  
Health And Disease ◽  
Reducing Substances

It is generally believed that diseases caused by oxidative stress should be treated with antioxidants. However, clinical trials with such antioxidants as ascorbic acid and vitamin E, failed to produce the expected beneficial results. On the other hand, important biomolecules can be modified by the introduction of oxygen atoms by means of non-oxidative hydroxyl radicals. In addition, hydroxyl radicals can reduce disulfide bonds in proteins, specifically fibrinogen, resulting in their unfolding and scrambled refolding into abnormal spatial configurations. Consequences of this reaction are observed in many diseases such as atherosclerosis, cancer and neurological disorders, and can be prevented by the action of non-reducing substances. Moreover, many therapeutic substances, traditionally classified as antioxidants, accept electrons and thus are effective oxidants. It is described in this paper that hydroxyl radicals can be generated by ferric ions without any oxidizing agent. In view of the well-known damaging effect of poorly chelated iron in the human body, numerous natural products containing iron binding agents can be essential in the maintenance of human health. However, beneficial effects of the great number of phytochemicals that are endowed with hydroxyl radical scavenging and/or iron chelating activities should not be considered as a proof for oxidative stress.

scholarly journals Potential Antioxidant and Anti-Inflammatory Effects of Spilanthes acmella and Its Health Beneficial Effects: A Review

2021 ◽  
Vol 18 (7) ◽  
pp. 3532
Author(s):  
Rohanizah Abdul Rahim ◽  
Putri Ayu Jayusman ◽  
Norliza Muhammad ◽  
Norazlina Mohamed ◽  
Vuanghao Lim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Potential Role ◽  
Radical Scavenging ◽  
Mapk Signaling ◽  
Total Phenolic ◽  
Thiobarbituric Acid Reactive Substance ◽  
Potential Health ◽  
Beneficial Effects ◽  
Spilanthes Acmella ◽  
Anti Inflammatory

Oxidative stress and inflammation are two common risk factors of various life-threatening disease pathogenesis. In recent years, medicinal plants that possess antioxidant and anti-inflammatory activities were extensively studied for their potential role in treating and preventing diseases. Spilanthes acmella (S. acmella), which has been traditionally used to treat toothache in Malaysia, contains various active metabolites responsible for its anti-inflammatory, antiseptic, and anesthetic bioactivities. These bioactivities were attributed to bioactive compounds, such as phenolic, flavonoids, and alkamides. The review focused on the summarization of in vitro and in vivo experimental reports on the antioxidant and anti-inflammatory actions of S. acmella, as well as how they contributed to potential health benefits in lowering the risk of diseases that were related to oxidative stress. The molecular mechanism of S. acmella in reducing oxidative stress and inflammatory targets, such as inducible nitric oxide synthase (iNOS), transcription factors of the nuclear factor-κB family (NF-κB), cyclooxygenase-2 (COX-2), and mitogen-activated protein kinase (MAPK) signaling pathways were discussed. Besides, the antioxidant potential of S. acmella was measured by total phenolic content (TPC), total flavonid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide anion radical scavenging (SOD) and thiobarbituric acid reactive substance (TBARS) assays. This review revealed that S. acmella might have a potential role as a reservoir of bioactive agents contributing to the observed antioxidant, anti-inflammatory, and health beneficial effects.

scholarly journals Hydroxyl-radical scavenging activity of hydrogen does not significantly contribute to its biological function

2021 ◽  
Author(s):  
Qinjian Li ◽  
Fei Xie ◽  
Yang Yi ◽  
Pengxiang Zhao ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Published Data ◽  
Oh Radicals ◽  
Dependent Manner ◽  
Protective Effects ◽  
Beneficial Effects ◽  
Wide Range ◽  
Depth Study

AbstractSince Ohsawa et al. reported a biological antioxidant function of hydrogen in 2007, researchers have now shown it to exert protective effects in a wide range of human and animal disease models. Clinical observations and scientific arguments suggest that a selective scavenging property of H2 cannot adequately explain the beneficial effects of hydrogen. However, there is no experiment challenging the original published data, which suggested that molecular hydrogen dissolved in solution reacts with hydroxyl radicals in cell-free systems. Here we report that a hydrogen-saturated solution (0.6 mM) did not significantly reduce hydroxyl radicals in the Fenton system using 1 mM H2O2. We replicated the same condition as Ohsawa’s study (i.e. 5 μM H2O2), and observed a decrease in •OH radicals in both the H2-rich and N2-rich solutions, which may be caused by a decreased dissolved oxygen concentration. Finally, we determined the effect of hydrogen on a high-valence iron enzyme, horseradish peroxidase (HRP), and found that hydrogen could directly increase HRP activity in a dose-dependent manner. Overall, these results indicate that although H2 and •OH can react, the reaction rate is too low to have physiological function. The target of hydrogen is more complex, and its interaction with enzymes or other macro-molecules deserve more attention and in-depth study.

scholarly journals Baru Pulp (Dipteryx alata Vogel): Fruit from the Brazilian Savanna Protects against Oxidative Stress and Increases the Life Expectancy of Caenorhabditis elegans via SOD-3 and DAF-16

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1106
Author(s):  
Natasha Rios Leite ◽  
Laura Costa Alves de Araújo ◽  
Paola dos Santos da Rocha ◽  
Danielle Araujo Agarrayua ◽  
Daiana Silva Ávila ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Life Expectancy ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Brazilian Savanna ◽  
Beneficial Effects ◽  
Dipteryx Alata

Fruits are sources of bioactive compounds that are responsible for several biological activities. Therefore, this study aimed to identify the chemical composition of the pulp of the Brazilian Savanna fruit Dipteryx alata; evaluate its toxic effects, influence on the life expectancy of the nematode Caenorhabditis elegans, and its antioxidant activities in vitro and in vivo; and describe the mechanisms involved. The chemical compounds identified include phenols, terpenes, fatty acid derivatives, vitamins, and a carboxylic acid. The in vitro antioxidant activity was demonstrated by radical scavenging methods. in vivo, the D. alata fruit pulp was not toxic and promoted resistance to oxidative stress in nematodes exposed to a chemical oxidizing agent. Furthermore, it promoted an increased life expectancy in wild-type nematodes and increased the expression of superoxide dismutase and the nuclear translocation of DAF-16. These results suggest that the beneficial effects identified are related to these two genes, which are involved in the regulation of metabolic activities, the control of oxidative stress, and the lifespan of C. elegans. These beneficial effects, which may be related to its chemical constituents, demonstrate its potential use as a functional and/or nutraceutical food.

Multi-organ Toxicity Attenuation by Cerium Oxide and Yttrium Oxide Nanoparticles: Comparing the Beneficial Effects on Tissues Oxidative Damage Induced by Sub-acute Exposure to Diazinon

2020 ◽  
Vol 8 (3) ◽  
pp. 225-238
Author(s):  
Mona Navaei-Nigjeh ◽  
Marzieh Daniali ◽  
Mahban Rahimifard ◽  
Mohammad R. Khaksar
Keyword(s):  
Oxidative Stress ◽  
Cerium Oxide ◽  
Metal Oxide Nanoparticles ◽  
Radical Scavenging ◽  
Oxide Nanoparticles ◽  
Oxidative Stress Markers ◽  
Beneficial Effects ◽  
Stress Markers ◽  
Kidney Liver ◽  
The Brain

Background: Excessive use of diazinon, as an organophosphate pesticide (OP), contributes to cytotoxic and pathologic cellular damage and, in particular, oxidative stress. However, metal-oxide nanoparticles (NPs), such as cerium oxide (CeO2) and yttrium oxide (Y2O3), with the property of free radical scavenging demonstrated beneficial effects in the alleviation of oxidative stress biomarkers. Objective: The aims of this study include evaluating beneficial effects of CeO2 NPs, Y2O3 NPs, and their combination against diazinon-induced oxidative stress in different tissues of brain, heart, lung, kidney, liver, and spleen. Methods: Eight randomized groups of 6 adult male Wistar rats were formed. Each group of rats administered a different combination of diazinon, CeO2 and Y2O3 NPs daily and levels of oxidative stress markers, such as reactive oxygen species (ROS), lipid peroxidation (LPO), total thiol molecules (TTM) and total anti-oxidant power (TAP) and catalase enzyme, were measured after 2 weeks of the treatment. Results: Measurements of the mentioned markers in the brain, heart, lung, kidney, liver, and spleen showed that the administration of NPs could significantly alleviate the oxidative stress induced by diazinon. However, the findings of this study illustrated that the combination of both CeO2 and Y2O3 NPs led to a better reduction in oxidative stress markers. Conclusion: Sub-acute exposure of diazinon in rats led to increased levels of oxidative stress markers in pivotal tissues such as the brain, heart, lung, kidney, liver, and spleen. CeO2 and Y2O3 NPs neutralize the oxidative stress to compensate diazinon-induced tissue damages. Lay Summary: Organophosphate pesticides (OPs), which are mainly used for pest control, are responsible for the entry of pesticides into the human food cycle. Organophosphate such as diazinon increases the molecular biomarkers of oxidative stress inside the cells of vital tissues such as the heart, liver, lungs, etc. Metal oxide nanoparticles (NPs) such as cerium oxide (CeO2) and yitrium oxide (Y2O3) can have free radical scavenging potential under oxidative stress and through various mechanisms. Although these nanoparticles reduce oxidative stress, it should be borne in the design of the study that additional doses of these substances reverse the beneficial effects.

scholarly journals Nanotechnology Innovations to Enhance the Therapeutic Efficacy of Quercetin

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2658
Author(s):  
Rúben G. R. Pinheiro ◽  
Marina Pinheiro ◽  
Ana Rute Neves
Keyword(s):  
Oxidative Stress ◽  
Therapeutic Efficacy ◽  
Radical Scavenging ◽  
In Vitro Cytotoxicity ◽  
In Vivo Studies ◽  
Beneficial Effects ◽  
Cytotoxicity Effects ◽  
Vegetables And Fruits

Quercetin is a flavonol present in many vegetables and fruits. Generally, quercetin can be found in aglycone and glycoside forms, mainly in leaves. The absorption of this compound occurs in the large and small intestine, where it suffers glucuronidation, sulfidation, and methylation to improve hydrophilicity. After metabolization, which occurs mainly in the gut, it is distributed throughout the whole organism and is excreted by feces, urine, and exhalation of carbon dioxide. Despite its in vitro cytotoxicity effects, in vivo studies with animal models ensure its safety. This compound can protect against cancer, cardiovascular diseases, chronic inflammation, oxidative stress, and neurodegenerative diseases due to its radical scavenging and anti-inflammatory properties. However, its poor bioavailability dampens the potential beneficial effects of this flavonoid. In that sense, many types of nanocarriers have been developed to improve quercetin solubility, as well as to design tissue-specific delivery systems. All these studies manage to improve the bioavailability of quercetin, allowing it to increase its concentration in the desired places. Collectively, quercetin can become a promising compound if nanotechnology is employed as a tool to enhance its therapeutic efficacy.

MCI-186 (edaravone), a novel free radical scavenger, protects against acute autoimmune myocarditis in rats

2005 ◽  
Vol 289 (6) ◽  
pp. H2514-H2518 ◽  
Author(s):  
Masaomi Nimata ◽  
Taka-aki Okabe ◽  
Miki Hattori ◽  
Zuyi Yuan ◽  
Keisuke Shioji ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Hydroxyl Radicals ◽  
Radical Scavenging ◽  
Weight Ratio ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Cytotoxic Activities ◽  
Thiobarbituric Acid Reactive Substance ◽  
Autoimmune Myocarditis

In this study, we tested the hypothesis that MCI-186 (3-methyl-1-phenyl-2-pyrazolin-5-one; edaravone), a novel free radical scavenger, protects against acute experimental autoimmune myocarditis (EAM) in rats by the radical scavenging action associated with the suppression of cytotoxic myocardial injury. Recent evidence suggests that oxidative stress may play a role in myocarditis. We administered MCI-186 intraperitoneally at 1, 3, and 10 mg·kg−1·day−1 to rats with EAM for 3 wk. The results were compared with untreated rats with EAM. MCI-186 treatment did not affect hemodynamics. MCI-186 treatment (3 and 10 mg·kg−1·day−1) reduced the severity of myocarditis as assessed by comparing the heart-to-body weight ratio and pathological scores. Myocardial interleukin-1β (IL-1β)-positive cells and myocardial oxidative stress overload with DNA damage in rats with EAM given MCI-186 treatment were significantly less compared with those of the untreated rats with EAM. In addition, MCI-186 treatment decreased not only the myocardial protein carbonyl contents but also the myocardial thiobarbituric acid reactive substance products in rats with EAM. The formation of hydroxyl radicals in MCI-186-treated heart homogenates was decreased compared with untreated heart homogenates. Furthermore, cytotoxic activities of lymphocytes of rats with EAM treated with MCI-186 were significantly lower compared with those of the untreated rats with EAM. Hydroxyl radicals may be involved in the development of myocarditis. MCI-186 protects against acute EAM in rats associated with scavenging hydroxyl free radicals, resulting in the suppression of autoimmune-mediated myocardial damage associated with reduced oxidative stress state.

scholarly journals Radical Scavenging Activities of Novel Cationic Inulin Derivatives

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1295
Author(s):  
Yuan Chen ◽  
Yingqi Mi ◽  
Jingjing Zhang ◽  
Fang Dong ◽  
Qing Li ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Synthesis Process ◽  
Scavenging Activity ◽  
Scavenging Effect ◽  
Radical Scavenging Effect ◽  
Ft Ir

Many saccharides are attractive targets for biomaterial applications, due to their abundance, biocompatibility, and biodegradability. In this article, a synthesis process of 6-N-substituted cationic inulin derivatives, including 6-pyridyl-6-deoxyinulin bromide (PIL), 6-(2-amino-pyridyl)-6-deoxyinulin bromide (2APIL), 6-(3-amino-pyridyl)-6-deoxyinulin bromide (3APIL), 6-(4-amino-pyridyl)-6-deoxyinulin bromide (4APIL), 6-(2,3-diamino-pyridyl)-6-deoxyinulin bromide (2,3DAPIL), 6-(3,4-diamino-pyridyl)-6-deoxyinulin bromide (3,4DAPIL), and 6-(2,6-diamino-pyridyl)-6-deoxyinulin bromide (2,6DAPIL) was described. The C6-OH of inulin was first activated by PPh3/N-bromosuccinimide (NBS) bromination. Then, pyridine and different kinds of amino-pyridine groups (different position and different numbers of amino) were grafted onto inulin, respectively, via nucleophilic substitution. Then, we confirmed their structure by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. After this, their radical scavenging activities against hydroxyl radical and diphenylpicryl phenylhydrazine (DPPH) radical were tested in vitro. Each derivative showed a distinct improvement in radical scavenging activity when compared to inulin. The hydroxyl-radical scavenging effect decreased in the following order: 3APIL > PIL > 3,4DAPIL > 4APIL > 2,3DAPIL > 2,6DAPIL > 2APIL. Amongst them, 3APIL revealed the most powerful scavenging effect on hydroxyl radicals, as well as DPPH radicals. At 1.6 mg/mL, it could completely eliminate hydroxyl radicals and could clear 65% of DPPH radicals. The results also showed that the steric hindrance effect and the substitute position of the amino group had an effect on the radical scavenging activity. Moreover, the application prospects of inulin derivatives as natural antioxidant biomaterials are scientifically proven in this paper.

scholarly journals Inhibition of microsomal oxidation of alcohols and of hydroxyl-radical-scavenging agents by the iron-chelating agent desferrioxamine

1983 ◽  
Vol 210 (1) ◽  
pp. 107-113 ◽  
Author(s):  
A I Cederbaum ◽  
E Dicker
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Radical Scavenging ◽  
Chelating Agent ◽  
Dimethyl Sulphoxide ◽  
The Other ◽  
Radical Scavengers ◽  
Primary Alcohols ◽  
Hydroxyl Radical Scavengers ◽  
Oxidation Of Ethanol

Rat liver microsomes (microsomal fractions) catalyse the oxidation of straight-chain aliphatic alcohols and of hydroxyl-radical-scavenging agents during NADPH-dependent electron transfer. The iron-chelating agent desferrioxamine, which blocks the generation of hydroxyl radicals in other systems, was found to inhibit the following microsomal reactions: production of formaldehyde from either dimethyl sulphoxide or 2-methylpropan-2-ol (t-butylalcohol); generation of ethylene from 4-oxothiomethylbutyric acid; release of 14CO2 from [I-14C]benzoate; production of acetaldehyde from ethanol or butanal (butyraldehyde) from butan-1-ol. Desferrioxamine also blocked the increase in the oxidation of all these substrates produced by the addition of iron-EDTA to the microsomes. Desferrioxamine had no effect on a typical mixed-function-oxidase activity, the N-demethylation of aminopyrine, nor on the peroxidatic activity of catalase/H2O2 with ethanol. H2O2 appears to be the precursor of the oxidizing radical responsible for the oxidation of the alcohols and the other hydroxyl-radical scavengers. Chelation of microsomal iron by desferrioxamine most likely decreases the generation of hydroxyl radicals, which results in an inhibition of the oxidation of the alcohols and the hydroxyl-radical scavengers. Whereas desferrioxamine inhibited the oxidation of 2-methylpropan-2-ol, dimethyl sulphoxide, 4-oxothiomethylbutyrate and benzoate by more than 90%, the oxidation of ethanol and butanol could not be decreased by more than 45-60%. Higher concentrations of desferrioxamine were required to block the metabolism of the primary alcohols than to inhibit the metabolism of the other substrates. The desferrioxamine-insensitive rate of oxidation of ethanol was not inhibited by competitive hydroxyl-radical scavengers. These results suggest that primary alcohols may be oxidized by two pathways in microsomes, one dependent on the interaction of the alcohols with hydroxyl radicals (desferrioxamine-sensitive), the other which appears to be independent of these radicals (desferrioxamine-insensitive).

scholarly journals Contribution of Oxidative Damage to Antimicrobial Lethality

2009 ◽  
Vol 53 (4) ◽  
pp. 1395-1402 ◽  
Author(s):  
Xiuhong Wang ◽  
Xilin Zhao
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Fenton Reaction ◽  
Iron Chelator ◽  
Radical Scavenger ◽  
Alkyl Hydroperoxide ◽  
Hydroxyl Radical Scavenger ◽  
Rapid Conversion

ABSTRACT A potential pathway linking hydroxyl radicals to antimicrobial lethality was examined by using mutational and chemical perturbations of Escherichia coli. Deficiencies of sodA or sodB had no effect on norfloxacin lethality; however, the absence of both genes together reduced lethal activity, consistent with rapid conversion of excessive superoxide to hydrogen peroxide contributing to quinolone lethality. Norfloxacin was more lethal with a mutant deficient in katG than with its isogenic parent, suggesting that detoxification of peroxide to water normally reduces quinolone lethality. An iron chelator (bipyridyl) and a hydroxyl radical scavenger (thiourea) reduced the lethal activity of norfloxacin, indicating that norfloxacin-stimulated accumulation of peroxide affects lethal activity via hydroxyl radicals generated through the Fenton reaction. Ampicillin and kanamycin, antibacterials unrelated to fluoroquinolones, displayed behavior similar to that of norfloxacin except that these two agents showed hyperlethality with an ahpC (alkyl hydroperoxide reductase) mutant rather than with a katG mutant. Collectively, these data are consistent with antimicrobial stress increasing the production of superoxide, which then undergoes dismutation to peroxide, from which a highly toxic hydroxyl radical is generated. Hydroxyl radicals then enhance antimicrobial lethality, as suggested by earlier work. Such findings indicate that oxidative stress networks may provide targets for antimicrobial potentiation.

scholarly journals Real Time Normalization of Fast Photochemical Oxidation of Proteins Experiments by Inline Adenine Radical Dosimetry

2018 ◽  
Author(s):  
Joshua S. Sharp ◽  
Sandeep K. Misra ◽  
Jeffrey J. Persoff ◽  
Robert W. Egan ◽  
Scot R. Weinberger
Keyword(s):  
Hydroxyl Radical ◽  
Real Time ◽  
Hydroxyl Radicals ◽  
Conformational Changes ◽  
Radical Scavenging ◽  
Photochemical Oxidation ◽  
Major Step ◽  
Simple Method ◽  
Radical Concentration ◽  
High Concentrations

AbstractHydroxyl radical protein footprinting (HRPF) is a powerful method for measuring protein topography, allowing researchers to monitor events that alter the solvent accessible surface of a protein (e.g. ligand binding, aggregation, conformational changes, etc.) by measuring changes in the apparent rate of reaction of portions of the protein to hydroxyl radicals diffusing in solution. Fast Photochemical Oxidation of Proteins (FPOP) offers an ultra-fast benchtop method for performing HRPF, photolyzing hydrogen peroxide using a UV laser to generate high concentrations of hydroxyl radicals that are consumed on roughly a microsecond timescale. The broad reactivity of hydroxyl radicals means that almost anything added to the solution (e.g. ligands, buffers, excipients, etc.) will scavenge hydroxyl radicals, altering their half-life and changing the effective radical concentration experienced by the protein. Similarly, minute changes in peroxide concentration, laser fluence, and buffer composition can alter the effective radical concentration, making reproduction of data challenging. Here, we present a simple method for radical dosimetry that can be carried out as part of the FPOP workflow, allowing for measurement of effective radical concentration in real time. Additionally, by modulating the amount of radical generated, we demonstrate that FPOP HRPF experiments carried out in buffers with widely differing levels of hydroxyl radical scavenging capacity can be normalized on the fly, yielding statistically indistinguishable results for the same conformer. This method represents a major step in transforming FPOP into a robust and reproducible technology capable of probing protein structure in a wide variety of contexts.

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