• Electron spin resonance was used to measure carbon-centered as well as hydroxyl radicals produced by a Fenton-like reaction with wildfire smoke. (cdc.gov)
  • A flow system was designed to generate superoxide radical anion (O2 -) at near-neutral pH by rapid mixing of potassium superoxide dissolved in dimethyl sulfoxide by two- stage mixing with aqueous buffers. (illinois.edu)
  • Metronidazole, being electron-affinic, can accept an electron from neutral free radical centres to generate a reactive cation that binds to an anion such as hydroxyl (OH-), causing a permanent lesion. (who.int)
  • To counteract the negative effects of excess ROS, spermatozoa and seminal plasma have several mechanisms to neutralize free radicals. (scialert.net)
  • To counteract oxidative damage, spermatozoa and seminal plasma have several mechanisms to neutralize free radicals. (scialert.net)
  • Compounds isolated in freeze-dried açaí extract have been shown to enter human cells and neutralize free radicals at very low doses. (lifeextension.com)
  • It produced 88% scavenging effect of DPPH radical at a concentration of 1.0 mg/ml. (antiox.org)
  • The IC 50 values of the ethanol extract of the Tayfi grape's scavenging abilities for ABTS˙+ and DPPH˙radicals wer. (researchgate.net)
  • The aim of our work was the study of the interaction of three red wine polyphenols-quercetin, resveratrol and caffeic acid-alone and in their equimolar binary and ternary mixtures in different antioxidant/scavenging assays (inhibition of 2-deoxy-D-ribose degradation by hydroxyl radical, FRAP, Fe(III) reducing power, DPPH, ABTS and NO scavenging, respectively). (mdpi.com)
  • One of the most significant current discussions in Cu biochemistry relates to the mechanisms of the positive and negative actions of Cu ions based on the generation of reactive oxygen species, including radicals that can interact with DNA molecules. (mdpi.com)
  • Free radicals can form naturally since some of the body's molecules have weak bonds that spontaneously break and cause the molecule to become a free radical. (positivehealth.com)
  • Reactive oxygen species (ROS) are unstable reactive molecules, physiologically produced by xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, lipoxygenases, and mitochondria [ 1 , 2 ]. (hindawi.com)
  • ROS exert a dual role as both deleterious and beneficial species, the latter being of pivotal importance as signaling molecules. (hindawi.com)
  • The enzymes convert reactive species in non-toxic molecules and also participate in the process of detoxification (which facilitates the biotransformation and excretion of "strange" molecules to the cells). (databasefootball.com)
  • Living polymerization requires a complete absence of termination reactions, whereas reversible-deactivation polymerization may contain a similar fraction of termination as conventional polymerization with the same concentration of active species. (wikipedia.org)
  • This has been seen to be due to the interaction of the radical centre with the catalyst during these polymerization reactions. (wikipedia.org)
  • The reversible reaction of the cobalt macrocycle with the growing radical is known as cobalt carbon bonding and in some cases leads to living polymerization reactions. (wikipedia.org)
  • This is because a new radical is created, able to participate in secondary reactions. (wikipedia.org)
  • In free radical halogenation reactions, radical substitution takes place with halogen reagents and alkane substrates. (wikipedia.org)
  • Many oxidation and reduction reactions in organic chemistry have free radical intermediates, for example the oxidation of aldehydes to carboxylic acids with chromic acid. (wikipedia.org)
  • Coupling reactions can also be considered radical substitutions. (wikipedia.org)
  • These are reactions which remove free radicals from the system without replacing them by new ones. (chemguide.co.uk)
  • Also, for unknown reasons a small proportion of normal oxidative reactions result in the formation of free radicals. (positivehealth.com)
  • Homolysis can be brought about by heat or ultraviolet light, but also by radical initiators such as organic peroxides or azo compounds. (wikipedia.org)
  • Finally, a great number of chemicals, especially human-produced synthetic compounds can cause free radical formation. (positivehealth.com)
  • essential nutritional dietary compounds such as vitamin C, and small plant-derived substances which intercept free radicals and prevent them from causing damage. (positivehealth.com)
  • The standard index for determining the antioxidant value of various organic compounds is known as oxygen radical absorbance capacity, or ORAC. (lifeextension.com)
  • A series of prostaglandin-like compounds that are produced by the attack of free-radical species on unsaturated fatty acids, especially ARACHIDONIC ACID, of cellular MEMBRANES. (bvsalud.org)
  • Free radicals have been associated with pathogenesis of various disorders like cancer, diabetes, cardiovascular diseases, autoimmune diseases, neurodegenerative disorders and are implicated in aging. (nutrimedical.com)
  • The production of reactive species/free radicals is enhanced during pathological conditions, such as in neurodegenerative diseases and cardiovascular diseases, among several others (including metabolic disturbances, cancer, and infection). (databasefootball.com)
  • Dietary polyphenols have gained public interest in recent times due to their roles in the prevention of various diseases that implicate free radicals/reactive oxygen species. (frontiersin.org)
  • You will also gain insight into the specific health benefits of açaí and similarly potent fruits and vegetables-and their unrivalled power to combat free radical damage and the killer diseases of aging. (lifeextension.com)
  • Every day, the human body undergoes several exogenous insults, such as ultraviolet (UV) rays, air pollution and tobacco smoke, which result in the production of reactive species, especially oxidants and free radicals, responsible for the onset of many diseases, including cancer. (who.int)
  • If the reaction is not terminated, but instead the radical group(s) go on to react further, the steps where new radicals are formed and then react are collectively known as propagation (4,5). (wikipedia.org)
  • Keap1 may be viewed as the regulator of Nrf2, and reactive species/free radicals and electrophiles react with the Nrf2-Keap1 complex causing the release of Nrf2, which migrates to the cell nucleus and triggers the expression of selected genes whose products, i.e. proteins with or without enzymatic activity, participate in the antioxidant defense and in the metabolism of xenobiotics in mammals. (databasefootball.com)
  • Under aerobic conditions, there is enough oxygen to react with all the free radicals and addition of metronidazole, or any other sensitizers, yields no further benefit. (who.int)
  • The data suggest a scavenging mechanism of metronidazole on reactive oxygen species generated by PMN. (who.int)
  • In organic chemistry, a radical-substitution reaction is a substitution reaction involving free radicals as a reactive intermediate. (wikipedia.org)
  • This page gives you the facts and a simple, uncluttered mechanism for the free radical substitution reaction between methylbenzene (previously known as toluene) and chlorine. (chemguide.co.uk)
  • The two options of SFRP are nitroxide mediated polymerization (NMP) and verdazyl mediated polymerization (VMP), SFRP was discovered while using a radical scavenger called TEMPO when investigating the rate of initiation during free radical polymerization. (wikipedia.org)
  • In view of these properties, L. alata can act as a prophylactic by intervening as electrophilic, free radical and ROS scavenger and detoxifier. (antiox.org)
  • Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? (oregonstate.edu)
  • The ability of carnosic acid in exerting antioxidant effects is not associated only with its chemical structure, i.e. carnosic acid is not just a scavenger of reactive species. (databasefootball.com)
  • SECTION A: ESR spectroscopic studies of the addition of α-(alkoxycarbonyl)alkyl radicals to terminal alkenes, furan and isocyanides were carried out in cyclopropane solution at low temperatures. (ucl.ac.uk)
  • For all acceptors, addition of each of the electrophilic α-(alkoxycarbonyl)alkyl radicals is faster than the corresponding addition of simple (nucleophilic) alkyl radicals, a result which is attributed to the importance of polar effects in the transition states. (ucl.ac.uk)
  • The metal has a number of different oxidation states that allows it to abstract a halide from the organohalide, creating a radical that then starts free radical polymerization. (wikipedia.org)
  • According to the Free Radical Theory of ageing (the most widely accepted theory of ageing) proposed by Herman in 1956, age-related impairment is caused by oxygen-derived free radicals through oxidative damage to biomolecules, with mitochondria being the main target of free radical attack. (scirp.org)
  • Over-reduction of PET chain can damage protein complexes and result in production of the excess amounts of reactive oxygen species (ROS) 6 . (nature.com)
  • Subcutaneous injection of sodium selenite led to severe oxidative damage in the lenticular tissues, shown by increased formation of formazan crystals, elevated generation of superoxide, hydroxyl, and nitric oxide radicals, and elevated inducible nitric oxide synthase gene and protein expression that possibly contributed to the opacification of the lens and thus cataract formation. (molvis.org)
  • These work by either stopping free radical damage by donating an electron without becoming a damaging free radical themselves, or by preventing oxidation commencing. (positivehealth.com)
  • The damage induced by free radicals causes the denaturing of hemoglobin. (medscape.com)
  • Chaga - Antioxidant support against daily free-radical damage. (fungi.com)
  • Oxidants (also called reactive oxygen species or free radicals) are continuously generated in our body, and we rely on sophisticated antioxidant systems to prevent them from causing damage. (otago.ac.nz)
  • Find out how these and other findings confirm berry polyphenols' unrivalled capacity to blunt free radical damage and thwart degenerative disease. (lifeextension.com)
  • In the older cells of aging animals, to take one example, researchers have found that one out of every three proteins is rendered dysfunctional by unchecked free radical damage. (lifeextension.com)
  • These results indicate that the radical generation and the damage caused by them is not only a function of surface area but is also influenced by changing chemical and other characteristics due to particle size. (cdc.gov)
  • In order to prevent oxidative damage, the antioxidant system presents a group of cellular enzymes (SOD, catalase and glutathione system) responsible for the control of free radicals. (bvsalud.org)
  • Radiosensitizers are chemical agents that have the potential to increase the lethal effect of radicals induced during irradiation [1-6].The extent of radiation damage to cells is dependent on the amount of oxygen available to the cell [1,2,7,8]. (who.int)
  • Reactive oxygen species (ROS) are produced as a result of aerobic metabolism and as by-products through numerous physiological and biochemical processes. (hindawi.com)
  • Reactive oxidant species and free radicals are produced in an extensive range of physiological processes. (springer.com)
  • However, the over production of oxygen free radicals in sperm membrane decreases the antioxidant defense activity thereby leading to low sperm motility and viability, DNA fragmentation and protein denaturation. (scialert.net)
  • Though oxygen is peremptory for life, imbalances between antioxidant defense mechanisms, overproduction of ROS, or incorporation of free radicals from the environment to living systems lead to oxidative stress. (hindawi.com)
  • In the search for optimal defense against free radicals, scientists have focused intensely on berry extracts. (lifeextension.com)
  • Yousuf Azeemi, S. , Shaukat, S. , Qasim, R. and Khawar, H. (2016) Elimination of Free Radicals and Immunity Enhancement with 644 nm (Red Colour) Radiation: A Randomised Controlled Clinical Trial. (scirp.org)
  • Thus, after presenting solid scientific reasoning behind this therapeutic mode of treatment pertaining to the activity of SOD in the presence of 644 nm radiation, a randomised controlled clinical trial has been carried out which builds a unique relationship of 644 nm irradiated SOD with the elimination of free radicals and hence the enhancement of immunity. (scirp.org)
  • Other causes of damaging free radicals are ionising radiation, such as light, or ultra violet, or other forms of radiation. (positivehealth.com)
  • However, the in vivo quantification of these free radicals in patients is not applicable due to bioethical restrictions. (molvis.org)
  • There has been accumulating evidence that an additional mechanism to generate reactive oxygen species occurs in vivo (Moore et al . (scialert.net)
  • This optically isolated four-channel free radical analyser has ultra low noise and independently operated channels. (coherent.com.au)
  • Oxygen free radicals are naturally produced by mitochondrial and sperm plasma membrane and have beneficial and detrimental effects that cannot be overlooked. (scialert.net)
  • The apparent ability of manganese in its divalent form to promote formation of reactive oxygen species (ROS) within a cortical mitochondrial-synaptosomal (P2) fraction was completely abolished by the addition of one five hundredth of its molarity of desferroxamine (DFO), a trivalent metal chelator. (cdc.gov)
  • These spermatozoa also experienced increased mitochondrial generation of reactive oxygen species after 1 week of exposure, with elevated DNA oxidation and fragmentation across all exposure periods. (nature.com)
  • Free radical now appears to be the fundamental mechanism underlying a number of neurologic and other disorders. (scialert.net)
  • While there is disagreement of the reactive species involved and the mechanism of destruction, it is plausible that arsine causes cellular destruction by multiple mechanisms and the oxidative pathophysiology of arsine is well supported. (medscape.com)
  • Importantly, these proteins will defend the cells against reactive species/free radicals that are produced by several sources, including those originated as part of the mechanism of action of toxicants (pollutants, agrochemicals, other). (databasefootball.com)
  • We have employed electron paramagnetic resonance (EPR) spectroscopy to study free radical formation and electron partitioning in TROL-depleted chloroplasts. (nature.com)
  • Production of the free radicals in the cells is a constant process as a part of normal cellular function. (scirp.org)
  • Therefore, preventing ROS production or scavenging of free radicals may be an effective strategy for preventing or delaying cataract formation or progression. (molvis.org)
  • In treating malignant melanoma, a widely known oxidant named menadione was used in combination with arsenic to increase reactive oxidative species (ROS) production and subsequent apoptosis in tumor cells. (medscape.com)
  • During exercise, production of reactive oxygen species and other free radicals can increase. (dsm.com)
  • other agents commonly ingested by the humans, such as drugs and food additives), the production of reactive species/free radicals may increase, leading to oxidative or nitrosative stress, depending on the specific reactive species are generated. (databasefootball.com)
  • There is rising interest in endemic species because these can be used for preparing phytopharmaceuticals with considerable antioxidant potential or for the production of raw materials and health confidants [ 26 - 28 ]. (ijpsonline.com)
  • The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear (PMN) cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. (who.int)
  • At therapeutic doses of metronidazole (4.98-24.86 μg/mL) significant inhibition of the production of reactive oxygen species was noted in both methods. (who.int)
  • this is attributed to the electrophilic nature of the radical centre in the former species. (ucl.ac.uk)
  • Redox-active transition metals, containing unpaired electrons in their d-orbital, are able to generate, or remove, reactive species with unpaired electrons. (scialert.net)
  • Skeletal muscle fibers regularly generate reactive oxygen species (ROS) at a sluggish price that will increase throughout muscle contraction. (ncbcs.org)
  • In this article, you will learn how the antioxidant potency of açaí and other foods is assessed, using a measurement known as oxygen radical absorbance capacity, or ORAC. (lifeextension.com)
  • Fruits and vegetables with a higher ORAC value-or richer color-have been shown to suppress free radicals more effectively than lightly pigmented foods. (lifeextension.com)
  • The excessive generation of oxygen free radicals in the form of ROS by abnormal spermatozoa and by contaminating leukocytes has been identified as one of the few defined etiologies for male infertility. (scialert.net)
  • formation, while the generation of other free radicals was monitored by Tiron. (nature.com)
  • Generation of other radical forms was elevated in trol chloroplasts in all tested conditions, except for the plants pre-acclimated to high-light. (nature.com)
  • When rat pups were treated with intraperitoneal administration of the extract of C. maritima , the generation of free radicals as well as the messenger ribonucleic acid and protein expression of inducible nitric oxide synthase were maintained at near normal levels. (molvis.org)
  • The data generated by this study suggest that an ethanolic extract of C. maritima possibly prevents cataractogenesis in a rat model by minimizing free radical generation. (molvis.org)
  • Particle size-dependent radical generation from wildland fire smoke. (cdc.gov)
  • Our investigation looked into the involvement of free radicals in smoke toxicity and the relationship between particle size and radical generation. (cdc.gov)
  • After initiation and propagation, the radical on the active chain terminus is reversibly terminated (with the halide) by reacting with the catalyst in its higher oxidation state. (wikipedia.org)
  • This study assessed endogenous knowledge and impact of human disturbance on the abundance of two underutilized wild fruit tree species: Drypetes floribunda (Mu¨ll. (researchgate.net)
  • A survey was conducted with 145 randomly selected people amongst the surrounding communities of LFR in order to assess the endogenous knowledge of the species. (researchgate.net)
  • of LFR in order to assess the endogenous knowledge of the species. (researchgate.net)
  • ATRP involves the chain initiation of free radical polymerization by a halogenated organic species in the presence of a metal halide. (wikipedia.org)
  • In the first step called initiation (2,3), a free radical is created by homolysis. (wikipedia.org)
  • Here we evaluated the ethanolic extracts from five species of duckweeds by HPLC-DAD/MS-MS for chemical characterization. (rsc.org)
  • are able to initiate a range of oxidative chemistry with similar reactivity to the hydroxyl radical (Sutton and Winterbourn, 1989). (scialert.net)
  • We define the term 'supersulfides' as sulfur species with catenated sulfur atoms. (nih.gov)
  • Carnosic acid is an antioxidant, meaning that it may decrease the impact of reactive species/free radicals in biological systems. (databasefootball.com)
  • The tumor was considered free of node involvement and metastases. (cdc.gov)
  • Although many factors have been implicated, cataract formation is primarily associated with oxidative stress produced by free radicals. (molvis.org)
  • Non-transferrin-bound circulating iron is readily taken up by hepatocytes, where it promotes the formation of free radical oxygen species that cause cell injury. (medscape.com)