Article

1998 ◽  
Vol 76 (7) ◽  
pp. 1064-1069 ◽  
Author(s):  
X -Z Zhang ◽  
R C Francis ◽  
D B Dutton ◽  
R T Hill
Keyword(s):  
Aqueous Solution ◽  
Free Radicals ◽  
Free Radical ◽  
Peracetic Acid ◽  
Kinetic Data ◽  
Radical Scavenging ◽  
Similar Type ◽  
Pulp Fibers ◽  
Radical Decomposition ◽  
Wood Pulps

Peracetic acid (Pa) is now being used for totally chlorine-free delignification and bleaching of wood pulps. During the process, metals desorb from the pulp fibers into the aqueous solution. Of the relevant metals in bleaching systems, cobalt(II) and vanadium(V) are the most potent in wastefully decomposing Pa to O2. In the present study, radical scavenging by N,N'-(5-nitro-1,3-phenylene)-bisglutaramide (GAMID) indicates that free-radical mechanisms are operative. Kinetic data support a free-radical decomposition mechanism previously described for Co(II). A similar type of mechanism, involving VO(OH)2(aq) and VO(OH)3(aq), is postulated to partially explain catalysis by vanadium.Key words: peracetic acid, peroxymonosulfuric acid, transition metals, free radicals, acetoxy radical, peracetoxy radical.

Study of antioxidant potential in leaves, stems, nuts of Juglans regia L.

2012 ◽  
Vol 1 (10) ◽  
pp. 79 ◽  
Author(s):  
G. Raja* ◽  
Ivvala Anand Shaker ◽  
Inampudi Sailaja ◽  
R. Swaminathan ◽  
S. Saleem Basha ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Juglans Regia ◽  
Radical Scavenging ◽  
Antioxidant Compounds ◽  
Free Radical Damage ◽  
Radical Damage

Natural antioxidants can protect the human body from free radicals and retard the progress of many chronic diseases as well as lipid oxidative rancidity in foods. The role of antioxidants has protected effect against free radical damage that may cause many diseases including cancer. Primary sources of naturally occurring antioxidants are known as whole grains, fruits, and vegetables. Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. The role of antioxidants has attracted much interest with respect to their protective effect against free radical damage that may cause many diseases including cancer. Juglans regia L. (walnut) contains antioxidant compounds, which are thought to contribute to their biological properties. Polyphenols, flavonoids and flavonols concentrations and antioxidant activity of Leaves, Stems and Nuts extract of Juglans regia L. as evaluated using DPPH, ABTS, Nitric acid, hydroxyl and superoxide radical scavenging activity, lipid peroxidation and total oxidation activity were determined. The antioxidant activities of Leaves, Stems and Nuts extract of Juglans regia L. were concentration dependent in different experimental models and it was observed that free radicals were scavenged by the test compounds in all the models.

scholarly journals Free Radical–Mediated Cell Damage After Experimental Status Epilepticus in Hippocampal Slice Cultures

2002 ◽  
Vol 88 (6) ◽  
pp. 2909-2918 ◽  
Author(s):  
Richard Kovács ◽  
Sebastian Schuchmann ◽  
Siegrun Gabriel ◽  
Oliver Kann ◽  
Julianna Kardos ◽  
...  
Keyword(s):  
Free Radicals ◽  
Status Epilepticus ◽  
Free Radical ◽  
Hippocampal Slice ◽  
Cell Damage ◽  
Radical Scavenging ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Mitochondrial Depolarization ◽  
Hippocampal Slice Cultures

Generation of free radicals may have a key role in the nerve cell damage induced by prolonged or frequently recurring convulsions (status epilepticus). Mitochondrial function may also be altered due to production of free radicals during seizures. We therefore studied changes in field potentials (fp) together with measurements of extracellular, intracellular, and intramitochondrial calcium concentration ([Ca2+]e, [Ca2+]i, and [Ca2+]m, respectively), mitochondrial membrane potential (ΔΨ), NAD(P)H auto-fluorescence, and dihydroethidium (HEt) fluorescence in hippocampal slice cultures by means of simultaneous electrophysiological and microfluorimetric measurements. As reported previously, each seizure-like event (SLE) resulted in mitochondrial depolarization associated with a delayed rise in oxidation of HEt to ethidum, presumably indicating ROS production. We show here that repeated SLEs led to a decline in intracellular and intramitochondrial Ca2+ signals despite unaltered Ca2+ influx. Also, mitochondrial depolarization and the NAD(P)H signal became smaller during recurring SLEs. By contrast, the ethidium fluorescence rises remained constant or even increased from SLE to SLE. After about 15 SLEs, activity changed to continuous afterdischarges with steady depolarization of mitochondrial membranes. Staining with a cell death marker, propidium iodide, indicated widespread cell damage after 2 h of recurring SLEs. The free radical scavenger, α-tocopherol, protected the slice cultures against this damage and also reduced the ongoing impairment of NAD(P)H production. These findings suggest involvement of reactive oxygen species (ROS) of mitochondrial origin in the epileptic cell damage and that free radical scavenging may prevent status epilepticus–induced cell loss.

scholarly journals Modulation of rabbit muscle sarcoplasmic reticulum Ca2+-ATPase activity by novel quercetin derivatives

2013 ◽  
Vol 6 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Dušan Blaškovič ◽  
Petronela Žižková ◽  
Filip Držík ◽  
Jana Viskupičová ◽  
Miroslav Veverka ◽  
...  
Keyword(s):  
Heart Failure ◽  
Free Radicals ◽  
Free Radical ◽  
Sarcoplasmic Reticulum ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Rabbit Muscle ◽  
Scavenging Activity ◽  
Quercetin Derivatives

Abstract Sarcoplasmic reticulum Ca2+-ATPase (SERCA) is the pump crucial for calcium homeostasis and its impairment results in pathologies such as myopathy, heart failure or diabetes. Modulation of SERCA activity may represent an approach to the therapy of diseases with SERCA impairment involvment. Quercetin is flavonoid known to modulate SERCA activity. We examined the effect of nine novel quercetin derivatives on the activity of the pump. We found that 5-morpholinohydroxypoxyquercetin, di(prenylferuoyl)quercetin, di(diacetylcaffeoyl)-mono-(monoacetylcaffeoyl)quercetin and monoacetylferuloylquercetin stimulated the activity of SERCA. On the contrary, monochloropivaloylquercetin, tri(chloropivaloyl)quercetin, pentaacetylquercetin, tri(trimethylgalloyl)quercetin and diquercetin inhibited the activity of the pump. To identify compounds with a potential to protect SERCA against free radicals, we assessed the free radical scavenging activity of quercetin derivatives. We also related lipophilicity, an index of the ability to incorporate into the membrane of sarcoplasmic reticulum, to the modulatury effect of quercetin derivatives on SERCA activity. In addition to its ability to stimulate SERCA, di(prenylferuloyl)quercetin showed excellent radical scavenging activity.

scholarly journals Assessment of Free Radical Scavenging Potential and Oxidative DNA Damage Preventive Activity ofTrachyspermum ammiL. (Carom) andFoeniculum vulgareMill. (Fennel) Seed Extracts

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Nandini Goswami ◽  
Sreemoyee Chatterjee
Keyword(s):  
Dna Damage ◽  
Free Radicals ◽  
Free Radical ◽  
Oxidative Dna Damage ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Dpph Radical ◽  
Preventive Activity ◽  
Dpph Radical Scavenging ◽  
Seed Extracts

Oxidation of biomolecules such as carbohydrates, proteins, lipids, and nucleic acids results in generation of free radicals in an organism which is the major cause of onset of various degenerative diseases. Antioxidants scavenge these free radicals, thereby protecting the cell from damage. The present study was designed to examine the free radical scavenging potential and oxidative DNA damage preventive activity of traditionally used spicesTrachyspermum ammiL. (carom) andFoeniculum vulgareMill. (fennel). The aqueous, methanolic, and acetonic extracts ofT. ammiandF. vulgareseeds were prepared using soxhlet extraction assembly and subjected to qualitative and quantitative estimation of phytochemical constituents. Free radical scavenging potential was investigated using standard methods, namely, DPPH radical scavenging assay and ferric reducing antioxidant power assay along with the protection against oxidative DNA damage. The results stated that acetonic seed extracts (AAcSE and FAcSE) of both the spices possessed comparatively high amount of total phenolics whereas methanolic seed extracts (AMSE and FMSE) were found to have highest amount of total flavonoids. At 1 mg/mL concentration, highest DPPH radical scavenging activity was shown by FMSE (96.2%), AAcSE was recorded with highest FRAP value (2270.27 ± 0.005 μmol/L), and all the seed extracts have been shown to mitigate the damage induced by Fenton reaction on calf thymus DNA. Therefore, the study suggests thatT. ammiandF. vulgareseed extracts could contribute as a highly significant bioresource of antioxidants to be used in our day-to-day life and in food and pharmaceutical industry.

scholarly journals Mechanistic studies on the free radical decomposition of some oxalic acid arylhydrazides: a source of aryl radicals in aqueous solution

ARKIVOC ◽  
2005 ◽  
Vol 2006 (3) ◽  
pp. 127-147
Author(s):  
Bruce C Gilbert ◽  
Petre Ionita ◽  
John R Lindsay Smith ◽  
John Oakes ◽  
Niels Ouwerkerk
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Oxalic Acid ◽  
Mechanistic Studies ◽  
Aryl Radicals ◽  
Radical Decomposition

scholarly journals Free Radical Scavenging and Antioxidant Potential of Ethanolic Leaf Extract of Diodia sarmentosa on High Fat Fed Wistar Rats

2020 ◽  
pp. 54-63
Author(s):  
Ezejiofor Tobias I. Ndubuisi ◽  
Korie Stephen Chinedumije ◽  
Peter Chukwudi
Keyword(s):  
Nitric Oxide ◽  
Antioxidant Enzymes ◽  
Free Radicals ◽  
Free Radical ◽  
Wistar Rats ◽  
Leaf Extract ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
High Fat ◽  
Ethanolic Leaf Extract

Diodia sarmentosa (Sw) commonly known as Zimbabwe flora or Tropical button weed is a straggling or procumbent perennial herb which grows in evergreen forest, riverine vegetation and bush land. It has been used traditionally for the treatment of ulcer, diabetes and other ailments. This study investigated the Free radical scavenging and antioxidant potential of ethanolic leaf extract of Diodia sarmentosa on high fat fed wistar rats. Thirty (30) male wistar rats (150 g-200 g) were divided into five (5) groups: Negative control rats, Positive control rats, Low dose extract rats treated with 250 mg/kg, High dose extract rats treated with 500mg/kg of the extract, and Standard antihyperlipidaemic drug rats treated with 5 mg/kg of Simvastatin. High fat diet was fed to the rats with Ghee and Coconut oil in the ratio of 3:1 for six (6) weeks, and administration of the treatments started from the 3rd week till the 6th week. The free radical scavenging and antioxidant potentials of Diodia sarmentosa was determined by assessing parameters like nitric oxide radical, hydroxyl radical, malondialdehyde (MDA), Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx) and Glutathione S-transferase (GST) in the serum of the test rats. Diodia sarmentosa scavenged free radicals In vitro by inhibiting Nitric oxide and Hydroxyl radicals in a concentration-dependent manner, showing an inhibitory concentration at 50% (IC50) of 907.17 µg/ml ± 45.36 and 2173.44 µg/ml ± 100.11 respectively. Results obtained showed antioxidant enzymes like SOD, GPx and CAT in the serum of the test rats were significantly increased (p<0.05) by both doses of the extract when compared to the PC group and was similar to the standard drug used. GST activity was decreased in the serum by both doses of the extract, this decrease was not significant (p>0.05), while Malondialdehyde level was significantly decreased (p<0.05) by both doses of the extract in the serum of the tests rats. Diodia sarmentosa has antioxidants potentials because of its ability to scavenge free radicals, replenish antioxidant enzymes and reduce lipid peroxidation.

scholarly journals Evaluation of the Free Radical Scavenging Activities of Ellagic Acid and Ellagic Acid Peracetate by EPR Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4800
Author(s):  
Ajit Kumar ◽  
Preeti Kaushik ◽  
Sandra Incerpi ◽  
Jens Z. Pedersen ◽  
Sanjay Goel ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Free Radical ◽  
Ellagic Acid ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Cellular Systems ◽  
Ros Production ◽  
Microsomal Lipid Peroxidation

The purpose of this study was to examine the free radical scavenging and antioxidant activities of ellagic acid (EA) and ellagic acid peracetate (EAPA) by measuring their reactions with the radicals, 2,2-diphenyl-1-picrylhydrazyl and galvinoxyl using EPR spectroscopy. We have also evaluated the influence of EA and EAPA on the ROS production in L-6 myoblasts and rat liver microsomal lipid peroxidation catalyzed by NADPH. The results obtained clearly indicated that EA has tremendous ability to scavenge free radicals, even at concentration of 1 µM. Interestingly even in the absence of esterase, EAPA, the acetylated product of EA, was also found to be a good scavenger but at a relatively slower rate. Kinetic studies revealed that both EA and EAPA have ability to scavenge free radicals at the concentrations of 1 µM over extended periods of time. In cellular systems, EA and EAPA were found to have similar potentials for the inhibition of ROS production in L-6 myoblasts and NADPH-dependent catalyzed microsomal lipid peroxidation.

Discovery of New N-hydrazinecarbothioamide Indazole Hybrids: As Potential Radical (ABTS and DPPH) Scavengers

2020 ◽  
Vol 17 (9) ◽  
pp. 1177-1185
Author(s):  
Rafaila Rafique ◽  
Arshia ◽  
Kanwal ◽  
Khalid Mohammed Khan ◽  
Sridevi Chigurupati ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radicals ◽  
Free Radical ◽  
Radical Scavenging ◽  
Free Radical Scavengers ◽  
Radical Scavengers ◽  
Synthetic Compounds ◽  
Free Radical Generation ◽  
Radical Generation

Background: Free radicals are the main cause of numerous diseases. Their overproduction needs to be controlled in order to combat several ailments. The current study deals with the discovery of new free radical scavengers. Methods: Substituted N-hydrazinecarbothioamide indazoles 1-18 were evaluated for DPPH and ABTS radical scavenging activities. Results: All synthetic compounds possess good radical DPPH and ABTS scavenging potential in the ranges of IC50 = 2.11 ± 0.17 - 5.3 ± 0.11 μM and IC50 = 2.31 ± 0.06 - 5.5 ± 0.07 μM, respectively, as compared to standard ascorbic acid having IC50 = 2.02 ± 0.11 μM for DPPH and IC50 = 2.1 ± 0.07 μM for ABTS. Conclusion: These compounds could serve as leads for antioxidant activity that have the ability to control free radical generation and ward off free radical-induced disorders.

Free radicals scavenging aptitude of Spilanthes acmella

2021 ◽  
pp. 2631-2634
Author(s):  
K. Gouri Sankar ◽  
B. S. Venkateswarlu
Keyword(s):  
Antioxidant Activity ◽  
Free Radicals ◽  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Bioactive Molecules ◽  
Scavenging Activity ◽  
Spilanthes Acmella

Now a days, oxidative stress is one of the major disease around the world. The excess production of oxidants in the body are key source for development of different chronic diseases and are leading to damage the multiple organs' function, finally to cellular mortality. The natural remedy is the most important medicine to control the overproduction of oxidants and to obtain more antioxidants. Natural product have been using to treat diseases and as food supplements as nutrients. In this point of view, the current study was carried to evaluate the antioxidant activity of Spilanthes acmella root parts. The free radical scavenging activity was studied against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide and hydroxyl free radicals using standard methods. The Spilanthes acmella root part extracts showed concentration dependent antioxidant activity on tested free radicals. The extracts showed modest effect on free radicals compared to the standard drug ascorbic acid and hydro-alcoholic extract possesses more activity than other two extracts. The end results of current study clearly state that Spilanthes acmella root possess free radical scavenging activity and also confirms its' traditional value in traditional medicine. The further research is worthful on isolation of different bioactive molecules and different biological activities evaluation on Spilanthes acmella.

Utilization Phase Transition Component Method to Prepare Specially Functionalized Nanoemulsion by Adding Resveratrol/Phenethyl Resorcinol Mixed Active Components and Application in Free Radicals Removal

2020 ◽  
Vol 20 (12) ◽  
pp. 7769-7774
Author(s):  
Wenwen Liu ◽  
Songzhu Cui ◽  
Jianhua Ji ◽  
Dejun Sun ◽  
Tao Wu
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Ionic Strength ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Mass Ratio ◽  
Hydrogen Binding ◽  
Active Components ◽  
Hydrophobic Binding ◽  
Radical Scavenging Ability

To explore the possibility of using a specially functionalized nanoemulsion for the removal of free radical, resveratrol and phenethyl resorcinol were employed to form resveratrol/phenethyl resorcinol mixed active components, and the removal efficiency of free radicals was evaluated. Original nanoemulsion and specially functionalized-nanoemulsion were characterized by DLS and EPR. The free radical scavenging ability of the mixed active components of resveratrol/phenethyl resorcinol was determined as a function of the mass ratio of resveratrol to phenethyl resorcinol, temperature, and ionic strength. In the results, the removal of free radicals by the resveratrol/phenethyl resorcinol nanoemulsion system was found to be more effective than the nanoemulsion alone. At a higher resveratrol ratio, more than 68% of free radicals could be removed. The efficiency was also found to increase with rising temperature. However, efficiency decreased with the increase in ionic strength. In conclusion, compared with conventional nanoemulsion, the combined utilization of nanoemulsion and the mixed active components of resveratrol/phenethyl resorcinol achieved better results for the removal of free radicals because of synergistic effect between nanoemulsion droplets and the mixed active components of resveratrol/phenethyl resorcinol, involving hydrophobic binding, hydrogen binding, and partitioning.

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