Analysis of the soybean metallothionein system under free radical stress: protein modification connected to lipid membrane damage

Metallomics ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1792-1804 ◽  
Author(s):  
Mireia Tomàs Giner ◽  
Elena Jiménez-Martí ◽  
Roger Bofill Arasa ◽  
Anna Tinti ◽  
Michele Di Foggia ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Protein Modification ◽  
Cell Membranes ◽  
Lipid Membrane ◽  
Metal Clusters ◽  
Membrane Damage ◽  
Stress Protein ◽  
Structural Rearrangement ◽  
Free Radical Stress

Metal clusters act as good interceptors of free radicals for four plant metallothioneins: partial deconstruction, structural rearrangement and damage transfer to cell membranes.

scholarly journals Lipid Peroxidation

2021 ◽  
Author(s):  
Suzan Onur Yaman ◽  
Adnan Ayhanci
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Structural Changes ◽  
Lipid Membrane ◽  
Membrane Damage ◽  
Lipid Hydroperoxide ◽  
Electrolyte Balance ◽  
Lipid Hydroperoxides ◽  
Carbon Centered Radical ◽  
Cellular Components

Lipid peroxidation (LPO) is initiated by the attack of free radicals (eg OH ·, O2- and H2O2) on cellular or organelle membranes phospholipids or polyunsaturated fatty acids (PUFA), and with the formation of various types of aldehydes, ketones, alkanes, carboxylic acids and polymerization products. It is an autoxidation process that results. These products are highly reactive with other cellular components and serve as biological markers of LPO. Malondialdehyde (MDA), a toxic aldehyde end product of LPO, causes structural changes that mediate its oxidation, such as fragmentation, modification, and aggregation, especially in DNA and protein. The excessive binding of these reactive aldehydes to cellular proteins alters membrane permeability and electrolyte balance. Degradation of proteins leads to progressive degradation of the biological system mediated by oxidative stress. The chain reaction (CR) of LPO is initiated by the attack of free radicals on the PUFA of the cell membrane to form a carbon centered radical (R*). The O2 · - radical attacks the other lipid molecule to form lipid hydroperoxide (ROOH), thereby spreading the CR and forming the lipid peroxyl radical (ROO). These lipid hydroperoxides severely inhibit membrane functionality by allowing ions such as increased hardness and calcium to leak through the membrane. Damage to the lipid membrane and macromolecule oxidation can result in activation of necrotic or apoptotic tissue death pathways if severe enough.

Effects of Enzymatic Activation of Bleaching Gels on Hydrogen Peroxide Degradation Rates, Bleaching Effectiveness, and Cytotoxicity

2019 ◽  
Vol 44 (4) ◽  
pp. 414-423 ◽  
Author(s):  
U Ortecho-Zuta ◽  
CC de Oliveira Duque ◽  
ML Leite ◽  
EAF Bordini ◽  
FG Basso ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Free Radicals ◽  
Free Radical ◽  
Membrane Damage ◽  
Positive Control ◽  
Degradation Rates ◽  
Enzymatic Activation ◽  
Negative Controls ◽  
Bleaching Gels ◽  
Harmful Effects

SUMMARY Objectives: The aim of this study was to evaluate the effect of horseradish peroxidase (HRP) on the release of free radicals, bleaching effectiveness, and indirect cytotoxicity of a 35% hydrogen peroxide (HP) bleaching gel. Methods and Materials: First, HP degradation rates and free radical release were evaluated for 35% HP in contact or not with HRP (10 mg/mL). The bleaching gel associated or not with HRP was then applied (3 × 15 minutes) to enamel/dentin discs adapted to artificial pulp chambers, and the culture medium in contact with dentin surfaces (extract) was collected and exposed to cultured odontoblast-like cells. Membrane damage and viability of cells as well as oxidative stress were evaluated. Residual HP/free radical diffusion was quantified, and bleaching effectiveness (ΔE) was assessed. Unbleached discs served as negative controls. Results: The addition of HRP to the 35% HP bleaching gel enhanced the release of free radicals in comparison with plain HP gel. The 35% HP-mediated cytotoxicity significantly decreased with HRP in the bleaching gel and was associated with reduced HP/free radical diffusion through the enamel/dentin discs. ΔE values increased every bleaching session for HRP-containing gel relative to positive control, accelerating the whitening outcome. Conclusion: The enzymatic activation of a 35% HP bleaching gel with HRP accelerated HP degradation mediated by intensification of free radical release. This effect optimized whitening outcome as well as minimized residual HP and free radical diffusion through enamel and dentin, decreasing the harmful effects on odontoblast-like cells.

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.

THE KINETICS OF THE THERMAL REACTIONS OF ETHYLENE OXIDE

1963 ◽  
Vol 41 (12) ◽  
pp. 2956-2961 ◽  
Author(s):  
M. Lynne Neufeld ◽  
Arthur T. Blades
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Ethylene Oxide ◽  
Thermal Reactions ◽  
Kinetics Of

The thermal reactions of ethylene oxide in the presence of an excess of propylene have been studied as a function of pressure and it has been found that there are two sets of products, acetaldehyde and free radicals, presumably methyl and formyl. These products are believed to arise from an excited acetaldehyde intermediate. Some evidence has been obtained for the occurrence of a surface-catalyzed rearrangement to acetaldehyde but the free radical products are uninfluenced by surface.

scholarly journals Mechanistic Insight into Antimicrobial and Antioxidant Potential of Jasminum Species: A Herbal Approach for Disease Management

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1089
Author(s):  
Acharya Balkrishna ◽  
Akansha Rohela ◽  
Abhishek Kumar ◽  
Ashwani Kumar ◽  
Vedpriya Arya ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Drug Resistance ◽  
Free Radicals ◽  
Free Radical ◽  
Microbial Pathogens ◽  
Free Radical Scavengers ◽  
Bioactive Constituents ◽  
Global Issues ◽  
Iridoid Glucosides ◽  
Insight Into

Drug resistance among microbial pathogens and oxidative stress caused by reactive oxygen species are two of the most challenging global issues. Firstly, drug-resistant pathogens cause several fatalities every year. Secondly aging and a variety of diseases, such as cardiovascular disease and cancer, are associated with free radical generated oxidative stress. The treatments currently available are limited, ineffective, or less efficient, so there is an immediate need to tackle these issues by looking for new therapies to resolve resistance and neutralize the harmful effects of free radicals. In the 21st century, the best way to save humans from them could be by using plants as well as their bioactive constituents. In this specific context, Jasminum is a major plant genus that is used in the Ayurvedic system of medicine to treat a variety of ailments. The information in this review was gathered from a variety of sources, including books, websites, and databases such as Science Direct, PubMed, and Google Scholar. In this review, a total of 14 species of Jasminum have been found to be efficient and effective against a wide variety of microbial pathogens. In addition, 14 species were found to be active free radical scavengers. The review is also focused on the disorders related to oxidative stress, and it was concluded that Jasminum grandiflorum and J. sambac normalized various parameters that were elevated by free radical generation. Alkaloids, flavonoids (rutoside), terpenes, phenols, and iridoid glucosides are among the main phytoconstituents found in various Jasminum species. Furthermore, this review also provides insight into the mechanistic basis of drug resistance, the generation of free radicals, and the role of Jasminum plants in combating resistance and neutralizing free radicals.

Mechanochemical Reactions Leading to Reinforcement in Rubbers

1960 ◽  
Vol 33 (4) ◽  
pp. 929-939
Author(s):  
R. J. Ceresa
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Covalent Bond ◽  
Vinyl Monomers ◽  
Research Association ◽  
Block Copolymerization ◽  
Wide Range ◽  
Carbon Gel ◽  
Internal Mixer ◽  
Mechanochemical Reactions

Abstract The development of the single rotor internal mixer (at the British Rubber Producers' Research Association) has facilitated the research into mechanochemical reactions of a wide range of high polymers. The term “mechanochemical” has been applied to reactions such as mastication, the mechanism of which involves the primary step of mechanical scission of a polymer chain into polymeric free radicals at a carbon to carbon or other covalent bond. The processes which have been studied previously include the cold mastication of rubberlike polymers, the formation of carbon gel, the interpolymerization of two elastomers during blending, and block copolymerization by the cold mastication of polymers plasticized by vinyl monomers. The evidence for the polymeric free radical nature of these reactions has recently been reviewed.

scholarly journals The Impact of O-Glycosylation on Cyanidin Interaction with POPC Membranes: Structure-Activity Relationship

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2771
Author(s):  
Sylwia Cyboran-Mikołajczyk ◽  
Piotr Jurkiewicz ◽  
Martin Hof ◽  
Halina Kleszczyńska
Keyword(s):  
Biological Activity ◽  
Free Radicals ◽  
Lipid Bilayer ◽  
Lipid Membrane ◽  
Lipid Vesicles ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Beneficial Effects ◽  
Structure Activity ◽  
The Impact

Cyanidin and its O-glycosides have many important physiological functions in plants and beneficial effects on human health. Their biological activity is not entirely clear and depends on the structure of the molecule, in particular, on the number and type of sugar substituents. Therefore, in this study the detailed structure-activity relationship (SARs) of the anthocyanins/anthocyanidins in relation to their interactions with lipid bilayer was determined. On the basis of their antioxidant activity and the changes induced by them in size and Zeta potential of lipid vesicles, and mobility and order of lipid acyl chains, the impact of the number and type of sugar substituents on the biological activity of the compounds was evaluated. The obtained results have shown, that 3-O-glycosylation changes the interaction of cyanidin with lipid bilayer entirely. The 3-O-glycosides containing a monosaccharide induces greater changes in physical properties of the lipid membrane than those containing disaccharides. The presence of additional sugar significantly reduces glycoside interaction with model lipid membrane. Furthermore, O-glycosylation alters the ability of cyanidin to scavenge free radicals. This alteration depends on the type of free radicals and the sensitivity of the method used for their determination.

Oxygen free radical-mediated selective endothelial dysfunction in isolated coronary artery

1992 ◽  
Vol 262 (3) ◽  
pp. H806-H812 ◽  
Author(s):  
K. Todoki ◽  
E. Okabe ◽  
T. Kiyose ◽  
T. Sekishita ◽  
H. Ito
Keyword(s):  
Lipid Peroxidation ◽  
Superoxide Dismutase ◽  
Free Radicals ◽  
Free Radical ◽  
Coronary Artery ◽  
Iron Chelator ◽  
Oxygen Free Radical ◽  
Alpha Tocopherol ◽  
Endothelium Dependent Relaxation ◽  
Iron Chelator Deferoxamine

To understand the direct involvement of free radicals causing reduction in endothelium-dependent relaxation of isolated canine coronary ring preparations, this study was undertaken to examine the effect of free radicals generated from dihydroxy fumarate (DHF) plus Fe(3+)-ADP or from H2O2 plus FeSO4. The vasodilators (acetylcholine, bradykinin, A23187, and nitroglycerin) were given after DHF/Fe(3+)-ADP or H2O2/FeSO4 was removed from the organ chamber. The earlier DHF/Fe(3+)-ADP exposure produced an attenuation of the relaxation of the rings induced by acetylcholine, bradykinin, or A23187 but not of the relaxation induced by nitroglycerin. The observed effect of previous DHF/Fe(3+)-ADP exposure was significantly protected in the vessels isolated from the dogs treated with alpha-tocopherol. In the experiments for assessing the effect of various scavengers, 1O2 scavenger histidine or iron chelator deferoxamine effectively protected the attenuation induced by DHF/Fe(3+)-ADP exposure of the relaxation elicited by acetylcholine; superoxide dismutase (SOD), catalase, or dimethyl sulfoxide (DMSO) had no effect on this system. Furthermore, the relaxation elicited by acetylcholine, but not nitroglycerin, was significantly attenuated by the earlier exposure to .OH generated by Fenton's reagent (H2O2+FeSO4); the attenuation was significantly protected by DMSO. These results are consistent with the view that .OH, 1O2, and/or iron-dependent reactive species selectively damage endothelium-dependent relaxation as opposed to endothelium-independent relaxation in endothelium-intact coronary ring preparations. It is also postulated that lipid peroxidation may be responsible for this effect.

Sign in / Sign up

Export Citation Format

Share Document