scholarly journals Complexity of free radical Metabolism in human Erythrocytes

2010 ◽  
Vol 29 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Aleksandra Nikolić-Kokić ◽  
Duško Blagojević ◽  
Mihajlo Spasić
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Superoxide Anion ◽  
Anion Radical ◽  
De Novo ◽  
Human Erythrocytes ◽  
Low Molecular Weight ◽  
Valuable Data ◽  
Vitamins E And C ◽  
Free Radical Metabolism

Complexity of free radical Metabolism in human ErythrocytesThe auto-oxidation of oxyhaemoglobin to methaemoglobin generating superoxide anion radical (O2.-) represents the main source of free radicals in the erythro-cytes. Hydrogen peroxide is produced by O2.-dismutation or originates from the circulation. Human erythrocytes are also exposed to the prooxidative actions of nitric oxide (NO) from circulation. Free radicals that may induce reactions with direct dangerous consequences to erythrocytes are also preceded by the reaction of O2.-and NO producing peroxynitrite. In physiological settings, erythrocytes show a self-sustaining activity of antioxidative defence (AD) enzymes, such as: superoxide dismutase (SOD, EC 1.11.16), catalase (CAT, EC 1.11.1.6), glutathione peroxidase (GSHPx, EC 1.11.1.9) and glutathione reductase (GR, EC 1.6.4.2), as well as low molecular weight antioxidants: glutathione and vitamins E and C. Their coordinate actions protect the erythrocyte's bio-macromolecules from free radical-mediated damage. Since there is node novosynthesis of AD enzymes in mature erythrocytes, their defence capacity is limited. Free radicals influence antioxidative enzymes capacities and relative share of particular components in the whole antioxidative system. Therefore, by measuring changes in the activity of individual AD components, as well as their interrelations by statistical canonical discriminant methods, valuable data about the complexity, overall relations and coordinated actions in the AD system in erythrocytes and its relevance for systemic effects can be acquired.

Antioxidant and ROS inhibitory activities of heterocyclic 2-Aryl-4(3H)-quinazolinone derivatives

2021 ◽  
Vol 18 ◽  
Author(s):  
Shahida Perveen ◽  
Syed Muhammad Saad ◽  
Khalid Mohammed Khan ◽  
Muhammad Iqbal Choudhary
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Free Radicals ◽  
Cell Line ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Radical Scavenging ◽  
Superoxide Anion Radical ◽  
Inhibitory Activities ◽  
Quinazolinone Derivatives

Background: Antioxidants are small molecules that prevent or delay the process of oxidations caused by highly reactive free radicals. These molecules are known for their ability to protect various cellular architecture and other biomolecules from oxidative stress and free radicals. Thus, antioxidants play a key role in the prevention of oxidative damages caused by highly reactive free radicals. Method: In the present study, a series of previously synthesized heterocyclic 2-aryl-4(3H)-quinazolinone derivatives 1-25 was screened for antioxidant activity by employing in vitro DPPH and superoxide anion radical scavenging activities. ROS inhibitory activities were also evaluated by serum-opsonized zymosan activated whole blood phagocytes and isolated neutrophils. Cytotoxicity studies were carried out by employing an MTT assay against the 3T3 cell line. Results: Most of the 2-aryl-4(3H)-quinazolinone derivatives showed potent antioxidant activities in superoxide anion radical scavenging assay with IC50 value ranging between 0.57 µM – 48.93 µM, as compared to positive control quercetin dihydrate (IC50 = 94.1± 1.1 µM ). Compounds 5, 6, and 14 showed excellent activity in DPPH assay. Compounds 5-8, 12-15, 17, and 20 showed promising activities in the ROS inhibition assay. All compounds were found to be non-cytotoxic against the 3T3 cell line. Structure antioxidant activity has been established. Conclusion: It can be concluded that most of the heterocyclic 2-aryl-4(3H)-quinazolinone derivatives 1-25 are identified as promising antioxidant agents that are capable of fighting against free radicals and oxidative stress. Thus, they can serve as a lead towards treating oxidative stress and related pathologies.

Study on Scavenging Free Radical Activity with Polysaccharides Materials in Chuanxiong Based on Composite Properties of Biomaterials

2012 ◽  
Vol 583 ◽  
pp. 244-247
Author(s):  
Yong Guang Bi ◽  
Chun Chun Liu
Keyword(s):  
Free Radical ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Superoxide Anion Radical ◽  
Dose Effect ◽  
Spectrophotometric Detection ◽  
Free Radical Activity ◽  
Composite Properties

By using spectrophotometric detection of the Chuanxiong polysaccharides on the free radical scavenging. The results show that the Chuanxiong polysaccharides on DPPH radical, hydroxyl radical (HO•) and superoxide anion radical (•) clearance. Scavenging ability with the the Chuanxiong polysaccharide concentration increased, and showed the dose-effect relationship. Concentration of 2.0mg/mL when DPPH radicals clear the rate of 35.61%, while the rate of hydroxyl radicals and superoxide anion radical scavenging, clear the rate of 57.78% and 57.14%. Chuanxiong polysaccharide is an ideal natural antioxidants and good prospects for the development of biomedical composites.

Extraction of Polyphenols from Porphyra and Scavenging Activity of Oxygen Free Radicals

2013 ◽  
Vol 864-867 ◽  
pp. 531-535
Author(s):  
Ying Chang Li ◽  
Xiao Zhang ◽  
Jian Rong Li
Keyword(s):  
Free Radicals ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Oxygen Free Radicals ◽  
Ethanol Concentration ◽  
Industrial Process ◽  
Superoxide Anion Radical ◽  
Process Conditions ◽  
Extraction Temperature

Polyphenols from Porphyra are important biological active substances. The effects of temperature, times, ethanol concentration and liquid to solid ratio were studied for the extraction yield of polyphenols from Porphyra through a single-factor exploration.Then, through an orthogonal experiment, it was investigated to get the best extraction conditions. The content of polyphenols was determined by Folin-Ciocalteu method. Scavenging ability to oxygen free radicals was also assessed. The results show that extraction temperature is 75°C, the extraction time is 2.5 h, ethanol concentration is 70% and the ratio of liquid to solid is 25:1(mL/g).The proportion of the extraction of the polyphenols from Porphyra under these industrial process conditions is 6.263mg/g. Polyphenols from Porphyra have strong scavenging hydroxyl radical and superoxide anion radical. IC50 of polyphenols from Porphyra on hydroxyl radical and superoxide anion radical is 0.405 mg/mL, 0.539mg/mL, respectively.

Study on Antioxidant Activity of Dihydromyricetin-Zinc(II) Complex

2011 ◽  
Vol 183-185 ◽  
pp. 863-867 ◽  
Author(s):  
Chun Wu ◽  
Xin Ping Zheng ◽  
Lin Lin Chen
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Free Radical Scavenger ◽  
Superoxide Anion Radical ◽  
Radical Scavenger ◽  
Scavenging Activity ◽  
Dpph Radical

Dihydromyricetin-zinc(II) complex was synthesized. The scavenging activity of DPPH radical, hydroxyl radical, superoxide anion radical and alkane radical by dihydromyricetin-zinc(II) complex were determine, moreover compared with Vc. The results showed that dihydromyricetin-zinc(II) complex possessed strong scavenging activities on DPPH•, hydroxyl radical, superoxide anion radical and alkane radical with correspounding maximum scavenging rate 74%, 70% , 65% and 50% at the concentration from 0.1 mmol/L to 0.5 mmol/L, respectively, which were higher than Vc. These results suggested that dihydromyricetin-zinc(II) complex would be an effective free radical scavenger.

scholarly journals Exploration of Antioxidant and Anticancer Activity of Stephania japonica Leaves Extract

2021 ◽  
pp. 256-272
Author(s):  
Md. Dobirul Islam ◽  
Ariful Islam ◽  
Naoshia Tasnin ◽  
Syeda Farida Akter ◽  
Md. Salim Uddin
Keyword(s):  
Free Radical ◽  
Cell Growth ◽  
Anticancer Activity ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Cell Growth Inhibition

Aims: The demand for antioxidants from the natural source has drawn promising attention to outturn desired pharmacological effect by subsidizing the adverse effect for treating cancer. This study evaluated the antioxidant activity of Stephania japonica leaves extracts to explore the anticancer activity.    Methods: Antioxidant potential of crude extracts were evaluated using various methods which include total antioxidant activity, ferric reducing antioxidant assay, DPPH free radical, ABTS free radical, nitric oxide and superoxide anion radical scavenging assay. Anticancer activity was determined in vitro by MTT assay and in vivo on mice against Ehrlich ascites carcinoma (EAC) cell. Results: Phytoconstituents with free radical scavenging capacity were quantified in terms of inhibitory concentration (IC50) with the values of 17.00±3.22 µg/mL, 33.30 ± 5.45 µg/mL, 43.70±5.26 µg/mL and 52.30±1.07 µg/mL in DPPH, ABTS, superoxide anion radical and nitric oxide free radical scavenging assay, respectively as the highest quencher, acetone extract of S. japonica leaves (ASJL). ASJL and methanol extract (MSJL) showed low lethal dose (LD50) values of 21.76 and 26.63, respectively indicating higher toxicity.  In vitro anti-proliferative activity (MTT assay), ASJL and MSJL were exhibited 15.44±2.96 to 80.94±2.87 and 11.76±3.74 to 74.25±1.49 percent of cell growth inhibition, respectively at the concentration of 10.28 µg/mL to 833.33 µg/mL. In in vivo test, ASJL and MSJL at the dose of 100 mg/kg/day and 200 mg/kg/day (i.p.) showed cell growth inhibition of 58.25±4.24% to 79.09±2.45% and 46.26±2.68% to 61.74±4.41%, respectively on EAC cell tumor-bearing mice. The life span of intraperitoneal induced EAC cell bearing mice was increased to 29.05% and 57.02% on the treatment of ASJL with 100 and 200 mg/kg/day, respectively. Conclusions: The free radical scavenger of S. japonica leaves extract was stimulated the host immunity and inhibited the EAC cell growth through initiating the apoptosis cell death program. Therefore, S. japonica leaves might be utilized as a potent anticancer natural source.

scholarly journals Non-Enzymatic Methylglyoxal Formation From glucose Metabolites and Generation of Superoxide Anion Radical During Methylglyoxal-Dependent Cross-Links Reaction

2019 ◽  
Vol 1 (4) ◽  
pp. 33-45 ◽  
Author(s):  
V.Z. Lankin ◽  
O.I. Shadyro ◽  
K.B. Shumaev ◽  
K.B. Shumaev ◽  
A.K. Tikhaze ◽  
...  
Keyword(s):  
Free Radicals ◽  
Superoxide Anion ◽  
High Performance ◽  
Anion Radical ◽  
Reaction Medium ◽  
Cation Radical ◽  
Superoxide Anion Radical ◽  
Hypoxic Conditions ◽  
Fructose 1,6 Bisphosphate ◽  
Glucose Metabolites

The paper explores the formation of a-oxoaldehydes during the interaction of glucose metabolites with hydroxyl or alkoxyl radicals. Hydroxyl radicals were generated under radiolysis of aqueous solutions, and alkoxyl radicals (t-BuO) were obtained in the model system tert-butyl hydroperoxide/Fe2+. High-performance liquid chromatography revealed that methylglyoxal was one of the organic products resulting from t-BuO-induced transformations of fructose-1,6-bisphosphate under hypoxic conditions. The interaction of lysine and methylglyoxal one of the main targets of a-oxoaldehydes in proteins was also studied. As chemiluminescence and EPR spectroscopy demonstrated, this reaction generates a methylglyoxal anion radical, a cation-radical of methylglyoxal dialkylamine and a superoxide anion radical. EPR signal of methylglyoxal-derived free radicals was observed in hypoxia, whereas only the trace amounts of these free radicals were recorded in the aerated reaction medium.

Researches on the Structure and Antioxidant Activity of Apigenin-La (III) Complex

2013 ◽  
Vol 781-784 ◽  
pp. 1138-1143
Author(s):  
Feng Qiu Wen ◽  
Lang Sheng Pan ◽  
Lei Lei
Keyword(s):  
Thermal Analysis ◽  
Antioxidant Activity ◽  
Free Radicals ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Superoxide Anion Radical ◽  
Scavenging Activity ◽  
Scavenging Effect ◽  
Pyrogallic Acid ◽  
Better Than

La (III) complex with apigenin was synthesized and characterized by UV, IR, 1HNMR and thermal analysis. The scavenging activity of the complex on superoxide anion radical (O2-·) and hdroxyl radical (·OH) was also investigated by improved pyrogallic acid way and ortho-oxybenzoic acid way. The results show that the complex had remarkable scavenging effects on O2-· and ·OH, and its scavenging effect on free radicals was better than apigenin.

scholarly journals DETERMINATION OF ANTIOXIDANT POTENTIAL OF SUBSTANCES OF DIFFERENT NATURE IN THE SYSTEM GENERATING SUPEROXIDE ANION RADICAL USING THE METHOD OF MATHEMATICAL MODELING

2020 ◽  
pp. 79-87
Author(s):  
Лариса Тихоновна Рязанцева ◽  
Валерий Павлович Октябрьский
Keyword(s):  
Mathematical Modeling ◽  
Antioxidant Activity ◽  
Free Radical ◽  
Rate Constant ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Kinetics Of ◽  
Superoxide Anion Radicals ◽  
Single Reaction

С использованием метода математического моделирования кинетики люминолзависимой хемилюминесценции изучено действие некоторых антиоксидантов (АО) на реакцию окисления люминола супероксидными анион-радикалами, образующимися в системе ТЕМЭД-рибофлавин. Установлено, что для описания вклада антиоксидантов в изменение кинетики люминолзависимой хемилюминесценции (ХЛ) достаточно использовать единственную реакцию взаимодействия антиоксиданта со свободным радикалом. Предложено использование константы скорости этой реакции в качестве меры «антиоксидантной активности». Using the method of mathematical modeling of the kinetics of luminol-dependent chemiluminescence, the effect of certain antioxidants on the reaction of oxidation of luminol by superoxide anion radicals formed in the TEMED-Riboflavin system was studied. It was found that to describe the contribution of antioxidants to the change in the kinetics of luminol-dependent chemiluminescence (ChL), it is sufficient to use a single reaction of the interaction of an antioxidant (AO) with a free radical. It is proposed to use the rate constant of this reaction as a measure of «antioxidant activity».

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