linoleic-acid and ferric-thiocyanate

Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Biphenyl Compounds; Chromatography, Gel; Egg Proteins; Free Radical Scavengers; Hydrogen Peroxide; Hydrolysis; Hydroxyl Radical; Iron; Linoleic Acid; Oxidation-Reduction; Pancreatin; Pepsin A; Peptidyl-Dipeptidase A; Picrates; Proteolysis; Sequence Analysis, Protein; Superoxides; Thiobarbituric Acid Reactive Substances; Thiocyanates

Ellagic acid (EA, C14H6O8) is a natural dietary polyphenol whose benefits in a variety of diseases shown in epidemiological and experimental studies involve anti-inflammation, anti-proliferation, anti-angiogenesis, anticarcinogenesis and anti-oxidation properties. In vitro radical scavenging and antioxidant capacity of EA were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. EA inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-tocopherol and ascorbic acid displayed 69.8%, 66.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, EA had an effective DPPH• scavenging, ABTS+ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that EA can be used in the pharmacological, food industry and medicine because of these properties.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxyanisole; Butylated Hydroxytoluene; Chelating Agents; Ellagic Acid; Emulsions; Free Radical Scavengers; Free Radicals; Hydrogen Peroxide; Iron; Linoleic Acid; Lipids; Oxygen; Picrates; Spectrophotometry; Superoxides; Thiocyanates; Time Factors

Literature data are scarce on the activities of analogous pairs of hydrophilic and lipophilic antioxidants related to the 'polar paradox' distinguishing antioxidants based on their partitioning between lipids and water. The peroxidation of linoleic acid (LA) in the presence of either Cu(II) ions alone or Cu(II) ions combined with Trolox (TR), ascorbic acid (AA), hydroquinone (HQ) and gallic acid (GA), as hydrophilic antioxidants, or with α-tocopherol (TocH), ascorbyl palmitate (AP), tert-butyl hydroquinone (TBHQ) and propyl gallate (PG), as their respective lipophilic analogues, was investigated in aerated and incubated emulsions at 37 °C and pH 7.. LA peroxidation induced by Cu(II) followed pseudo-first-order kinetics with respect to the formation of primary (hydroperoxides) and secondary (aldehyde- and ketone-like) oxidation products, which were determined by ferric thiocyanate (Fe(III)-SCN) and thiobarbituric acid-reactive substances (TBARS) methods respectively. With the exception of TocH at certain concentrations, the tested compounds showed antioxidant behaviour depending on their polarities. The results were evaluated in the light of structure-activity relationships and the polar paradox.. The results of this study partly confirm the hypothesis that the polar paradox experiences limitations in oil-in-water emulsions and that its validity is also dependent on the concentrations of the antioxidants employed.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Chromans; Copper; Emulsions; Gallic Acid; Hydrophobic and Hydrophilic Interactions; Hydroquinones; Iron; Kinetics; Linoleic Acid; Lipid Peroxidation; Peroxides; Propyl Gallate; Structure-Activity Relationship; Thiobarbituric Acid Reactive Substances; Thiocyanates

The purpose of this study was to evaluate the antioxidative activities of water and 70% ethanolic extracts from the Thymus quinquecostatus Celak (TQC) for natural antioxidant source. The antioxidant activities were compared with other natural and synthetic antioxidants. The levels of total polyphenols and flavonoids were also determined. The extracts were found to have different levels of antioxidant properties in a few kind of assay. The results showed that higher radical scavenging activity, reducing power and antioxidant capacity in FRAP than those of BHT as a positive control. In addition, the extracts from the TQC leaf and stem showed stronger antioxidant activity than that of vitamin C, α-tocopherol in ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. Cytoprotective and anti-apoptotic effect of water extracts from TQC was also prevented t-BHP-induced toxicity in Chang liver cells. Therefore, these results indicate that TQC extracts have antioxidant properties through its ability to enhance the cell viability, reduction of production of ROS, inhibition of oxidative damage, mitochondria dysfunction and ultimately inhibition of cell apoptosis. Based on the results described above, it is suggested that TQC has the potential to protect liver on t-BHP-induced cell damage and should be considered as a prospective functional food.

Topics: alpha-Tocopherol; Antioxidants; Apoptosis; Benzothiazoles; Biphenyl Compounds; Cell Cycle; Cells, Cultured; Drug Evaluation, Preclinical; Flavonoids; Free Radical Scavengers; Humans; Iron; Linoleic Acid; Lipid Peroxidation; Membrane Potential, Mitochondrial; Picrates; Plant Extracts; Plant Leaves; Polyphenols; Reactive Oxygen Species; Sulfonic Acids; tert-Butylhydroperoxide; Thiazoles; Thiocyanates; Thymus Plant

The antioxidant properties of plants have been investigated, in the light of recent scientific developments, throughout the world due to their potent pharmacological activities and food viability. Basil (Ocimum basilicum L. Family Lamiaceae) is used as a kitchen herb and as an ornamental plant in house gardens. In the present study, the possible radical scavenging and antioxidant activity of the water (WEB) and ethanol extracts (EEB) of basil was investigated using different antioxidant methodologies: 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, scavenging of superoxide anion radical-generated non-enzymatic system, ferric thiocyanate method, reducing power, hydrogen peroxide scavenging and metal chelating activities. Experiments revealed that WEB and EEB have an antioxidant effects which are concentration-dependent. The total antioxidant activity was performed according to the ferric thiocyanate method. At the 50 microg/mL concentration, the inhibition effects of WEB and EEB on peroxidation of linoleic acid emulsion were found to be 94.8% and 97.5%, respectively. On the other hand, the percentage inhibition of a 50 microg/mL concentration of BHA, BHT and alpha-tocopherol was found to be 97.1%, 98.5% and 70.4% inhibition of peroxidation of linoleic acid emulsion, respectively. In addition, WEB and EEB had effective DPPH radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, reducing power and metal chelating activities. Additionally, these various antioxidant activities were compared with BHA, BHT and alpha-tocopherol as reference antioxidants. The additional total phenolic content of these basil extracts was determined as the gallic acid equivalent and were found to be equivalent.

Topics: Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Hydrogen Peroxide; Iron; Iron Chelating Agents; Linoleic Acid; Ocimum basilicum; Oxidation-Reduction; Picrates; Plant Extracts; Superoxides; Thiocyanates

In this study, di(2,6-dimethylphenol) (Di-DMP), di(2,6-diisopropylphenol) (Di-DIP, dipropofol) and di(2,6-di-t-butylphenol) (Di-DTP) were synthesized by the reaction of monomeric phenol derivatives with catalytic CuCl(OH). TMEDA and Na2S2O4. Their antioxidant capacity and radical scavenging activity were examined using different in vitro methodologies such as 1,1-diphenyl-2-picryl-hydrazyl (DPPH*) free radical scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity by ferric thiocyanate, total reducing power by potassium ferricyanide reduction method, superoxide anion radical scavenging, hydrogen peroxide scavenging and ferrous ions chelating activities.

Topics: Antioxidants; Chelating Agents; Dimerization; Emulsions; Free Radical Scavengers; Hydrogen Peroxide; Iron; Linoleic Acid; Molecular Structure; Oxidation-Reduction; Phenol; Thiocyanates

Caffeic acid (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids present in wine; sinapic acid, which is a potent antioxidant. It has also been identified as one of the active antioxidant. In the present study, the antioxidant properties of the caffeic acid were evaluated by using different in vitro antioxidant assays such as 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, total antioxidant activity by ferric thiocyanate method, total reductive capability using the potassium ferricyanide reduction method, superoxide anion radical scavenging and metal chelating activities. alpha-Tocopherol, trolox, a water-soluble analogue of tocopherol, butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) were used as the reference antioxidant compounds. At the concentrations of 10 and 30 microg/mL, caffeic acid showed 68.2 and 75.8% inhibition on lipid peroxidation of linoleic acid emulsion, respectively. On the other hand, 20 microg/mL of standard antioxidant such as BHA, BHT, alpha-tocopherol and trolox indicated an inhibition of 74.4, 71.2, 54.7 and 20.1% on peroxidation of linoleic acid emulsion, respectively. In addition, caffeic acid is an effective ABTS(+) scavenging, DPPH scavenging, superoxide anion radical scavenging, total reducing power and metal chelating on ferrous ions activities.

Topics: alpha-Tocopherol; Antioxidants; Benzothiazoles; Biphenyl Compounds; Butylated Hydroxyanisole; Butylated Hydroxytoluene; Caffeic Acids; Chelating Agents; Chromans; Dose-Response Relationship, Drug; Emulsions; Ferricyanides; Ferrous Compounds; Free Radical Scavengers; Hydrazines; Iron; Linoleic Acid; Lipid Peroxidation; Picrates; Reducing Agents; Sulfonic Acids; Superoxides; Thiocyanates

Propofol (2,6-diisopropylphenol) is a hypnotic intravenous agent with in vivo antioxidant properties. This study was undertaken to examine the in vitro antioxidant activity of propofol using different antioxidant tests including by 1,1-diphenyl-2-picryl-hydrazil (DPPH.) radical scavenging, metal chelating, hydrogen peroxide scavenging, superoxide anion radical scavenging, reducing power and total antioxidant activities. At the concentrations of 25, 50, and 75 microg/ml, propofol exhibited 97.7, 98.6 and 100% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, at the 75 microg/ml concentration of standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and alpha-tocopherol exhibited 88.7, 94.5, and 70.4% inhibition on peroxidation of linoleic acid emulsion, respectively. In addition, at same concentrations, propofol was shown that it had effective reducing power, DPPH. free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities. These various antioxidant activities were compared to standard antioxidants such as BHA, BHT and alpha-tocopherol. These results indicate that propofol prevents lipid peroxidation and radicalic chain reactions. At the same time, propofol revealed more effective antioxidant capacity than BHA, BHT and alpha-tocopherol.

Topics: Antioxidants; Free Radical Scavengers; Free Radicals; Iron; Iron Chelating Agents; Linoleic Acid; Oxidation-Reduction; Propofol; Thiocyanates

The (-)-(1S, 3S) isomer of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid was synthesised by Pictet-Spengler condensation of tryptophan with acetaldehyde. It was evaluated for its antioxidative activity in the linoleic acid autooxidation system by the ferric thiocynate method. Butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), and alpha-tocopherol were used as the reference standards. The compound showed moderate antioxidative activity and also synergistic effect with the reference standards. The synergistic effect was in the increasing order of BHT, alpha-tocopherol and BHA. The synergistic effect was higher at higher concentrations studied.

Topics: Antioxidants; Butylated Hydroxyanisole; Butylated Hydroxytoluene; Carbolines; Indicators and Reagents; Iron; Linoleic Acid; Thiocyanates