Journal ArticleDOI
Antioxidant activities of some extracts of Thymus zygis
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TLDR
There is a relationship between antioxidant potency and the total phenolic groups content in each extract, and Methanolic extracts are more potent as scavengers of peroxyl and superoxide radicals than the ethyl ether extracts.Abstract:
The antioxidant activities of methanol and ethyl ether extracts obtained from Thymus zygis, collected during the flowering or non-flowering period, were evaluated and compared. To investigate this potential, extracts were tested on their capacity to react with diphenylpicrylhydrazyl (DPPH) in a homogeneous medium, and to inhibit Fe2+/ascorbate-induced membrane lipid peroxidation, as estimated by the formation of thiobarbituric acid-reactive substances (TBARS). Although methanol extracts reduce DPPH radicals more efficiently than ethyl ether extracts, suggesting a potent radical scavenger activity, the ethyl ether extracts were found to be most active in inhibiting lipid peroxidation in sarcoplasmic reticulum (SR) membranes. In addition, both extracts present peroxyl and superoxide radical scavenging activities. Peroxyl radicals were generated by the water soluble 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) azoinitiator, and the scavenging activities of the extracts were measured by the inhibition of cis-parinaric acid (PnA) fluorescence decay in SR. Superoxide radicals were generated either by an enzymatic or a non-enzymatic system, and the scavenger ability was evaluated by the inhibition of nitroblue tetrazolium reduction. Methanolic extracts are more potent as scavengers of peroxyl and superoxide radicals than the ethyl ether extracts. Apparently, there is a relationship between antioxidant potency and the total phenolic groups content in each extract.read more
Citations
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Journal ArticleDOI
Antioxidant and radical scavenging properties of curcumin.
Tuba Ak,İlhami Gülçin +1 more
TL;DR: The antioxidant activity of curcumin was determined by employing various in vitro antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH*) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, N,N-dimethyl-p-phenylenediamine dihydrochloride
Journal ArticleDOI
Antioxidant activity of food constituents: an overview
TL;DR: The most commonly methods used in vitro determination of antioxidant capacity of food constituents are reviewed and presented, and the general chemistry underlying the assays in the present paper was clarified.
Journal ArticleDOI
HPLC method for evaluation of the free radical-scavenging activity of foods by using 1,1-diphenyl-2-picrylhydrazyl
TL;DR: An HPLC method using 1,1-diphenyl-2-picrylhydrazyl (DPPH) determined the free radical-scavenging activity of several antioxidants: ascorbic acid, alpha-tocopherol, Trolox, and cysteine, and the results well agree with those of previous reports.
Journal ArticleDOI
In vitro antioxidant activities of methanol extracts of five Phyllanthus species from India
TL;DR: In this paper, the antioxidant activity of methanol extracts of five plants from the genus Phyllanthus was evaluated by various antioxidant assays, including total antioxidant, free radical scavenging, superoxide anion radical scavenges, hydrogen peroxide scavenging and reducing power and metal ion chelating activities.
Journal ArticleDOI
Determination of in vitro antioxidant activity of fennel (Foeniculum vulgare) seed extracts
TL;DR: In this article, the antioxidant activity of water and ethanol extracts of fennel (Foeniculum vulgare) seed (FS) was evaluated by various antioxidant assay, including total antioxidant, free radical scavenging, superoxide anion radical scavenges, hydrogen peroxide scavenging and metal chelating activities.
References
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Book ChapterDOI
Microsomal lipid peroxidation.
John A. Buege,Steven D. Aust +1 more
TL;DR: This chapter discusses microsomal lipid peroxidation, a complex process known to occur in both plants and animals that involves the formation and propagation of lipid radicals, the uptake of oxygen, a rearrangement of the double bonds in unsaturated lipids, and the eventual destruction of membrane lipids.
Journal ArticleDOI
Antioxidant Determinations by the Use of a Stable Free Radical
TL;DR: In this paper, the chemical nature of the antioxidant is known and a test specific for the compound or group of interest; for example, the nitroprusside test for sulphydryl groups.
Journal ArticleDOI
Malondialdehyde and thiobarbituric acid-reactivity as diagnostic indices of lipid peroxidation and peroxidative tissue injury.
TL;DR: The conclusion is reached that MDA determination and the TBA test can offer, at best, a narrow and somewhat empirical window on the complex process of lipid peroxidation.
Journal ArticleDOI
Action of Phenolic Derivatives (Acetaminophen, Salicylate, and 5-Aminosalicylate) as Inhibitors of Membrane Lipid Peroxidation and as Peroxyl Radical Scavengers
TL;DR: 5-Aminosalicylate reacts promptly with DPPH, suggesting a potent radical scavenger activity and was found to be the most active in inhibiting Fe2+/ascorbate-induced lipid peroxidation, suggesting an antioxidant activity of chain-breaking type.
Journal ArticleDOI
The relative antioxidant activities of plant-derived polyphenolic flavonoids
TL;DR: The relative antioxidant activities, against radicals generated in the aqueous phase, of a range of plant-derived polyphenolic flavonoids, constituents of fruit, vegetables, tea and wine, have been assessed and compounds such as quercetin and cyanidin have antioxidant potentials four times that of Trolox, the vitamin E analogue.