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Showing papers on "DPPH published in 2008"


Journal ArticleDOI
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

1,464 citations


Journal ArticleDOI
TL;DR: The essential oils investigated, exhibited good antioxidant activity as measurements by DPPH free radical-scavenging ability, bleaching β-carotene in linoleic acid system and inhibition of linolesic acid oxidation, as seasons changed.

958 citations


Journal ArticleDOI
TL;DR: The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy.
Abstract: Purpose : Oxidative stress has been shown to play an important role in the development of anaemia in malaria. Indeed, increase in total antioxidant status has been shown to be important in recovery from malaria. The antioxidant activities of four medicinal plants traditionally used in the treatment of malaria in southwestern Nigeria were determined. Methods : The ethanolic extracts of the leaves of Carica papaya Linn. [Caricaceae] , stem bark of Magnifera indica Linn. [Anacardiaceae], leaves of Psidium guajava Linn. [Myrtaceae] and the leaves of Vernonia amygdalina Del. [Compositae], were used in the present study. The plant parts commonly used in the locality in malaria therapy were employed in this study. The plants were screened for the presence of phytochemicals and, their effect on 2,2-Diphenyl-1-picryl-hydrazyl radical (DPPH) was used to determine their free radical scavenging activity. Results : Phytochemical screening of the plants showed the presence of flavonoids, terpenoids, saponins, tannins and reducing sugars. M. indica did not contain cardiac glycosides and alkaloids while, P. guajava also showed the absence of alkaloids and anthraquinones. Anthraquinones was similarly absent from V. amygdalina. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC 50 ) were recorded as 0.04 mg/ml, 0.313 mg/ml, 0.58 mg/ml, 2.30 mg/ml and 0.054 mg/ml for P. guajava, M. Indica, C. papaya, V. amygdalina and Vitamin C, respectively. Conclusion : All the plants showed potent inhibition of DPPH radical scavenging activity, P. guajava being the most potent. The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy.

732 citations


Journal ArticleDOI
TL;DR: Several of the most commonly used methods for in vitro determination of antioxidant capacity are reviewed and the advantages and shortcomings of each method are highlighted.

666 citations


Journal ArticleDOI
TL;DR: Rosemary extract was found to have a higher phenolic content than blackseed essential oil, which was utilised in explaining the higher antioxidant activity of rosemary extract.

661 citations


Journal ArticleDOI
Yanhong Li1, Bo Jiang1, Tao Zhang1, Wanmeng Mu1, Jian Liu1 
TL;DR: In this paper, chicken protein hydrolysate (CPH) was fractionated by gel filtration on Sephadex G-25 and the antioxidant and free radical-scavenging activities of four CPH fractions were measured using reducing power, inhibition of linoleic acid autoxidation, and 1,1-diphenyl-2- pycrylhydrazyl (DPPH)/superoxide/hydroxyl radical scavenging assay.

658 citations


Journal ArticleDOI
TL;DR: In this article, Andean blackberry, capuli cherry peel and banana passion fruit were analysed for total soluble phenolic compounds content and for antioxidant capacity, using three different methods (DPPH, FRAP and ABTS + ).

634 citations


Journal ArticleDOI
TL;DR: Although in vitro antioxidant potency does not prove in vivo biological activity, there is also consistent clinical evidence of antioxidant potency for the most potent beverages including both PJ and red wine.
Abstract: A number of different beverage products claim to have antioxidant potency due to their perceived high content of polyphenols. Basic and applied research indicates that pomegranate juice (PJ), produced from the Wonderful variety of Punica granatum fruits, has strong antioxidant activity and related health benefits. Although consumers are familiar with the concept of free radicals and antioxidants, they are often misled by claims of superior antioxidant activity of different beverages, which are usually based only on testing of a limited spectrum of antioxidant activities. There is no available direct comparison of PJ’s antioxidant activity to those of other widely available polyphenol-rich beverage products using a comprehensive variety of antioxidant tests. The present study applied (1) four tests of antioxidant potency [Trolox equivalent antioxidant capacity (TEAC), total oxygen radical absorbance capacity (ORAC), free radical scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reduci...

631 citations


Journal ArticleDOI
TL;DR: In this article, an updated methodology to determine the antioxidant capacity in plant foods, oils and beverages is presented, including extraction of antioxidants, measurement of antioxidant capacity, and expression of results.

609 citations


Journal ArticleDOI
TL;DR: In this paper, the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavengence assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavengent assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source.
Abstract: Much work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. We analysed the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavenging assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source. Total antioxidant capacity was determined by the assay based on the decrease in absorbance of β-carotene by the sample. Rutin exhibited strong DPPH radical scavenging activity. At the concentration of 0.05 mg/ml, ascorbic acid (Vc), butylated hydroxytoluene (BHT) and rutin showed 92.8%, 58.8%, and 90.4% inhibition, respectively. In addition, rutin had effective inhibition of lipid peroxidation. Those various antioxidant activities were compared to standard antioxidants such as BHT and Vc.

552 citations


Journal ArticleDOI
Yi Chen1, Mingyong Xie1, Shaoping Nie1, Chang Li1, Yuanxing Wang1 
TL;DR: A water-soluble protein-bound polysaccharide was extracted from the fruiting bodies of Ganoderma atrum and isolated by gel-filtration chromatography as mentioned in this paper.

Journal ArticleDOI
TL;DR: Antioxidant potential was dependent of honey extract concentration and the results showed that dark honey phenolic compounds had higher activity than the obtained from clear Honey, and S. aureus were the most sensitive microrganisms.

Journal Article
TL;DR: In this paper, the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavengence assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavengent assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source.
Abstract: Much work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. We analysed the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavenging assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source. Total antioxidant capacity was determined by the assay based on the decrease in absorbance of β-carotene by the sample. Rutin exhibited strong DPPH radical scavenging activity. At the concentration of 0.05 mg/ml, ascorbic acid (Vc), butylated hydroxytoluene (BHT) and rutin showed 92.8%, 58.8%, and 90.4% inhibition, respectively. In addition, rutin had effective inhibition of lipid peroxidation. Those various antioxidant activities were compared to standard antioxidants such as BHT and Vc.

Journal ArticleDOI
TL;DR: In this article, the authors evaluated the antioxidant activity of 10 native Tuscan and international Vitis vinifera varieties extracted from the skin and seeds of 10 varieties of the plant.

Journal ArticleDOI
TL;DR: Alfalfa leaf peptides was believed to have high nutritive value in addition to antioxidant activity and compared with that of a native antioxidant, reduced glutathione (GSH), which was used as a reference.

Journal ArticleDOI
TL;DR: In this article, the total phenols content and antioxidant and antimicrobial activities were studied in walnut (Juglans regia L.) green husks aqueous extracts of five different cultivars (Franquette, Mayette, Marbot, Mellanaise and Parisienne).

Journal ArticleDOI
TL;DR: It is demonstrated that the water extract fractions of bitter gourd have different responses with different antioxidant methods, namely DPPH radical-scavenging activity and ferric reducing power.

Journal ArticleDOI
TL;DR: In this article, the antioxidant activity of mature garlic bulbs and immature plants in four different model systems is presented. And the effect on lipid peroxidation (LP) is evaluated by following the activities of examined garlic extracts in Fe 2+ /ascorbate and Fe 2 + /H 2 O 2 systems of induction.

Journal ArticleDOI
TL;DR: MTT assay showed that this antioxidant peptide from bullfrog skin protein (APBSP) inhibited lipid peroxidation higher than that of alpha-tocopherol as positive control and efficiently quenched different sources of free radicals.

Journal ArticleDOI
TL;DR: In this article, the antioxidant properties of chestnut (flowers, leaves, skins and fruits) extracts were evaluated through several biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, reducing power, inhibition of β-carotene bleaching, and inhibition of oxidative hemolysis induced by 2,2′-azobis(2-amidinopropane)dihydrochloride (AAPH).

Journal ArticleDOI
TL;DR: In vitro antioxidant activities of three selected Indian brown seaweeds (Sargassum marginatum, Padina tetrastomatica and Turbinaria conoides) were investigated as discussed by the authors.

Journal ArticleDOI
TL;DR: This is the first systematic screening for the quantification of polyphenols and antioxidant activity in tea commercialized in Argentine markets and concludes that Argentine tea is of very good quality when compared to teas from other sources.
Abstract: Tea, Camellia sinensis (L.) O. Kuntze (Theaceae) is cultivated in Argentina in the northeastern region (provinces of Misiones and Corrientes), between 26 degrees and 28 degrees south latitude, the southernmost area of the world where tea is cultivated. The objective of this work was to determine the total polyphenol content and the in vitro antioxidant capacity of green and black tea cultivated and industrialized in Argentina. Twelve samples of eight brands were analyzed. The total polyphenol content was determined according to the International Organization for Standardization method (ISO) 14502-1 for the determination of substances characteristic of green and black tea. The antioxidant capacity was determined by the ferric thiocyanate method (FTC) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging assay. Green tea showed a higher polyphenol content than black tea. The total polyphenol concentration in green tea was found to vary from 21.02 +/- 1.54 to 14.32 +/- 0.45% of gallic acid equivalents (GAE), whereas in black tea, the polyphenol content ranged from 17.62 +/- 0.42 to 8.42 +/- 0.55% of GAE (P < 0.05). A similar profile was observed for the antioxidant capacity determined by both methods. The antioxidant activities were well correlated with the total polyphenol content (r (2) = 0.9935 for the ferric thiocyanate method and r (2) = 0.9141 for the 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging assay). This is the first systematic screening for the quantification of polyphenols and antioxidant activity in tea commercialized in Argentine markets. The results obtained herein allow one to conclude that Argentine tea is of very good quality when compared to teas from other sources.

Journal ArticleDOI
TL;DR: In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.

Journal ArticleDOI
TL;DR: In this paper, the antioxidant activity of porcine and bovine ground ground meat was determined using three experimental treatments, namely: control (no antioxidant), oregano (oregano essential oil 3% w/w) and sage (sage essential oil three% w)/w), and after 1, 4, 8 and 12 days of storage.

Journal ArticleDOI
TL;DR: The in vitro antioxidant capacity of cereals is only an approximate reflection of their in vivo antioxidant effect due to differences in antioxidant solubility/bioavailability within the digestive tract and the metabolism/conjugation of compounds such as polyphenols as mentioned in this paper.

Journal ArticleDOI
TL;DR: Results of these studies demonstrated that extracts of chloroform/methanol extracted oils possessed higher antioxidant activities than extracts of their hexane extracted counterparts.

Journal Article
TL;DR: The study reveals that the consumption of these spices would exert several beneficial effects by virtue of their antioxidant activity, followed in descending order by green tea, black tea, and Elettaria cardamomum.
Abstract: The methanolic crude extracts of some commonly used medicinal plants were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical. The overall antioxidant activity of green tea (Camellia sinensis Linn.) was the strongest, followed in descending order by black tea (Camellia sinensis Linn.), Eugenia caryophyllus (Spreng.) Bullock and Harrison, Piper cubeba Linn., Zingiber officinale Roscoe and Piper nigrum Linn. Trigonella foenum graecum Linn. and Elettaria cardamomum (Linn.) Maton showed weak free radical scavenging activity with the DPPH method. All the methanolic extracts exhibited antioxidant activity significantly. The IC50 of the methanolic extracts ranged between 6.7 ± 0.1 and 681.5 ± 8.4 µg/ml and that of ascorbic acid was 8.9 ± 0.1 µg/ml. The study reveals that the consumption of these spices would exert several beneficial effects by virtue of their antioxidant activity.

Journal ArticleDOI
TL;DR: The results indicate that this plant possesses antioxidant, hypolipidaemic and antiatherosclerotic activities and has therapeutic potential for the prevention of cardiovascular diseases.

Journal ArticleDOI
TL;DR: The seasonal variation of the essential oil composition, the antioxidant activity (DPPH, FRAP assays) and the total phenolic content (Folin-Ciocalteu assay) of two aromatic wild plants, Pistacia lentiscus L. (Anacardiaceae), grown in Zakynthos, a Greek island, was investigated.

Journal ArticleDOI
TL;DR: In general, R. officinalis L. essential oil showed greater activity than its components in both systems, and the antioxidant activities of all the tested samples were mostly related to their concentrations.