Radical scavenging ability of polyphenolic compounds towards DPPH free radical

Villaño, Débora; Fernández-Pachón, María-Soledad; Moyá, Marı́a Luisa; Troncoso, Ana M.; García-Parrilla, M.C.

doi:10.1016/j.talanta.2006.03.050

Cited by 760 publications

(511 citation statements)

References 25 publications

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“…A similar effect was observed in the DPPH assay ( Figure 12) indicating that the polyphenols with a greater number of hydroxyl groups can effectively scavenge the DPPH_ radical which is also evident from the lower EC 50 (amount of antioxidant needed to decrease the radical concentration by 50%) of ECG (4.2 6 0.1) and EGCG (3.6 6 0.0) as compared to GA (5.1 6 0.1). [80] Although the percentage inhibition values of the polyphenols are close to one another, the tread in antioxidant activity obtained from the DPPH assay is consistent with the result obtained from the DT fluorescence study. This indicates that the number of hydroxyl groups present in the polyphenols play an important role in regulating its antioxidant ability.…”

Section: Docking Studiessupporting

confidence: 84%

β‐cyclodextrin encapsulated polyphenols as effective antioxidants

et al. 2017

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Formation of dityrosine (DT) cross-linkages in proteins is one of the most widely used markers of oxidative stress. Ribonuclease A (RNase A) has 6 Tyr residues and shows a characteristic DT fluorescence peak upon oxidation in addition to major changes in its secondary structure. DT formation can be prevented by using polyphenols (GA, ECG, and EGCG) which are known to have strong antioxidant activity. However, it has been observed that ECG and EGCG initiate protein oligomerization due to protein-polyphenol cross-linkages. To prevent the formation of such crosslinkages we have used b-cyclodextrin (b-CD) to encapsulate the polyphenols and studied its antioxidant properties along with that of free polyphenols. The polyphenol/b-cyclodextrin (b-CD) inclusion complexes not only prevent DT formation but also reduce protein oligomerization. This may be attributed to the fact that the quinone forming rings of ECG and EGCG become encapsulated in the cavity of b-CD and are no longer available for protein cross-linking.b-cyclodextrin encapsulation, dityrosine, oxidative stress, polyphenols, protein oligomerization | I N TR ODU C TI ONBiological aging in mammalian cells is a direct indication of oxidative stress in proteins. [1] These oxidatively modified forms of proteins are generated due to the presence of reactive oxygen species (ROS) such as hydroxyl and superoxide free radicals. [2,3] Persulfates, a key ingredient in flour, are a source of sulfate (SO 2 4 ) free radicals under neutral pH. [4,5] Due to the higher oxidizing power of the sulfate radical (E 0 5 12.60 V) and longer half-life period over the OH radical, it has drawn attention in recent times as a powerful oxidizing agent. [6][7][8] Many chemical and cosmetic industries require persulfates as their key components [9] and workers often suffer from skin and respiratory diseases due to hypersensitive reactions. [10] Generally, the lower thermal energy at room temperature (25-508C) is not sufficient enough to activate persulfate, but generation of SO 2 4 radical is facilitated in presence of metal cations. Since proteins tend to lose their structure and function at high temperatures, [11] we have carried out the oxidation of ribonuclease A (RNase A) in presence of persulfate using cobalt (II) ion at 378C. [12] Cobalt is an integral component of vitamin B12 and thus physiologically found in most tissues mainly in liver and kidney. [13,14] Gill et al., reported the formation of oligomeric species (dimer, trimer, tetramer) when RNase A was exposed to KHSO 5 in presence of metal ions such as Ni 21 and Cu 21 and the high molecular weight species were identified using SDS-PAGE. [12] An important biomarker of oxidative stress is the dityrosine moiety generated due to the covalent linkage of two Tyr residues. [15] Dityrosine bond formation is an indication of aging, and disease related problems since it generally occurs during amyloid fibril formation, [16] Parkinson disease, [17] cerebrospinal fluid damage, [18] and also in the cataract of the eye lens. [19,20] D...

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Section: Docking Studiessupporting

confidence: 84%

β‐cyclodextrin encapsulated polyphenols as effective antioxidants

et al. 2017

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“…A 0.1 mL volume of the sample was added to 3.9 mL of DPPH• dissolved in methanolic solution and carefully homogenized. Free radical was freshly prepared before each assay while protected from light (Villaño et al, 2007). Absorbance was read at 515 nm at different time intervals until the reaction reached stability.…”

Section: Antioxidant Activity -Dpph• Methodsmentioning

confidence: 99%

Total polyphenol content and antioxidant activity of commercial Noni (Morinda citrifolia L.) juice and its components

Bramorski

Cherem

Marmentini

et al. 2010

Braz. J. Pharm. Sci.

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The plant Morinda citrifolia L. (noni) has been the focus of many recent studies due to its potential effects on treatment and prevention of several diseases. However, there are few in vivo and in vitro studies concerning its composition and antioxidant capacity. The aim of the present study was to determine the total polyphenol content (TPC) and antioxidant capacity of a juice commercialized as noni juice, but containing grape, blueberry and noni fruits. Commercial noni juice was compared against its separate constituents of blueberry and grape juice. Folin-Ciocalteu and DPPH• methods were used to determine the concentration of total polyphenol content and antioxidant activity, respectively. Commercial noni juice presented higher values of TPC (91.90 mg of gallic acid/100 mL juice) and antioxidant activity (5.85 mmol/L) compared to its 5% diluted constituents. Concentrated blueberry juice presented higher TPC and antioxidant activity than the other juices analyzed. Considering that the blueberry and grape juices account for only 10% in the composition of commercial noni juice, it can be inferred that these two components contribute significantly to the antioxidant activity. Therefore, additional studies are necessary in order to elucidate the contribution of the noni juice as an antioxidant.Uniterms: Noni juice/antioxidant activity. Morinda citrifolia L. Total polyphenols/determination. Antioxidants.A planta Morinda citrifolia L. tem sido objeto de muitas pesquisas decorrente de seus efeitos benéficos no tratamento e prevenção de muitas doenças. No entanto, são escassos os estudos in vivo e in vitro sobre os compostos presentes e sua capacidade de atuar como antioxidante. Objetivou-se com este trabalho determinar o índice de polifenóis totais (IPT) e a capacidade antioxidante do suco de noni comercial, constituído de uva, mirtilo e a fruta do noni. O suco de noni comercial foi comparado com seus constituintes (mirtilo e suco de uva) separadamente. Os métodos Folin-Ciocalteu e DPPH• foram utilizados para determinar a concentração de polifenóis totais e capacidade antioxidante, respectivamente. O suco de noni apresentou valores superiores de IPT (91,90 mg ácido gálico/100 mL de suco) e atividade antioxidante (5,85 mmol/L) quando comparado aos seus constituintes diluídos a 5%. O suco de mirtilo, na sua forma concentrada, apresentou IPT e atividade antioxidante superior aos demais sucos. Considerando que os sucos de mirtilo e de uva representam apenas 10% na composição do suco de noni, pode-se inferir que estes dois constituintes contribuem de forma significativa para a atividade antioxidante. Assim, estudos adicionais são necessários para elucidar a contribuição do suco de noni como sequestrador de radicais livres. Unitermos: Suco de noni/atividade antioxidante. Morinda citrifolia L. Polifenóis totais/determinação. Antioxidantes.

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“…To assess the radical scavenging capacity of crude extract and four sub-fractions from longan pericarp, DPPH, ABTS and hydroxyl radical scavenging activity were investigated (Villaño et al, 2007;Vissotto et al, 2013;Re et al, 1999). DPPH and ABTS radical-scavenging activity were calculated as Inhibition Ratio(%) = [(A 0 -A 1 )/A 0 ]×100, hydroxyl radicalscavenging activity was calculated as Inhibition Ratio(%) = [A 0 -(A 1 -A 2 )/A 0 ]×100, where A 0 is the absorbance without sample, A 1 is the absorbance with samples and A 2 is reagent blank.…”

Section: Radical Scavenging Capacitymentioning

confidence: 99%