scholarly journals Antioxidant Activity of Magnolol and Honokiol: Kinetic and Mechanistic Investigations of Their Reaction with Peroxyl Radicals

2015 ◽  
Vol 80 (21) ◽  
pp. 10651-10659 ◽  
Author(s):  
Riccardo Amorati ◽  
Julija Zotova ◽  
Andrea Baschieri ◽  
Luca Valgimigli
Keyword(s):  
Antioxidant Activity ◽  
Peroxyl Radicals ◽  
Mechanistic Investigations

Antioxidant activity of sugarcane molasses against 2,2′-azobis(2-amidinopropane) dihydrochloride-induced peroxyl radicals

2013 ◽  
Vol 141 (1) ◽  
pp. 466-472 ◽  
Author(s):  
Yonathan Asikin ◽  
Makoto Takahashi ◽  
Takashi Mishima ◽  
Masami Mizu ◽  
Kensaku Takara ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Peroxyl Radicals ◽  
Sugarcane Molasses

scholarly journals The antioxidant activity of polysulfides: it's radical!

2019 ◽  
Vol 10 (19) ◽  
pp. 4999-5010 ◽  
Author(s):  
Jean-Philippe R. Chauvin ◽  
Markus Griesser ◽  
Derek A. Pratt
Keyword(s):  
Antioxidant Activity ◽  
Peroxyl Radicals ◽  
Primary Antioxidant ◽  
Homolytic Substitution

Sulfurized olefins (polysulfides) containing four (or more) sulfur atoms react efficiently with peroxyl radicals by homolytic substitution, accounting for their primary antioxidant activity.

Evidence of Trolox and some gallates as synergistic protectors of erythrocytes against peroxyl radicals

1998 ◽  
Vol 76 (4) ◽  
pp. 661-664 ◽  
Author(s):  
J Wu ◽  
H Sugiyama ◽  
L -H Zeng ◽  
D Mickle ◽  
T -W Wu
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Protective Effect ◽  
Propyl Gallate ◽  
Peroxyl Radical ◽  
Human Erythrocytes ◽  
Peroxyl Radicals ◽  
Methyl Ethyl ◽  
Radical Initiator ◽  
Individual Contributions

The peroxidation of human erythrocytes induced by peroxyl radical initiator and its inhibition by several gallate esters (e.g., propyl, methyl, ethyl) and Trolox (a more polar analogue of vitamin E) have been studied. The antioxidant activity was determined on erythrocytes against hemolysis generated by a thermal activator, 2,2prime-azobis-(2-amidinopropane)dihydrogenchloride. It was found that propyl gallate and its two analogues were more effective than Trolox in preventing cell lysis. However, the combination of gallate esters and Trolox produced a protective effect exceeding the arithmetic sum of their individual contributions. These perceived synergisms occur at more than one level of Trolox at a given level of a gallate ester.Key words: Trolox, gallates, synergism, peroxyl radicals.

scholarly journals Penetapan Total Flavonoid, Aktivitas Antioksidan dan Karakterisasi Nanopartikel Ekstrak Etanol Daun Kelor (Moringa pterygosperma Gaertn.)

2019 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Tinta Julianawati ◽  
Hendy Hendarto ◽  
Widjiati Widjiati
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Herbal Medicine ◽  
Leaf Extract ◽  
Total Flavonoid ◽  
Peroxyl Radicals ◽  
Chemical Components ◽  
Dpph Method ◽  
Moringa Leaf Extract

Moringa pterygosperma is one of the plants in Indonesia that is often used in herbal medicine. Moringa leaves contain many phytochemical compounds, one of the compounds is flavonoids which function as antioxidants. Flavonoid compounds in vitro can inhibit lipid peroxidation by breaking the chain of peroxyl radicals. Moringa leaf benefits in the field of herbal medicine are formed with a variety of preparations. One of the preparations is in the form of extracts with the aim of attracting chemical components to natural materials The extraction process has a disadvantage because the level of solubility in water is still low. The nanoparticle technique is a strategy to increase the bioavalbicibility of herbal active compounds. This research was experimental in order to determine the total flavonoid levels contained in Moringa leaf extract. In addition, it was also to find out the antioxidant activity and particle size of the moringa leaf extract nanoparticles. Determination of flavonoid levels using spectrophotometric methods. The antioxidant activity of moringa leaf extract nanoparticles was tested using the DPPH method (2,2-diphenyl-picrylhdrazyl) and to determine the particle size used by using the Particle Size Analyzer (PSA). The results of the study showed total flavonoid levels in moringa leaf extract (1.97 ± 1.07)%. Antioxidant activity of 451.8 ppm with a reduction of 2.8% and particle size in the moringa leaf extract nanoparticles of ± 134.78 nm. Moringa leaf extract nanoparticles include low antioxidants. Keywords: moringa; nanoparticles; antioxidants

scholarly journals Penetapan Total Flavonoid, Aktivitas Antioksidan dan Karakterisasi Nanopartikel Ekstrak Etanol Daun Kelor (Moringa pterygosperma Gaertn.)

2019 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Tinta Julianawati ◽  
Hendy Hendarto ◽  
Widjiati Widjiati
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Herbal Medicine ◽  
Leaf Extract ◽  
Total Flavonoid ◽  
Peroxyl Radicals ◽  
Chemical Components ◽  
Dpph Method ◽  
Moringa Leaf Extract

Moringa pterygosperma is one of the plants in Indonesia that is often used in herbal medicine. Moringa leaves contain many phytochemical compounds, one of the compounds is flavonoids which function as antioxidants. Flavonoid compounds in vitro can inhibit lipid peroxidation by breaking the chain of peroxyl radicals. Moringa leaf benefits in the field of herbal medicine are formed with a variety of preparations. One of the preparations is in the form of extracts with the aim of attracting chemical components to natural materials The extraction process has a disadvantage because the level of solubility in water is still low. The nanoparticle technique is a strategy to increase the bioavalbicibility of herbal active compounds. This research was experimental in order to determine the total flavonoid levels contained in Moringa leaf extract. In addition, it was also to find out the antioxidant activity and particle size of the moringa leaf extract nanoparticles. Determination of flavonoid levels using spectrophotometric methods. The antioxidant activity of moringa leaf extract nanoparticles was tested using the DPPH method (2,2-diphenyl-picrylhdrazyl) and to determine the particle size used by using the Particle Size Analyzer (PSA). The results of the study showed total flavonoid levels in moringa leaf extract (1.97 ± 1.07)%. Antioxidant activity of 451.8 ppm with a reduction of 2.8% and particle size in the moringa leaf extract nanoparticles of ± 134.78 nm. Moringa leaf extract nanoparticles include low antioxidants. Keywords: moringa; nanoparticles; antioxidants

scholarly journals Enhanced Antioxidant Activity under Biomimetic Settings of Ascorbic Acid Included in Halloysite Nanotubes

Antioxidants ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 30 ◽  
Author(s):  
Andrea Baschieri ◽  
Riccardo Amorati ◽  
Tiziana Benelli ◽  
Laura Mazzocchetti ◽  
Emanuele D’Angelo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Halloysite Nanotubes ◽  
Peroxyl Radicals ◽  
Organic Substrates ◽  
Dpph Radical ◽  
Organic Solution ◽  
Water Ph ◽  
Improved Performance

Antioxidant activity of native vitamin C (ascorbic acid, AH2) is hampered by instability in solution. Selective loading of AH2 into the inner lumen of natural halloysite nanotubes (HNT) yields a composite nanoantioxidant (HNT/AH2), which was characterized and investigated for its reactivity with the persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical and with transient peroxyl radicals in the inhibited autoxidation of organic substrates, both in organic solution (acetonitrile) and in buffered (pH 7.4) water in comparison with native AH2. HNT/AH2 showed excellent antioxidant performance being more effective than native ascorbic acid by 131% in acetonitrile and 290% (three-fold) in aqueous solution, under identical settings. Reaction with peroxyl radicals has a rate constant of 1.4 × 106 M−1 s−1 and 5.1 × 104 M−1 s−1, respectively, in buffered water (pH 7.4) and acetonitrile, at 30 °C. Results offer physical understanding of the factors governing HNT/AH2 reactivity. Improved performance of HNT/AH2 is unprecedented among forms of stabilized ascorbic acid and its relevance is discussed on kinetic grounds.

scholarly journals The effects of berberine on reactive oxygen species production in human neutrophils and in cell-free assays

2017 ◽  
Vol 10 (2) ◽  
pp. 61-65 ◽  
Author(s):  
Rami B. Kassab ◽  
Ondrej Vasicek ◽  
Milan Ciz ◽  
Antonin Lojek ◽  
Tomas Perecko
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Activity ◽  
Whole Blood ◽  
Reactive Oxygen Species Production ◽  
Reactive Oxygen ◽  
Immune Defense ◽  
Peroxyl Radicals ◽  
Human Neutrophils ◽  
Oxygen Species ◽  
Species Production

AbstractThe health benefits of berberine have been recognized for years. Even so, its effects on human neutrophils, the first line of immune defense, have not been reported. The purpose of this study was to investigate the effects of berberine on the human neutrophil oxidative burst. Reactive oxygen species production was analyzed by luminol-enhanced chemiluminescence. The analysis was performed in spontaneous and stimulated (phorbol myristate acetate (PMA) or opsonized zymosan particles (OZP)) whole blood and isolated neutrophils in the presence or absence of berberine. The effects of berberine on oxidant production in cell-free assays were evaluated using luminescence (H2O2-peroxidase-luminol) and fluorescence (Oxygen Radical Absorbance Capacity – ORAC) techniques. Berberine decreased the production of reactive oxygen species in human whole blood and isolated neutrophils stimulated with either PMA or OZP with a different efficiency (EC50was 69 μM and 197 μM for PMA and OZP, respectively). The effect was more pronounced in isolated neutrophils. Cell-free assays showed the antioxidant activity of berberine against peroxyl radicals and hydrogen peroxide. Based on our results, we suggest that the effects of berberine on reactive oxygen species production in human neutrophils are due to its antioxidant activity.

Antioxidant Activity of Anthocyanin Glycoside Derivatives Evaluated by the Inhibition of Liposome Oxidation

2005 ◽  
Vol 60 (5-6) ◽  
pp. 399-407 ◽  
Author(s):  
Janina Gabrielska ◽  
Jan Oszmiański
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Membrane System ◽  
Water Soluble ◽  
Peroxyl Radicals ◽  
Liposome Membrane ◽  
Membrane Oxidation ◽  
Inhibit Lipid Peroxidation ◽  
Antioxidant Potency

Cyanidin-3-glycosides (arabinoside, rutinoside, galactoside and glucoside) and delphinidin- 3-rutinoside were examined for their ability to inhibit lipid peroxidation induced either by Fe(II) ions, UV irradiation or 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) peroxyl radicals in a liposomal membrane system. The antioxidant abilities of anthocyanins were compared with a water-soluble tocopherol derivative, trolox. The antioxidant efficacies of these compounds were evaluated by their ability to inhibit the fluorescence intensity decay of the extrinsic probe 3-[p-(6-phenyl)-1,3,5,-hexatrienyl] phenylpropionic acid, caused by the free radicals generated during peroxidation. All the anthocyanins tested (at concentrations of 15-20 μm) exhibited higher antioxidant activities against Fe(II)-induced peroxidation than UV- and AAPH-induced peroxidation, suggesting that metal chelation may play an important role in determining the antioxidant potency of these compounds. It was also found that delphinidin-3-rutinoside had a higher antioxidant activity against Fe(II)-induced liposome oxidation than cyanidin-3-rutinoside, which indicates an important role of the OH group in the B ring of delphinidin-3-rutinoside in its antioxidant action. The antioxidant activity of all the anthocyanins studied was higher than that of trolox in the case of Fe(II)-induced liposome oxidation and was comparable with the action of trolox in the case of UV- and AAPHinduced liposome membrane oxidation.

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