Effects of solvents and media on the antioxidant activity of α-tocopherol

Iwatsuki, Misato; Tsuchiya, Jyunichi; Komuro, Erika; Yamamoto, Yorihiro; Niki, Etsuo

doi:10.1016/0304-4165(94)90022-1

Cited by 46 publications

(33 citation statements)

References 37 publications

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“…Except ORAC assay, there was no significant difference in the results of T compared to the related T3. As yet, this relation was only observed for a-T and a-T3 in systems working with organic solvents [20,24] and against lipid peroxidation in solution and liposomal membranes [14].…”

Section: Antioxidant Activity Of Tocopherols and Tocotrienolsmentioning

confidence: 51%

“…Furthermore, in a system with multi-lamellar vesicles, T3 were more active against the typical synthetic radicals 2,2 0 -azobis-(2-amidinopropane) hydrochloride (AAPH), AMVN, and SIN-1 in the order a>b>g>d [22]. Other articles showed that the relative effectiveness depends on the experimental conditions [14,20,[23][24][25]. In summary, there is only a marginal and controversial knowledge on the antioxidant activity of vitamin E active substances [26], especially tocotrienols, when reacting in in vitro methods.…”

Section: Introductionmentioning

confidence: 93%

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In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

Müller

Theile

Böhm

2010

Molecular Nutrition Food Res

173

112

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A comparative study investigated four tocopherols, four tocotrienols, and alpha-tocopheryl acetate on their antioxidative activities in five different popular assays, which were adapted to non-polar antioxidants. alpha-Tocopherol, used as calibration standard, showed the highest ferric reducing antioxidant power. Greater ring methyl substitution not only led to an increase of scavenging activity against the stable 2,2-diphenyl-1-picrylhydrazyl radical, but also to a decrease in oxygen radical absorbance capacity. Regarding alpha-tocopherol equivalent antioxidant capacity no significant differences in the antioxidant activity of all vitamin E isoforms were found. In contrast, a significantly lower peroxyl radical-scavenging activity of alpha-tocochromanols was determined in a chemiluminescence assay. Except oxygen radical absorbance capacity, no significant differences of the antioxidant activity related to the side chain could be detected. The data show that the reducing ability and radical chain-breaking activity of the several vitamin E forms depends on the circumstances under which the assays are performed. In our opinion, the used lipophilic methods can be useful for estimating the antioxidant activity of strong non-polar antioxidants, e.g. carotenoids, too. Furthermore, we could show a significant correlation between the total tocopherol content in human plasma and the lipophilic antioxidant capacity measured by alpha-tocopherol equivalent antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl.

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Section: Antioxidant Activity Of Tocopherols and Tocotrienolsmentioning

confidence: 51%

Section: Introductionmentioning

confidence: 93%

In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

Müller

Theile

Böhm

2010

Molecular Nutrition Food Res

173

112

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“…Protic solvents decrease the antioxidant potential of 3 through formation of solvent hydrogen bonds. [30] Esterification or etherification are assumed to cause complete biological inactivity. [31] Oral applications of tocopherol esters are potent, because they are hydrolyzed in the gut to free tocopherol.…”

Section: Introductionmentioning

confidence: 99%

Combination of Vitamin E with a Carotenoid:α-Tocopherol and Trolox Linked toβ-Apo-8′-carotenoic Acid

et al. 1998

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Vitamin E and carotenoids show many similar and complementary properties and protect living tissues against a variety of pathological processes. A mixture of both compounds often exhibits a significantly greater effect than the sum of the individual activities. The synthetic linkage of carotenoids with vitamin E might thus increase the synergistic effects. We therefore esterified b-apo-8'-carotenoic acid with all-rac-a-tocopherol to give atocopheryl-b-apo-8'-carotenoate. The carotenoic acid was also connected to a-tocopherol in a glyceride ether, 1-O-(a-tocopheryl)-3-(b-apo-8'-carotenoyl)-glycerol, whereas the water-soluble vitamin E analogue, trolox, was combined with b-apo-8'-carotenoic acid in a diglyceride: 1-(6-hydroxy-2,5,7,8-tetramethylchroman-2-acyl)-3-(b-apo-8'-carotenoyl)-glycerol.

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“…, and 5-nitro-␥-tocopheroxyl (NGT • ) radicals were monitored by ESR (22). ESR measurements were performed at ambient temperature by using a Varian E-109 spectrometer operating at 9.5 GHz (X-band) by using 100 kHz field modulation.…”

Section: Methodsmentioning

confidence: 99%

“…The mechanism of ␣-TQ and NGTH formation was investigated by ESR (22,24,25). Addition of H 2 O 2 (10 mM) to an incubation mixture containing ␣-TH (2 mM), SOD (10 mg͞ml), and nitrite (10 mM) produced a seven-line ESR spectrum (Fig.…”

Section: Lipid Peroxidation By Sod͞hmentioning

confidence: 99%

Nitration of γ-tocopherol and oxidation of α-tocopherol by copper-zinc superoxide dismutase/H ₂ O ₂ /NO ₂ ⁻ : Role of nitrogen dioxide free radical

Singh

Goss

Joseph

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

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Copper-zinc superoxide dismutase (Cu,Zn-SOD) is the antioxidant enzyme that catalyzes the dismutation of superoxide (O 2•؊ ) to O 2 and H 2 O 2 . In addition, Cu,ZnSOD also exhibits peroxidase activity in the presence of H 2 O 2 , leading to self-inactivation and formation of a potent enzyme-bound oxidant. We report in this study that lipid peroxidation of L-␣-lecithin liposomes was enhanced greatly during the SOD͞H 2 O 2 reaction in the presence of nitrite anion (NO 2 ؊ ) with or without the metal ion chelator, diethylenetriaminepentacetic acid. The presence of NO 2 ؊ also greatly enhanced ␣-tocopherol (␣-TH) oxidation by SOD͞H 2 O 2 in saturated 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine liposomes. The major product identified by HPLC and UVstudies was ␣-tocopheryl quinone. When 1,2-diauroyl-snglycero-3-phosphatidylcholine liposomes containing ␥-tocopherol (␥-TH) were incubated with SOD͞H 2 O 2 ͞NO 2 ؊ , the major product identified was 5-NO 2 -␥-TH. Nitrone spin traps significantly inhibited the formation of ␣-tocopheryl quinone and 5-NO 2 -␥-TH. NO 2 ؊ inhibited H 2 O 2 -dependent inactivation of SOD. A proposed mechanism of this protection involves the oxidation of NO 2 ؊ by an SOD-bound oxidant to the nitrogen dioxide radical ( • NO 2 ). In this study, we have shown a new mechanism of nitration catalyzed by the peroxidase activity of SOD. We conclude that NO 2 ؊ is a suitable probe for investigating the peroxidase activity of familial Amyotrophic Lateral Sclerosis-linked SOD mutants.

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Effects of solvents and media on the antioxidant activity of α-tocopherol

Cited by 46 publications

References 37 publications

In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

Combination of Vitamin E with a Carotenoid:α-Tocopherol and Trolox Linked toβ-Apo-8′-carotenoic Acid

Nitration of γ-tocopherol and oxidation of α-tocopherol by copper-zinc superoxide dismutase/H ₂ O ₂ /NO ₂ ⁻ : Role of nitrogen dioxide free radical

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Effects of solvents and media on the antioxidant activity of α-tocopherol

Cited by 46 publications

References 37 publications

In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

In vitro antioxidant activity of tocopherols and tocotrienols and comparison of vitamin E concentration and lipophilic antioxidant capacity in human plasma

Combination of Vitamin E with a Carotenoid:α-Tocopherol and Trolox Linked toβ-Apo-8′-carotenoic Acid

Nitration of γ-tocopherol and oxidation of α-tocopherol by copper-zinc superoxide dismutase/H 2 O 2 /NO 2 − : Role of nitrogen dioxide free radical

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Nitration of γ-tocopherol and oxidation of α-tocopherol by copper-zinc superoxide dismutase/H ₂ O ₂ /NO ₂ ⁻ : Role of nitrogen dioxide free radical