Doc:Antioxidant

From Metabolomics.JP
(Difference between revisions)
Jump to: navigation, search
({{Bilingual|食べた場合|In vivo study}})
m
Line 38: Line 38:
 
==={{Bilingual|食べた場合|In vivo study}}===
 
==={{Bilingual|食べた場合|In vivo study}}===
 
{{Twocolumn|
 
{{Twocolumn|
Although antioxidant activities of flavonoids are several times higher than vitamin C or E in vitro, their plasma and intracellular concentration after intake is 100-1000 times lower than vitamin C or uric acid. The antioxidant function in vivo is therefore considered negligible<ref>Lotito SB, Frei B (2006) "Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomenon?" ''Free Radic Biol Med'' 41(12):1727-1746 PMID 17157175</ref>.
+
Although antioxidant activities of flavonoids are several times higher than vitamin C or E in vitro, their plasma and intracellular concentration after intake is over 100 times lower than vitamin C or uric acid. The antioxidant function in vivo is therefore considered negligible<ref>Lotito SB, Frei B (2006) "Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomenon?" ''Free Radic Biol Med'' 41(12):1727-1746 PMID 17157175</ref>.
 
|
 
|
試験管内ではフラボノイドの抗酸化能はビタミンCやEの数倍あるのですが、摂取後の血中濃度はビタミンCや尿酸の100から1000倍も低くなります。そのため、体内における抗酸化作用は殆ど無いと考えられます。
+
試験管内ではフラボノイドの抗酸化能はビタミンCやEの数倍あるのですが、摂取後の血中濃度はビタミンCや尿酸の100倍以上も低くなります。そのため、体内における抗酸化作用は殆ど無いと考えられます。
 
}}
 
}}
  
Line 55: Line 55:
 
<ref>Maxwell SR, Thomason H, Sandler D, Leguen C, Baxter MA, Thorpe GH, Jones AF, Barnett AH (1997) "Antioxidant status in patients with uncomplicated insulin-dependent and non-insulin-dependent diabetes mellitus" ''Eur J Clin Invest'' 27(6):484-490 PMID 9229228</ref>
 
<ref>Maxwell SR, Thomason H, Sandler D, Leguen C, Baxter MA, Thorpe GH, Jones AF, Barnett AH (1997) "Antioxidant status in patients with uncomplicated insulin-dependent and non-insulin-dependent diabetes mellitus" ''Eur J Clin Invest'' 27(6):484-490 PMID 9229228</ref>
 
|-
 
|-
| vitamin E || 8-28 &mu;mol/L  || <ref>Farrell PM (1980) Vitamin E: a comprehensive treaties (Machlin LJ ed.) pp.520-620, Marcel Dekker, New York</ref>
+
| vitamin E || 8-28 &mu;mol/L  ||
 +
{{Bilingual|36実験の平均的ビタミンEレベル|Mean plasma tocopherol from 36 different studies.}}<ref>Farrell PM (1980) Vitamin E: a comprehensive treaties (Machlin LJ ed.) pp.520-620, Marcel Dekker, New York</ref>
 
|-
 
|-
 
| flavonoids || < 10 &mu;mol/L for flavanones<br/> < 1 &mu;mol/L for anthocyanins ||
 
| flavonoids || < 10 &mu;mol/L for flavanones<br/> < 1 &mu;mol/L for anthocyanins ||

Revision as of 11:02, 1 October 2010

Flavonoid Top Molecule Index Author Index Journals Structure Search Food New Input

Antioxidant Activity of Flavonoid

In vitro study

The reactivity of an antioxidant is determined by its reactivity as a hydrogen or electron-donating agent, the fate of the resulting radical (unpaired electron), its reactivity with other antioxidant, and its metal-chelating potential. The reactivity can be assessed by applying the chromogenic redox indicator ABTS+(radical cation of 2,2'-azino-bis (3-ethylbenzthiazoline 6-sulphonic acid) relative to Trolox (water-soluble vitamin E analogue).

The strength of antioxidant activities is ordered as:

  • the ortho 3',4'-dihydoroxy moiety in the B-ring,
  • the meta 5,7-dihydroxy moiety in the A-ring, and
  • the 2,3-double bond together with both 4-keto and 3/5-hydroxy group in the C-ring.
Glycosylation decreases the activity. Metal chelation is achieved by the first and the third items above.

For example, quercetin is a more effective photoprotectant and anti-oxidant than kaempferol. [1] [2]

  1. Ryan KG, Swinny EE, Markham KR, Winefield C (2002) "Flavonoid gene expression and UV photoprotection in transgenic and mutant Penunia leaves" Phytochem 59:23-32 PMID 11754940
  2. Li J, Ou-Lee T-M, Raba R, Amundson RG, Last RL (1993) "Arabidopsis flavonoid mutants are hypersensitive to UV-B irradiation" Plant Cell 5: 171-179 PMID 12271060

In vivo study

Although antioxidant activities of flavonoids are several times higher than vitamin C or E in vitro, their plasma and intracellular concentration after intake is over 100 times lower than vitamin C or uric acid. The antioxidant function in vivo is therefore considered negligible[1].

Plasma concentration of major antioxidants
vitamin C 40-60 μmol/L

Vitamin C level predicts strokes. [2]

uric acid 200-300 μmol/L

Urate, vitamin C and E account for the total antioxidant activity. [3]

vitamin E 8-28 μmol/L

Mean plasma tocopherol from 36 different studies.[4]

flavonoids < 10 μmol/L for flavanones
< 1 μmol/L for anthocyanins
  1. Lotito SB, Frei B (2006) "Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomenon?" Free Radic Biol Med 41(12):1727-1746 PMID 17157175
  2. Myint PK, Luben RN, Welch AA, Bingham SA, Wareham NJ, Khaw KT (2008) "Plasma vitamin C concentrations predict risk of incident stroke over 10 y in 20649 participants of the European Prospective Investigation into Cancer–Norfolk prospective population study" Am J Clin Nutr 87(1)64-69 PMID 18175738
  3. Maxwell SR, Thomason H, Sandler D, Leguen C, Baxter MA, Thorpe GH, Jones AF, Barnett AH (1997) "Antioxidant status in patients with uncomplicated insulin-dependent and non-insulin-dependent diabetes mellitus" Eur J Clin Invest 27(6):484-490 PMID 9229228
  4. Farrell PM (1980) Vitamin E: a comprehensive treaties (Machlin LJ ed.) pp.520-620, Marcel Dekker, New York


Relative total antioxidant activities[1]
Antioxidant Sources Activity* (mM)
Vitamins
Vitamin C fruit and vegetables 1.0 ± 0.02
Vitamin E grains, nuts and oils 1.0 ± 0.03
Anthocyanins
Oenin black grapes/red wine 1.8 ± 0.02
Cyanidin grapes, raspberries and strawberries 4.4 ± 0.12
Delphinidin aubergine skin 4.4 ± 0.11
Flavonols
Quercetin onion, apple skin, berries, black grapes, tea and broccoli 4.7 ± 0.10
Kaempferol endive, leek, broccoli, grapefruit and tea 1.3 ± 0.08
Flavones
Rutin onion, apple skin, berries, black grapes, tea and broccoli 2.4 ± 0.12
Luteolin lemon, olive, celery and red pepper 2.1 ± 0.05
Chrysin fruit skin 1.4 ± 0.07
Apigenin celery and parsley 1.5 ± 0.08
Flavan 3-ols
(Epi)catechin black grapes/red wine 2.4 ± 0.02
Epigallocatechin teas 3.8 ± 0.06
Epigallocatechin gallate teas 4.8 ± 0.06
Epicatechin gallate teas 4.9 ± 0.02
Flavanones
Taxifolin citrus fruit 1.9 ± 0.03
Naringenin 7-rutinoside citrus fruit 0.8 ± 0.5
Naringenin citrus fruit 1.5 ± 0.05
Hesperetin 7-rutinoside orange juice 1.0 ± 0.03
Hesperetin orange juice 1.4 ± 0.08
Teaflavins
Teaflavin black tea 2.9 ± 0.08
Teaflavin 3-gallate black tea 4.7 ± 0.16
Teaflavin 3'-gallate black tea 4.8 ± 0.19
Teaflavin digallate black tea 6.2 ± 0.43
Hydroxycinnamates
Caffic acid white grapes, olive, cabbage and asparagus 1.3 ± 0.01
Chlorogenic acid apple, pear, cherry, tomato and peach 1.3 ± 0.02
Ferulic acid grains, tomato, cabbage and asparagus 1.9 ± 0.02
p-Coumaric acid white grapes, tomato, cabbage and asparagus 2.2 ± 0.06
* ... Measured as the Trolox equivalent antioxidant activity (TEAC) - the concentration of Trolox with the equivalent antioxidant activity of a 1 mM concentration of the experimental substance
  1. Rice-Evans C, Miller N, Paganga G (1997) "Antioxidant properties of phenolic compounds" Trends Plant Sci 2(4):152-159
Personal tools
Namespaces

Variants
Actions
Navigation
metabolites
Toolbox