| 1. |
- Carney Almroth, Bethanie, 1974, et al.
(author)
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Oxidative stress in growth hormone transgenic coho salmon with compressed lifespan - a model for addressing aging
- 2012
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In: Free Radical Research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 46:10, s. 1183-1189
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Journal article (peer-reviewed)abstract
- Growth hormone (GH) transgenic fish have dramatically enhanced growth rates, increased oxygen demands and reactive oxygen species production. GH-transgenic coho salmon provide an opportunity to address effects of increased metabolism on physiological aging. The objective of this study was to compare oxidative stress in wild-type (WT) and GH-transgenic (T) coho salmon (Oncorhynchus kisutch) of different ages (1 and 2 years). Antioxidant enzyme activity, protein carbonyls (PC) and glutathione (GSH, GSSG) were measured. PC correlated to growth rates in individual fish. T fish exhibited lower antioxidant enzyme activities and GSH levels compared to the WT, while levels of PC and GSSG were higher. Age affects were observed in both WT and T fish; enzyme activities and GSH decreased while PC and GSSG increased. Our results support the metabolic rate theory of aging. This study aims to be a platform for continued studies of the theories of aging using fish as model organisms.
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| 2. |
- Lindström, Emma, et al.
(author)
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Associations between oxidative parameters in pregnancy and birth anthropometry in a cohort of women and children in rural Bangladesh : The MINIMat-cohort
- 2012
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In: Free radical research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 46:3, s. 253-264
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Journal article (peer-reviewed)abstract
- Oxidative stress is suggested as a potential mechanism in impaired foetal growth, smaller birth size and thus subsequently adult chronic diseases. We have investigated associations between oxidative stress in pregnancy and birth anthropometry (weight, height, head and chest circumferences). In the MINIMat-trial (Maternal and Infant Nutrition Interventions, Matlab) in rural Bangladesh, free 8-iso-prostaglandin P-2 alpha (lipid peroxidation) was analysed in pregnancy week 14 and 30 and 8-Hydroxy-2 '-Deoxyguanosine (DNA oxidation) in week 19. We found that higher levels of lipid peroxidation in early pregnancy were associated with larger infant size (birth length and chest circumference). In late pregnancy, no clear pattern of associations was found. Increasing level of DNA oxidation was associated with lower birth length in girls but no other associations were found. In conclusion, a higher level of lipid peroxidation in early (but not late) pregnancy was associated with a favourable larger birth size suggesting that timing of lipid peroxidation is of importance.
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| 3. |
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| 4. |
- Rutardottir, Sigurbjörg, et al.
(author)
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The cysteine 34 residue of A1M/α1-microglobulin is essential for protection of irradiated cell cultures and reduction of carbonyl groups.
- 2013
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In: Free Radical Research. - : Informa UK Limited. - 1029-2470 .- 1071-5762. ; 47:6-7, s. 541-550
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Journal article (peer-reviewed)abstract
- α1-microglobulin (A1M) is a 26 kDa plasma and a tissue protein belonging to the lipocalin family. The reductase and free radical scavenger A1M has been shown to protect cells and extracellular matrix against oxidative and irradiation-induced damage. The reductase activity was previously shown to depend upon an unpaired cysteinyl side-chain, C34, and three lysyl side-chains, K92, 118, and 130, located around the open end of the lipocalin pocket. The aim of this work was to investigate whether the cell and matrix protection by A1M is a result of its reductase activity by using A1M-variants with site-directed mutations of the C34, K92, K118, and K130 positions. The results show that the C34 side-chain is an absolute requirement for protection of HepG2 cell cultures against alpha-particle irradiation-induced cell death, upregulation of stress response and cell cycle regulation genes. Mutation of C34 also resulted in loss of the reduction capacity toward heme- and hydrogen peroxide-oxidized collagen, and the radical species 2,2´-azino-bis (3-ethyl-benzo-thiazoline-6-sulphonic acid) (ABTS). Furthermore, mutation of C34 significantly suppressed the cell-uptake of A1M. The K92, K118, and K130 side-chains were of minor importance in cell protection and reduction of oxidized collagen but strongly influenced the reduction of the ABTS-radical. It is concluded that antioxidative protection of cells and collagen by A1M is totally dependent on its C34 amino acid residue. A model of the cell protection mechanism of A1M should be based on the redox activity of the free thiolyl group of the C34 side-chain and a regulatory role of the K92, K118, and K130 residues.
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| 5. |
- Rytter, Elisabet, 1960-, et al.
(author)
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Biomarkers of oxidative stress in overweight men are not influenced by a combination of antioxidants
- 2010
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In: Free radical research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 44:5, s. 522-528
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Journal article (peer-reviewed)abstract
- The effect of antioxidant supplementation on biomarkers of oxidative stress was investigated in a 6-week intervention study in 60 overweight men. The supplement contained a combination of antioxidants aiming to correspond to the antioxidant content found in a diet rich in fruit and vegetables. Placebo, single or double dose of antioxidants was provided to the subjects. Metabolic variables, plasma antioxidants and biomarkers of oxidative stress (lipid peroxidation and DNA damage) were measured. No effect of supplementation on biomarkers of oxidative stress was observed. Both intervention groups showed substantial increases of plasma antioxidants. This study demonstrated that supplementation with a combination of antioxidants did not affect lipid peroxidation and DNA damage in overweight men, despite increased concentrations of plasma antioxidants. The absence of antioxidant supplement effect might possibly be explained by the chosen study group having a normal level of oxidative stress, duration of the intervention and/or doses of antioxidants.
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| 6. |
- Rytter, Elisabet, 1960-, et al.
(author)
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Supplementation with a combination of antioxidants does not affect glycaemic control, oxidative stress or inflammation in type 2 diabetes subjects
- 2010
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In: Free radical research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 44:12, s. 1445-1453
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Journal article (peer-reviewed)abstract
- The present clinical trial examined the influence of a supplement, containing a combination of antioxidants extracted from fruit, berries and vegetables, on levels of plasma antioxidants (tocopherols, carotenoids and ascorbate), glycaemic control (blood glucose, HbA1c, insulin), oxidative stress biomarkers (F2-isoprostane, malondialdehyd, nitrotyrosine, 8-oxo-7, 8-dihydro-2'-deoxyguanosine, formamidopyrimidine glycosylase sites, frequency of micronucleated erythrocytes) and inflammatory markers (interleukin-6, C-reactive protein, prostaglandin F2α-metabolite) in type 2 diabetes. Forty subjects were randomly assigned to control, single or double dose group and completed the study. In summary, 12 weeks of antioxidant supplementation did neither affect glycaemic control nor the levels of biomarkers of oxidative stress or inflammation, despite substantially increased plasma concentrations of antioxidants. The absence of an effect may be explained by the selected study subjects with relatively well-controlled diabetes, a high intake of fruit and vegetable and levels of plasma antioxidants, biomarkers of oxidative stress and inflammatory markers comparable to those found in healthy subjects.
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| 7. |
- Åsgård, Rikard, et al.
(author)
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Effect of beta-carotene on catechol-induced genotoxicity in vitro : Evidence of both enhanced and reduced DNA damage
- 2013
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In: Free radical research. - : Informa UK Limited. - 1071-5762 .- 1029-2470. ; 47:9, s. 692-698
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Journal article (peer-reviewed)abstract
- Intake of antioxidants from the diet has been recognized to have beneficial health effects, but the potential benefit of taking antioxidants such as beta-carotene as supplements is controversial. The aim of the present study was to evaluate the potential protective effects of a physiologically relevant concentration (2 mu M) of beta-carotene on the DNA damaging effects of catechol in mouse lymphoma L5178Y cells. Two different exposure protocols were used: simultaneous exposure to beta-carotene and catechol for 3 h; and exposure to catechol for 3 h after 18 h pre-treatment with the vitamin. DNA damage was evaluated using the comet assay (employing one procedure for general damage, and another procedure, which also included oxidative DNA damage). Independent of exposure protocol and procedure for comet assay, beta-carotene did not increase the basal level of DNA damage. However, at the highest concentration of catechol (1 mM), beta-carotene was found to clearly increase the level of catechol-induced DNA damage, especially in the pre-treated cells. Interestingly, an opposite effect was observed at lower concentrations of catechol, but the beta-carotene related reduction of catechol-induced genotoxicity was significant (P < 0.05) only for the procedure including oxidative damage induced by 0.5 mM catechol. Taken together our results indicate that beta-carotene can both reduce and enhance the DNA damaging effects of a genotoxic agent such as catechol. This indicates that it is the level of catechol-induced DNA damage that seems to determine whether beta-carotene should be regarded as a beneficial or detrimental agent when it comes to its use as a dietary supplement.
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