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991.
Stefanie Reichhold Oliver Neubauer Christine Hoelzl Barbara Stadlmayr Judit Valentini Franziska Ferk 《Free radical research》2013,47(8):753-760
The major aims of this study were to investigate the effect of an Ironman triathlon on DNA migration in the single cell gel electrophoresis assay, apoptosis and necrosis in the cytokinesis-block micronucleus cytome assay with lymphocytes and on changes of total antioxidant capacity in plasma. Blood samples were taken 2 days (d) before, within 20 min, 1 d, 5 d and 19 d post-race. The level of strand breaks decreased (p<0.05) immediately after the race, then increased (p<0.01) 1 d post-race and declined (p<0.01) until 19 d post-race. Apoptotic and necrotic cells decreased (p<0.01) and the total antioxidant status increased (p<0.01) immediately after the race. The results indicate that ultra-endurance exercise does not cause prolonged DNA damage in well-trained male athletes. 相似文献
992.
Biomarkers of oxidative stress in overweight men are not influenced by a combination of antioxidants
《Free radical research》2013,47(5):522-528
AbstractThe 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. 相似文献
993.
Vanessa Pitozzi Stefania Pallotta Manuela Balzi Marta Bucciolini Aldo Becciolini Piero Dolara 《Free radical research》2013,47(11):1149-1154
We used X-rays from a linear accelerator and from a low energy therapeutic source to calibrate the single cell gel electrophoresis (comet assay), a widely used method to measure DNA damage. γ-Rays from 60Co, with known efficiency in inducing DNA breakage, were used as reference. Human lymphocytes and one murine tumour cell line, F10-M3 cells, were irradiated under different experimental conditions. A similar relationship between radiation dose and induced DNA damage was obtained with γ- and X-rays. A calibration curve was constructed to convert the comet assay raw data into break frequency. The median levels of DNA breaks and oxidative damage in circulating lymphocytes from healthy volunteers were calculated to be 0.76 and 0.80 breaks/109 Da, respectively, (0.50 and 0.52 breaks/106 bp). The values of oxidative DNA damage were in the same order of magnitude as those found by others with HPLC methods. 相似文献
994.
《Free radical research》2013,47(1-3):117-125
Four 9,10-anthraquinones (AQ) mono- or bis-substituted with the -NH(CH2)2 NH(CH2)2OH group were studied. 1-AQ, 1,5-AQ and 1,8-AQ but not 1,4-AQ (100°M) generated pBR322 plasmid DNA single strand breaks in the presence of purified NADPH dependent cytochrome P450 reductase. 1-AQ, 1,5-AQ and 1,8-AQ (at 100 °M) stimulated hydroxyl radical formation in MCF-7 S9 cell fraction (as measured by dimethyl pyrolline N-oxide spin trapping) and MCF-7 DNA strand breaks as measured by alkaline filter elution. In contrast 1,4-AQ did not stimulate hydroxyl radical formation and produced considerably less strand breaks in MCF-7 cells compared to the other AQ's. It would appear that the position of the -NH(CH2)2 NH(CH2)2OH groups on the chromophore is an important determinant in the metabolic activation of cytotoxic anthraquinones. This may contribute to the cytotoxicity (ID50 values) of 1-AQ (0.06 °M), 1-8-AQ (0.5 °M) and 1,5-AQ (12.3 °M) but not the 1,4-AQ (1.2 °M). 相似文献
995.
《Free radical research》2013,47(3):163-172
DNA or 2-deoxyguanosine reacts with hydroxyl free radical to form 8-hydroxy-deoxyguanosine (8-OH-dG). We found that 8-OH-dG can be effectively separated from deoxyguanosine by high pressure liquid chromatography and very sensitively detected using electrochemical detection. The sensitivity by electrochemical detection is about one-thousand fold enhanced over optical detection. Utilizing deoxyguanosine in bicarbonate buffer it was found that ferrous ion, but not ferric ion, was effective in forming 8-OH-dG. The hydroxyl free radical scavenging agents, thiourea and ethanol, were very effective in quenching Fe(11) mediated 8-OH-dG formation, but superoxide dismutase had very little effect. 相似文献
996.
《Free radical research》2013,47(1):479-488
Washed or growing E. coli cells are killed by epinephrine, norepinephrine or dopamine in the presence of non lethal concentrations of Cu(II). Killing is enhanced by anoxia and by sublethal Concentrations of H2O1. The rate of killing is proportional to the rate of catecholamine oxidation. The copper epinephrine complex binds to E. coli cells, induces membrane damage and depletion of the cellular ATP pool. The cells may be partially protected by SOD or catalase but not by OH radical scavengers. Addition of H2O2 to cells which were sensitized by preincubation with the epinephrine-copper complex, causes rapid killing and DNA degradation. Sensitized cells are not protected by BSA. 相似文献
997.
998.
Tiago L. Duarte 《Free radical research》2013,47(7):671-686
Vitamin C (or ascorbic acid) is regarded as the most important water-soluble antioxidant in human plasma and mammalian cells which have mechanisms to recycle and accumulate it against a concentration gradient, suggesting that the vitamin might also have important intracellular functions. In this review we summarize evidence from human trials that have attempted an association between vitamin C supplementation and an effect on biomarkers of oxidative DNA damage. Most studies reviewed herein showed either a vitamin C-mediated reduction in oxidative DNA damage or a null effect, whereas only a few studies showed an increase in specific base lesions. We also address the possible beneficial effects of vitamin C supplementation for the prevention of cancer and cardiovascular disease. Finally, we discuss the contribution of cell culture studies to our understanding of the mode of action of vitamin C and we review recent evidence that vitamin C is able to modulate gene expression and cellular function, with a particular interest in cell differentiation. 相似文献
999.
1000.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):243-248
AbstractA series of eight thiosemicarbazide derivatives was examined for cytotoxicity in breast cancer cell cultures. Among them, 4-benzoylthiosemicarbazides proved to be only slightly less potent than chlorambucil in both MDA-MB-231 and MCF-7 lines. In contrast, 4-aryl/alkylthiosemicarbazides revealed significantly lower cytotoxicity effect. Subsequently, all titled compounds were tested as potential human topoisomerase I and II (topo I and topo II) inhibitors. Mechanistic studies revealed that tested thiosemicarbazides act as both topoisomerase I and topoisomerase II inhibitors. Among them, the best inhibitory activity was found for 4-benzoylthiosemicarbazides (1 and 2) with IC50 at 50?µM against topo II. 相似文献