Abstract:
:Intake of antioxidants from the diet has been recognized to have beneficial health effects, but the potential benefit of taking antioxidants such as β-carotene as supplements is controversial. The aim of the present study was to evaluate the potential protective effects of a physiologically relevant concentration (2 μM) of β-carotene on the DNA damaging effects of catechol in mouse lymphoma L5178Y cells. Two different exposure protocols were used: simultaneous exposure to β-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, β-carotene did not increase the basal level of DNA damage. However, at the highest concentration of catechol (1 mM), β-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 β-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 β- 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 β-carotene should be regarded as a beneficial or detrimental agent when it comes to its use as a dietary supplement.
journal_name
Free Radic Resjournal_title
Free radical researchauthors
Åsgård R,Hellman Bdoi
10.3109/10715762.2013.815346subject
Has Abstractpub_date
2013-09-01 00:00:00pages
692-8issue
9eissn
1071-5762issn
1029-2470journal_volume
47pub_type
杂志文章abstract::Various lines of evidence indicate that an important part in the pathogenesis of atherosclerosis is the modification of the plasma low-density lipoproteins (LDLs). A large number of pro-inflammatory and pro-atherogenic properties have been ascribed to the oxidatively modified LDLs and their components. There is consid...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.3109/10715762.2015.1036052
更新日期:2015-01-01 00:00:00
abstract::Silver nanoparticles (AgNPs) are the most widely used nanomaterials as antimicrobial agents. AgNPs have been shown to inhibit the growth of and induce apoptosis-like death in Escherichia coli. However, the precise mechanism of AgNPs-induced apoptosis-like death and association with DNA damage-inducible protein F (dinF...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2020.1866178
更新日期:2021-01-06 00:00:00
abstract::Liposomes composed of soybean phosphatidylcholine were peroxidized using the reagent sodium hypochlorite or the myeloperoxidase-hydrogen peroxide-Cl- system. Linoleic acid hydroperoxide previously prepared from linoleic acid by means of lipoxidase was incorporated into liposomes. The yield of thiobarbituric acid react...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715769900300521
更新日期:1999-06-01 00:00:00
abstract::Heme oxygenase is the rate limiting enzyme in heme degradation to carbon monoxide (CO), iron and bilirubin. The inducible isoform of the protein, heme oxygenase-1 (HO-1), is susceptible to up-regulation by a diverse variety of conditions and agents in mammalian tissue, leading to the common conception that HO-1 is a s...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.1080/10715769900301031
更新日期:1999-12-01 00:00:00
abstract::Expression of multiple drug resistant (MDR) phenotype and over-expression of P-glycoprotein (P-gp) in the human hepatocellular carcinoma (HCC) cell clone P1(0.5), derived from the PLC/PRF/5 cell line (P5), are associated with strong resistance to oxidative stress and a significant (p < 0.01) increase in intracellular ...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760410001705140
更新日期:2004-07-01 00:00:00
abstract::Subjecting selected peptides to in vitro analyses covering their ability to interfere with the lipid oxidation chain reaction as well as to protect proteins from direct and indirect oxidation has provided the basis for a more detailed understanding of peptide-mediated protection in biological systems. The efficiency o...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760903137101
更新日期:2009-10-01 00:00:00
abstract::The purpose of this double clinical study was (1) to evaluate the effect of one single intake (300 ml) of red wine (RW) on the plasma antioxidant capacity (pAOC) and plasma phenolics over the 24-h time period following the intake, and (2) to compare the long-term effects of daily intakes (250 ml/d) of RW, white wine (...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760310001598097
更新日期:2003-09-01 00:00:00
abstract::The turning point between apoptosis and necrosis induced by hydrogen peroxide (H2O2) have been investigated using human T-lymphoma Jurkat cells. Cells treated with 50 microM H2O2 exhibited caspase-9 and caspase-3 activation, finally leading to apoptotic cell death. Treatment with 500 microM H2O2 did not exhibit caspas...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760600632552
更新日期:2006-06-01 00:00:00
abstract::Several papers have claimed that mitochondria contain nitric oxide synthase (NOS) and make nitric oxide (NO*) in amounts sufficient to affect mitochondrial respiration. However, we found that the addition of L-arginine or the NOS inhibitor L-NMMA to intact rat liver mitochondria did not have any effect on the respirat...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760410001694008
更新日期:2004-06-01 00:00:00
abstract::3-Nitrotyrosine (3NT) is known as an important indicator of nitrosative stress and has been linked to various diseases. Our aim was to develop an indirect ELISA (enzyme-linked immunosorbent assay) method suitable for the detection of protein-bound 3NT in clinical plasma and serum samples. Nitrated protein standards an...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2011.652627
更新日期:2012-03-01 00:00:00
abstract::Hypoxia is a well-known threat to neuronal cells and triggers the pathophysiological syndromes in extreme environments such as high altitudes and traumatic conditions such as stroke. Among several prophylactic molecules proven suitable for ameliorating free radical damage, NAP (an octapeptide with initial amino acids:...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2015.1011153
更新日期:2015-04-01 00:00:00
abstract::Paraquat is a synthetic bipyridylium salt widely used as herbicide and defoliant. Enzyme-catalyzed redoxcycling of paraquat generates oxygen radicals. The toxic, even lethal, effects of paraquat are due to free radical-mediated tissue injury. Ocular lesions, sometimes quite severe, have been observed following acciden...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715769509064020
更新日期:1995-07-01 00:00:00
abstract::Epidemiologically, a high-carotenoid intake via a fruit- and vegetable-rich diet is associated with a decreased risk of various forms of cancer. The mechanisms by which carotenoids exert this protective effect are controversial. In this study, we examined the potency of a range of carotenoids commonly found in human p...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760290032539
更新日期:2002-07-01 00:00:00
abstract::Dietary flavonoids, present in different amount in foods, are associated with the prevention of hypertension, but little is known about the interactions between them. The aim of this study was to explore the effect of quercetin (Q), catechin (C) and the mixture, on Angiotensin II (AngII)-induced redox-dependent signal...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2012.660527
更新日期:2012-05-01 00:00:00
abstract::To examine local and systemic oxidative status of lung cancer (LC) and oxidant effects of radiotherapy (RT), this study evaluated antioxidants and markers of oxidative and nitrosative stress in bronchoalveolar lavage (BAL) fluid and in the blood of 36 LC patients and 36 non-cancer controls at baseline and during and a...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760902942824
更新日期:2009-07-01 00:00:00
abstract::Stichodactyla heliantus II (St II) is a haemolytic toxin whose activity depends of the characteristics of red blood cells (RBC). Among the factors that may tune the response of the RBC to the toxin activity stand the oxidative status of the cell. This study investigates how pre-oxidation of RBC modifies St II activity...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2010.536838
更新日期:2011-04-01 00:00:00
abstract::We describe an altered membrane band 3 protein-mediated anion transport in erythrocytes exposed to peroxynitrite, and relate the loss of anion transport to cell damage and to band 3 oxidative modifications. We found that peroxynitrite down-regulate anion transport in a dose dependent relation (100-300 micromoles/l). H...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760601090305
更新日期:2007-03-01 00:00:00
abstract::Oxygen radical generating systems, namely, Cu(II)/ H2O2, Cu(II)/ascorbate, Cu(II)/NAD(P)H, Cu(II)/ H2O2/catecholamine and Cu(II)/H2O2/SH-compounds irreversibly inhibited yeast glutathione reductase (GR) but Cu(II)/H2O2 enhanced the enzyme diaphorase activity. The time course of GR inactivation by Cu(II)/H2O2 dependent...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.3109/10715769709097858
更新日期:1997-12-01 00:00:00
abstract::Formation of the alpha-hydroxyethyl radical (CH3 degree CHOH) has already been extensively demonstrated after ethanol metabolism in the liver. Despite favourable conditions, this formation in the brain has remained speculative since there is no direct experimental evidence in intact brain cells. In this preliminary st...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715769709097868
更新日期:1997-12-01 00:00:00
abstract::Validation of markers requires two different steps. The first one is the analytical validation including analytical procedures, definition of standard reference, and round-tests analysis. The second one is the assessment of the biological relevance of the selected marker. This biological relevance may be in the field ...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:
更新日期:2000-11-01 00:00:00
abstract::Cellular exposure to ionising radiation leads to oxidative stress events, which refer to elevated intracellular levels of reactive oxygen species (ROS). The elevated levels of ROS significantly contributed to γ-radiation (IR) induced cytotoxicity. In an attempt to minimise these cytotoxic effects, antioxidant compound...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2017.1395025
更新日期:2017-12-01 00:00:00
abstract::The risk of chronic oxidative stress in the retinal pigment epithelium (RPE) increases with age due to accumulation of the photoreactive age pigment lipofuscin (LFG). Here, we asked whether sublethal and weakly lethal photic stress, induced by irradiation of ARPE-19 cells containing phagocytised LFG, affected the cell...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2017.1380307
更新日期:2017-10-01 00:00:00
abstract::2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) has been identified as a major water-soluble metabolite of vitamin E, which circulates in the blood and is excreted with the urine. The aim of this study was to assess the antioxidant activity of alpha-CEHC using several methods with different proox...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/1071576021000005357
更新日期:2002-08-01 00:00:00
abstract::Carotenoids scavenge simple lipid-like alkylperoxyl radicals. However, the rate constant is too low to be determined directly and the mechanism is likewise not known with certainty [Mortensen, A. and Skibsted, L.H. (1998) FEBS Lett. 426, 392-396]. It is demonstrated that carotenoids react with peroxyl radicals only sl...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760290006501
更新日期:2002-02-01 00:00:00
abstract::The effect of antioxidants on ammonia induced CNS and renal pathobiology in 10 sheep infested by L. Cuprina larvae was investigated. The condition produces severe dermatitis, proliferation of macrophages and hyperammonaemia, and free radicals may therefore be involved in the pathogenesis. Five of the sheep (treated gr...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715769409056553
更新日期:1994-07-01 00:00:00
abstract::Autophagy modulation is a potential therapeutic strategy for breast cancer, and a previous study indicated that metformin exhibits significant anti-carcinogenic activity. However, the ability of metformin to induce autophagy and its role in breast cancer cell death remains unclear. In this study, we exposed MCF-7 cell...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2018.1485075
更新日期:2018-08-01 00:00:00
abstract::Interactions between transition metal ions and polyphenols can result in complexation, redox or polymerization, but the relative importance of these reactions is unclear. The present paper reports results from the reaction of gallic acid (GA) with Cu(II) using electron paramagnetic resonance (EPR) and UV/visible spect...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2010.515220
更新日期:2011-02-01 00:00:00
abstract::A range of catechins and oligomeric procyanidins was purified by high performance liquid chromatography (HPLC) from grape seed, apple skin, lentil and almond flesh. Catechins, galloylated epicatechin, glycosylated catechin, procyanidin dimers, galloylated dimers, trimer, and tetramer species were all identified, purif...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715769800300391
更新日期:1998-10-01 00:00:00
abstract::Peroxisome proliferator-activated receptor gamma (PPARγ) is known to be activated via exercise-associated transient increases in oxidative stress. However, the precise mechanism(s) triggering PPARγ activation in monocytes during/following exercise remain to be confirmed. Here, two cohorts of five healthy male individu...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2014.978311
更新日期:2015-01-01 00:00:00
abstract::Degenerative diseases such as cancer are induced by oxidative genetic damage. Antioxidants can scavenge reactive oxygen species, but to prevent disease, they must do so quickly, before the DNA bases are damaged. In the present study, a novel method was established for evaluating the potency of antioxidants employing 2...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760290019336
更新日期:2002-03-01 00:00:00