Abstract:
:Peroxynitrite anion is a reactive and short-lived species and its formation in vivo has been implicated in several human diseases. In view of the potential usefulness of compounds that can protect against peroxynitrite or their reactive intermediates, a study focused on flavonoid compounds was carried out. Since the reactivity of peroxynitrite may be modified by Co2/HCO3-, which is an important plasma buffer, the protection of flavonoids against peroxynitrite was evaluated by their ability to inhibit the peroxynitrite-mediated dihydrorhodamine (DHR123) oxidation with or without physiological concentrations of bicarbonate. Flavonoids from different classes were studied to elucidate which structural features are required for an effective protection. The most efficient flavonoids on protecting DHR123 against oxidation by peroxynitrite have their ability diminished in the presence of bicarbonate, but they maintain the hierarchy established in the absence of bicarbonate. The flavones are the most effective flavonoids and their effects depend mainly on the number of hydroxyl groups. These must include either a catechol group in the B-ring or a hydroxyl group at the 3-position. This work also included some isoflavones, flavanones and a flavanol, which enable us to conclude about the importance of another structural feature: the 2,3-double bond. These results indicate that the ability of flavonoids to protect against peroxynitrite depends on some structural features, also important to scavenge oxygen free radicals and to chelate metal ions. The most efficient flavonoids are effective at low concentrations with IC50 of the same magnitude as Ebselen, a selenocompound that has been reported to be excellent at protecting against peroxynitrite. Their effectiveness at low concentrations is an important aspect to take into account when characterizing a compound as an antioxidant with biological interest.
journal_name
Free Radic Resjournal_title
Free radical researchauthors
Santos MR,Mira Ldoi
10.1080/10715760400003384keywords:
subject
Has Abstractpub_date
2004-09-01 00:00:00pages
1011-8issue
9eissn
1071-5762issn
1029-2470pii
KWN5HCJC9CH3EJBBjournal_volume
38pub_type
杂志文章abstract::In cells, NADH and NADPH are mainly bound to dehydrogenases such as lactate dehydrogenase (LDH). In cell-free systems, the binary LDH-NADH complex has been demonstrated to produce reactive oxygen species via a chain oxidation of NADH initiated and propagated by superoxide. We studied here whether this chain radical re...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760500231786
更新日期:2005-10-01 00:00:00
abstract::The significance of 5-lipoxygenase and myeloperoxidase activities has not been extensively studied among young male smokers. Leukotriene B(4), 20-hydroxy-leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were measured in plasma and urinary samples of young male smokers at 8 hours following cigarette a...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2012.701291
更新日期:2012-10-01 00:00:00
abstract::In addition to insulin, glycemic control involves thyroid hormones. However, an excess of thyroid hormone can disturb the blood glucose equilibrium, leading to alterations of carbohydrate metabolism and, eventually, diabetes. Indeed, experimental and clinical hyperthyroidism is often accompanied by abnormal glucose to...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.1080/10715762.2019.1590567
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journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2020.1791843
更新日期:2020-07-28 00:00:00
abstract::Involvement of oxidative stress is implicated in the progression of complication of diabetes mellitus. With respect to heart diseases, we have studied role of oxidative stress/antioxidants using rats treated with streptozotocin to induce diabetes (DM). Hemodynamic and echocardiographic measurements showed thickening o...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760100300231
更新日期:2001-03-01 00:00:00
abstract::Tetrahydrobiopterin (BH4) is a ubiquitous pteridine metabolite that serves as a NOS cofactor. Recently, we showed that BH4 efficiently inhibits superoxide generation from the heme group at the oxygenase domain of eNOS. This role indicates that BH4 acts as a redox switch in the catalytic mechanism of the enzyme, which ...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.1080/1071576021000040655
更新日期:2003-02-01 00:00:00
abstract::Silibinin, a major active constituent of silymarin, is clinically used as a hepatoprotectant, and in recent years, it has been used for the treatment of cancer in China. Because the mechanism of silibinin action on cancer cells was still unclear, we investigated the contribution of silibinin to the induction of apopto...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2012.715369
更新日期:2012-11-01 00:00:00
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 doubl...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715761003647101
更新日期:2010-05-01 00:00:00
abstract::Hepatic sinusoidal obstruction syndrome (HSOS) is a rare and life-threatening liver disease. (+)-Catechin is a natural dietary flavonol with high antioxidant capacity. This study aims to investigate the involvement of nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant signalling pathway in the protection o...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2018.1437914
更新日期:2018-04-01 00:00:00
abstract::In this study, we studied whether chronic oral administration of the natural antioxidant, malabaricone C (mal C) can reduce blood pressure (BP) and attenuate cardio-vascular remodeling in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. The dose of mal C for its anti-hypertensive action was optimized by meas...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2015.1112005
更新日期:2016-01-01 00:00:00
abstract::Obesity enhances the frequency and severity of acute kidney injury (AKI). Telmisartan pre-treatment was used experimentally in the amelioration of ischemia/reperfusion (IR)-induced AKI. However, there is a lack of evidence regarding its beneficial effects on AKI in obese animals. The present study, therefore, aimed to...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2016.1211644
更新日期:2016-09-01 00:00:00
abstract::Hyperthermia-induced apoptosis and its enhancement in the presence of a temperature-dependent free radical initiator, 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH) were examined in human uterine cervical cancer cell lines, CaSki and HeLa. When both cell lines were treated with hyperthermia at 44 degrees C for 60...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/1071576031000088292
更新日期:2003-06-01 00:00:00
abstract::We investigated effect of aldehydic products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenal (HNE) on prostaglandin (PG) E2 receptors of liver plasma membranes. The modification of the membranes by MDA diminished PGE2 binding, decreasing receptor affinity for PGE2 and receptor density whereas HNE inc...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715769609149064
更新日期:1996-11-01 00:00:00
abstract::In aerobes, oxygen is essential for maintenance of life. However, incomplete reduction of oxygen leads to generation of reactive oxygen species. These oxidants oxidise biological macromolecules present in their vicinity and thereby impair cellular functions causing oxidative stress (OS). Aerobes have evolved both enzy...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.1080/10715762.2019.1702656
更新日期:2020-01-01 00:00:00
abstract::Cystine, an oxidized form of cysteine (Cys), is imported into cells via the protein xCT, which is also associated with the export of glutamate as the counter amino acid. In the current study, we attempted to rationalize roles of xCT in the livers of male mice. While xCT was not expressed in the livers of ordinary mice...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715762.2017.1282157
更新日期:2017-01-01 00:00:00
abstract::Oxidative stress is associated with many cardiovascular diseases, such as hypertension and arteriosclerosis. Oxidative stress reportedly activates the L-type voltage-gated calcium channel (VDCCL) and elevates [Ca2+]i in many cells. However, how oxidative stress activates VDCCL under clinical setting and the consequenc...
journal_title:Free radical research
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doi:10.1080/10715762.2018.1556394
更新日期:2019-01-01 00:00:00
abstract::The metabolism of paraquat generates oxygen radicals. Paraquat has thus been suggested as a model compound to induce oxidative damage to DNA, lipids and proteins in different cells and tissues, although experimental data are inconsistent. In order to explore the possibilities for an animal model of oxidative DNA damag...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760000300421
更新日期:2000-05-01 00:00:00
abstract::The present study was designed to determine whether hydroxymethylglutaryl-CoA reductase inhibitors (statins) modulate the NO production via iNOS in adipocytes stimulated by lipopolysaccharide (L) and tumour necrosis factor-alpha (T). Well-differentiated 3T3-L1 adipocytes significantly produced NO by LT-treatment. Pre-...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760701534368
更新日期:2007-09-01 00:00:00
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journal_title:Free radical research
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doi:10.1080/10715760600632545
更新日期:2006-07-01 00:00:00
abstract::Anxiety disorders are the most common mental illness in the USA affecting 18% of the population. The cause(s) of anxiety disorders is/are not completely clear, and research in the neurobiology of anxiety at the molecular level is still rather limited. Although mounting clinical and preclinical evidence now indicates t...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.1080/10715762.2018.1475733
更新日期:2018-07-01 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
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更新日期:2012-03-01 00:00:00
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journal_title:Free radical research
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doi:10.3109/10715769509065268
更新日期:1995-11-01 00:00:00
abstract::Hydroxyl radical (*OH) generation in the kidney of mice treated with ferric nitrilotriacetate (Fe-NTA) or potassium bromate (KBrO3) in vivo was estimated by the salicylate hydroxylation method, using the optimal experimental conditions we recently reported. Induction of DNA lesions and lipid peroxidation in the kidney...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760701644019
更新日期:2007-11-01 00:00:00
abstract::Mammalian odorant-binding proteins (OBPs) are soluble lipocalins produced in the nasal mucosa and in other epithelial tissues of several animal species, where they are supposed to serve as scavengers for small structurally unrelated hydrophobic molecules. These would include odorants and toxic aldehydes like 4-hydroxy...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2014.910867
更新日期:2014-07-01 00:00:00
abstract::To determine effect of nitric oxide (NO) on cellular glutathione peroxidase (GPX) level in living cells, we measured the activity, protein and mRNA of GPX in rat kidney (KNRK) cells under a high NO condition. Combined treatment of lipopolysaccharide (LPS, 1 microgram/ml) and tumor necrosis factor-alpha (TNF-alpha, 50 ...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715760100300851
更新日期:2001-09-01 00:00:00
abstract::Penicillins, as bactericidal antibiotics, have been widely used to treat infections for several decades. Their structure contains both aromatic and thioether moieties susceptible to free radical oxidation. The (•)OH induced oxidation mechanism of amoxicillin was investigated by pulse radiolysis techniques and by final...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715762.2015.1100729
更新日期:2016-01-01 00:00:00
abstract::Individuals with low serum cholesterol experience greater than expected age-adjusted mortality from non-atherosclerotic diseases, including cancer, respiratory and digestive illnesses, but the basis for these associations remains unclear. The current investigation considered the hypothesis that hypocholesterolemia is ...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.3109/10715769609149049
更新日期:1996-09-01 00:00:00
abstract::Recent research about the role of free radical derivatives of oxygen and nitrogen in biological systems has highlighted the possibility that antioxidants, such as vitamin E, that prevent these processes in vitro may be capable of carrying out a similar function in living organisms in vivo. There is increasing evidence...
journal_title:Free radical research
pub_type: 杂志文章,评审
doi:10.3109/10715769709097827
更新日期:1997-06-01 00:00:00
abstract::The toxic effect of copper was evaluated in sunflower plants by means of root elongation, lipid peroxidation and antioxidative enzyme activities. Plants were grown under controlled environmental conditions in hydroponic culture for two weeks and exposed to different copper concentrations for an additional week. Determ...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715769900301311
更新日期:1999-12-01 00:00:00
abstract::The concentration of taurine is high in the lens. However, its function therein remains unknown. Studies from other tissues suggest that in addition to several other modes of action, it acts as an antioxidant. We therefore hypothesize that taurine may be a part of the antioxidant defense mechanisms involved in protect...
journal_title:Free radical research
pub_type: 杂志文章
doi:10.1080/10715769800300221
更新日期:1998-09-01 00:00:00