Search results for "Oxidants"
showing 10 items of 878 documents
Elucidation of antioxidant properties of wood bark derived saturated diarylheptanoids: a comprehensive (DFT-supported) understanding.
2013
A series of diarylheptanoids, namely 1,7-bis-(3,4-dihydroxyphenyl)-heptan-3-one-5-O-D-xylopyranoside (oregonin), 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-β-D-xylopyranoside and 1,7-bis-(4-hydroxyphenyl)-heptane-3-one-5-O-β-D-glucopyranoside (platyphylloside), were isolated from the bark of alder family trees, a species widely spread over in Europe. As antioxidants, these natural polyphenols have a promising potential in various fields of application, but their redox reactivity is insufficiently characterized. In this work, their antioxidant activity is described using assays based on DPPH and ABTS(+) radical scavenging, oxygen anion radicals (O2(-)) quenching. The standardized ORA…
Cabbage and fermented vegetables: from death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
2021
International audience; Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT1 R) axis associated with oxidative stress. This leads to insulin resistance …
Trans-epithelial transport of the betalain pigments indicaxanthin and betanin across Caco-2 cell monolayers and influence of food matrix.
2012
Purpose: This study investigated the absorption mechanism of the phytochemicals indicaxanthin and betanin and the influence of their food matrix (cactus pear and red beet) on the intestinal transport. Methods: Trans-epithelial transport of dietary-consistent amounts of indicaxanthin and betanin in Caco-2 cell monolayers seeded on TranswellR inserts was measured in apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction, under an inwardly directed pH gradient (pH 6.0/7.4, AP/BL) mimicking luminal and serosal sides of human intestinal epithelium. The effect of inhibitors of membrane transporters on the absorption was also evaluated. Contribution of the paracellular route was…
Biodiversity, evolution and adaptation of fungi in exstreme environments
2013
Fungi play irreplaceable roles for ecosystem functioning. They may adopt different life styles, for example saprotrophs, symbionts or parasites: some species are cosmopolitan with a wide distribution and others, thanks to they ecological plasticity, may adapt to harsh environments precluded to most of life forms. In stressing conditions, their role is even more crucial for the recycling of organic matter or favouring nutrients uptake. When the conditions become really extreme and competion is low, fungi focus on extremotollerance and evolve peculiar competences to exploit natural or xenobiotic resources in the particular constraints imposed by the environment. This paper focuses on three di…
A metabolomic approach to dry eye disorders. The role of oral supplements with antioxidants and omega 3 fatty acids.
2014
Purpose We used nuclear magnetic resonance spectroscopy of hydrogen-1 nuclei (1H NMR S) to analyze the metabolic profile of reflex tears from patients with dry eye disorders. Methods We performed a prospective case-control study involving 90 participants: 55 patients diagnosed with dry eye syndrome (DESG) and 35 healthy subjects (control group, CG). From the DESG, two subgroups were formed: mild DES (n=22) and moderate DES (n=33). Participants were prescribed an oral nutraceutic supplementation containing antioxidants and essential polyunsaturated fatty acids to be taken as three capsules per day for 3 months. Reflex tears (20–30 µl) were collected from the tear meniscus of both eyes of eac…
Synthetic antioxidants: biochemical actions and interference with radiation, toxic compounds, chemical mutagens and chemical carcinogens.
1984
Abstract Biological actions of 4 commonly used synthetic antioxidants — butylated hydroxyanisole, butylated hydroxytoluene, ethoxquin and propul gallate — on the molecular, cellular and organ level are compiled. Such actions may be divided into modulation of growth, macromolecule synthesis and differentiation, modulation of immune response, interference with oxygen activation and miscellaneous. Moreover, an overview of beneficial and adverse interactions of these antioxidants with exogenous noxae is given. Beneficial interactions include radioprotection, protection against acute toxicity of chemicals, antimutagenic activity and antitumorigenic action. Possible mechanisms of the antitumorige…
Behavior of the total antioxidant status in a group of subjects with metabolic syndrome.
2014
AIM: Our purpose was to examine the total antioxidant status (TAS) in subjects with metabolic syndrome (MS) subdivided according to the presence or not of diabetes mellitus. METHODS: We enrolled 106 subjects (45 women, 61 men) with MS subsequently subdivided in diabetics (14 women, 29 men) and nondiabetics (31 women, 29 men). TAS was obtained using an Assay kit which relies on the ability of plasma antioxidant substances to inhibit the oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline sulfonic acid) to the radical ABTS+. RESULTS: In the group of MS subjects a significant decrease in TAS (p<0.05) in comparison with normal controls was evident. This difference was present between normal subje…
Involvement of hydrogen and lipid peroxides in acute tobacco smoking-induced platelet hyperactivity
1995
Previous studies have established that cigarette smoking results in acute platelet hyperaggregability. We investigated whether changes in plasma oxidative properties could occur after smoking and whether such changes could be responsible for this enhanced platelet activity. In the present work, we report that platelets from nonsmokers become hyperactive after incubation with plasma prepared from blood of smokers obtained 10 min after smoking. This effect was not observed with presmoking plasma and could be inhibited in vitro by adding either catalase or reduced glutathione plus peroxidase to plasma or 2,6-di-tert-butyl-p-cresol (BHT) to platelets before incubation. Comparison of pre- and p…
Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity
2021
Abstract Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells. Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4+ as well as CD8+ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T…
Absorption, excretion, and distribution of dietary antioxidant betalains in LDLs: potential health effects of betalains in humans
2004
Background: Betalains were recently identified as natural antioxidants. However, little is known about their bioavailability from dietary sources. Objective: The objective was to evaluate the bioavailability of betalains from dietary sources. Design: The plasma kinetics and urinary excretion of betalains were studied in healthy volunteers (n 8) after a single ingestion of 500 g cactus pear fruit pulp, which provided 28 and 16 mg indicaxanthin and betanin, respectively. The incorporation of betalains in LDL and the resistance of the particles to ex vivo–induced oxidation was also researched. Results: Betanin and indicaxanthin reached their maximum plasma concentrations 3 h after the fruit me…