Antioxidants

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Open AccessReview

Silymarin as a Natural Antioxidant: An Overview of the Current Evidence and Perspectives

by Peter F. Surai

Antioxidants 2015, 4(1), 204-247; https://doi.org/10.3390/antiox4010204 - 20 Mar 2015

Cited by 500 | Viewed by 29353

Silymarin (SM), an extract from the Silybum marianum (milk thistle) plant containing various flavonolignans (with silybin being the major one), has received a tremendous amount of attention over the last decade as a herbal remedy for liver treatment. In many cases, the antioxidant [...] Read more.

Silymarin (SM), an extract from the Silybum marianum (milk thistle) plant containing various flavonolignans (with silybin being the major one), has received a tremendous amount of attention over the last decade as a herbal remedy for liver treatment. In many cases, the antioxidant properties of SM are considered to be responsible for its protective actions. Possible antioxidant mechanisms of SM are evaluated in this review. (1) Direct scavenging free radicals and chelating free Fe and Cu are mainly effective in the gut. (2) Preventing free radical formation by inhibiting specific ROS-producing enzymes, or improving an integrity of mitochondria in stress conditions, are of great importance. (3) Maintaining an optimal redox balance in the cell by activating a range of antioxidant enzymes and non-enzymatic antioxidants, mainly via Nrf2 activation is probably the main driving force of antioxidant (AO) action of SM. (4) Decreasing inflammatory responses by inhibiting NF-κB pathways is an emerging mechanism of SM protective effects in liver toxicity and various liver diseases. (5) Activating vitagenes, responsible for synthesis of protective molecules, including heat shock proteins (HSPs), thioredoxin and sirtuins and providing additional protection in stress conditions deserves more attention. (6) Affecting the microenvironment of the gut, including SM-bacteria interactions, awaits future investigations. (7) In animal nutrition and disease prevention strategy, SM alone, or in combination with other hepatho-active compounds (carnitine, betaine, vitamin B₁₂, etc.), might have similar hepatoprotective effects as described in human nutrition. Full article

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Open AccessArticle

Antioxidant, Biomolecule Oxidation Protective Activities of Nardostachys jatamansi DC and Its Phytochemical Analysis by RP-HPLC and GC-MS

by Sakina Razack, Kandikattu Hemanth Kumar, Ilaiyaraja Nallamuthu, Mahadeva Naika and Farhath Khanum

Antioxidants 2015, 4(1), 185-203; https://doi.org/10.3390/antiox4010185 - 12 Mar 2015

Cited by 64 | Viewed by 10332

Abstract

The study aimed at analyzing the metabolite profile of Nardostachys jatamansi using RP-HPLC, GC-MS and also its antioxidant, biomolecule protective and cytoprotective properties. The 70% ethanolic extract of Nardostachys jatamansi (NJE) showed the presence of polyphenols and flavonoids (gallic acid, catechin, chlorogenic acid, [...] Read more.

The study aimed at analyzing the metabolite profile of Nardostachys jatamansi using RP-HPLC, GC-MS and also its antioxidant, biomolecule protective and cytoprotective properties. The 70% ethanolic extract of Nardostachys jatamansi (NJE) showed the presence of polyphenols and flavonoids (gallic acid, catechin, chlorogenic acid, homovanillin, epicatechin, rutin hydrate and quercetin-3-rhamnoside) analyzed by RP-HPLC, whereas hexane extract revealed an array of metabolites (fatty acids, sesquiterpenes, alkane hydrocarbons and esters) by GC-MS analysis. The antioxidant assays showed the enhanced potency of NJE with a half maximal inhibitory concentration (IC₅₀) value of 222.22 ± 7.4 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 13.90 ± 0.5 μg/mL for 2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 113.81 ± 4.2 μg/mL for superoxide, 948 ± 21.1 μg/mL for metal chelating and 12.3 ± 0.43 mg FeSO₄ equivalent/g of extract for ferric reducing antioxidant power assays and was more potent than hexane extract. NJE effectively inhibited 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidation of biomolecules analyzed by pBR322 plasmid DNA damage, protein oxidation of bovine serum albumin and lipid peroxidation assays. The observed effects might be due to the high content of polyphenols, 53.06 ± 2.2 mg gallic acid equivalents/g, and flavonoids, 25.303 ± 0.9 mg catechin equivalents/g, of NJE compared to the hexane fraction. Additionally, the extract abrogated the protein, carbonyl, and ROS formation, and NJE showed cytotoxicity in SH-SY5Y neuronal cells above 75 μg/mL. Thus, the study suggests that the herb unequivocally is a potential source of antioxidants and could aid in alleviating oxidative stress-mediated disorders. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
RP-HPLC chromatogram of the identified polyphenols in the ethanolic extract of N. jatamansi. Full article ">Figure 2
Total ion chromatogram of the hexane fraction of N. jatamansi. Full article ">Figure 3
Inhibition of DNA damage by NJE. Lane 1, plasmid DNA (pBR322); Lane 2, DNA + 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH); Lane 3, DNA + AAPH + 5 μg extract; Lane 4, DNA + AAPH + 10 μg extract; Lane 5, DNA + AAPH + 15 μg extract; Lane 6, DNA + AAPH + 10 μg GA. Full article ">Figure 4
Inhibition of protein oxidation by NJE. Lane 1, BSA; Lane 2, BSA + AAPH; Lane 3, BSA + AAPH + 5 μg extract; Lane 4, BSA + AAPH + 10 μg extract; Lane 5, BSA + AAPH + 15 μg extract; Lane 6, BSA + AAPH + 20 μg extract; Lane 7, BSA + AAPH + 25 μg extract; Lane 8, BSA + AAPH + 10 μg GA. Full article ">Figure 5
Antioxidant effects of NJE and gallic acid on AAPH-induced ROS generation. Full article ">Figure 6
Inhibitory effects of NJE and gallic acid on AAPH-induced protein carbonyl formation. Full article ">Figure 7
Effects of NJE on LDH release in SH-SY5Y neuronal cells (* p < 0.05 vs. control). Full article ">

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Open AccessArticle

The Effect of Convolvulus arvensis Dried Extract as a Potential Antioxidant in Food Models

by Nurul Aini Mohd Azman, Maria Gabriela Gallego, Luis Juliá, Lluis Fajari and MaríaPilar Almajano

Antioxidants 2015, 4(1), 170-184; https://doi.org/10.3390/antiox4010170 - 10 Mar 2015

Cited by 22 | Viewed by 8055

Abstract

In this study, the antioxidant activity of the Convolvulus arvensis Linn (CA) ethanol extract has been evaluated by different ways. The antioxidant activity of the extract assessed by 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing [...] Read more.

In this study, the antioxidant activity of the Convolvulus arvensis Linn (CA) ethanol extract has been evaluated by different ways. The antioxidant activity of the extract assessed by 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) was 1.62 mmol Trolox equivalents (TE)/g DW, 1.71 mmol TE/g DW and 2.11 mmol TE/g DW, respectively. CA ethanol extract exhibited scavenging activity against the methoxy radical initiated by the Fenton reaction and measured by Electron Paramagnetic Resonance (EPR). The antioxidant effects of lyophilised CA measured in beef patties containing 0.1% and 0.3% (w/w) CA stored in modified atmosphere packaging (MAP) (80% O₂ and 20% CO₂) was determined. A preliminary study of gelatine based film containing CA showed a strong antioxidant effect in preventing the degradation of lipid in muscle food. Thus, the present results indicate that CA extract can be used as a natural food antioxidant. Full article

(This article belongs to the Special Issue Natural Products as Antioxidants)

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Open AccessArticle

Ceruloplasmin and Hypoferremia: Studies in Burn and Non-Burn Trauma Patients

by Michael A. Dubick, Johnny L. Barr, Carl L. Keen and James L. Atkins

Antioxidants 2015, 4(1), 153-169; https://doi.org/10.3390/antiox4010153 - 6 Mar 2015

Cited by 15 | Viewed by 7240

Abstract

Objective: Normal iron handling appears to be disrupted in critically ill patients leading to hypoferremia that may contribute to systemic inflammation. Ceruloplasmin (Cp), an acute phase reactant protein that can convert ferrous iron to its less reactive ferric form facilitating binding to [...] Read more.

Objective: Normal iron handling appears to be disrupted in critically ill patients leading to hypoferremia that may contribute to systemic inflammation. Ceruloplasmin (Cp), an acute phase reactant protein that can convert ferrous iron to its less reactive ferric form facilitating binding to ferritin, has ferroxidase activity that is important to iron handling. Genetic absence of Cp decreases iron export resulting in iron accumulation in many organs. The objective of this study was to characterize iron metabolism and Cp activity in burn and non-burn trauma patients to determine if changes in Cp activity are a potential contributor to the observed hypoferremia. Material and Methods: Under Brooke Army Medical Center Institutional Review Board approved protocols, serum or plasma was collected from burn and non-burn trauma patients on admission to the ICU and at times up to 14 days and measured for indices of iron status, Cp protein and oxidase activity and cytokines. Results: Burn patients showed evidence of anemia and normal or elevated ferritin levels. Plasma Cp oxidase activity in burn and trauma patients were markedly lower than controls on admission and increased to control levels by day 3, particularly in burn patients. Plasma cytokines were elevated throughout the 14 days study along with evidence of an oxidative stress. No significant differences in soluble transferrin receptor were noted among groups on admission, but levels in burn patients were lower than controls for the first 5 days after injury. Conclusion: This study further established the hypoferremia and inflammation associated with burns and trauma. To our knowledge, this is the first study to show an early decrease in Cp oxidase activity in burn and non-burn trauma patients. The results support the hypothesis that transient loss of Cp activity contributes to hypoferremia and inflammation. Further studies are warranted to determine if decreased Cp activity increases the risk of iron-induced injury following therapeutic interventions such as transfusions with blood that has undergone prolonged storage in trauma resuscitation. Full article

(This article belongs to the Special Issue Redox Stress and Redox Homeostatic Response to Trauma and Injury)

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Serum iron (Fe+2), unsaturated iron binding capacity and total iron binding capacity over 14 days in 10 thermally injured patients. Data expressed as mean ± SE. Dotted lines denote the upper and lower normal limits. Full article ">Figure 2
Total serum iron, zinc and copper concentrations in 10 thermally injured patients. Data expressed as mean ± SE. Control data were from historic normal subjects. Full article ">Figure 3
Serum transferrin and ferritin concentrations in 10 thermally injured patients. Data expressed as mean ± SE. Dotted lines denote the upper and lower normal limits. Full article ">Figure 4
Serum glutathione peroxidase activity, Fe+2 reducing potential and uric acid concentrations in 10 thermally injured subjects. Data expressed as mean ± SE. Dotted lines denote the upper and lower normal limits. Full article ">Figure 5
Ceruloplasmin protein concentrations and oxidase activity over 14 days in thermally injured and non-burned trauma patients. Data expressed as mean ± SE from 24 burned and 35 non-burned trauma patients and 10 healthy controls. Full article ">Figure 6
Soluble transferrin receptor levels in plasma from thermally injured and non-burned trauma patients. Data expressed as mean ± SE from 24 burned and 35 non-burned trauma patients and 10 healthy controls. Full article ">

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Open AccessReview

Protracted Oxidative Alterations in the Mechanism of Hematopoietic Acute Radiation Syndrome

by Nikolai V. Gorbunov and Pushpa Sharma

Antioxidants 2015, 4(1), 134-152; https://doi.org/10.3390/antiox4010134 - 27 Feb 2015

Cited by 22 | Viewed by 9441

Abstract

The biological effects of high-dose total body ionizing irradiation [(thereafter, irradiation (IR)] are attributed to primary oxidative breakage of biomolecule targets, mitotic, apoptotic and necrotic cell death in the dose-limiting tissues, clastogenic and epigenetic effects, and cascades of functional and reactive responses leading [...] Read more.

The biological effects of high-dose total body ionizing irradiation [(thereafter, irradiation (IR)] are attributed to primary oxidative breakage of biomolecule targets, mitotic, apoptotic and necrotic cell death in the dose-limiting tissues, clastogenic and epigenetic effects, and cascades of functional and reactive responses leading to radiation sickness defined as the acute radiation syndrome (ARS). The range of remaining and protracted injuries at any given radiation dose as well as the dynamics of post-IR alterations is tissue-specific. Therefore, functional integrity of the homeostatic tissue barriers may decline gradually within weeks in the post-IR period culminating with sepsis and failure of organs and systems. Multiple organ failure (MOF) leading to moribundity is a common sequela of the hemotapoietic form of ARS (hARS). Onset of MOF in hARS can be presented as “two-hit phenomenon” where the “first hit” is the underlying consequences of the IR-induced radiolysis in cells and biofluids, non-septic inflammation, metabolic up-regulation of pro-oxidative metabolic reactions, suppression of the radiosensitive hematopoietic and lymphoid tissues and the damage to gut mucosa and vascular endothelium. While the “second hit” derives from bacterial translocation and spread of the bacterial pathogens and inflammagens through the vascular system leading to septic inflammatory, metabolic responses and a cascade of redox pro-oxidative and adaptive reactions. This sequence of events can create a ground for development of prolonged metabolic, inflammatory, oxidative, nitrative, and carbonyl, electrophilic stress in crucial tissues and thus exacerbate the hARS outcomes. With this perspective, the redox mechanisms, which can mediate the IR-induced protracted oxidative post-translational modification of proteins, oxidation of lipids and carbohydrates and their countermeasures in hARS are subjects of the current review. Potential role of ubiquitous, radioresistant mesenchymal stromal cells in the protracted responses to IR and IR-related septicemia is also discussed. Full article

(This article belongs to the Special Issue Redox Stress and Redox Homeostatic Response to Trauma and Injury)

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Figure 1
Kaplan–Meier survival plot and post-irradiation (post-IR) events in mouse model of the hematopoietic acute radiation syndrome (hARS). 1—Radiolysis due to pulse-irradiation and associated formation of (i) electrophilic and nucleophilic species; (ii) reactive oxygen and nitrogen species (ROS and RNS); (iii) electrophil-derived danger-associated molecular patterns (DAMPs), pro-inflammatory oxysterols, and clastogenic plasma factors in the target-cells and fluids. Time-lag is minutes; 2—Induction of cell and organ system responses to the targeted and non-targeted effects including redox-stress due to disruption of mitochondrial redox circuitry in the photon-targeted mitochondria; electrophilic stress; epigenetic changes. Time-lag is hours; 3—Direct cytocidal response (time lag is from hours through two to three days, end of prodrome); Development of clonogenic suppression, acute phase response, non-septic inflammation, lymphopenia, neutropenia, immunosuppression (time lag is days); 4—Protracted oxidative, nitrative, electrophilic and proteotoxic stress; development of clastogenic, metabolic and epigenetic responses; tissue remodeling and repopulation. Time lag for the reactive response is days; 5—Morbidity latent period: regressive hematological changes, development of coagulopathy and anemia, impairment of tissue barriers. Time-lag is 1–1.5 week; 6—Enteric bacteria breach the gut barriers; development of bacteremia, interstitial hemorrhage, moribundity and mortality (time-lag is 1–1.5 week); 7—Recovery during post-survival period (time-lag is days). The survival plot is adapted with modifications from: Kiang et al., 2014 [<a href="#B23-antioxidants-04-00134" class="html-bibr">23</a>]. Experimental conditions: hARS was induced by exposure of B6D2F1/J mice to 9.5 Gy whole-body bilateral 60Co gamma-photon radiation, delivered at a dose rate of 0.4 Gy/min (LD50/30). Full article ">Figure 2
Development of hemorrhagic vasculopathy in irradiated B6D2F1/J mice at the mortality period. Gross pathology and histopathology assessment (hematoxylin and eosin staining, i.e., H & E) of intracranial hemorrhage in moribund B6D2F1/J mice subjected to hARS. Panel A. (1) Images a mouse skull: dorsal plane (left) and lateral plan (right); (2) Image of tongue; (3) Image of a fragment of skull shown in (1). Brownish areas of extravasated blood are indicated with red arrows. Panels B1 and B2 are specimens from a sham animal. Tongue is indicated with a black arrow in B1. Panels C1, C2, and D are specimens from an irradiated animal. A fragment of cranium is indicated with a black arrow in C1 where the presence of epidural hemorrhage is observable. Panels B2 and C2 display H & E-staining images of coronal sections through the cerebellar cortex. Panel D displays gross-image of coronal sections through entire brain. As shown in C1 and D subdural and interstitial hemorrhage randomly occurred in different part of the brain; predominantly affecting cerebellum and olfactory. Experimental conditions: as indicated in the <a href="#antioxidants-04-00134-f001" class="html-fig">Figure 1</a>. Full article ">Figure 3
Radiation-induced depletion of bone marrow tissue with hematopoietic cells occurs in mice experienced hARS. Hematopoietic cells are indicated with white arrows in a “sham” specimen (left panel). Depletion with hematopoietic cells is observed after IR (ionizing irradiation ) with 9.5 Gy (gray). The myeloablation reveals the presence of the open reticular meshwork of the stromal cells. The stromal cells (in blue) are indicated with black arrows in the right panel. A large macrophage containing phagocytized hematopoietic cells is shown with a red arrow in the right panel. Collected at 22nd day following IR. Hematoxylin and eosin staining. Experimental conditions are indicated in <a href="#antioxidants-04-00134-f001" class="html-fig">Figure 1</a>. Full article ">

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Open AccessArticle

Oil Content, Fatty Acid Composition and Distributions of Vitamin-E-Active Compounds of Some Fruit Seed Oils

by Bertrand Matthäus and Mehmet Musazcan Özcan

Antioxidants 2015, 4(1), 124-133; https://doi.org/10.3390/antiox4010124 - 29 Jan 2015

Cited by 73 | Viewed by 8052

Abstract

Oil content, fatty acid composition and the distribution of vitamin-E-active compounds of selected Turkish seeds that are typically by-products of the food processing industries (linseed, apricot, pear, fennel, peanut, apple, cotton, quince and chufa), were determined. The oil content of the samples ranged [...] Read more.

Oil content, fatty acid composition and the distribution of vitamin-E-active compounds of selected Turkish seeds that are typically by-products of the food processing industries (linseed, apricot, pear, fennel, peanut, apple, cotton, quince and chufa), were determined. The oil content of the samples ranged from 16.9 to 53.4 g/100 g. The dominating fatty acids were oleic acid (apricot seed oil, peanut oil, and chufa seed oil) in the range of 52.5 to 68.4 g/100 g and linoleic acid (pear seed oil, apple seed oil, cottonseed oil and quince seed oil) with 48.1 to 56.3 g/100 g, while in linseed oil mainly α-linolenic acid (53.2 g/100 g) and in fennel seed oil mainly 18:1 fatty acids (80.5 g/100 g) with petroselinic acid predominating. The total content of vitamin-E-active compounds ranged from 20.1 (fennel seed oil) to 96 mg/100 g (apple seed oil). The predominant isomers were established as α- and γ-tocopherol. Full article

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Open AccessArticle

Oxidation Stability of Pig Liver Pâté with Increasing Levels of Natural Antioxidants (Grape and Tea)

by Mirian Pateiro, José M. Lorenzo, José A. Vázquez and Daniel Franco

Antioxidants 2015, 4(1), 102-123; https://doi.org/10.3390/antiox4010102 - 27 Jan 2015

Cited by 25 | Viewed by 7020

Abstract

The present study investigated the effect of the addition of increasing levels of the natural antioxidants tea (TEA) and grape seed extracts (GRA) on the physiochemical and oxidative stability of refrigerated stored pig pâtés. In addition, a synthetic antioxidant and a control batch [...] Read more.

The present study investigated the effect of the addition of increasing levels of the natural antioxidants tea (TEA) and grape seed extracts (GRA) on the physiochemical and oxidative stability of refrigerated stored pig pâtés. In addition, a synthetic antioxidant and a control batch were used, thus a total of eight batches of liver pâté were prepared: CON, BHT, TEA (TEA₅₀, TEA₂₀₀ and TEA₁₀₀₀) and GRA (GRA₅₀, GRA₂₀₀ and GRA₁₀₀₀). Pâté samples were analyzed following 0, 4, 8 and 24 weeks of storage. Color parameters were affected by storage period and level of antioxidant extract. Samples with TEA₂₀₀ and GRA₁₀₀₀levels of extracts showed lower total color difference between 0 and 24 weeks. At the end of storage period, the lower TBARs values were obtained in samples with the highest concentration on natural extract. Overall, the evolution of volatile compounds showed an increase in those ones that arise from the lipid oxidation and samples with TEA₁₀₀₀ extract showed the lowest values. Full article

(This article belongs to the Special Issue Natural Products as Antioxidants)

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Open AccessArticle

Antioxidant Approaches to Management of Ionizing Irradiation Injury

by Joel Greenberger, Valerian Kagan, Hulya Bayir, Peter Wipf and Michael Epperly

Antioxidants 2015, 4(1), 82-101; https://doi.org/10.3390/antiox4010082 - 23 Jan 2015

Cited by 19 | Viewed by 7540

Abstract

Ionizing irradiation induces acute and chronic injury to tissues and organs. Applications of antioxidant therapies for the management of ionizing irradiation injury fall into three categories: (1) radiation counter measures against total or partial body irradiation; (2) normal tissue protection against acute organ [...] Read more.

Ionizing irradiation induces acute and chronic injury to tissues and organs. Applications of antioxidant therapies for the management of ionizing irradiation injury fall into three categories: (1) radiation counter measures against total or partial body irradiation; (2) normal tissue protection against acute organ specific ionizing irradiation injury; and (3) prevention of chronic/late radiation tissue and organ injury. The development of antioxidant therapies to ameliorate ionizing irradiation injury began with initial studies on gene therapy using Manganese Superoxide Dismutase (MnSOD) transgene approaches and evolved into applications of small molecule radiation protectors and mitigators. The understanding of the multiple steps in ionizing radiation-induced cellular, tissue, and organ injury, as well as total body effects is required to optimize the use of antioxidant therapies, and to sequence such approaches with targeted therapies for the multiple steps in the irradiation damage response. Full article

(This article belongs to the Special Issue Redox Stress and Redox Homeostatic Response to Trauma and Injury)

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Figure 1
Structures of 4-Amino-Tempo (A); XJB-5-131 (B); JP4-039 (C); and MMS350 (D). Full article ">Figure 2
Effective radiation mitigation by two GS-nitroxide analogs (XJB-5-131 and JP4-039). Groups of 15 C57BL/6NHsd mice received total body irradiation, and then 24 h later intravenous administration of 100 μL of F14 liposomes containing either XJB-5-131 or JP4-039, standardized for equimolar concentration. The heavier molecular weight of XJB-5-131 requires larger quantities to achieve an equimolar concentration with JP4-039. There was equivalent radiation mitigation by both drugs. Full article ">Figure 3
Effective mitigation of total body irradiation damage in C57BL/6NHsd mice by intravenous administration of JP4-039. Experiments shown are over a course of a year accounting for the TBI dose “drift” of the LD50/30. At 3 different time points during a single calendar year, experiments were carried out delivering JP4-039/F15 in 100 μL volume containing 20 mg/kg drug, to mice. In these experiments, the LD50/30 was noted to “drift” over the course of the year and could not be explained by changes in the Cesium-70 Gamma Cell irradiator, supplier of mice, age of mice, gender of mice (all were female), diet, or other factors in the animal care facility. In all experiments, despite the “drift” of the LD50/30, JP4-039 was an effective mitigator against total body irradiation. Full article ">Figure 4
Mitigation of total body irradiation damage to C3H/HeNHsd mice by intravenous JP4-039/F14 antioxidant small molecule therapy. Groups of C3H/HeNHsd mice (n = 15) received total body irradiation, and 24 h later intravenous administration of 100 μL of F14 liposomes containing 100 μg of JP4-039. Survival was quantitated, and there was a significant increase in survival in mice given JP4-039. Full article ">

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Open AccessReview

Modulation of Radiation Response by the Tetrahydrobiopterin Pathway

by Rupak Pathak, Amrita K. Cheema, Simina M. Boca, Kimberly J. Krager, Martin Hauer-Jensen and Nukhet Aykin-Burns

Antioxidants 2015, 4(1), 68-81; https://doi.org/10.3390/antiox4010068 - 22 Jan 2015

Cited by 15 | Viewed by 9102

Abstract

Ionizing radiation (IR) is an integral component of our lives due to highly prevalent sources such as medical, environmental, and/or accidental. Thus, understanding of the mechanisms by which radiation toxicity develops is crucial to address acute and chronic health problems that occur following [...] Read more.

Ionizing radiation (IR) is an integral component of our lives due to highly prevalent sources such as medical, environmental, and/or accidental. Thus, understanding of the mechanisms by which radiation toxicity develops is crucial to address acute and chronic health problems that occur following IR exposure. Immediate formation of IR-induced free radicals as well as their persistent effects on metabolism through subsequent alterations in redox mediated inter- and intracellular processes are globally accepted as significant contributors to early and late effects of IR exposure. This includes but is not limited to cytotoxicity, genomic instability, fibrosis and inflammation. Damage to the critical biomolecules leading to detrimental long-term alterations in metabolic redox homeostasis following IR exposure has been the focus of various independent investigations over last several decades. The growth of the “omics” technologies during the past decade has enabled integration of “data from traditional radiobiology research”, with data from metabolomics studies. This review will focus on the role of tetrahydrobiopterin (BH4), an understudied redox-sensitive metabolite, plays in the pathogenesis of post-irradiation normal tissue injury as well as how the metabolomic readout of BH4 metabolism fits in the overall picture of disrupted oxidative metabolism following IR exposure. Full article

(This article belongs to the Special Issue Redox Stress and Redox Homeostatic Response to Trauma and Injury)

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Open AccessArticle

Effect of Addition of Natural Antioxidants on the Shelf-Life of “Chorizo”, a Spanish Dry-Cured Sausage

by Mirian Pateiro, Roberto Bermúdez, José Manuel Lorenzo and Daniel Franco

Antioxidants 2015, 4(1), 42-67; https://doi.org/10.3390/antiox4010042 - 14 Jan 2015

Cited by 62 | Viewed by 8402

Abstract

The dose effect of the addition of natural antioxidants (tea, chestnut, grape seed and beer extracts) on physicochemical, microbiological changes and on oxidative stability of dry-cured “chorizo”, as well as their effect during the storage under vacuum conditions was evaluated. Color parameters were [...] Read more.

The dose effect of the addition of natural antioxidants (tea, chestnut, grape seed and beer extracts) on physicochemical, microbiological changes and on oxidative stability of dry-cured “chorizo”, as well as their effect during the storage under vacuum conditions was evaluated. Color parameters were significantly (p < 0.05) affected by the addition of antioxidants so that samples that contained antioxidants were more effective in maintaining color. The improving effects were dose-dependent with highest values with the dose of 50 mg/kg during ripening and depend on the extract during vacuum packaging. Addition of antioxidants decreased (p < 0.05) the oxidation, showing thiobarbituric acid reactive substances (TBARS) values below 0.4 mg MDA/kg. Natural antioxidants matched or even improved the results obtained for butylated hydroxytoluene (BHT). Regarding texture profile analysis (TPA) analysis, hardness values significantly (p < 0.001) decreased with the addition of antioxidants, obtaining the lower results with the dose of 200 mg/kg both during ripening and vacuum packaging. Antioxidants reduced the counts of total viable counts (TVC), lactic acid bacteria (LAB), mold and yeast. Free fatty acid content during ripening and under vacuum conditions showed a gradual and significant (p < 0.05) release as a result of lipolysis. At the end of ripening, the addition of GRA₁₀₀₀ protected chorizos from oxidative degradation. Full article

(This article belongs to the Special Issue Natural Products as Antioxidants)

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Open AccessArticle

Curcumin Stimulates the Antioxidant Mechanisms in Mouse Skin Exposed to Fractionated γ-Irradiation

by Ganesh Chandra Jagetia and Golgod Krishnamurthy Rajanikant

Antioxidants 2015, 4(1), 25-41; https://doi.org/10.3390/antiox4010025 - 13 Jan 2015

Cited by 50 | Viewed by 9394

Abstract

Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect [...] Read more.

Fractionated irradiation is one of the important radiotherapy regimens to treat different types of neoplasia. Despite of the immense therapeutic gains accrued by delivering fractionated irradiation to tumors, the radiation burden on skin increases significantly. Low doses of irradiation to skin adversely affect its molecular and metabolic status. The use of antioxidant/s may help to alleviate the radiation-induced changes in the skin and allow delivering a higher dose of radiation to attain better therapeutic gains. Curcumin is an antioxidant and a free radical scavenging dietary supplement, commonly used as a flavoring agent in curries. Therefore, the effect of 100 mg/kg body weight curcumin was studied on the antioxidant status of mice skin exposed to a total dose of 10, 20 and 40 Gy γ-radiation below the rib cage delivered as a single fraction of 2 Gy per day for 5, 10 or 20 days. Skin biopsies from both the curcumin treated or untreated irradiated groups were collected for the biochemical estimations at various post-irradiation times. The irradiation of animals caused a dose dependent decline in the glutathione concentration, glutathione peroxidase, and superoxide dismutase activities and increased the lipid peroxidation in the irradiated skin. Curcumin treatment before irradiation resulted in a significant rise in the glutathione concentration and activities of both the glutathione peroxidase and superoxide dismutase enzymes in mouse skin, whereas lipid peroxidation declined significantly. The present study indicates that curcumin treatment increased the antioxidant status of mouse exposed to different doses of fractionated γ-radiation. Full article

(This article belongs to the Special Issue Redox Stress and Redox Homeostatic Response to Trauma and Injury)

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Open AccessEditorial

Acknowledgement to Reviewers of Antioxidants in 2014

by Antioxidants Editorial Office

Antioxidants 2015, 4(1), 22-24; https://doi.org/10.3390/antiox4010022 - 7 Jan 2015

Viewed by 4121

Abstract

The editors of Antioxidants would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2014:[...] Full article

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Open AccessReview

Studies on Modulation of Gut Microbiota by Wine Polyphenols: From Isolated Cultures to Omic Approaches

by Montserrat Dueñas, Carolina Cueva, Irene Muñoz-González, Ana Jiménez-Girón, Fernando Sánchez-Patán, Celestino Santos-Buelga, M. Victoria Moreno-Arribas and Begoña Bartolomé

Antioxidants 2015, 4(1), 1-21; https://doi.org/10.3390/antiox4010001 - 5 Jan 2015

Cited by 82 | Viewed by 12708

Abstract

Moderate consumption of wine seems to produce positive health effects derived from the occurrence of bioactive polyphenols. The gut microbiota is involved in the metabolism of phenolic compounds, and these compounds and/or their metabolites may modulate gut microbiota through the stimulation of the [...] Read more.

Moderate consumption of wine seems to produce positive health effects derived from the occurrence of bioactive polyphenols. The gut microbiota is involved in the metabolism of phenolic compounds, and these compounds and/or their metabolites may modulate gut microbiota through the stimulation of the growth of beneficial bacteria and the inhibition of pathogenic bacteria. The characterization of bacterial metabolites derived from polyphenols is essential in order to understand their effects, including microbial modulation, and therefore to associate dietary intake with particular health effects. This review aims to summarize the current information about the two-way “wine polyphenols–gut microbiota” interaction, from a perspective based on the experimental and analytical designs used. The availability of advanced methods for monitoring bacterial communities, along with the combination of in vitro and in vivo models, could help to assess the metabolism of polyphenols in the human body and to monitor total bacterial communities, and, therefore, to elucidate the implications of diet on the modulation of microbiota for delivering health benefits. Full article

(This article belongs to the Special Issue Interactions between Dietary Flavonoids and Gut Microbiota: Functional Outcomes)

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Antioxidants, Volume 4, Issue 1 (March 2015) – 13 articles , Pages 1-247

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