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Antioxidants, Volume 5, Issue 3 (September 2016)

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Open AccessReview
A Review of Antioxidant Peptides Derived from Meat Muscle and By-Products
Antioxidants 2016, 5(3), 32; https://doi.org/10.3390/antiox5030032
Received: 12 May 2016 / Revised: 8 September 2016 / Accepted: 9 September 2016 / Published: 20 September 2016
Cited by 34 | Viewed by 2720 | PDF Full-text (556 KB) | HTML Full-text | XML Full-text
Abstract
Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded [...] Read more.
Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded as good materials for the production of bioactive peptides by use of enzymatic hydrolysis or direct solvent extraction. In recent years, there has been a growing number of studies conducted to characterize antioxidant peptides or hydrolysates derived from meat muscle and by-products as well as processed meat products, including dry-cured hams. Antioxidant peptides obtained from animal sources could exert not only nutritional value but also bioavailability to benefit human health. This paper reviews the antioxidant peptides or protein hydrolysates identified in muscle protein and by-products. We focus on the procedure for the generation of peptides with antioxidant capacity including the acquisition of crude peptides, the assessment of antioxidant activity, and the purification and identification of the active fraction. It remains critical to perform validation experiments with a cell model, animal model or clinical trial to eliminate safety concerns before final application in the food system. In addition, some of the common characteristics on structure-activity relationship are also reviewed based on the identified antioxidant peptides. Full article
(This article belongs to the Special Issue Lipid Oxidation in Meat and Poultry)
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Open AccessArticle
Phenolic Compounds and Antioxidant Activity of Phalaenopsis Orchid Hybrids
Antioxidants 2016, 5(3), 31; https://doi.org/10.3390/antiox5030031
Received: 3 July 2016 / Revised: 3 September 2016 / Accepted: 9 September 2016 / Published: 14 September 2016
Cited by 6 | Viewed by 2433 | PDF Full-text (1282 KB) | HTML Full-text | XML Full-text
Abstract
Phalaenopsis spp. is the most commercially and economically important orchid, but their plant parts are often left unused, which has caused environmental problems. To date, reports on phytochemical analyses were most available on endangered and medicinal orchids. The present study was conducted to [...] Read more.
Phalaenopsis spp. is the most commercially and economically important orchid, but their plant parts are often left unused, which has caused environmental problems. To date, reports on phytochemical analyses were most available on endangered and medicinal orchids. The present study was conducted to determine the total phenolics, total flavonoids, and antioxidant activity of ethanol extracts prepared from leaves and roots of six commercial hybrid Phalaenopsis spp. Leaf extracts of “Chian Xen Queen” contained the highest total phenolics with a value of 11.52 ± 0.43 mg gallic acid equivalent per g dry weight and the highest total flavonoids (4.98 ± 0.27 mg rutin equivalent per g dry weight). The antioxidant activity of root extracts evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay and β-carotene bleaching method was higher than those of the leaf extracts. Eleven phenolic compounds were identified, namely, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, vanillin, ferulic acid, sinapic acid, p-coumaric acid, benzoic acid, and ellagic acid. Ferulic, p-coumaric and sinapic acids were concentrated largely in the roots. The results suggested that the root extracts from hybrid Phalaenopsis spp. could be a potential source of natural antioxidants. This study also helps to reduce the amount of this orchid waste in industrial production, as its roots can be exploited for pharmaceutical purposes. Full article
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Open AccessArticle
Protandim Protects Oligodendrocytes against an Oxidative Insult
Antioxidants 2016, 5(3), 30; https://doi.org/10.3390/antiox5030030
Received: 29 June 2016 / Accepted: 2 August 2016 / Published: 7 September 2016
Cited by 2 | Viewed by 5314 | PDF Full-text (5418 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Oligodendrocyte damage and loss are key features of multiple sclerosis (MS) pathology. Oligodendrocytes appear to be particularly vulnerable to reactive oxygen species (ROS) and cytokines, such as tumor necrosis factor-α (TNF), which induce cell death and prevent the differentiation of oligodendrocyte progenitor cells [...] Read more.
Oligodendrocyte damage and loss are key features of multiple sclerosis (MS) pathology. Oligodendrocytes appear to be particularly vulnerable to reactive oxygen species (ROS) and cytokines, such as tumor necrosis factor-α (TNF), which induce cell death and prevent the differentiation of oligodendrocyte progenitor cells (OPCs). Here, we investigated the efficacy of sulforaphane (SFN), monomethyl fumarate (MMF) and Protandim to induce Nrf2-regulated antioxidant enzyme expression, and protect oligodendrocytes against ROS-induced cell death and ROS-and TNF-mediated inhibition of OPC differentiation. OLN-93 cells and primary rat oligodendrocytes were treated with SFN, MMF or Protandim resulting in significant induction of Nrf2-driven (antioxidant) proteins heme oygenase-1, nicotinamide adenine dinucleotide phosphate (NADPH): quinone oxidoreductase-1 and p62/SQSTM1, as analysed by Western blotting. After incubation with the compounds, oligodendrocytes were exposed to hydrogen peroxide. Protandim most potently promoted oligodendrocyte cell survival as measured by live/death viability assay. Moreover, OPCs were treated with Protandim or vehicle control prior to exposing them to TNF or hydrogen peroxide for five days, which inhibited OPC differentiation. Protandim significantly promoted OPC differentiation under influence of ROS, but not TNF. Protandim, a combination of five herbal ingredients, potently induces antioxidants in oligodendrocytes and is able to protect oligodendrocytes against oxidative stress by preventing ROS-induced cell death and promoting OPC differentiation. Full article
(This article belongs to the Special Issue Feature Papers 2016)
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Open AccessArticle
Effects of (+)-Catechin on the Composition, Phenolic Content and Antioxidant Activity of Full-Fat Cheese during Ripening and Recovery of (+)-Catechin after Simulated In Vitro Digestion
Antioxidants 2016, 5(3), 29; https://doi.org/10.3390/antiox5030029
Received: 24 May 2016 / Revised: 24 August 2016 / Accepted: 24 August 2016 / Published: 27 August 2016
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Abstract
(+)-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (at 125–500 ppm) followed by ripening for 90 days at 8 °C and digesting for six hours. Determination of pH, proximate composition, total phenolic content (TPC) and antioxidant activity (AA) [...] Read more.
(+)-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (at 125–500 ppm) followed by ripening for 90 days at 8 °C and digesting for six hours. Determination of pH, proximate composition, total phenolic content (TPC) and antioxidant activity (AA) after manufacture and ripening demonstrated that the addition of (+)-catechin significantly (p ≤ 0.05) decreased the pH of both whey and curd during cheese manufacturing and ripening with no significant (p > 0.05) effect on the moisture, protein and fat contents. (+)-Catechin increased TPC, as well as AA, though the increase was not proportional with increasing the concentration of added (+)-catechin. About 57%–69% of (+)-catechin was retained in the cheese curd, whereas about 19%–39% (depending on the concentration) was recovered from the cheese digesta. Transmission electron micrographs showed that the ripened control cheese had a homogeneous pattern of milk fat globules with regular spacing entrapped in a homogenous structure of casein proteins, whereas the addition of (+)-catechin disrupted this homogenous structure. The apparent interaction between (+)-catechin and cheese fat globules was confirmed by Fourier transform infrared spectroscopy. These associations should be taken into account when incorporating antioxidants, such as (+)-catechin, to create functional dairy products, such as cheese. Full article
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Open AccessArticle
Pharmacognostic and Antioxidant Properties of Dracaena sanderiana Leaves
Antioxidants 2016, 5(3), 28; https://doi.org/10.3390/antiox5030028
Received: 11 July 2016 / Revised: 15 August 2016 / Accepted: 16 August 2016 / Published: 20 August 2016
Cited by 1 | Viewed by 2222 | PDF Full-text (676 KB) | HTML Full-text | XML Full-text
Abstract
Endogenous and exogenous antioxidants are used to neutralise free radicals and protect the body from free radicals by maintaining the redox balance. The antioxidant properties of Dracaena sanderiana leaves were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the total phenolic and flavonoid contents [...] Read more.
Endogenous and exogenous antioxidants are used to neutralise free radicals and protect the body from free radicals by maintaining the redox balance. The antioxidant properties of Dracaena sanderiana leaves were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the total phenolic and flavonoid contents were measured. The classes of secondary metabolites were evaluated through pharmacognostic studies, and active compounds were identified by gas chromatography mass-spectrometry (GC-MS). All ethanol-water extracts and D. sanderiana leaf powder were positive for tannins, saponins, terpenoids, cardiac glycosides, and quinones. Flavonoids were present in 100%, 80%, 60%, and 40% ethanol extracts (E100, E80, E60, and E40). E100 showed the highest total flavonoid content, whereas E60 extract showed the highest antioxidant activity and total phenolic content. GC-MS revealed the presence of glycerol, 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one, n-dodecanoic acid, tetradecanoid acid, (n-) hexadecanoid acid, and n-octadecanoic acid in the E60 extract. Full article
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Open AccessReview
Cranberries and Cancer: An Update of Preclinical Studies Evaluating the Cancer Inhibitory Potential of Cranberry and Cranberry Derived Constituents
Antioxidants 2016, 5(3), 27; https://doi.org/10.3390/antiox5030027
Received: 30 June 2016 / Revised: 11 August 2016 / Accepted: 15 August 2016 / Published: 18 August 2016
Cited by 8 | Viewed by 3070 | PDF Full-text (652 KB) | HTML Full-text | XML Full-text
Abstract
Cranberries are rich in bioactive constituents reported to influence a variety of health benefits, ranging from improved immune function and decreased infections to reduced cardiovascular disease and more recently cancer inhibition. A review of cranberry research targeting cancer revealed positive effects of cranberries [...] Read more.
Cranberries are rich in bioactive constituents reported to influence a variety of health benefits, ranging from improved immune function and decreased infections to reduced cardiovascular disease and more recently cancer inhibition. A review of cranberry research targeting cancer revealed positive effects of cranberries or cranberry derived constituents against 17 different cancers utilizing a variety of in vitro techniques, whereas in vivo studies supported the inhibitory action of cranberries toward cancers of the esophagus, stomach, colon, bladder, prostate, glioblastoma and lymphoma. Mechanisms of cranberry-linked cancer inhibition include cellular death induction via apoptosis, necrosis and autophagy; reduction of cellular proliferation; alterations in reactive oxygen species; and modification of cytokine and signal transduction pathways. Given the emerging positive preclinical effects of cranberries, future clinical directions targeting cancer or premalignancy in high risk cohorts should be considered. Full article
(This article belongs to the Special Issue Berry Antioxidants in Health and Disease) Printed Edition available
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Open AccessArticle
Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls
Antioxidants 2016, 5(3), 26; https://doi.org/10.3390/antiox5030026
Received: 21 June 2016 / Revised: 20 July 2016 / Accepted: 27 July 2016 / Published: 2 August 2016
Cited by 13 | Viewed by 1985 | PDF Full-text (1153 KB) | HTML Full-text | XML Full-text
Abstract
Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching [...] Read more.
Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL−1), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL−1), high reducing power capacity (RPSFG = 5 mg·mL−1), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg·mL−1). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls. Full article
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Open AccessReview
The Role of Copper Chaperone Atox1 in Coupling Redox Homeostasis to Intracellular Copper Distribution
Antioxidants 2016, 5(3), 25; https://doi.org/10.3390/antiox5030025
Received: 24 May 2016 / Revised: 13 July 2016 / Accepted: 22 July 2016 / Published: 27 July 2016
Cited by 21 | Viewed by 2655 | PDF Full-text (1734 KB) | HTML Full-text | XML Full-text
Abstract
Human antioxidant protein 1 (Atox1) is a small cytosolic protein with an essential role in copper homeostasis. Atox1 functions as a copper carrier facilitating copper transfer to the secretory pathway. This process is required for activation of copper dependent enzymes involved in neurotransmitter [...] Read more.
Human antioxidant protein 1 (Atox1) is a small cytosolic protein with an essential role in copper homeostasis. Atox1 functions as a copper carrier facilitating copper transfer to the secretory pathway. This process is required for activation of copper dependent enzymes involved in neurotransmitter biosynthesis, iron efflux, neovascularization, wound healing, and regulation of blood pressure. Recently, new cellular roles for Atox1 have emerged. Changing levels of Atox1 were shown to modulate response to cancer therapies, contribute to inflammatory response, and protect cells against various oxidative stresses. It has also become apparent that the activity of Atox1 is tightly linked to the cellular redox status. In this review, we summarize biochemical information related to a dual role of Atox1 as a copper chaperone and an antioxidant. We discuss how these two activities could be linked and contribute to establishing the intracellular copper balance and functional identity of cells during differentiation. Full article
(This article belongs to the Special Issue Oxidative Stress and Metals Metabolism)
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Open AccessReview
Beyond Diabetes: Does Obesity-Induced Oxidative Stress Drive the Aging Process?
Antioxidants 2016, 5(3), 24; https://doi.org/10.3390/antiox5030024
Received: 22 June 2016 / Revised: 6 July 2016 / Accepted: 12 July 2016 / Published: 18 July 2016
Cited by 17 | Viewed by 2917 | PDF Full-text (235 KB) | HTML Full-text | XML Full-text
Abstract
Despite numerous correlative data, a causative role for oxidative stress in mammalian longevity has remained elusive. However, there is strong evidence that increased oxidative stress is associated with exacerbation of many diseases and pathologies that are also strongly related to advanced age. Obesity, [...] Read more.
Despite numerous correlative data, a causative role for oxidative stress in mammalian longevity has remained elusive. However, there is strong evidence that increased oxidative stress is associated with exacerbation of many diseases and pathologies that are also strongly related to advanced age. Obesity, or increased fat accumulation, is one of the most common chronic conditions worldwide and is associated with not only metabolic dysfunction but also increased levels of oxidative stress in vivo. Moreover, obesity is also associated with significantly increased risks of cardiovascular disease, neurological decline and cancer among many other diseases as well as a significantly increased risk of mortality. In this review, we investigate the possible interpretation that the increased incidence of these diseases in obesity may be due to chronic oxidative stress mediating segmental acceleration of the aging process. Understanding how obesity can alter cellular physiology beyond that directly related to metabolic function could open new therapeutic areas of approach to extend the period of healthy aging among people of all body composition. Full article
(This article belongs to the Special Issue Oxidative Stress and Aging: Past, Present and Future Concepts)
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Open AccessTechnical Note
Electrochemical Potential Gradient as a Quantitative in Vitro Test Platform for Cellular Oxidative Stress
Antioxidants 2016, 5(3), 23; https://doi.org/10.3390/antiox5030023
Received: 25 April 2016 / Revised: 29 June 2016 / Accepted: 2 July 2016 / Published: 11 July 2016
Cited by 1 | Viewed by 2184 | PDF Full-text (6222 KB) | HTML Full-text | XML Full-text
Abstract
Oxidative stress in a biological system is often defined as a redox imbalance within cells or groups of cells within an organism. Reductive-oxidative (redox) imbalances in cellular systems have been implicated in several diseases, such as cancer. To better understand the redox environment [...] Read more.
Oxidative stress in a biological system is often defined as a redox imbalance within cells or groups of cells within an organism. Reductive-oxidative (redox) imbalances in cellular systems have been implicated in several diseases, such as cancer. To better understand the redox environment within cellular systems, it is important to be able to characterize the relationship between the intensity of the oxidative environment, characterized by redox potential, and the biomolecular consequences of oxidative damage. In this study, we show that an in situ electrochemical potential gradient can serve as a tool to simulate exogenous oxidative stress in surface-attached mammalian cells. A culture plate design, which permits direct imaging and analysis of the cell viability, following exposure to a range of solution redox potentials, was developed. The in vitro oxidative stress test vessel consists of a cell growth flask fitted with two platinum electrodes that support a direct current along the flask bottom. The applied potential span and gradient slope can be controlled by adjusting the constant current magnitude across the vessel with spatially localized media potentials measured with a sliding reference electrode. For example, the viability of Chinese Hamster Ovary cells under a gradient of redox potentials indicated that cell death was initiated at approximately 0.4 V vs. standard hydrogen electrode (SHE) media potential and this potential could be modified with antioxidants. This experimental platform may facilitate studies of oxidative stress characteristics on different types of cells by enabling imaging live cell cultures that have been exposed to a gradient of exogenous redox potentials. Full article
(This article belongs to the Special Issue Nanomaterial Oxidative Stress)
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Open AccessReview
Protection against Radiotherapy-Induced Toxicity
Antioxidants 2016, 5(3), 22; https://doi.org/10.3390/antiox5030022
Received: 30 May 2016 / Revised: 27 June 2016 / Accepted: 28 June 2016 / Published: 5 July 2016
Cited by 16 | Viewed by 3498 | PDF Full-text (613 KB) | HTML Full-text | XML Full-text
Abstract
Radiation therapy is a highly utilized therapy in the treatment of malignancies with up to 60% of cancer patients receiving radiation therapy as a part of their treatment regimen. Radiation therapy does, however, cause a wide range of adverse effects that can be [...] Read more.
Radiation therapy is a highly utilized therapy in the treatment of malignancies with up to 60% of cancer patients receiving radiation therapy as a part of their treatment regimen. Radiation therapy does, however, cause a wide range of adverse effects that can be severe and cause permanent damage to the patient. In an attempt to minimize these effects, a small number of compounds have been identified and are in use clinically for the prevention and treatment of radiation associated toxicities. Furthermore, there are a number of emerging therapies being developed for use as agents that protect against radiation-induced toxicities. The aim of this review was to evaluate and summarise the evidence that exists for both the known radioprotectant agents and the agents that show promise as future radioprotectant agents. Full article
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Open AccessArticle
Antioxidant Effect of Extracts from the Coffee Residue in Raw and Cooked Meat
Antioxidants 2016, 5(3), 21; https://doi.org/10.3390/antiox5030021
Received: 30 April 2016 / Revised: 22 June 2016 / Accepted: 24 June 2016 / Published: 4 July 2016
Cited by 10 | Viewed by 1976 | PDF Full-text (212 KB) | HTML Full-text | XML Full-text
Abstract
The residue of ground coffee obtained after the brewing process (spent coffee) still contains various functional components with high antioxidant capacity and health benefits, but no attempts have been made to use it as a resource to produce value-added food ingredients. This study [...] Read more.
The residue of ground coffee obtained after the brewing process (spent coffee) still contains various functional components with high antioxidant capacity and health benefits, but no attempts have been made to use it as a resource to produce value-added food ingredients. This study evaluates the antioxidant activity of ethanol or hot water extracts from the residues of coffee after brewing. An extraction experiment was carried out using the conventional solid–liquid methods, including ethanol and water as the extraction media at different temperatures and liquid/solid ratios. The antioxidant activity of extracts was tested for total phenolic compound (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2-thiobarbituric acid reactive substances (TBARS) using oil emulsion and raw/cooked meat systems. The DPPH radical scavenging activity of the ethanol extracts with heating (HEE) and without heating (CEE) were higher than that of the hot water extracts (WE). The highest DPPH value of HEE and CEE at 1000 ppm was 91.22% and 90.21%, respectively. In oil emulsion and raw/cooked systems, both the water and ethanol extracts had similar antioxidant effects to the positive control (BHA), but HEE and CEE extracts showed stronger antioxidant activities than WE extract. These results indicated that the ethanol extracts of coffee residue have a strong antioxidant activity and have the potential to be used as a natural antioxidant in meat. Full article
(This article belongs to the Special Issue Lipid Oxidation in Meat and Poultry)
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Antioxidants EISSN 2076-3921 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
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