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Open AccessArticle Fruit Antioxidants during Vinegar Processing: Changes in Content and in Vitro Bio-Accessibility

by Sena Bakir, Gamze Toydemir, Dilek Boyacioglu, Jules Beekwilder and Esra Capanoglu

Int. J. Mol. Sci. 2016, 17(10), 1658; doi:10.3390/ijms17101658

Received: 19 August 2016 / Revised: 19 September 2016 / Accepted: 21 September 2016 / Published: 29 September 2016

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Abstract

Background: Vinegars based on fruit juices could conserve part of the health-associated compounds present in the fruits. However, in general very limited knowledge exists on the consequences of vinegar-making on different antioxidant compounds from fruit. In this study vinegars derived from apple and

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Background: Vinegars based on fruit juices could conserve part of the health-associated compounds present in the fruits. However, in general very limited knowledge exists on the consequences of vinegar-making on different antioxidant compounds from fruit. In this study vinegars derived from apple and grape are studied. Methods: A number of steps, starting from the fermentation of the fruit juices to the formation of the final vinegars, were studied from an industrial vinegar process. The effect of each of the vinegar processing steps on content of antioxidants, phenolic compounds and flavonoids was studied, by spectroscopic methods and by high-performance liquid chromatography (HPLC). Results: The major observation was that spectrophotometric methods indicate a strong loss of antioxidant phenolic compounds during the transition from fruit wine to fruit vinegar. A targeted HPLC analysis indicates that metabolites such as gallic acid are lost in later stages of the vinegar process. Conclusion: The major conclusion of this work is that major changes occur in phenolic compounds during vinegar making. An untargeted metabolite analysis should be used to reveal these changes in more detail. In addition, the effect of vinegar processing on bio-accessibility of phenolic compounds was investigated by mimicking the digestive tract in an in vitro set up. This study is meant to provide insight into the potential of vinegar as a source of health-related compounds from fruit. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Effects of Hormone Therapy on Oxidative Stress in Postmenopausal Women with Metabolic Syndrome

by Martha A. Sánchez-Rodríguez, Mariano Zacarías-Flores, Lizett Castrejón-Delgado, Ana Karen Ruiz-Rodríguez and Víctor Manuel Mendoza-Núñez

Int. J. Mol. Sci. 2016, 17(9), 1388; doi:10.3390/ijms17091388

Received: 17 July 2016 / Revised: 11 August 2016 / Accepted: 16 August 2016 / Published: 24 August 2016

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Abstract

The aim of this study was to determine the effect of oral hormone therapy (HT) on oxidative stress (OS) in postmenopausal women with metabolic syndrome (MetS). A randomized, double blind, placebo-controlled trial was carried out. We formed four groups of 25 women each;

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The aim of this study was to determine the effect of oral hormone therapy (HT) on oxidative stress (OS) in postmenopausal women with metabolic syndrome (MetS). A randomized, double blind, placebo-controlled trial was carried out. We formed four groups of 25 women each; healthy (HW) and MetS women (MSW) were assigned to HT (1 mg/day of estradiol valerate plus 5 mg/10 day of medroxiprogesterone) or placebo. We measured plasma lipoperoxides, erythrocyte superoxide dismutase and glutathione peroxidase, total plasma antioxidant status and uric acid, as OS markers. Alternative cut-off values of each parameter were defined and a stress score (SS) ranging from 0 to 7 was used as total OS. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) criteria. Participants were seen at baseline, 3 and 6 months. After 6 months, MetS decreased in MSW-HT (48%), their triglycerides and high-density lipoprotein cholesterol (HDL-c) improved; in the other groups no difference was found. SS in MSW-HT decreased (3.8 ± 0.3 to 1.7 ± 0.3, p < 0.05) and OS was also reduced (44%), this effect was evident since 3 mo. HW-HT with high OS also decreased (40%). In placebo groups there was no change. Our findings suggest that HT improve lipids and OS associated to MetS in postmenopausal women. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Spectrophotometric Determination of Phenolic Antioxidants in the Presence of Thiols and Proteins

by Aslı Neslihan Avan, Sema Demirci Çekiç, Seda Uzunboy and Reşat Apak

Int. J. Mol. Sci. 2016, 17(8), 1325; doi:10.3390/ijms17081325

Received: 29 June 2016 / Revised: 4 August 2016 / Accepted: 5 August 2016 / Published: 12 August 2016

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Abstract

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and

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Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive to the probe reagent. In this study, three of the most common TAC determination methods, namely cupric ion reducing antioxidant capacity (CUPRAC), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt/trolox equivalent antioxidant capacity (ABTS/TEAC), and ferric reducing antioxidant power (FRAP), were tested for the assay of phenolics in the presence of selected thiol and protein compounds. Although the FRAP method is almost non-responsive to thiol compounds individually, surprising overoxidations with large positive deviations from additivity were observed when using this method for (phenols + thiols) mixtures. Among the tested TAC methods, CUPRAC gave the most additive results for all studied (phenol + thiol) and (phenol + protein) mixtures with minimal relative error. As ABTS/TEAC and FRAP methods gave small and large deviations, respectively, from additivity of absorbances arising from these components in mixtures, mercury(II) compounds were added to stabilize the thiol components in the form of Hg(II)-thiol complexes so as to enable selective spectrophotometric determination of phenolic components. This error compensation was most efficient for the FRAP method in testing (thiols + phenols) mixtures. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Electrochemical Determination of Food Preservative Nitrite with Gold Nanoparticles/p-Aminothiophenol-Modified Gold Electrode

by Ayşem Üzer, Şener Sağlam, Ziya Can, Erol Erçağ and Reşat Apak

Int. J. Mol. Sci. 2016, 17(8), 1253; doi:10.3390/ijms17081253

Received: 17 June 2016 / Revised: 24 July 2016 / Accepted: 28 July 2016 / Published: 2 August 2016

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Abstract

Due to the negative impact of nitrate and nitrite on human health, their presence exceeding acceptable levels is not desired in foodstuffs. Thus, nitrite determination at low concentrations is a major challenge in electroanalytical chemistry, which can be achieved by fast, cheap, and

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Due to the negative impact of nitrate and nitrite on human health, their presence exceeding acceptable levels is not desired in foodstuffs. Thus, nitrite determination at low concentrations is a major challenge in electroanalytical chemistry, which can be achieved by fast, cheap, and safe electrochemical sensors. In this work, the working electrode (Au) was functionalized with p-aminothiophenol (p-ATP) and modified with gold nanoparticles (Au-NPs) to manufacture the final (Au/p-ATP-Au_nano) electrode in a two-step procedure. In the first step, p-ATP was electropolymerized on the electrode surface to obtain a polyaminothiophenol (PATP) coating. In the second step, Au/p-ATP-Au_nano working electrode was prepared by coating the surface with the use of HAuCl₄ solution and cyclic voltammetry. Determination of aqueous nitrite samples was performed with the proposed electrode (Au/p-ATP-Au_nano) using square wave voltammetry (SWV) in pH 4 buffer medium. Characteristic peak potential of nitrite samples was 0.76 V, and linear calibration curves of current intensity versus concentration was linear in the range of 0.5–50 mg·L⁻¹ nitrite with a limit of detection (LOD) of 0.12 mg·L⁻¹. Alternatively, nitrite in sausage samples could be colorimetrically determined with high sensitivity by means of p-ATP‒modified gold nanoparticles (AuNPs) and naphthylethylene diamine as coupling agents for azo-dye formation due to enhanced charge-transfer interactions with the AuNPs surface. The slopes of the calibration lines in pure NO₂⁻ solution and in sausage sample solution, to which different concentrations of NO₂⁻ standards were added, were not significantly different from each other, confirming the robustness and interference tolerance of the method. The proposed voltammetric sensing method was validated against the colorimetric nanosensing method in sausage samples. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Strawberry Achenes Are an Important Source of Bioactive Compounds for Human Health

by María Teresa Ariza, Patricia Reboredo-Rodríguez, Luca Mazzoni, Tamara Yuliett Forbes-Hernández, Francesca Giampieri, Sadia Afrin, Massimiliano Gasparrini, Carmen Soria, Elsa Martínez-Ferri, Maurizio Battino and Bruno Mezzetti

Int. J. Mol. Sci. 2016, 17(7), 1103; doi:10.3390/ijms17071103

Received: 23 May 2016 / Revised: 20 June 2016 / Accepted: 4 July 2016 / Published: 11 July 2016

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Abstract

Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the

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Strawberries are highly appreciated for their taste, nutritional value and antioxidant compounds, mainly phenolics. Fruit antioxidants derive from achenes and flesh, but achene contribution to the total fruit antioxidant capacity and to the bioaccessibility after intake is still unknown. In this work, the content of total phenolic compounds, flavonoids, anthocyanins and antioxidant capacity (TEAC, FRAP and DPPH) of achenes and flesh were compared in non-digested as well as in gastric and intestinal extracts after in vitro digestion. Results showed that, despite strawberry achenes represent a small fraction of the fruit, their contribution to total fruit antioxidant content was more than 41% and accounted for 81% of antioxidant capacity (TEAC). Achenes have higher quantity and different quality of antioxidants in non-digested and digested extracts. Antioxidant release was higher in the in vitro gastric digested extracts, but digestion conditions did not only affect quantity but quality, resulting in differences in antioxidant capacity and highlighting the importance of simulating physiological-like extraction conditions for assessing fruit antioxidant properties on human health. These results give new insights into the use of strawberry achenes as a source of bioactive compounds to be considered in strawberry breeding programs for improving human health. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

Open AccessArticle Use of Different Proteases to Obtain Flaxseed Protein Hydrolysates with Antioxidant Activity

by Magdalena Karamać, Agnieszka Kosińska-Cagnazzo and Anna Kulczyk

Int. J. Mol. Sci. 2016, 17(7), 1027; doi:10.3390/ijms17071027

Received: 19 May 2016 / Revised: 17 June 2016 / Accepted: 17 June 2016 / Published: 29 June 2016

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Abstract

The antioxidant activity of flaxseed protein hydrolysates obtained using five different enzymes was evaluated. Proteins were isolated from flaxseed cake and were separately treated with papain, trypsin, pancreatin, Alcalase and Flavourzyme. The degree of hydrolysis (DH) was determined as the percentage of cleaved

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The antioxidant activity of flaxseed protein hydrolysates obtained using five different enzymes was evaluated. Proteins were isolated from flaxseed cake and were separately treated with papain, trypsin, pancreatin, Alcalase and Flavourzyme. The degree of hydrolysis (DH) was determined as the percentage of cleaved peptide bonds using a spectrophotometric method with o-phthaldialdehyde. The distribution of the molecular weights (MW) of the hydrolysis products was profiled using Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) and size exclusion-high performance liquid chromatography (SE-HPLC) separations. The antioxidant activities of the protein isolate and hydrolysates were probed for their radical scavenging activity using 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS^•+) and photochemiluminescence (PCL-ACL) assays, and for their ferric reducing antioxidant power (FRAP) and ability to bind Fe²⁺. The hydrolysates were more effective as antioxidants than the protein isolate in all systems. The PCL-ACL values of the hydrolysates ranged from 7.2 to 35.7 μmol Trolox/g. Both the FRAP and ABTS^•+ scavenging activity differed among the hydrolysates to a lower extent, with the ranges of 0.20–0.24 mmol Fe²⁺/g and 0.17–0.22 mmol Trolox/g, respectively. The highest chelating activity (71.5%) was noted for the pancreatin hydrolysate. In general, the hydrolysates obtained using Alcalase and pancreatin had the highest antioxidant activity, even though their DH (15.4% and 29.3%, respectively) and the MW profiles of the peptides varied substantially. The O₂^•− scavenging activity and the ability to chelate Fe²⁺ of the Flavourzyme hydrolysate were lower than those of the Alcalase and pancreatin hydrolysates. Papain was the least effective in releasing the peptides with antioxidant activity. The study showed that the type of enzyme used for flaxseed protein hydrolysis determines the antioxidant activity of the hydrolysates. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties

by Eva Vavříková, Fanny Langschwager, Lubica Jezova-Kalachova, Alena Křenková, Barbora Mikulová, Marek Kuzma, Vladimír Křen and Kateřina Valentová

Int. J. Mol. Sci. 2016, 17(6), 899; doi:10.3390/ijms17060899

Received: 14 April 2016 / Revised: 25 May 2016 / Accepted: 30 May 2016 / Published: 7 June 2016

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Abstract

A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which

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A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C₅- to C₁₂-dicarboxylic acids; the shorter ones, such as oxalic (C₂), malonic (C₃), succinic (C₄) and maleic (C₄) acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin–Ciocalteau reagent (FCR) and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) than isoquercitrin; ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Home-Processed Red Beetroot (Beta vulgaris L.) Products: Changes in Antioxidant Properties and Bioaccessibility

by Burcu Guldiken, Gamze Toydemir, Kubra Nur Memis, Sena Okur, Dilek Boyacioglu and Esra Capanoglu

Int. J. Mol. Sci. 2016, 17(6), 858; doi:10.3390/ijms17060858

Received: 23 March 2016 / Revised: 3 May 2016 / Accepted: 23 May 2016 / Published: 1 June 2016

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Abstract

In this study, the effects of home-processing on the antioxidant properties and in vitro bioaccessibility of red beetroot bioactives were investigated. For this purpose, fresh red beetroot and six different home-processed red beetroot products—including boiled, oven-dried, pickled, pureed, juice-processed, and jam-processed—were analyzed and

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In this study, the effects of home-processing on the antioxidant properties and in vitro bioaccessibility of red beetroot bioactives were investigated. For this purpose, fresh red beetroot and six different home-processed red beetroot products—including boiled, oven-dried, pickled, pureed, juice-processed, and jam-processed—were analyzed and compared for their total phenolic (TP) and total flavonoid (TF) contents, total antioxidant capacities (TAC), and individual anthocyanin contents. In addition, bioaccessibility of red beetroot antioxidants was determined using an in vitro simulated gastrointestinal digestion method. Dried, pureed, and fresh red beetroot samples had the highest TP, TF, and TAC values, which were 347 ± 23 mg gallic acid equivalent (GAE)/100 g, 289 ± 53 mg rutin equivalent (RE)/100 g, 3889 ± 982 mg trolox equivalent antioxidant capacity (TEAC)/100 g, respectively. The in vitro digestion method revealed the highest recovery for TP (16%) and TAC (1.3%) in jam. This study provides comparative data to evaluate the effects of various home-processing techniques on antioxidant potential of red beetroot products. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Antioxidant and Hepatoprotective Effects of Procyanidins from Wild Grape (Vitis amurensis) Seeds in Ethanol-Induced Cells and Rats

by Min Ji Bak, Van-Long Truong, Se-Yeon Ko, Xuan Ngan Giang Nguyen, Pajaree Ingkasupart, Mira Jun, Jin Young Shin and Woo-Sik Jeong

Int. J. Mol. Sci. 2016, 17(5), 758; doi:10.3390/ijms17050758

Received: 12 April 2016 / Revised: 6 May 2016 / Accepted: 12 May 2016 / Published: 18 May 2016

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Abstract

In the present study, we characterized the antioxidant and hepatoprotective mechanisms underlying of wild grape seed procyanidins (WGP) against oxidative stress damage in ethanol-treated HepG2 cell and Sprague-Dawley (SD)-rat models. In HepG2 cells, WGP not only diminished the ethanol (EtOH, 100 mM)-induced reactive

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In the present study, we characterized the antioxidant and hepatoprotective mechanisms underlying of wild grape seed procyanidins (WGP) against oxidative stress damage in ethanol-treated HepG2 cell and Sprague-Dawley (SD)-rat models. In HepG2 cells, WGP not only diminished the ethanol (EtOH, 100 mM)-induced reactive oxygen species (ROS) formation and cytochrome P450 2E1 (CYP2E1) expression, but also renovated both the activity and expression of antioxidant enzymes including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, to investigate the hepatoprotective effect of WGP, rats were orally administered 10 or 50 mg/kg WGP once daily for seven days prior to the single oral administration of EtOH (6 g/kg). The results show that WGP administration decreased the EtOH-induced augment of the levels of serum aspartate transaminase and alanine transaminase as well as serum alcohol and acetaldehyde. WGP treatment upregulated the activities and protein levels of hepatic alcohol dehydrogenase, aldehyde dehydrogenase, and antioxidant enzymes but downregulated the protein expression level of liver CYP2E1 in EtOH-treated rats. Moreover, the decreased phosphorylation levels of mitogen activated protein kinases (MAPKs) by ethanol were induced in both HepG2 cell and rat models. Overall, pretreatment of WGP displayed the protective activity against EtOH-mediated toxicity through the regulation of antioxidant enzymes and alcohol metabolism systems via MAPKs pathways. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessCommunication Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

by Diego A. Esquivel-Hernández, Víctor H. López, José Rodríguez-Rodríguez, Gibrán S. Alemán-Nava, Sara P. Cuéllar-Bermúdez, Magdalena Rostro-Alanis and Roberto Parra-Saldívar

Int. J. Mol. Sci. 2016, 17(5), 658; doi:10.3390/ijms17050658

Received: 20 March 2016 / Revised: 20 April 2016 / Accepted: 22 April 2016 / Published: 5 May 2016

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Abstract

Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T),

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Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T), and co-solvent (ethanol) (CS) were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14%) and (4.27% ± 0.10%) for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO₂ produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessArticle Free Radical Scavenging and Cellular Antioxidant Properties of Astaxanthin

by Janina Dose, Seiichi Matsugo, Haruka Yokokawa, Yutaro Koshida, Shigetoshi Okazaki, Ulrike Seidel, Manfred Eggersdorfer, Gerald Rimbach and Tuba Esatbeyoglu

Int. J. Mol. Sci. 2016, 17(1), 103; doi:10.3390/ijms17010103

Received: 12 October 2015 / Revised: 5 January 2016 / Accepted: 8 January 2016 / Published: 14 January 2016

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Abstract

Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and

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Astaxanthin is a coloring agent which is used as a feed additive in aquaculture nutrition. Recently, potential health benefits of astaxanthin have been discussed which may be partly related to its free radical scavenging and antioxidant properties. Our electron spin resonance (ESR) and spin trapping data suggest that synthetic astaxanthin is a potent free radical scavenger in terms of diphenylpicryl-hydrazyl (DPPH) and galvinoxyl free radicals. Furthermore, astaxanthin dose-dependently quenched singlet oxygen as determined by photon counting. In addition to free radical scavenging and singlet oxygen quenching properties, astaxanthin induced the antioxidant enzyme paroxoanase-1, enhanced glutathione concentrations and prevented lipid peroxidation in cultured hepatocytes. Present results suggest that, beyond its coloring properties, synthetic astaxanthin exhibits free radical scavenging, singlet oxygen quenching, and antioxidant activities which could probably positively affect animal and human health. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Review

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Open AccessReview Micronutrient Antioxidants and Nonalcoholic Fatty Liver Disease

by Guanliang Chen, Yinhua Ni, Naoto Nagata, Liang Xu and Tsuguhito Ota

Int. J. Mol. Sci. 2016, 17(9), 1379; doi:10.3390/ijms17091379

Received: 26 July 2016 / Revised: 12 August 2016 / Accepted: 17 August 2016 / Published: 23 August 2016

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Abstract

Nonalcoholic fatty liver disease (NAFLD) is one of the most important chronic liver diseases worldwide and has garnered increasing attention in recent decades. NAFLD is characterized by a wide range of liver changes, from simple steatosis to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma.

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Nonalcoholic fatty liver disease (NAFLD) is one of the most important chronic liver diseases worldwide and has garnered increasing attention in recent decades. NAFLD is characterized by a wide range of liver changes, from simple steatosis to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. The blurred pathogenesis of NAFLD is very complicated and involves lipid accumulation, insulin resistance, inflammation, and fibrogenesis. NAFLD is closely associated with complications such as obesity, diabetes, steatohepatitis, and liver fibrosis. During the progression of NAFLD, reactive oxygen species (ROS) are activated and induce oxidative stress. Recent attempts at establishing effective NAFLD therapy have identified potential micronutrient antioxidants that may reduce the accumulation of ROS and finally ameliorate the disease. In this review, we present the molecular mechanisms involved in the pathogenesis of NAFLD and introduce some dietary antioxidants that may be used to prevent or cure NAFLD, such as vitamin D, E, and astaxanthin. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessReview Antioxidant Activity of γ-Oryzanol: A Complex Network of Interactions

by Igor Otavio Minatel, Fabiane Valentini Francisqueti, Camila Renata Corrêa and Giuseppina Pace Pereira Lima

Int. J. Mol. Sci. 2016, 17(8), 1107; doi:10.3390/ijms17081107

Received: 20 May 2016 / Revised: 29 June 2016 / Accepted: 7 July 2016 / Published: 9 August 2016

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Abstract

γ-oryzanol (Orz), a steryl ferulate extracted from rice bran layer, exerts a wide spectrum of biological activities. In addition to its antioxidant activity, Orz is often associated with cholesterol-lowering, anti-inflammatory, anti-cancer and anti-diabetic effects. In recent years, the usefulness of Orz has been

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γ-oryzanol (Orz), a steryl ferulate extracted from rice bran layer, exerts a wide spectrum of biological activities. In addition to its antioxidant activity, Orz is often associated with cholesterol-lowering, anti-inflammatory, anti-cancer and anti-diabetic effects. In recent years, the usefulness of Orz has been studied for the treatment of metabolic diseases, as it acts to ameliorate insulin activity, cholesterol metabolism, and associated chronic inflammation. Previous studies have shown the direct action of Orz when downregulating the expression of genes that encode proteins related to adiposity (CCAAT/enhancer binding proteins (C/EBPs)), inflammatory responses (nuclear factor kappa-B (NF-κB)), and metabolic syndrome (peroxisome proliferator-activated receptors (PPARs)). It is likely that this wide range of beneficial activities results from a complex network of interactions and signals triggered, and/or inhibited by its antioxidant properties. This review focuses on the significance of Orz in metabolic disorders, which feature remarkable oxidative imbalance, such as impaired glucose metabolism, obesity, and inflammation. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessReview Role of Lipids in the Onset, Progression and Treatment of Periodontal Disease. A Systematic Review of Studies in Humans

by Alfonso Varela-López, Francesca Giampieri, Pedro Bullón, Maurizio Battino and José L. Quiles

Int. J. Mol. Sci. 2016, 17(8), 1202; doi:10.3390/ijms17081202

Received: 1 June 2016 / Revised: 8 July 2016 / Accepted: 20 July 2016 / Published: 25 July 2016

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Abstract

The risk of different oral problems (root caries, tooth mobility, and tooth loss) can be increased by the presence of periodontal disease, which has also been associated with a growing list of systemic diseases. The presence of some bacteria is the primary etiology

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The risk of different oral problems (root caries, tooth mobility, and tooth loss) can be increased by the presence of periodontal disease, which has also been associated with a growing list of systemic diseases. The presence of some bacteria is the primary etiology of this disease; a susceptible host is also necessary for disease initiation. In this respect, the progression of periodontal disease and healing of the periodontal tissues can be modulated by nutritional status. To clarify the role of lipids in the establishment, progression, and/or treatment of this pathology, a systematic review was conducted of English-written literature in PubMed until May 2016, which included research on the relationship of these dietary components with the onset and progression of periodontal disease. According to publication type, randomized-controlled trials, cohort, case-control and cross-sectional studies were included. Among all the analyzed components, those that have any effect on oxidative stress and/or inflammation seem to be the most interesting according to current evidence. On one hand, there is quite a lot of information in favor of a positive role of n-3 fatty acids, due to their antioxidant and immunomodulatory effects. On the other hand, saturated fat-rich diets increase oxidative stress as well the as intensity and duration of inflammatory processes, so they must be avoided. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessReview A Review of the Latest Advances in Encrypted Bioactive Peptides from Protein-Rich Waste

by Ailton Cesar Lemes, Luisa Sala, Joana da Costa Ores, Anna Rafaela Cavalcante Braga, Mariana Buranelo Egea and Kátia Flávia Fernandes

Int. J. Mol. Sci. 2016, 17(6), 950; doi:10.3390/ijms17060950

Received: 9 May 2016 / Revised: 31 May 2016 / Accepted: 9 June 2016 / Published: 16 June 2016

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Abstract

Bioactive peptides are considered the new generation of biologically active regulators that not only prevent the mechanism of oxidation and microbial degradation in foods but also enhanced the treatment of various diseases and disorders, thus increasing quality of life. This review article emphasizes

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Bioactive peptides are considered the new generation of biologically active regulators that not only prevent the mechanism of oxidation and microbial degradation in foods but also enhanced the treatment of various diseases and disorders, thus increasing quality of life. This review article emphasizes recent advances in bioactive peptide technology, such as: (i) new strategies for transforming bioactive peptides from residual waste into added-value products; (ii) nanotechnology for the encapsulation, protection and release of controlled peptides; and (iii) use of techniques of large-scale recovery and purification of peptides aiming at future applications to pharmaceutical and food industries. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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Open AccessReview Resveratrol Inhibition of Cellular Respiration: New Paradigm for an Old Mechanism

by Luis Alberto Madrigal-Perez and Minerva Ramos-Gomez

Int. J. Mol. Sci. 2016, 17(3), 368; doi:10.3390/ijms17030368

Received: 21 January 2016 / Revised: 26 February 2016 / Accepted: 8 March 2016 / Published: 17 March 2016

Cited by 6 | PDF Full-text (1119 KB) | HTML Full-text | XML Full-text

Abstract

Resveratrol (3,4′,5-trihydroxy-trans-stilbene, RSV) has emerged as an important molecule in the biomedical area. This is due to its antioxidant and health benefits exerted in mammals. Nonetheless, early studies have also demonstrated its toxic properties toward plant-pathogenic fungi of this phytochemical. Both

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Resveratrol (3,4′,5-trihydroxy-trans-stilbene, RSV) has emerged as an important molecule in the biomedical area. This is due to its antioxidant and health benefits exerted in mammals. Nonetheless, early studies have also demonstrated its toxic properties toward plant-pathogenic fungi of this phytochemical. Both effects appear to be opposed and caused by different molecular mechanisms. However, the inhibition of cellular respiration is a hypothesis that might explain both toxic and beneficial properties of resveratrol, since this phytochemical: (1) decreases the production of energy of plant-pathogenic organisms, which prevents their proliferation; (2) increases adenosine monophosphate/adenosine diphosphate (AMP/ADP) ratio that can lead to AMP protein kinase (AMPK) activation, which is related to its health effects, and (3) increases the reactive oxygen species generation by the inhibition of electron transport. This pro-oxidant effect induces expression of antioxidant enzymes as a mechanism to counteract oxidative stress. In this review, evidence is discussed that supports the hypothesis that cellular respiration is the main target of resveratrol. Full article

(This article belongs to the Special Issue Macro- and Micro-nutrient Antioxidants)

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