Antioxidants: Sources, Methods, Health Benefits and Industrial Applications

A special issue of Antioxidants (ISSN 2076-3921). This special issue belongs to the section "Extraction and Industrial Applications of Antioxidants".

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 65338

Special Issue Editors


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Guest Editor
Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia 4, I-80126 Naples, Italy
Interests: polyphenol antioxidants of dietary origin; conjugates of polyphenols with sulphydryl compounds of biological relevance; antioxidants from marine sources; valorization of agri food wastes; synthesis and exploitation of biopolymers from natural polyphenols; chemistry and structural investigation of natural polymers from catechols including human epidermal pigments melanins; oxidation chemistry of catecholamines in relation to neurodegenerative disorders; design and preparation of polydopamine related biomaterials with peculiar adhesive properties
Special Issues, Collections and Topics in MDPI journals

grade E-Mail Website
Guest Editor
1. Department of Nutrition, Food Science and Gastronomy-XARTA-INSA-UB, School of Pharmacy and Food Science, University of Barcelona, 08028 Barcelona, Spain
2. Consorcio CIBER, M.P. Fisiopatología de la Obesidad y Nutrición (CIBERObn), Instituto de Salud Carlos III (ISCIII), 28029 Madrid, Spain
Interests: polyphenols; carotenoids; Mediterranean diet; health; diabetes; cardiovascular; processing; cooking; sofrito; tomato; wine
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

The importance of antioxidants in a variety of fields ranging from health to food to innovative materials has increasingly been appreciated. Yet, despite the wealth of research work related to antioxidants in recent literature, there are still many issues to be addressed concerning the mechanism of action, the bioavailability of dietary antioxidants, oxidative stress and antioxidant defense systems, antioxidant-based therapeutic strategies, antioxidant functional food, and design of biomaterials with antioxidant properties for use in biomedical applications or functional packaging. We also have to continue pursuing new natural sources of antioxidants, while shifting toward sustainable methodologies for their extraction and, finally, we need to standardize the methods for evaluating and ranking antioxidant power. This Special Issue will collect contributions from attendees of “The First International Conference on Antioxidants: Sources, Methods, Health Benefits and Industrial Applications” scheduled on March 2022, but it is open to researchers that are interested in publishing their work related to the following main topics covered by the conference sessions 

  • Health Outcomes of Antioxidants and Oxidative Stress with special emphasis on:
    Cancer; cardiovascular diseases; microbiome and gut health; metabolic disorders; neurodegenerative pathologies
  • Antioxidant Enzyme Systems with special emphasis on:
    ROS; RNS and RSS; mitochondria; redox signaling; photooxidative stress
  • Natural and Synthetic Antioxidants with special emphasis on:
    Occurrence; preparation methods; mechanisms of action; evaluation/measurement methodologies; green extraction procedures
  • Industrial Applications with special emphasis on:
    Biomaterials; functional packaging; biomedical devices

Prof. Dr. Alessandra Napolitano
Dr. Rosa M. Lamuela-Raventos
Guest Editors

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Keywords

  • antioxidant prebiotics
  • anti-inflammatory compounds
  • biomaterials
  • food
  • sustainable recovery methodologies
  • metabolites
  • mitochondria

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Published Papers (13 papers)

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Research

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17 pages, 2743 KiB  
Article
Development and Recovery of Liver Injury in Piglets by Incremental Injection of LPS
by Geyan Duan, Pan Huang, Changbing Zheng, Jie Zheng, Jiayi Yu, Peiwen Zhang, Mengliao Wan, Fengna Li, Qiuping Guo, Yulong Yin and Yehui Duan
Antioxidants 2023, 12(6), 1143; https://doi.org/10.3390/antiox12061143 - 24 May 2023
Cited by 5 | Viewed by 1635
Abstract
This study aimed to explore the effects of the incremental injection of lipopolysaccharide (LPS) on liver histopathology, inflammation, oxidative status, and mitochondrial function in piglets. Forty healthy Duroc × Landrace × Yorkshire castrated boars (21 ± 2 days old, weight 6.84 ± 0.11 [...] Read more.
This study aimed to explore the effects of the incremental injection of lipopolysaccharide (LPS) on liver histopathology, inflammation, oxidative status, and mitochondrial function in piglets. Forty healthy Duroc × Landrace × Yorkshire castrated boars (21 ± 2 days old, weight 6.84 ± 0.11 kg) were randomly assigned to five groups (n = 8) and then slaughtered on days 0 (group 0, without LPS injection), 1 (group 1), 5 (group 5), 9 (group 9), and 15 (group 15) of LPS injection, respectively. The results showed that, compared to the piglets without LPS injection, LPS injection caused liver injury in the early phase, as manifested by the increased activities of serum liver injury-related parameters (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase, cholinesterase, and total bile acid) on day 1, and impaired liver morphology (disordered hepatic cell cord arrangement, dissolved and vacuolized hepatocytes, karyopycnosis, and inflammatory cell infiltration and congestion) on days 1 and 5. Meanwhile, LPS injection caused liver inflammation, oxidative stress, and mitochondrial dysfunction on days 1 and 5, as reflected by the upregulated mRNA expression of TNF-α, IL-6, IL-1β, TLR4, MyD88, and NF-κB; increased MPO and MDA content; and impaired mitochondrial morphology. However, these parameters were ameliorated in the later phase (days 9~15). Taken together, our data indicate that the incremental injection of the LPS-induced liver injury of piglets could be self-repaired. Full article
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16 pages, 587 KiB  
Article
Urinary Phenolic Metabolites Associated with Peanut Consumption May Have a Beneficial Impact on Vascular Health Biomarkers
by Isabella Parilli-Moser, Inés Domínguez-López, Anna Vallverdú-Queralt, Sara Hurtado-Barroso and Rosa M. Lamuela-Raventós
Antioxidants 2023, 12(3), 698; https://doi.org/10.3390/antiox12030698 - 11 Mar 2023
Cited by 2 | Viewed by 7399
Abstract
Phenolic compounds in peanuts may moderate inflammation and endothelial function. Thus, the aim of this study was to evaluate the association of urinary phenolic metabolites (UPMs) with vascular biomarkers after peanut product consumption. A three-arm parallel-group randomized controlled trial was conducted in 63 [...] Read more.
Phenolic compounds in peanuts may moderate inflammation and endothelial function. Thus, the aim of this study was to evaluate the association of urinary phenolic metabolites (UPMs) with vascular biomarkers after peanut product consumption. A three-arm parallel-group randomized controlled trial was conducted in 63 healthy young adults who consumed 25 g/day of skin roasted peanuts (SRP), 32 g/day of peanut butter (PB), or 32 g/day of a control butter for six months. UPMs were analyzed by liquid chromatography coupled to mass spectrometry. Additionally, urinary eicosanoids, prostacyclin I2 (PGI2), and thromboxane A2 (TXA2) were determined using two competitive enzyme-linked immunosorbent assay kits. Consumers of SRP and PB presented significantly higher excretion of UPMs (enterodiol glucuronide (p = 0.018 and p = 0.031), 3-hydroxybenzoic acid (p = 0.002 and p < 0.001), vanillic acid sulfate (p = 0.048 and p = 0.006), p-coumaric acid (p = 0.046 and p = 0.016), coumaric acid glucuronide I (p = 0.001 and p = 0.030) and II (p = 0.003 and p = 0.036), and isoferulic acid (p = 0.013 and p = 0.015) in comparison with the control group. An improvement in PGI2 (p = 0.037) levels and the TXA2:PGI2 ratio (p = 0.008) was also observed after the peanut interventions compared to the control. Interestingly, UPMs with significantly higher post-intervention levels were correlated with an improvement in vascular biomarkers, lower TXA2 (r from −0.25 to −0.48, p < 0.050) and TXA2:PGI2 ratio (r from −0.25 to −0.43, p < 0.050) and higher PGI2 (r from 0.24 to 0.36, p < 0.050). These findings suggest that the UPMs with higher excretion after peanut product consumption could have a positive impact on vascular health. Full article
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16 pages, 4246 KiB  
Article
Facile Detection of Light-Controlled Radical Scavengers from Natural Products Using In Situ UV-LED NMR Spectroscopy
by InWha Park, Goeun Park, Yoojin Choi, Seung-Woo Jo, Hak Cheol Kwon, Jin-Soo Park and Jin Wook Cha
Antioxidants 2022, 11(11), 2206; https://doi.org/10.3390/antiox11112206 - 8 Nov 2022
Cited by 1 | Viewed by 2675
Abstract
With the recent development of chemical analysis technology, attention has been placed on natural light-sensitive compounds that exhibit photoreactivity to expand the structural diversity of natural product chemistry. Photochemical reactions that proceed via a free radical mechanism could be used to modulate the [...] Read more.
With the recent development of chemical analysis technology, attention has been placed on natural light-sensitive compounds that exhibit photoreactivity to expand the structural diversity of natural product chemistry. Photochemical reactions that proceed via a free radical mechanism could be used to modulate the radical-scavenging ability of natural products as well as involve structural change. As the health benefits of radicals are also presented, there is a need for a controllable radical scavenging method for topical and selective application. In this study, we developed a novel acquisition and processing method to identify light-controlled radical scavengers in plant extracts and evaluate their antioxidant activity under light irradiation based on in situ UV-LED NMR spectroscopy. Using the developed method, licochalcones A and B, in which the trans and cis isomers undergo reversible photoisomerization, were selectively identified from licorice root extract, and their light-induced free radical scavenging activity was confirmed. Full article
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13 pages, 3950 KiB  
Article
Recovery of Lignins with Potent Antioxidant Properties from Shells of Edible Nuts by a Green Ball Milling/Deep Eutectic Solvent (DES)-Based Protocol
by Rita Argenziano, Federica Moccia, Rodolfo Esposito, Gerardino D’Errico, Lucia Panzella and Alessandra Napolitano
Antioxidants 2022, 11(10), 1860; https://doi.org/10.3390/antiox11101860 - 21 Sep 2022
Cited by 10 | Viewed by 2728
Abstract
Lignins are phenolic polymers endowed with potent antioxidant properties that are finding increasing applications in a variety of fields. Consequently, there is a growing need for easily available and sustainable sources, as well as for green extraction methodologies of these compounds. Herein, a [...] Read more.
Lignins are phenolic polymers endowed with potent antioxidant properties that are finding increasing applications in a variety of fields. Consequently, there is a growing need for easily available and sustainable sources, as well as for green extraction methodologies of these compounds. Herein, a ball milling/deep eutectic solvent (DES)-based treatment is reported as an efficient strategy for the recovery of antioxidant lignins from the shells of edible nuts, namely chestnuts, hazelnuts, peanuts, pecan nuts, and pistachios. In particular, preliminarily ball-milled shells were treated with 1:2 mol/mol choline chloride:lactic acid at 120 °C for 24 h, and the extracted material was recovered in 19–27% w/w yields after precipitation by the addition of 0.01 M HCl. Extensive spectroscopic and chromatographic analysis allowed for confirmation that the main phenolic constituents present in the shell extracts were lignins, accompanied by small amounts (0.9% w/w) of ellagic acid, in the case of chestnut shells. The recovered samples exhibited very promising antioxidant properties, particularly in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay (EC50 values ranging from 0.03 to 0.19 mg/mL). These results open new perspectives for the valorization of nut shells as green sources of lignins for applications as antioxidants, e.g., in the biomedical, food, and/or cosmetic sector. Full article
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18 pages, 2028 KiB  
Article
Hepatic Insulin Resistance in Hyperthyroid Rat Liver: Vitamin E Supplementation Highlights a Possible Role of ROS
by Gianluca Fasciolo, Gaetana Napolitano, Marianna Aprile, Simona Cataldi, Valerio Costa, Alfredo Ciccodicola, Sergio Di Meo and Paola Venditti
Antioxidants 2022, 11(7), 1295; https://doi.org/10.3390/antiox11071295 - 29 Jun 2022
Cited by 14 | Viewed by 2620
Abstract
Thyroid hormones are normally involved in glycaemic control, but their excess can lead to altered glucose metabolism and insulin resistance (IR). Since hyperthyroidism-linked increase in ROS results in tissue oxidative stress that is considered a hallmark of conditions leading to IR, it is [...] Read more.
Thyroid hormones are normally involved in glycaemic control, but their excess can lead to altered glucose metabolism and insulin resistance (IR). Since hyperthyroidism-linked increase in ROS results in tissue oxidative stress that is considered a hallmark of conditions leading to IR, it is conceivable a role of ROS in the onset of IR in hyperthyroidism. To verify this hypothesis, we evaluated the effects of vitamin E on thyroid hormone-induced oxidative damage, insulin resistance, and on gene expression of key molecules involved in IR in the rat liver. The factors involved in oxidative damage, namely the total content of ROS, the mitochondrial production of ROS, the activity of antioxidant enzymes, the in vitro susceptibility to oxidative stress, have been correlated to insulin resistance indices, such as insulin activation of hepatic Akt and plasma level of glucose, insulin and HOMA index. Our results indicate that increased levels of oxidative damage ROS content and production and susceptibility to oxidative damage, parallel increased fasting plasma level of glucose and insulin, reduced activation of Akt and increased activation of JNK. This last result suggests a role for JNK in the insulin resistance induced by hyperthyroidism. Furthermore, the variation of the genes Pparg, Ppara, Cd36 and Slc2a2 could explain, at least in part, the observed metabolic phenotypes. Full article
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22 pages, 6566 KiB  
Article
Antioxidant Activity Evaluation and Assessment of the Binding Affinity to HSA of a New Catechol Hydrazinyl-Thiazole Derivative
by Mihaela Mic, Adrian Pîrnău, Călin G. Floare, Raluca Borlan, Monica Focsan, Ovidiu Oniga, Mircea Bogdan, Laurian Vlase, Ilioara Oniga and Gabriel Marc
Antioxidants 2022, 11(7), 1245; https://doi.org/10.3390/antiox11071245 - 24 Jun 2022
Cited by 4 | Viewed by 2277
Abstract
Polyphenols have attained pronounced attention due to their ability to provide numerous health benefits and prevent several chronic diseases. In this study, we designed, synthesized and analyzed a water-soluble molecule presenting a good antioxidant activity, namely catechol hydrazinyl-thiazole (CHT). This molecule contains 3′,4′-dihydroxyphenyl [...] Read more.
Polyphenols have attained pronounced attention due to their ability to provide numerous health benefits and prevent several chronic diseases. In this study, we designed, synthesized and analyzed a water-soluble molecule presenting a good antioxidant activity, namely catechol hydrazinyl-thiazole (CHT). This molecule contains 3′,4′-dihydroxyphenyl and 2-hydrazinyl-4-methyl-thiazole moieties linked through a hydrazone group with very good antioxidant activity in the in vitro evaluations performed. A preliminary validation of the CHT developing hypothesis was performed evaluating in silico the bond dissociation enthalpy (BDE) of the phenol O-H bonds, compared to our previous findings in the compounds previously reported by our group. In this paper, we report the binding mechanism of CHT to human serum albumin (HSA) using biophysical methods in combination with computational studies. ITC experiments reveal that the dominant forces in the binding mechanism are involved in the hydrogen bond or van der Waals interactions and that the binding was an enthalpy-driven process. NMR relaxation measurements were applied to study the CHT–protein interaction by changing the drug concentration in the solution. A molecular docking study added an additional insight to the experimental ITC and NMR analysis regarding the binding conformation of CHT to HSA. Full article
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19 pages, 1223 KiB  
Article
LC-MS Identification and Quantification of Phenolic Compounds in Solid Residues from the Essential Oil Industry
by Maria Irakli, Adriana Skendi, Elisavet Bouloumpasi, Paschalina Chatzopoulou and Costas G. Biliaderis
Antioxidants 2021, 10(12), 2016; https://doi.org/10.3390/antiox10122016 - 19 Dec 2021
Cited by 38 | Viewed by 5561
Abstract
Plant solid residues obtained from the essential oil industry represent a rich source of phenolic compounds with bioactive properties to be used in the food and pharmaceutical industries. A selective and sensitive liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous determination [...] Read more.
Plant solid residues obtained from the essential oil industry represent a rich source of phenolic compounds with bioactive properties to be used in the food and pharmaceutical industries. A selective and sensitive liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous determination of phenolic compounds in solid residues of the Lamiaceae family plants. A total of 48 compounds can be separated within 35 min by using the Poroshell-120 EC-C18 column, and a gradient mobile phase of 0.1% formic acid and acetonitrile with flow rate of 0.5 mL/min; salicylic acid was used as internal standard. The calibration curves showed good linearity in the tested concentration range for each analyte (R2 > 0.9921), while recoveries ranged from 70.1% to 115.0% with an intra-day and inter-day precision of less than 6.63% and 15.00%, respectively. Based on the retention behavior, as well as absorption and mass spectra, 17 phenolic acids, 19 flavonoids and 2 phenolic diterpenes were identified and quantified in the solid residues obtained by distillation of six aromatic plants: oregano, rosemary, sage, satureja, lemon balm, and spearmint. The method constitutes an accurate analytical and quality control tool for the simultaneous quantitation of phenolics present in solid waste residues from the essential oil industry. Full article
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16 pages, 5080 KiB  
Article
A Study on Myogenesis by Regulation of Reactive Oxygen Species and Cytotoxic Activity by Selenium Nanoparticles
by Sang-Cheol Lee, Na-Hyun Lee, Kapil D. Patel, Soo-Kyung Jun, Jeong-Hui Park, Jonathan Campbell Knowles, Hae-Won Kim, Hae-Hyoung Lee and Jung-Hwan Lee
Antioxidants 2021, 10(11), 1727; https://doi.org/10.3390/antiox10111727 - 29 Oct 2021
Cited by 7 | Viewed by 2801
Abstract
Reactive oxygen species (ROS) are continuously produced by skeletal muscle during contractile activity and even at rest. However, the ROS generated from excessive exercise or traumatic damage may produce more ROS than can be neutralized by an antioxidant capacity, which can be harmful [...] Read more.
Reactive oxygen species (ROS) are continuously produced by skeletal muscle during contractile activity and even at rest. However, the ROS generated from excessive exercise or traumatic damage may produce more ROS than can be neutralized by an antioxidant capacity, which can be harmful to muscle function. In particular, selenium is a known antioxidant that regulates physiological functions such as cell differentiation and anti-inflammatory function. In this study, we developed nano-sized antioxidative biomaterials using selenium to investigate the protective and differentiation effects against C2C12 myoblasts in an H2O2-induced oxidative stress environment. The selenium nanoparticles (SeNPs) were produced with a size of 35.6 ± 4.3 nm and showed antioxidant effects according to the 3,3′,5,5′-tetramethylbenzidine assay. Then, SeNPs were treated to C2C12 cells with or without H2O2. Our results showed that SeNPs reduced C2C12 apoptosis and intracellular ROS levels. Additionally, SeNPs effectively up-regulated in the presence of H2O2, MyoD, MyoG, α-actinin, and myosin heavy chain, which are well known to increase during myoblast differentiation as assayed by qRT-PCR, immunocytochemistry-staining, western blotting. These results demonstrate that SeNPs can accelerate differentiation with its protective effects from the ROS environment and can be applied to the treatment of skeletal muscle in a cellular redox environment. Full article
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15 pages, 1708 KiB  
Article
Targeting Pro-Oxidant Iron with Deferoxamine as a Treatment for Ischemic Stroke: Safety and Optimal Dose Selection in a Randomized Clinical Trial
by Mònica Millán, Núria DeGregorio-Rocasolano, Natàlia Pérez de la Ossa, Sílvia Reverté, Joan Costa, Pilar Giner, Yolanda Silva, Tomás Sobrino, Manuel Rodríguez-Yáñez, Florentino Nombela, Francisco Campos, Joaquín Serena, José Vivancos, Octavi Martí-Sistac, Jordi Cortés, Antoni Dávalos and Teresa Gasull
Antioxidants 2021, 10(8), 1270; https://doi.org/10.3390/antiox10081270 - 10 Aug 2021
Cited by 29 | Viewed by 4212
Abstract
A role of iron as a target to prevent stroke-induced neurodegeneration has been recently revisited due to new evidence showing that ferroptosis inhibitors are protective in experimental ischemic stroke and might be therapeutic in other neurodegenerative brain pathologies. Ferroptosis is a new form [...] Read more.
A role of iron as a target to prevent stroke-induced neurodegeneration has been recently revisited due to new evidence showing that ferroptosis inhibitors are protective in experimental ischemic stroke and might be therapeutic in other neurodegenerative brain pathologies. Ferroptosis is a new form of programmed cell death attributed to an overwhelming lipidic peroxidation due to excessive free iron and reactive oxygen species (ROS). This study aims to evaluate the safety and tolerability and to explore the therapeutic efficacy of the iron chelator and antioxidant deferoxamine mesylate (DFO) in ischemic stroke patients. Administration of placebo or a single DFO bolus followed by a 72 h continuous infusion of three escalating doses was initiated during the tPA infusion, and the impact on blood transferrin iron was determined. Primary endpoint was safety and tolerability, and secondary endpoint was good clinical outcome (clinicalTrials.gov NCT00777140). DFO was found safe as adverse effects were not different between placebo and DFO arms. DFO (40–60 mg/Kg/day) reduced the iron saturation of blood transferrin. A trend to efficacy was observed in patients with moderate-severe ischemic stroke (NIHSS > 7) treated with DFO 40–60 mg/Kg/day. A good outcome was observed at day 90 in 31% of placebo vs. 50–58% of the 40–60 mg/Kg/day DFO-treated patients. Full article
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10 pages, 572 KiB  
Article
A Study of the Antioxidant, Cytotoxic Activity and Adsorption Properties of Karelian Shungite by Physicochemical Methods
by Liubov Skrypnik, Olga Babich, Stanislav Sukhikh, Olga Shishko, Svetlana Ivanova, Oleg Mozhei, Ivan Kochish and Ilia Nikonov
Antioxidants 2021, 10(7), 1121; https://doi.org/10.3390/antiox10071121 - 14 Jul 2021
Cited by 13 | Viewed by 6128
Abstract
This study reveals that fossil shungite samples exhibit antioxidant activity, can reduce oxidized components, and bind to free radicals. A sample of Sh20 (size fraction—20 μm) (1.30 mg equivalents of ascorbic acid/g of shungite; 3.46 mg equivalents of trolox/g of shungite; 0.99 mg [...] Read more.
This study reveals that fossil shungite samples exhibit antioxidant activity, can reduce oxidized components, and bind to free radicals. A sample of Sh20 (size fraction—20 μm) (1.30 mg equivalents of ascorbic acid/g of shungite; 3.46 mg equivalents of trolox/g of shungite; 0.99 mg equivalents of quercetin/g of shungite) had the maximal activity according to the amperometric method. The obtained data indicate that shungite has antioxidant properties, but these are approximately 1000 times less pronounced than those of quercetin. A ShT20 sample (size fraction—20 μm + heat treatment) was found to have the highest antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl radical and cytotoxicity. Further studies, including the optimization of the antioxidant extraction conditions of shungite, and the analysis of the qualitative and quantitative composition of the obtained extracts, are required for a more accurate interpretation of the results. Shungite can be applied as an alternative to activated carbon in water purification, due to its absorption, catalytic, antioxidant, regenerating, and antibacterial properties, as well as its high environmental safety and relatively low cost. It is possible to identify new structural forms of carbon within, and other valuable properties of, shungite substance, which will make it possible to create effective technologies for the practical use of shungite rocks, particularly in the production of fullerenes and other carbon nanoclusters. Full article
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Review

Jump to: Research

18 pages, 565 KiB  
Review
Phlorotannins: Novel Orally Administrated Bioactive Compounds That Induce Mitochondrial Dysfunction and Oxidative Stress in Cancer
by Layla Simón, Migdalia Arazo-Rusindo, Andrew F. G. Quest and María Salomé Mariotti-Celis
Antioxidants 2023, 12(9), 1734; https://doi.org/10.3390/antiox12091734 - 7 Sep 2023
Cited by 3 | Viewed by 1907
Abstract
Mitochondrial dysfunction is an interesting therapeutic target to help reduce cancer deaths, and the use of bioactive compounds has emerged as a novel and safe approach to solve this problem. Here, we discuss the information available related to phlorotannins, a type of polyphenol [...] Read more.
Mitochondrial dysfunction is an interesting therapeutic target to help reduce cancer deaths, and the use of bioactive compounds has emerged as a novel and safe approach to solve this problem. Here, we discuss the information available related to phlorotannins, a type of polyphenol present in brown seaweeds that reportedly functions as antioxidants/pro-oxidants and anti-inflammatory and anti-tumorigenic agents. Specifically, available evidence indicates that dieckol and phloroglucinol promote mitochondrial membrane depolarization and mitochondria-dependent apoptosis. Phlorotannins also reduce pro-tumorigenic, -inflammatory, and -angiogenic signaling mechanisms involving RAS/MAPK/ERK, PI3K/Akt/mTOR, NF-κB, and VEGF. In doing so, they inhibit pathways that favor cancer development and progression. Unfortunately, these compounds are rather labile and, therefore, this review also summarizes approaches permitting the encapsulation of bioactive compounds, like phlorotannins, and their subsequent oral administration as novel and non-invasive therapeutic alternatives for cancer treatment. Full article
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33 pages, 9995 KiB  
Review
Spectrophotometric Methods for Measurement of Antioxidant Activity in Food and Pharmaceuticals
by Marios C. Christodoulou, Jose C. Orellana Palacios, Golnaz Hesami, Shima Jafarzadeh, José M. Lorenzo, Rubén Domínguez, Andres Moreno and Milad Hadidi
Antioxidants 2022, 11(11), 2213; https://doi.org/10.3390/antiox11112213 - 8 Nov 2022
Cited by 77 | Viewed by 17741
Abstract
In recent years, there has been a growing interest in the application of antioxidants in food and pharmaceuticals due to their association with beneficial health effects against numerous oxidative-related human diseases. The antioxidant potential can be measured by various assays with specific mechanisms [...] Read more.
In recent years, there has been a growing interest in the application of antioxidants in food and pharmaceuticals due to their association with beneficial health effects against numerous oxidative-related human diseases. The antioxidant potential can be measured by various assays with specific mechanisms of action, including hydrogen atom transfer, single electron transfer, and targeted scavenging activities. Understanding the chemistry of mechanisms, advantages, and limitations of the methods is critical for the proper selection of techniques for the valid assessment of antioxidant activity in specific samples or conditions. There are various analytical techniques available for determining the antioxidant activity of biological samples, including food and plant extracts. The different methods are categorized into three main groups, such as spectrometry, chromatography, and electrochemistry techniques. Among these assays, spectrophotometric methods are considered the most common analytical technique for the determination of the antioxidant potential due to their sensitivity, rapidness, low cost, and reproducibility. This review covers the mechanism of actions and color changes that occur in each method. Furthermore, the advantages and limitations of spectrophotometric methods are described and discussed in this review. Full article
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25 pages, 3252 KiB  
Review
Metabolomics Technologies for the Identification and Quantification of Dietary Phenolic Compound Metabolites: An Overview
by Anallely López-Yerena, Inés Domínguez-López, Anna Vallverdú-Queralt, Maria Pérez, Olga Jáuregui, Elvira Escribano-Ferrer and Rosa M. Lamuela-Raventós
Antioxidants 2021, 10(6), 846; https://doi.org/10.3390/antiox10060846 - 25 May 2021
Cited by 24 | Viewed by 4863
Abstract
In the search for natural products with properties that may protect against or slow down chronic and degenerative diseases (e.g., cancer, and cardiovascular and neurodegenerative conditions), phenolic compounds (PC) with benefits for human health have been identified. The biological effects of PC in [...] Read more.
In the search for natural products with properties that may protect against or slow down chronic and degenerative diseases (e.g., cancer, and cardiovascular and neurodegenerative conditions), phenolic compounds (PC) with benefits for human health have been identified. The biological effects of PC in vivo depend on their bioavailability, intestinal absorption, metabolism, and interaction with target tissues. The identification of phenolic compounds metabolites (PCM), in biological samples, after food ingestion rich in PC is a first step to understand the overall effect on human health. However, their wide range of physicochemical properties, levels of abundance, and lack of reference standards, renders its identification and quantification a challenging task for existing analytical platforms. The most frequent approaches to metabolomics analysis combine mass spectrometry and NMR, parallel technologies that provide an overview of the metabolome and high-power compound elucidation. In this scenario, the aim of this review is to summarize the pre-analytical separation processes for plasma and urine samples and the technologies applied in quantitative and qualitative analysis of PCM. Additionally, a comparison of targeted and non-targeted approaches is presented, not available in previous reviews, which may be useful for future metabolomics studies of PCM. Full article
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