Topic Editors

Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal
Instituto Politécnico de Bragança, Centro de Investigação de Montanha (CIMO), Campus Santa Apolonia, Braganca, Portugal
Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal
LAQV/REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal

Antioxidant Activity of Natural Products

Abstract submission deadline
closed (31 March 2023)
Manuscript submission deadline
closed (30 June 2023)
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Topic Information

Dear Colleagues,

Natural products play an important role in the discovery and development of active ingredients with a wide range of applications. Interest in them stems mainly from their antioxidant effects, which have been widely studied and pursued by researchers from different disciplines. Antioxidants can neutralize free radicals and reactive species, thereby counteracting oxidative damage, and consequently, they are able to reduce the incidence of oxidative stress-related diseases and interrupt free radical-mediated chain reactions. This justifies their wide range of applications in medical and therapeutic goods, cosmetics, food additives, and biomaterials.

Natural products from different sources have been studied over the last few decades, but much more remains to be discovered regarding the structural elucidation and mechanisms of antioxidant action of their molecules. The discovery of new sources and compounds, more sustainable and selective extraction and isolation techniques, and more reliable and accurate analytical methods is still ongoing, as is the assessment of the role of antioxidants in human health and wellbeing. The development and standardization of model systems to accurately assess the biological or technological relevance of the antioxidant effect has been challenging but still necessary.

This transdisciplinary Topic aims to bring together original research and review articles focusing on recent advances in the extraction, isolation, and characterization of plant, fungal, algal, microbial, and animal-derived antioxidants; bioactivity, bioaccessibility, and bioavailability of antioxidants and their interaction with other compounds; molecular mechanisms of antioxidant action and effects on particular metabolic or signaling pathways; the role of antioxidants in the prevention and treatment of health conditions; and stabilization and application of antioxidants in foods, nutraceuticals, pharmaceuticals, and biomaterials. Other subjects related to this topic are also welcome.

Dr. José Pinela
Dr. Maria Inês Dias
Dr. Carla Pereira
Dr. Alexandra Plácido
Topic Editors

Keywords

  • secondary metabolites
  • natural antioxidants
  • in vitro, in vivo, and in silico models
  • structure–activity relationship
  • natural product chemistry
  • oxidative stress and antioxidant defense
  • free-radical-mediated chain reactions
  • extraction and separation methods
  • antioxidant ingredients and biomaterials

Participating Journals

Journal Name Impact Factor CiteScore Launched Year First Decision (median) APC
Antioxidants
antioxidants
7.0 8.8 2012 13.9 Days CHF 2900
BioChem
biochem
- - 2021 54 Days CHF 1000
Biomolecules
biomolecules
5.5 8.3 2011 16.9 Days CHF 2700
International Journal of Molecular Sciences
ijms
5.6 7.8 2000 16.3 Days CHF 2900
Marine Drugs
marinedrugs
5.4 9.6 2003 14 Days CHF 2900
Molecules
molecules
4.6 6.7 1996 14.6 Days CHF 2700

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Published Papers (33 papers)

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16 pages, 4559 KiB  
Article
Antioxidant Peptides from the Collagen of Antler Ossified Tissue and Their Protective Effects against H2O2-Induced Oxidative Damage toward HaCaT Cells
by Xi Chen, Peijun Xia, Shuo Zheng, Yi Li, Jiayuan Fang, Ze Ma, Libo Zhang, Xunming Zhang, Linlin Hao and Hong Zhang
Molecules 2023, 28(19), 6887; https://doi.org/10.3390/molecules28196887 - 30 Sep 2023
Cited by 1 | Viewed by 1029
Abstract
Antler ossified tissue has been widely used for the extraction of bioactive peptides. In this study, collagen was prepared from antler ossified tissue via acetic acid and pepsin. Five different proteases were used to hydrolyze the collagen and the hydrolysate treated by neutrase [...] Read more.
Antler ossified tissue has been widely used for the extraction of bioactive peptides. In this study, collagen was prepared from antler ossified tissue via acetic acid and pepsin. Five different proteases were used to hydrolyze the collagen and the hydrolysate treated by neutrase (collagen peptide named ACP) showed the highest DPPH radical clearance rate. The extraction process of ACP was optimized by response surface methodology, and the optimal conditions were as follows: a temperature of 52 °C, a pH of 6.1, and an enzyme concentration of 3200 U/g, which resulted in the maximum DPPH clearance rate of 74.41 ± 0.48%. The peptides (ACP-3) with the strongest antioxidant activity were obtained after isolation and purification, and its DPPH free radical clearance rate was 90.58 ± 1.27%; at the same time, it exhibited good scavenging activity for ABTS, hydroxyl radical, and superoxide anion radical. The study investigated the protective effect of ACP-3 on oxidative damage in HaCaT cells. The findings revealed that all groups that received ACP-3 pretreatment exhibited increased activities of SOD, GSH-Px, and CAT compared to the model group. Furthermore, ACP-3 pretreatment reduced the levels of ROS and MDA in HaCaT cells subjected to H2O2-induced oxidative damage. These results suggest that collagen peptides derived from deer antler ossified tissue can effectively mitigate the oxidative damage caused by H2O2 in HaCaT cells, thereby providing a foundation for the utilization of collagen peptides in pharmaceuticals and cosmetics. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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27 pages, 1073 KiB  
Article
Monofloral Corn Poppy Bee-Collected Pollen—A Detailed Insight into Its Phytochemical Composition and Antioxidant Properties
by Aleksandar Ž. Kostić, Danijel D. Milinčić, Bojana Špirović Trifunović, Nebojša Nedić, Uroš M. Gašić, Živoslav Lj. Tešić, Sladjana P. Stanojević and Mirjana B. Pešić
Antioxidants 2023, 12(7), 1424; https://doi.org/10.3390/antiox12071424 - 14 Jul 2023
Cited by 5 | Viewed by 1568
Abstract
The aim of this study was to compile a detailed phytochemical profile and assess the antioxidant properties of bee-collected pollen (PBP) obtained from corn poppy (Papaver rhoeas L.) plants. To achieve this, a lipid fraction was prepared for quantifying fatty acids using [...] Read more.
The aim of this study was to compile a detailed phytochemical profile and assess the antioxidant properties of bee-collected pollen (PBP) obtained from corn poppy (Papaver rhoeas L.) plants. To achieve this, a lipid fraction was prepared for quantifying fatty acids using GC-FID. Extractable and alkaline-hydrolysable PBP fractions (obtained from a defatted sample) were used to determine the qualitative and quantitative profiles of phenolic compounds, phenylamides and alkaloids using UHPLC/Q-ToF-MS. Additionally, various spectrophotometric assays (TAC, FRP, CUPRAC, DPPH) were conducted to evaluate the antioxidant properties. Phenolic compounds were more present in the extractable fraction than in the alkaline-hydrolysable fraction. Luteolin was the predominant compound in the extractable fraction, followed by tricetin and various derivatives of kaempferol. This study presents one of the first reports on the quantification of tricetin aglycone outside the Myrtaceae plant family. The alkaline-hydrolysable fraction exhibited a different phenolic profile, with a significantly lower amount of phenolics. Kaempferol/derivatives, specific compounds like ferulic and 5-carboxyvanillic acids, and (epi)catechin 3-O-gallate were the predominant compounds in this fraction. Regarding phenylamides, the extractable fraction demonstrated a diverse range of these bioactive compounds, with a notable abundance of different spermine derivatives. In contrast, the hydrolysable fraction contained six spermine derivatives and one spermidine derivative. The examined fractions also revealed the presence of seventeen different alkaloids, belonging to the benzylisoquinoline, berberine and isoquinoline classes. The fatty-acid profile confirmed the prevalence of unsaturated fatty acids. Furthermore, both fractions exhibited significant antioxidant activity, with the extractable fraction showing particularly high activity. Among the assays conducted, the CUPRAC assay highlighted the exceptional ability of PBP’s bioactive compounds to reduce cupric ions. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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12 pages, 2196 KiB  
Article
Radical Scavenging Capability and Mechanism of Three Isoflavonoids Extracted from Radix Astragali: A Theoretical Study
by Xiao-Qin Lu, Shu Qin and Jindong Li
Molecules 2023, 28(13), 5039; https://doi.org/10.3390/molecules28135039 - 28 Jun 2023
Cited by 3 | Viewed by 1260
Abstract
As a valuable traditional Chinese herbal medicine, Radix Astragali has attracted much attention due to its extensive pharmacological activities. In this study, density functional theory (DFT) was used thermodynamically and kinetically in detail to predict the antioxidant activity and reaction mechanisms involved in [...] Read more.
As a valuable traditional Chinese herbal medicine, Radix Astragali has attracted much attention due to its extensive pharmacological activities. In this study, density functional theory (DFT) was used thermodynamically and kinetically in detail to predict the antioxidant activity and reaction mechanisms involved in the free radical scavenging reactions of three representative isoflavonoids (formononetin, calycosin, and calycosin-7-glucoside) extracted from Radix Astragali. Three main mechanisms, including hydrogen atom transfer (HAT), proton transfer after electron transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were examined by calculating the thermodynamic parameters. It was found that HAT is the predominant mechanism in the gas phase, while SPLET is supported in the solvent environment. The isoflavonoids’ order of antioxidant activity was estimated as: calycosin > calycosin-7-glucoside > formononetin. For the calycosin compound, the result revealed the feasibility of double HAT mechanisms, which involve the formation of stable benzodioxazole with significantly reduced energy in the second H+/e reaction. In addition, the potential energy profiles and kinetic calculations show that the reaction of OH into the 3′-OH site of calycosin has a lower energy barrier (7.2 kcal/mol) and higher rate constant (4.55 × 109 M−1 s−1) compared with other reactions in the gas phase. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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16 pages, 2707 KiB  
Article
Enzymatic Modification of Pomace Olive Oil with Natural Antioxidants: Effect on Oxidative Stability
by Renia Fotiadou, Dimitrios Lefas, Despina Vougiouklaki, Aliki Tsakni, Dimitra Houhoula and Haralambos Stamatis
Biomolecules 2023, 13(7), 1034; https://doi.org/10.3390/biom13071034 - 23 Jun 2023
Cited by 2 | Viewed by 1221
Abstract
Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive [...] Read more.
Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive oil (POO) in solvent-free conditions using immobilized lipase on biogenic nanoparticles. The effect of temperature (30–70 °C) and enzyme concentration (0.1–1%, w/w) on the efficiency of the bioprocess as well as the reusability of the nanobiocatalyst were thoroughly investigated. The modified oils exhibited increased antioxidant activity compared to the control oil according to DPPH and CUPRAC assays (p < 0.05). The oxidative stability of pomace olive oil was also significantly enhanced after modification, as depicted by the K232 values and TBARS contents under accelerated oxidation at 60 °C (p < 0.05). Moreover, a fortified mayonnaise containing modified oil with HTYR was prepared that was noticeably stable compared to the control mayonnaise at 28 °C for 5 months (p < 0.05). Enzymatically modified oils have great potential for application in the nutraceutical and food industry, encouraging the exploitation of immobilized lipases as effective and green catalytic tools. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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15 pages, 4600 KiB  
Article
Baicalin Attenuates H2O2-Induced Oxidative Stress by Regulating the AMPK/Nrf2 Signaling Pathway in IPEC-J2 Cells
by Jiahua Liang, Ying Zhou, Xinyi Cheng, Jiaqi Chen, Huabin Cao, Xiaoquan Guo, Caiying Zhang, Yu Zhuang and Guoliang Hu
Int. J. Mol. Sci. 2023, 24(11), 9435; https://doi.org/10.3390/ijms24119435 - 29 May 2023
Cited by 5 | Viewed by 1493
Abstract
Oxidative stress can adversely affect the health status of the body, more specifically by causing intestinal damage by disrupting the permeability of the intestinal barrier. This is closely related to intestinal epithelial cell apoptosis caused by the mass production of reactive oxygen species [...] Read more.
Oxidative stress can adversely affect the health status of the body, more specifically by causing intestinal damage by disrupting the permeability of the intestinal barrier. This is closely related to intestinal epithelial cell apoptosis caused by the mass production of reactive oxygen species (ROS). Baicalin (Bai) is a major active ingredient in Chinese traditional herbal medicine that has antioxidant, anti-inflammatory, and anti-cancer properties. The purpose of this study was to explore the underlying mechanisms by which Bai protects against hydrogen peroxide (H2O2)-induced intestinal injury in vitro. Our results indicated that H2O2 treatment caused injury to IPEC-J2 cells, resulting in their apoptosis. However, Bai treatment attenuated H2O2-induced IPEC-J2 cell damage by up-regulating the mRNA and protein expression of ZO-1, Occludin, and Claudin1. Besides, Bai treatment prevented H2O2-induced ROS and MDA production and increased the activities of antioxidant enzymes (SOD, CAT, and GSH-PX). Moreover, Bai treatment also attenuated H2O2-induced apoptosis in IPEC-J2 cells by down-regulating the mRNA expression of Caspase-3 and Caspase-9 and up-regulating the mRNA expression of FAS and Bax, which are involved in the inhibition of mitochondrial pathways. The expression of Nrf2 increased after treatment with H2O2, and Bai can alleviate this phenomenon. Meanwhile, Bai down-regulated the ratio of phosphorylated AMPK to unphosphorylated AMPK, which is indicative of the mRNA abundance of antioxidant-related genes. In addition, knockdown of AMPK by short-hairpin RNA (shRNA) significantly reduced the protein levels of AMPK and Nrf2, increased the percentage of apoptotic cells, and abrogated Bai-mediated protection against oxidative stress. Collectively, our results indicated that Bai attenuated H2O2-induced cell injury and apoptosis in IPEC-J2 cells through improving the antioxidant capacity through the inhibition of the oxidative stress-mediated AMPK/Nrf2 signaling pathway. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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13 pages, 2269 KiB  
Article
A New Lignan from Annona squamosa L. (Annonaceae) Demonstrates Vasorelaxant Effects In Vitro
by Camilo Di Giulio, Juan Manuel Gonzalez Guzman, Joao Victor Dutra Gomes, Young Hae Choi, Pérola O. Magalhães, Yris M. Fonseca-Bazzo, Damaris Silveira and Omar Estrada
Molecules 2023, 28(11), 4256; https://doi.org/10.3390/molecules28114256 - 23 May 2023
Cited by 1 | Viewed by 1386
Abstract
Esquamosan, a new furofuran lignan, has been isolated by bio-guided assays from the methanolic extract of the leaves of Annona squamosa L., and its structure was elucidated by spectroscopic methods. Esquamosan inhibited the rat aortic ring contraction evoked by phenylephrine in a concentration-dependent [...] Read more.
Esquamosan, a new furofuran lignan, has been isolated by bio-guided assays from the methanolic extract of the leaves of Annona squamosa L., and its structure was elucidated by spectroscopic methods. Esquamosan inhibited the rat aortic ring contraction evoked by phenylephrine in a concentration-dependent manner and showed an inhibitory effect on vasocontraction of the depolarized aorta with high-concentration potassium. The vasorelaxant effect by esquamosan could be attributed mainly to the inhibition of calcium influx from extracellular space through voltage-dependent calcium channels or receptor-operated Ca2+ channels and also partly mediated through the increased release of NO from endothelial cells. The ability of esquamosan to modify the vascular reactivity of rat aortic rings incubated with high glucose (D-glucose 55 mM) was then evaluated, and this furofuran lignan reverted the endothelium-dependent impairment effect of high glucose in rat aortic rings. The antioxidant capacity of esquamosan was assessed using DPPH and FRAP assays. Esquamosan exhibited a similar antioxidant capacity compared to ascorbic acid, which was used as a positive control. In conclusion, this lignan showed a vasorelaxant effect, free radical scavenging capacity, and potential reductive power, suggesting its potential beneficial use to treat complex cardiometabolic diseases due to free radical-mediated diseases and its calcium antagonist effect. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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19 pages, 2125 KiB  
Review
The Role of Natural Antioxidant Products That Optimize Redox Status in the Prevention and Management of Type 2 Diabetes
by Dawn S. Tuell, Evan A. Los, George A. Ford and William L. Stone
Antioxidants 2023, 12(6), 1139; https://doi.org/10.3390/antiox12061139 - 23 May 2023
Cited by 4 | Viewed by 2152
Abstract
The worldwide prevalence of type 2 diabetes (T2D) and prediabetes is rapidly increasing, particularly in children, adolescents, and young adults. Oxidative stress (OxS) has emerged as a likely initiating factor in T2D. Natural antioxidant products may act to slow or prevent T2D by [...] Read more.
The worldwide prevalence of type 2 diabetes (T2D) and prediabetes is rapidly increasing, particularly in children, adolescents, and young adults. Oxidative stress (OxS) has emerged as a likely initiating factor in T2D. Natural antioxidant products may act to slow or prevent T2D by multiple mechanisms, i.e., (1) reducing mitochondrial oxidative stress, (2) preventing the damaging effects of lipid peroxidation, and (3) acting as essential cofactors for antioxidant enzymes. Natural antioxidant products should also be evaluated in the context of the complex physiological processes that modulate T2D-OxS such as glycemic control, postprandial OxS, the polyol pathway, high-calorie, high-fat diets, exercise, and sleep. Minimizing processes that induce chronic damaging OxS and maximizing the intake of natural antioxidant products may provide a means of preventing or slowing T2D progression. This “optimal redox” (OptRedox) approach also provides a framework in which to discuss the potential benefits of natural antioxidant products such as vitamin E, vitamin C, beta-carotene, selenium, and manganese. Although there is a consensus that early effective intervention is critical for preventing or reversing T2D progression, most research has focused on adults. It is critical, therefore, that future research include pediatric populations. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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17 pages, 5358 KiB  
Article
Salvianolic Acid B Inhibits Ferroptosis and Apoptosis during Myocardial Ischemia/Reperfusion Injury via Decreasing the Ubiquitin-Proteasome Degradation of GPX4 and the ROS-JNK/MAPK Pathways
by Xiaojin Xu, Chenhan Mao, Chengbo Zhang, Meng Zhang, Jianbin Gong and Xindong Wang
Molecules 2023, 28(10), 4117; https://doi.org/10.3390/molecules28104117 - 16 May 2023
Cited by 8 | Viewed by 1796
Abstract
Myocardial ischemia/reperfusion injury (MIRI) is related to ferroptosis and apoptosis elicited by reactive oxygen species (ROS). In this research, we investigated the protective effect of salvianolic acid B (SAB) as a natural antioxidant on ferroptosis and apoptosis in the MIRI process, and discussed [...] Read more.
Myocardial ischemia/reperfusion injury (MIRI) is related to ferroptosis and apoptosis elicited by reactive oxygen species (ROS). In this research, we investigated the protective effect of salvianolic acid B (SAB) as a natural antioxidant on ferroptosis and apoptosis in the MIRI process, and discussed the protective mechanism inhibiting ubiquitin-proteasome degradation of glutathione peroxidase 4 (GPX4) and the c-Jun N-terminal kinases (JNK) apoptosis signal pathway. We observed that ferroptosis and apoptosis occurred in the MIRI rat model in vivo and the H9c2 cardiomyocyte hypoxia/reoxygenation (H/R) damage model in vitro. SAB can alleviate tissue damage related to ROS, ferroptosis and apoptosis. Ubiquitin-proteasome degradation of GPX4 occurred in H/R models, and SAB reduced the ubiquitin-proteasome degradation of GPX4. SAB downregulates JNK phosphorylation and the expression of BCL2-Associated X (Bax)/B-cell lymphoma-2 (Bcl-2) and Caspase-3 to inhibit apoptosis. The role of GPX4 in the cardioprotection of SAB was further verified by the elimination effect of the GPX4 inhibitor RAS-selective lethal 3 (RSL3). This research shows that SAB may be used as a myocardial protective agent against oxidative stress, ferroptosis and apoptosis, and has potential clinical application prospects. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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17 pages, 5542 KiB  
Article
Protective Effects of a Jellyfish-Derived Thioredoxin Fused with Cell-Penetrating Peptide TAT-PTD on H2O2-Induced Oxidative Damage
by Bo Wang, Peipei Zhang, Qianqian Wang, Shuaijun Zou, Juxingsi Song, Fuhai Zhang, Guoyan Liu and Liming Zhang
Int. J. Mol. Sci. 2023, 24(8), 7340; https://doi.org/10.3390/ijms24087340 - 16 Apr 2023
Cited by 1 | Viewed by 1325
Abstract
Thioredoxin (Trx) plays a critical role in maintaining redox balance in various cells and exhibits anti-oxidative, anti-apoptotic, and anti-inflammatory effects. However, whether exogenous Trx can inhibit intracellular oxidative damage has not been investigated. In previous study, we have identified a novel Trx from [...] Read more.
Thioredoxin (Trx) plays a critical role in maintaining redox balance in various cells and exhibits anti-oxidative, anti-apoptotic, and anti-inflammatory effects. However, whether exogenous Trx can inhibit intracellular oxidative damage has not been investigated. In previous study, we have identified a novel Trx from the jellyfish Cyanea capillata, named CcTrx1, and confirmed its antioxidant activities in vitro. Here, we obtained a recombinant protein, PTD-CcTrx1, which is a fusion of CcTrx1 and protein transduction domain (PTD) of HIV TAT protein. The transmembrane ability and antioxidant activities of PTD-CcTrx1, and its protective effects against H2O2-induced oxidative damage in HaCaT cells were also detected. Our results revealed that PTD-CcTrx1 exhibited specific transmembrane ability and antioxidant activities, and it could significantly attenuate the intracellular oxidative stress, inhibit H2O2-induced apoptosis, and protect HaCaT cells from oxidative damage. The present study provides critical evidence for application of PTD-CcTrx1 as a novel antioxidant to treat skin oxidative damage in the future. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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14 pages, 4706 KiB  
Article
Moisturizing and Antioxidant Effects of Artemisia argyi Essence Liquid in HaCaT Keratinocytes
by Ziwen Wang, Qiaoli Wang, Wenshen Zhong, Feng Liang, Yuying Guo, Yifei Wang and Zhiping Wang
Int. J. Mol. Sci. 2023, 24(7), 6809; https://doi.org/10.3390/ijms24076809 - 6 Apr 2023
Cited by 1 | Viewed by 2014
Abstract
Artemisia argyi essence liquid (AL) is an aqueous solution extracted from A. argyi using CO2 supercritical fluid extraction. There have been few investigations on the aqueous solution of A. argyi extracted via CO2 supercritical fluid extraction. This study aimed to explore [...] Read more.
Artemisia argyi essence liquid (AL) is an aqueous solution extracted from A. argyi using CO2 supercritical fluid extraction. There have been few investigations on the aqueous solution of A. argyi extracted via CO2 supercritical fluid extraction. This study aimed to explore the moisturizing and antioxidant effects of AL and to clarify the potential mechanism underlying those effects. Expression levels of skin moisture-related components and the H2O2-induced oxidative stress responses in human keratinocyte cells were measured via quantitative RT-qPCR, Western blot, and immunofluorescence. Our results showed that AL enhanced the expression of AQP3 and HAS2 by activating the EGFR-mediated STAT3 and MAPK signaling pathways. In addition, AL can play an antioxidant role by inhibiting the NF-κB signaling pathway and activating the Nrf2/HO-1 signaling pathway, consequently increasing the expression of antioxidant enzymes (GPX1, SOD2) and decreasing the production of reactive oxygen species (ROS). This study revealed that AL could be used as a potential moisturizing and antioxidant cosmetic ingredient. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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25 pages, 1342 KiB  
Review
Food Antioxidants and Their Interaction with Human Proteins
by Olgica Nedić, Ana Penezić, Simeon Minić, Mirjana Radomirović, Milan Nikolić, Tanja Ćirković Veličković and Nikola Gligorijević
Antioxidants 2023, 12(4), 815; https://doi.org/10.3390/antiox12040815 - 27 Mar 2023
Cited by 6 | Viewed by 2275
Abstract
Common to all biological systems and living organisms are molecular interactions, which may lead to specific physiological events. Most often, a cascade of events occurs, establishing an equilibrium between possibly competing and/or synergistic processes. Biochemical pathways that sustain life depend on multiple intrinsic [...] Read more.
Common to all biological systems and living organisms are molecular interactions, which may lead to specific physiological events. Most often, a cascade of events occurs, establishing an equilibrium between possibly competing and/or synergistic processes. Biochemical pathways that sustain life depend on multiple intrinsic and extrinsic factors contributing to aging and/or diseases. This article deals with food antioxidants and human proteins from the circulation, their interaction, their effect on the structure, properties, and function of antioxidant-bound proteins, and the possible impact of complex formation on antioxidants. An overview of studies examining interactions between individual antioxidant compounds and major blood proteins is presented with findings. Investigating antioxidant/protein interactions at the level of the human organism and determining antioxidant distribution between proteins and involvement in the particular physiological role is a very complex and challenging task. However, by knowing the role of a particular protein in certain pathology or aging, and the effect exerted by a particular antioxidant bound to it, it is possible to recommend specific food intake or resistance to it to improve the condition or slow down the process. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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19 pages, 7081 KiB  
Article
Antioxidant Activity as an Indicator of the Efficiency of Plant Extract-Mediated Synthesis of Zinc Oxide Nanoparticles
by Joelis Vera, Wence Herrera, Edward Hermosilla, Marcela Díaz, Javiera Parada, Amedea B. Seabra, Gonzalo Tortella, Héctor Pesenti, Gustavo Ciudad and Olga Rubilar
Antioxidants 2023, 12(4), 784; https://doi.org/10.3390/antiox12040784 - 23 Mar 2023
Cited by 11 | Viewed by 2791
Abstract
The green synthesis of zinc oxide nanoparticles (ZnO NPs) using a diverse range of plant species has been extensively reported. Despite the success achieved by biogenic synthesis, there are problems with the control and prediction of the properties of ZnO NPs, due to [...] Read more.
The green synthesis of zinc oxide nanoparticles (ZnO NPs) using a diverse range of plant species has been extensively reported. Despite the success achieved by biogenic synthesis, there are problems with the control and prediction of the properties of ZnO NPs, due to phytochemical diversity between plant species. In this sense, the main objective of our work was to investigate the effect of the antioxidant activity (AA) of plant extracts on the physicochemical characteristics of ZnO NPs (production yield, chemical composition, polydispersity index (PDI), surface charge (ζ-potential) and average particle size). In order to accomplish this objective, four plant extract with different antioxidant activities were used: Galega officinalis, Buddleja globosa, Eucalyptus globulus, and Aristotelia chilensis. Phytochemical screening, quantitative analysis of phenolic compounds and antioxidant activity determination of the different extracts were carried out. Chemical species such as catechin, malvidin, quercetin, caffeic acid, and ellagic acid were the dominant components, found in the extracts studied. The A. chilensis extract showed the highest value of total phenolic compounds (TPC) and AA, followed by E. globulus, B. globosa and G. officinalis. Zetasizer, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) data show that plant extracts with lower AA leads to a decrease in the yield of ZnO NPs and an increase in the amount of residual organic extract that remains on the particles. The latter caused an increase in the average particle size, PDI and ζ-potential as a consequence of agglomeration and particle coarsening. Our result suggest that it is possible to use the AA as an indicator of the potential reducing capacity of plant extracts. In this way it is possible to guarantee the reproducibility of the synthesis process as well as ensure the formation of ZnO NPs with desired characteristics. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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17 pages, 4019 KiB  
Article
Jellyfish Peptide as an Alternative Source of Antioxidant
by Lichao Teng, Xueqin Wang, Huahua Yu, Rongfeng Li, Hao Geng, Ronge Xing, Song Liu and Pengcheng Li
Antioxidants 2023, 12(3), 742; https://doi.org/10.3390/antiox12030742 - 17 Mar 2023
Cited by 2 | Viewed by 2069
Abstract
Jellyfish is a valuable biological resource in marine ecosystems, and blooms been observed in numerous coastal regions. However, their utility is limited by their high water content. Recent research has focused on extracting antioxidants from marine sources. In this study, we obtained jellyfish [...] Read more.
Jellyfish is a valuable biological resource in marine ecosystems, and blooms been observed in numerous coastal regions. However, their utility is limited by their high water content. Recent research has focused on extracting antioxidants from marine sources. In this study, we obtained jellyfish peptides (JPHT-2) through enzymatic hydrolysis of lyophilized jellyfish powder under optimal conditions and measured their antioxidant activity. Our findings indicate that JPHT-2 possesses significant radical-scavenging activity and reducing power. At a concentration of 0.74 mg/mL, JPHT-2 exhibited a remarkable ability to scavenge hydroxyl radicals, with a rate of up to 50%. The EC50 values for scavenging superoxide anion and DPPH radical were 1.55 mg/mL and 1.99 mg/mL, respectively. At the cellular level, JPHT-2 was able to protect HaCaT cells from H2O2-induced oxidative damage by increasing the level of superoxide dismutase (SOD) in cells. In conclusion, jellyfish peptides with low molecular weight can be easily obtained through hydrolysis with three enzymes and exhibit excellent antioxidant activity and safety. Jellyfish can serve as a promising source of antioxidants. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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26 pages, 10632 KiB  
Article
Antioxidant, Anti-Inflammatory and Anti-Diabetic Activities of Tectona grandis Methanolic Extracts, Fractions, and Isolated Compounds
by Mei Han, Fengxian Yang, Kun Zhang, Jiyan Ni, Xia Zhao, Xuelin Chen, Zhennan Zhang, Hanlei Wang, Jing Lu and Yumei Zhang
Antioxidants 2023, 12(3), 664; https://doi.org/10.3390/antiox12030664 - 8 Mar 2023
Cited by 2 | Viewed by 2549
Abstract
Tectona grandis is a traditional Dai medicine plant belonging to the Lamiaceae family, which can be used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease and as an anti-helminthic. To find more novel therapeutic agents contained in this [...] Read more.
Tectona grandis is a traditional Dai medicine plant belonging to the Lamiaceae family, which can be used to treat malaria, inflammation, diabetes, liver disease, bronchitis, tumors, cholelithiasis, jaundice, skin disease and as an anti-helminthic. To find more novel therapeutic agents contained in this medicinal plant, the antioxidant, anti-inflammatory and anti-diabetic activities of T. grandis methanolic extract, fractions and compounds were evaluated. In this study, 26 compounds were isolated from the leaves and branches of T. grandis. Their structures were identified based on extensive spectral experiments, including NMR, ESI-MS and comparison with published spectral data. Among them, compounds 12, 46, 914 and 1622 were reported for the first time for this plant. The antioxidant activity screening results showed that compounds 5, 15 and 23 had potent antioxidant capacities, with SC50 values from 0.32 to 9.92 µmol/L, 0.92 to 1.10 mmol Trolox/L and 1.02 to 1.22 mmol Trolox/L for DPPH, ABTS and FRAP, respectively. In addition, their anti-inflammatory effects were investigated by releasing TNF-α, IL-1β and IL-6 through the use of mouse monocytic macrophages (RAW 264.7). Compounds 1, 13, 18 and 23 had the effects of reducing the expression of inflammatory factors. Compounds 13 and 18 were reported for the first time for their anti-inflammatory activities. Furthermore, the methanolic extract (ME), petroleum ether extract (PEE) and EtOAc extract (EAE) of T. grandis showed significant glucose uptake activities; compounds 21 and 23 significantly promoted glucose uptake of 3T3-L1 adipocytes at 40 µM. Meanwhile, compounds 4, 5 and 7 showed significant inhibitory activities against α-glucosidase, with IC50 values of 14.16 ± 0.34 µmol/L, 19.29 ± 0.26 µmol/L and 3.04 ± 0.08 µmol/L, respectively. Compounds 4 and 5 were reported for the first time for their α-glucosidase inhibitory activities. Our investigation explored the possible therapeutic material basis of T. grandis to prevent oxidative stress and related diseases, especially inflammation and diabetes. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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26 pages, 5673 KiB  
Article
A Novel Hyaluronic Acid Matrix Ingredient with Regenerative, Anti-Aging and Antioxidant Capacity
by Patricia Galvez-Martin, Cristina Soto-Fernandez, Jessica Romero-Rueda, Jesus Cabañas, Anna Torrent, Gloria Castells and Daniel Martinez-Puig
Int. J. Mol. Sci. 2023, 24(5), 4774; https://doi.org/10.3390/ijms24054774 - 1 Mar 2023
Cited by 10 | Viewed by 8195
Abstract
Hyaluronic acid (HA) and proteoglycans (such as dermatan sulphate (DS) and chondroitin sulphate (CS)) are the main components of the extracellular matrix of the skin, along with collagen and elastin. These components decrease with age, which implies a loss of skin moisture causing [...] Read more.
Hyaluronic acid (HA) and proteoglycans (such as dermatan sulphate (DS) and chondroitin sulphate (CS)) are the main components of the extracellular matrix of the skin, along with collagen and elastin. These components decrease with age, which implies a loss of skin moisture causing wrinkles, sagging and aging. Currently, the external and internal administration of effective ingredients that can reach the epidermis and dermis is the main alternative for combating skin aging. The objective of this work was to extract, characterise and evaluate the potential of an HA matrix ingredient to support anti-aging. The HA matrix was isolated and purified from rooster comb and characterised physicochemically and molecularly. In addition, its regenerative, anti-aging and antioxidant potential and intestinal absorption were evaluated. The results show that the HA matrix is composed of 67% HA, with an average molecular weight of 1.3 MDa; 12% sulphated glycosaminoglycans, including DS and CS; 17% protein, including collagen (10.4%); and water. The in vitro evaluation of the HA matrix’s biological activity showed regenerative properties in both fibroblasts and keratinocytes, as well as moisturising, anti-aging and antioxidant effects. Furthermore, the results suggest that the HA matrix could be absorbed in the intestine, implying a potential oral as well as topical use for skin care, either as an ingredient in a nutraceutical or a cosmetic product. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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14 pages, 8328 KiB  
Article
Berberine Ameliorates Metabolic-Associated Fatty Liver Disease Mediated Metabolism Disorder and Redox Homeostasis by Upregulating Clock Genes: Clock and Bmal1 Expressions
by Cunsi Ye, Yajing Zhang, Shaomin Lin, Yi Chen, Zimiao Wang, Haoyinghua Feng, Guangqing Fang and Shijian Quan
Molecules 2023, 28(4), 1874; https://doi.org/10.3390/molecules28041874 - 16 Feb 2023
Cited by 6 | Viewed by 1853
Abstract
Metabolic-associated fatty liver disease (MAFLD) is one of the most common chronic liver diseases, which in turn triggers mild inflammation, metabolic dysfunction, fibrosis, and even cancer. Accumulating evidence has suggested that Berberine (BBR) could significantly improve MAFLD progression. Clock and Bmal1 as heterodimer [...] Read more.
Metabolic-associated fatty liver disease (MAFLD) is one of the most common chronic liver diseases, which in turn triggers mild inflammation, metabolic dysfunction, fibrosis, and even cancer. Accumulating evidence has suggested that Berberine (BBR) could significantly improve MAFLD progression. Clock and Bmal1 as heterodimer proteins highly participated in the development of MAFLD, but whether BBR targets Clock and Bmal1 in MAFLD remains poorly understood. The result suggested that the protein levels of Clock and Bmal1 were decreased in MAFLD mice, which was negatively correlated with elevated reactive oxygen species (ROS) accumulation, the H2O2 level, liver inflammation, metabolic dysfunction, and insulin resistance. The mRNA and protein levels of Clock and Bmal1 were also decreased in glucosamine-induced HepG2 cells, which were are negatively related to glucose uptake, the ROS level, and the H2O2 level. More importantly, Bmal1 siRNA could mimic the effect of glucosamine in HepG2 cells. Interestingly, Berberine (BBR) could rescue metabolism disorder and redox homeostasis through enhancing Clock and Bmal1 expression in vivo and in vitro. Therefore, BBR might be an effective natural compound for alleviating redox homeostasis, metabolism disorder, and liver pathological changes in MAFLD by activating Clock and Bmal1 expression. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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16 pages, 6075 KiB  
Article
Multiple Beneficial Effects of Aloesone from Aloe vera on LPS-Induced RAW264.7 Cells, Including the Inhibition of Oxidative Stress, Inflammation, M1 Polarization, and Apoptosis
by Yan Wang, Zhongyv Xiong, Chang Li, Dong Liu, Xiaogang Li, Junyv Xu, Niangen Chen, Xuesong Wang, Qifu Li and Youbin Li
Molecules 2023, 28(4), 1617; https://doi.org/10.3390/molecules28041617 - 8 Feb 2023
Cited by 4 | Viewed by 2398
Abstract
Aloesone is a major metabolic compound in Aloe vera, which has been widely used as a food source and therapeutic agent in several countries. Our recent study demonstrated that aloesone has anti-epileptic effects on glutamate-induced neuronal injury by suppressing the production of [...] Read more.
Aloesone is a major metabolic compound in Aloe vera, which has been widely used as a food source and therapeutic agent in several countries. Our recent study demonstrated that aloesone has anti-epileptic effects on glutamate-induced neuronal injury by suppressing the production of reactive oxygen species (ROS). Unless ROS are naturally neutralized by the endogenous antioxidant system, they lead to the activation of inflammation, polarization, and apoptosis. This study aimed to identify the multiple beneficial effects of aloesone and explore its molecular mechanism in macrophages. Hence, the murine macrophage cell line RAW264.7 was pretreated with aloesone and then exposed to lipopolysaccharides (LPS). The results demonstrated that aloesone, within a dosage range of 0.1–100 µM, dramatically decreased the LPS-induced elevation of ROS production, reduced nitric oxide (NO) release, inhibited the M1 polarization of RAW264.7 cells, and prevented cells from entering the LPS-induced early and late phases of apoptosis in a dose-dependent manner. Simultaneously, aloesone significantly decreased the mRNA expression of inflammation-related genes (iNOS, IL-1ꞵ, TNF-α) and increased the expression of antioxidant enzymes (Gpx-1 and SOD-1). The core genes HSP90AA1, Stat3, Mapk1, mTOR, Fyn, Ptk2b, and Lck were closely related to these beneficial effects of aloesone. Furthermore, immunofluorescence staining and flow cytometry data confirmed that aloesone significantly repressed the activation of mTOR, p-mTOR, and HIF-1α induced by LPS and inhibited the protein expression of TLR4, which is the target of LPS. In conclusion, aloesone demonstrated multiple protective effects against LPS-induced oxidative stress, inflammation, M1 polarization, and apoptosis in macrophages, suggesting its potential as a prodrug. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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14 pages, 2641 KiB  
Article
Anti-Inflammatory and Antioxidant Properties of β-Sitosterol in Copper Sulfate-Induced Inflammation in Zebrafish (Danio rerio)
by Peng Zhang, Naicheng Liu, Mingyang Xue, Mengjie Zhang, Wei Liu, Chen Xu, Yuding Fan, Yan Meng, Qinghua Zhang and Yong Zhou
Antioxidants 2023, 12(2), 391; https://doi.org/10.3390/antiox12020391 - 6 Feb 2023
Cited by 10 | Viewed by 2929
Abstract
β-Sitosterol, which is used extensively in pharmaceuticals, nutraceuticals, and cosmetics, has high nutritional value along with immunomodulatory and anti-inflammatory properties. In this study, we investigated the antioxidant and anti-inflammatory effects of β-sitosterol in zebrafish and explored the associated molecular mechanisms. In an in [...] Read more.
β-Sitosterol, which is used extensively in pharmaceuticals, nutraceuticals, and cosmetics, has high nutritional value along with immunomodulatory and anti-inflammatory properties. In this study, we investigated the antioxidant and anti-inflammatory effects of β-sitosterol in zebrafish and explored the associated molecular mechanisms. In an in vivo antioxidant experiment, zebrafish (Danio rerio) larvae were treated with different concentrations of β-sitosterol and then exposed to a nonlethal concentration of CuSO4 to induce oxidative stress. Treatment with β-sitosterol at 70 or 100 μg/mL significantly reduced CuSO4-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of β-sitosterol. Treatment with β-sitosterol protected zebrafish larvae against oxidative damage from CuSO4 by upregulating the expressions of sod and gpx4b. In a zebrafish model of inflammation, pretreatment with β-sitosterol before CuSO4 exposure inhibited neutrophil recruitment and damage to lateral line neuromasts, indicating a potent anti-inflammatory effect derived from reductions in the expressions of il-8 and myd88. The results demonstrate the antioxidative and anti-inflammatory activities of β-sitosterol and suggest that β-sitosterol may be useful for the treatment of various inflammatory diseases. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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19 pages, 2477 KiB  
Article
Dietary Methionine Level Impacts the Growth, Nutrient Metabolism, Antioxidant Capacity and Immunity of the Chinese Mitten Crab (Eriocheir sinensis) under Chronic Heat Stress
by Jiadai Liu, Cong Zhang, Xiaodan Wang, Xinyu Li, Qincheng Huang, Han Wang, Yixin Miao, Erchao Li, Jianguang Qin and Liqiao Chen
Antioxidants 2023, 12(1), 209; https://doi.org/10.3390/antiox12010209 - 16 Jan 2023
Cited by 4 | Viewed by 1856
Abstract
This study examined whether diets with high dietary methionine levels could alleviate chronic heat stress in Chinese mitten crab Eriocheir sinensis. Crabs were fed three dietary methionine levels of 0.49%, 1.29% and 2.09% for six weeks. The analyzed methionine concentration of diets [...] Read more.
This study examined whether diets with high dietary methionine levels could alleviate chronic heat stress in Chinese mitten crab Eriocheir sinensis. Crabs were fed three dietary methionine levels of 0.49%, 1.29% and 2.09% for six weeks. The analyzed methionine concentration of diets was 0.48%, 1.05% and 1.72%, respectively. Crabs were fed three different supplemental concentrations of dietary methionine at 24 °C and 30 °C, respectively. The trial was divided into six groups with five replicates in each group, and 40 juvenile crabs (initial average weight 0.71 ± 0.01 g) in each replicate. During the trial, crabs were fed twice daily (the diet of 4% of the body weight was delivered daily). The effects of dietary methionine level on nutrient metabolism, antioxidant capacity, apoptosis factors and immunity were evaluated at a normal water temperature of 24 °C and high temperature of 30 °C. Feed conversion ratio decreased under chronic heat stress. Chronic heat stress increased weight gain, specific growth rate, molting frequency, and protein efficiency ratio. The survival of crabs decreased under chronic heat stress, whereas a high level of dietary methionine significantly improved survival. Chronic heat stress induced lipid accumulation and protein content reduction. The high-methionine diet decreased lipid in the body and hepatopancreas, but increased protein in the body, muscle and hepatopancreas under chronic heat stress. Simultaneously, the high dietary methionine levels mitigated oxidative stress by reducing lipid peroxidation, restoring the antioxidant enzyme system, decreasing apoptosis and activating immune function under chronic heat stress. This study suggests that supplementing 1.72% dietary methionine could alleviate the adverse effects of a high water temperature in E. sinensis farming. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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15 pages, 3861 KiB  
Article
The Interaction between Oxidative Stress Biomarkers and Gut Microbiota in the Antioxidant Effects of Extracts from Sonchus brachyotus DC. in Oxazolone-Induced Intestinal Oxidative Stress in Adult Zebrafish
by Juan Yang, Wei-Wei Zhou, Dong-Dong Shi, Fang-Fang Pan, Wen-Wen Sun, Pei-Long Yang and Xiu-Mei Li
Antioxidants 2023, 12(1), 192; https://doi.org/10.3390/antiox12010192 - 13 Jan 2023
Cited by 6 | Viewed by 2357
Abstract
Oxidative stress is a phenomenon caused by an imbalance between the production and accumulation of reactive oxygen species in cells and tissues that eventually leads to the production of various diseases. Here, we investigated the antioxidant effects of the extract from Sonchus brachyotus [...] Read more.
Oxidative stress is a phenomenon caused by an imbalance between the production and accumulation of reactive oxygen species in cells and tissues that eventually leads to the production of various diseases. Here, we investigated the antioxidant effects of the extract from Sonchus brachyotus DC. (SBE) based on the 0.2% oxazolone-induced intestinal oxidative stress model of zebrafish. Compared to the model group, the treatment group alleviated oxazolone-induced intestinal tissue damage and reduced the contents of malondialdehyde, reactive oxygen species, IL-1β, and TNF-α and then increased the contents of superoxide dismutase, glutathione peroxidase, and IL-10. The 16s rDNA gene sequencing findings demonstrated that SBE could increase the relative abundance of Fusobacteriota, Actinobacteriota, and Firmicutes and decrease the relative abundance of Proteobacteria. Based on the correlation analysis between the oxidative stress biomarkers and intestinal flora, we found that the trends of oxidative stress biomarkers were significantly correlated with intestinal microorganisms, especially at the genus level. The correlations of MDA, IL-1β, and TNF-α were significantly negative with Shewanella, while SOD, GSH-Px, and IL-10 were significantly positive with Cetobacterium, Gemmobacter, and Flavobacterium. Consequently, we concluded that the antioxidant effect of SBE was realized through the interaction between oxidative stress biomarkers and gut microbiota. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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17 pages, 2658 KiB  
Article
Oxidation of Quercetin and Kaempferol Markedly Amplifies Their Antioxidant, Cytoprotective, and Anti-Inflammatory Properties
by Hernán Speisky, María Fernanda Arias-Santé and Jocelyn Fuentes
Antioxidants 2023, 12(1), 155; https://doi.org/10.3390/antiox12010155 - 9 Jan 2023
Cited by 6 | Viewed by 2575
Abstract
The contention that flavonoids’ oxidation would necessarily lead to a loss of their antioxidant properties was recently challenged by the demonstration that quercetin oxidation leads to the formation of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Que-BZF), a metabolite whose antioxidant potency was notably higher than that of its [...] Read more.
The contention that flavonoids’ oxidation would necessarily lead to a loss of their antioxidant properties was recently challenged by the demonstration that quercetin oxidation leads to the formation of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Que-BZF), a metabolite whose antioxidant potency was notably higher than that of its precursor. Here, we compared and expanded the former observation to that of the quercetin analogue kaempferol. Oxidation of kaempferol led to the formation of a mixture of metabolites that included the 2-(4-hydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Kae-BZF). Following the chromatographic isolation of Kae-BZF from such a mixture, its antioxidant, mitochondria- and cell-protecting, and NF-kB-inhibiting effects were assessed, and compared with those of Que-BZF, in Caco-2 cells exposed to indomethacin as a source of ROS. The concentrations of Que-BZF (100 nm) and Kae-BZF (1 nm) needed to attain their maximal protection effects were 50- and 5000-fold lower than those of their respective precursors. The former differences in concentrations were also seen when the abilities of Que-BZF and Kae-BZF to inhibit the indomethacin-induced activation of NF-kB were compared. These data not only reveal that the oxidative conversion of quercetin and kaempferol into their respective 2-benzoyl-2-hydroxy-3(2H)-benzofuranones (BZF) results in a considerable amplification of their original antioxidant properties, but also that the in the case of kaempferol, such amplification is 100-fold greater than that of quercetin. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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16 pages, 2806 KiB  
Article
Theoretical and Experimental Investigation of the Antioxidation Mechanism of Loureirin C by Radical Scavenging for Treatment of Stroke
by Ye-Shu Liu, Guo-Ying Zhang and Yue Hou
Molecules 2023, 28(1), 380; https://doi.org/10.3390/molecules28010380 - 2 Jan 2023
Cited by 3 | Viewed by 1572
Abstract
Recent pharmacological studies have shown that dragon’s blood has an anti-cerebral ischemia effect. Loureirin C (LC), a kind of dihydrochalcone compound in dragon’s blood, is believed to be play an important role in the treatment of ischemia stroke, but fewer studies for LC [...] Read more.
Recent pharmacological studies have shown that dragon’s blood has an anti-cerebral ischemia effect. Loureirin C (LC), a kind of dihydrochalcone compound in dragon’s blood, is believed to be play an important role in the treatment of ischemia stroke, but fewer studies for LC have been done. In this paper, we report the first experimental and theoretical studies on the antioxidation mechanism of LC by radical scavenging. The experimental studies show that LC has almost no effect on cell viability under 15 μM for the SH-SY5Y cells without any treatments. For the SH-SY5Y cells with oxygen and glucose deprivation-reperfusion (OGD/R) treatment, LC increased the viability of SH-SY5Y cells. The results of 2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSox Red experiments indicate that LC is very efficient in inhibiting the generation of the intracellular/mitochondrial reactive oxygen species (ROS) or removing these two kinds of generated ROS. The density functional theory (DFT) calculations allowed us to elucidate the antioxidation mechanisms of LC. Fukui function analysis reveals the radical scavenging of LC by hydrogen abstraction mechanism, the complex formation by e-transfer, and radical adduct formation (RAF) mechanism. Among the H-abstraction, the complex formation by e-transfer, and radical adduct formation (RAF) reactions on LC, the H-abstraction at O-H35 position by OH is favorable with the smallest energy difference between the product and two reactants of the attack of OH to LC of −0.0748 Ha. The bond dissociation enthalpies (BDE), proton affinities (PA), ionization potential (IP), proton dissociation enthalpy (PDE), and electron transfer enthalpy (ETE) were calculated to determine thermodynamically preferred reaction pathway for hydrogen abstraction mechanism. In water, IP and the lowest PDE value at O3-H35 position are lower than the lowest BDE value at O3-H35 position; 41.8986 and 34.221 kcal/mol, respectively, indicating that SEPT mechanism is a preferred one in water in comparison with the HAT mechanism. The PA value of O3-H35 of LC in water is −17.8594 kcal/mol, thus the first step of SPLET would occur spontaneously. The minimum value of ETE is higher than the minimum value of PDE at O3-H35 position and IP value, 14.7332 and 22.4108 kcal/mol, respectively, which suggests that the SEPT mechanism is a preferred one in water in comparison with the SPLET mechanism. Thus, we can draw a conclusion that the SEPT mechanism of is the most favorite hydrogen abstraction mechanism in water, and O-H35 hydroxyl group has the greatest ability to donate H-atoms. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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14 pages, 3228 KiB  
Article
Therapeutic Potency of Ovothiol A on Ethanol-Induced Gastric Ulcers in Wistar Rats
by Amira Tarek Salaheldin, Mohamed Refaat Shehata, Hader I. Sakr, Tarek Atia and Ayman Saber Mohamed
Mar. Drugs 2023, 21(1), 25; https://doi.org/10.3390/md21010025 - 28 Dec 2022
Cited by 5 | Viewed by 1926
Abstract
Peptic ulcer is a widespread disease, with a lifetime frequency of 5–10% among the general population and an annual incidence of 0.1–0.3%. Ovothiol A is naturally produced from sea urchin eggs with special antioxidant activity. Gastric ulcers were induced in rats by a [...] Read more.
Peptic ulcer is a widespread disease, with a lifetime frequency of 5–10% among the general population and an annual incidence of 0.1–0.3%. Ovothiol A is naturally produced from sea urchin eggs with special antioxidant activity. Gastric ulcers were induced in rats by a single ethanol dose (5 mL/kg). The rats were divided into control, ulcer, and ulcer with 250 and 500 mg/kg ovothiol A doses. Molecular docking studies were used to examine the interactions between ovothiol A and the H+/K+ ATPase active site residues. Ovothiol A led to a significant decline (p < 0.05) in gastric juice volume, ulcer index, MDA, IL-6, and cytochrome c, while levels of gastric juice pH, GSH, CAT, GST, SOD, and NO increased. Histopathological investigation of stomach sections revealed architecture preservation of the gastric mucosa after ovothiol A administration. The anti-ulcerogenic activity of ovothiol A includes scavenging free radicals, inhibition of inflammation, regulation of apoptosis, and stabilization of fibroblast growth factors to promote gastric ulcers healing. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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14 pages, 3638 KiB  
Article
Magnolia officinalis Bark Extract Prevents Enterocyte Death in a Colitis Mouse Model by Inhibiting ROS-Mediated Necroptosis
by Kang-In Lee, Hye Jin Kim, Hyungjun Kim, Min-Soo Kim, Jung Im Kim and Ki-Sun Park
Antioxidants 2022, 11(12), 2435; https://doi.org/10.3390/antiox11122435 - 9 Dec 2022
Cited by 4 | Viewed by 1701
Abstract
Necroptosis is a form of programmed cell death with features of necrosis and apoptosis that occurs in the intestinal epithelium of patients with inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease. In addition, necroptosis has also been observed in enterocytes in [...] Read more.
Necroptosis is a form of programmed cell death with features of necrosis and apoptosis that occurs in the intestinal epithelium of patients with inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease. In addition, necroptosis has also been observed in enterocytes in animal models of dextran sulfate sodium (DSS)-induced colitis. Thus, the discovery of natural products for regulating necroptosis may represent an important therapeutic strategy for improving IBD. We found that Magnolia officinalis bark extract (MBE) prevented weight loss and suppressed the activation of the proinflammatory cytokine IL6 in DSS-induced colitis. Furthermore, MBE restored the length of the damaged colon and decreased the expression of necroptosis markers in mice with DSS-induced colitis. In vitro, necroptosis-induced reactive oxygen species (ROS) production was reduced by MBE, and the expression of COX2, a target protein of ROS, was simultaneously suppressed. Both magnolol and honokiol, the two major bioactive compounds in MBE, inhibited necroptosis in human primary intestinal epithelial cells and colorectal adenocarcinoma cells. Our findings highlight the effectiveness of MBE in modulating enterocyte necroptosis and suggest that MBE may be developed as a natural, disease-targeting drug for the treatment of colitis. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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16 pages, 20765 KiB  
Article
Citronellal Attenuates Oxidative Stress–Induced Mitochondrial Damage through TRPM2/NHE1 Pathway and Effectively Inhibits Endothelial Dysfunction in Type 2 Diabetes Mellitus
by Ya-Ling Yin, Huan-Huan Wang, Zi-Chen Gui, Shan Mi, Shuang Guo, Yue Wang, Qian-Qian Wang, Rui-Zhu Yue, Lai-Biao Lin, Jia-Xin Fan, Xue Zhang, Bing-Yan Mao, Tian-Heng Liu, Guang-Rui Wan, He-Qin Zhan, Mo-Li Zhu, Lin-Hua Jiang and Peng Li
Antioxidants 2022, 11(11), 2241; https://doi.org/10.3390/antiox11112241 - 14 Nov 2022
Cited by 1 | Viewed by 1902
Abstract
In type 2 diabetes mellitus (T2DM), oxidative stress induces endothelial dysfunction (ED), which is closely related to the formation of atherosclerosis. However, there are few effective drugs to prevent and cure it. Citronellal (CT) is an aromatic active substance extracted from citronella plants. [...] Read more.
In type 2 diabetes mellitus (T2DM), oxidative stress induces endothelial dysfunction (ED), which is closely related to the formation of atherosclerosis. However, there are few effective drugs to prevent and cure it. Citronellal (CT) is an aromatic active substance extracted from citronella plants. Recently, CT has been shown to prevent ED, but the underlying mechanism remains unclear. The purpose of this study was to investigate whether CT ameliorated T2DM-induced ED by inhibiting the TRPM2/NHE1 signal pathway. Transient receptor potential channel M2 (TRPM2) is a Ca2+-permeable cation channel activated by oxidative stress, which damages endothelial cell barrier function and further leads to ED or atherosclerosis in T2DM. The Na+/H+ exchanger 1 (NHE1), a transmembrane protein, also plays an important role in ED. Whether TRPM2 and NHE1 are involved in the mechanism of CT improving ED in T2DM still needs further study. Through the evaluations of ophthalmoscope, HE and Oil red staining, vascular function, oxidative stress level, and mitochondrial membrane potential evaluation, we observed that CT not only reduced the formation of lipid deposition but also inhibited ED and suppressed oxidative stress-induced mitochondrial damage in vasculature of T2DM rats. The expressions of NHE1 and TRPM2 was up-regulated in the carotid vessels of T2DM rats; NHE1 expression was also upregulated in endothelial cells with overexpression of TRPM2, but CT reversed the up-regulation of NHE1 in vivo and in vitro. In contrast, CT had no inhibitory effect on the expression of NHE1 in TRPM2 knockout mice. Our study show that CT suppressed the expression of NHE1 and TPRM2, alleviated oxidative stress-induced mitochondrial damage, and imposed a protective effect on ED in T2DM rats. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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22 pages, 4326 KiB  
Article
Ultrasonic Enhancement of Aqueous Two-Phase Extraction and Acid Hydrolysis of Flavonoids from Malvaviscus arboreus Cav. Flower for Evaluation of Antioxidant Activity
by Tiefeng Yuan, Jilong Huang, Lin Gan, Linzhou Chen, Jinjian Zhong, Zhaohan Liu, Liping Wang and Huajun Fan
Antioxidants 2022, 11(10), 2039; https://doi.org/10.3390/antiox11102039 - 16 Oct 2022
Cited by 6 | Viewed by 2294
Abstract
The ultrasonic-assisted aqueous two-phase extraction (UAATPE) of flavonoid glycosides from Malvaviscus arboreous Cav. flower (MACF) was developed using ethanol/ammonia sulfate systems, followed by the ultrasonic-assisted acid hydrolysis (UAAH) of the top extract with HCl solution. The optimization of UAATPE and UAAH processes was [...] Read more.
The ultrasonic-assisted aqueous two-phase extraction (UAATPE) of flavonoid glycosides from Malvaviscus arboreous Cav. flower (MACF) was developed using ethanol/ammonia sulfate systems, followed by the ultrasonic-assisted acid hydrolysis (UAAH) of the top extract with HCl solution. The optimization of UAATPE and UAAH processes was accomplished by single-factor experiments and response surface methodology. As a result, the flavonoid glycosides enriched in the top phase could achieve a maximum yield of 35.9 ± 1.1 mg/g by UAATPE and were completely hydrolyzed by UAAH deglycosylation. The flavonoid glycosides and their hydrolyzates were separated and characterized by high-performance liquid chromatography and ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Ultrasonic enhancement of the extraction and hydrolysis was explored by comparative study. Furthermore, the in vitro activity of the flavonoid glycosides and the aglycones were comprehensively evaluated by antioxidant activity assays, including ferric-reducing antioxidant power and scavenging DPPH, hydroxyl, and superoxide radicals. All of the IC50 values suggest that the antioxidant activity of flavonoid aglycones was stronger than that of their glucosides and even vitamin C, revealing that the deglycosylated flavonoids from MACF were the more powerful antioxidants. This study provided an effective and eco-friendly strategy for the extraction, separation, and purification of flavonoids from MACF, as well as for the development of the potential flavonoid antioxidants. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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11 pages, 2184 KiB  
Communication
Bioactive Phytochemicals from Salix pseudolasiogyne Twigs: Anti-Adipogenic Effect of 2′-O-Acetylsalicortin in 3T3-L1 Cells
by Hee Jung Kim, Yoon Seo Jang, Ji Won Ha, Moon-Jin Ra, Sang-Mi Jung, Jeong-Nam Yu, Kyunga Kim, Ki Hyun Kim and Sung Hee Um
Int. J. Mol. Sci. 2022, 23(19), 12006; https://doi.org/10.3390/ijms231912006 - 9 Oct 2022
Cited by 1 | Viewed by 1705
Abstract
Salix pseudolasiogyne (Salicaceae) is a willow tree and has been used as a medicinal herb in Korea to treat pain and fever. As a part of an ongoing study to identify bioactive natural products, potential anti-adipogenic compounds were investigated using the ethanol (EtOH) [...] Read more.
Salix pseudolasiogyne (Salicaceae) is a willow tree and has been used as a medicinal herb in Korea to treat pain and fever. As a part of an ongoing study to identify bioactive natural products, potential anti-adipogenic compounds were investigated using the ethanol (EtOH) extract of S. pseudolasiogyne twigs. Phytochemical investigation of the EtOH extracts using liquid chromatography–mass spectrometry (LC/MS) led to the separation of two compounds, oregonin (1) and 2′-O-acetylsalicortin (2). The structures of the isolates were identified using nuclear magnetic resonance spectroscopy and LC/MS analysis. To the best of our knowledge, it is the first report identifying oregonin (1) in twigs of S. pseudolasiogyne. Here, we found that the isolated compounds, oregonin (1) and 2′-O-acetylsalicortin (2), showed anti-adipogenic effects during 3T3-L1 cell differentiation. Notably, 2′-O-acetylsalicortin (2), at a concentration of 50 µM, significantly suppressed lipid accumulation. Moreover, the mRNA and protein levels of lipogenic and adipogenic transcription factors were reduced in 2′-O-acetylsalicortin (2)-treated 3T3-L1 cells. Taken together, these results indicate that 2′-O-acetylsalicortin (2), isolated from S. pseudolasiogyne twigs, has the potential to be applied as a therapeutic agent to effectively control adipocyte differentiation, a critical stage in the progression of obesity. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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18 pages, 2102 KiB  
Article
Chemical Composition, Antioxidant Activity, Cytoprotective and In Silico Study of Ethanolic Extracts of Bougainvillea × buttiana (Var. Orange and Rose)
by Vera L. Petricevich, Mayra Cedillo-Cortezano and Rodolfo Abarca-Vargas
Molecules 2022, 27(19), 6555; https://doi.org/10.3390/molecules27196555 - 3 Oct 2022
Cited by 2 | Viewed by 1996
Abstract
Bougainvillea × buttiana is a plant widely used in traditional Mexican medicine and other parts of the world for the treatment of various health disorders. In this study, the antioxidant and cytoprotective activities of three ethanolic extracts of B. × buttiana (BxbO [...] Read more.
Bougainvillea × buttiana is a plant widely used in traditional Mexican medicine and other parts of the world for the treatment of various health disorders. In this study, the antioxidant and cytoprotective activities of three ethanolic extracts of B. × buttiana (BxbO (Orange), BxbR1 (Rose1) and BxbR2 (Rose2)) were investigated. Antioxidant activities were determined by the oxygen radical absorbance capacity (ORAC), DPPH free radicals scavenging activity, and radical scavenging effects on nitric oxide (NO). The in vitro cytoprotective effect of the extracts against oxidative stress induced by hydrogen peroxide-(H2O2) in a model of L929 cells was also determined as well as NO uptake with or without H2O2 through the MTT assay. The results revealed that there was a difference between the compounds present in each of the extracts, with the 2-Hydroxycinnamic acid compound being observed in all the extracts. The 2-Hydroxycinnamic acid compound was tested in silico to predict its biological (PASSonline) and toxicological (Osiris Property Explorer) activity. All extracts with 1 to 4 mg/mL inhibited the activity of the NO radical. In cells exposed to 1 mg/mL of extracts followed by H2O2 exposure, cell protection ranged from 66.96 to 83.46%. The treatment of the cells with extracts prevented the morphological changes caused by H2O2. The 2-Hydroxycinnamic acid compound showed a probability of in silico antioxidant and cytoprotective activity greater than 0.5 and 0.6, respectively. Therefore, the results demonstrated that Bxb extracts exert antioxidant and protective activities against H2O2-induced oxidative stress in L929 cells. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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18 pages, 1905 KiB  
Article
Ethnomedicinal Plants with Protective Effects against Beta-Amyloid Peptide (Aβ)1-42 Indicate Therapeutic Potential in a New In Vivo Model of Alzheimer’s Disease
by Norah A. Althobaiti, Farid Menaa, Johnathan J. Dalzell, Aishah E. Albalawi, Hammad Ismail, Mousa A. Alghuthaymi, Reem D. Aldawsari, Haroon Iqbal, Claire McAlinney and Brian D. Green
Antioxidants 2022, 11(10), 1865; https://doi.org/10.3390/antiox11101865 - 21 Sep 2022
Cited by 5 | Viewed by 1844
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with unmet medical need. This investigation consisted of testing a range of ethanolic ethnomedicinal plant extracts (n = 18) traditionally used in the treatment of disorders such as anxiety, delirium, and memory loss. They [...] Read more.
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with unmet medical need. This investigation consisted of testing a range of ethanolic ethnomedicinal plant extracts (n = 18) traditionally used in the treatment of disorders such as anxiety, delirium, and memory loss. They were then screened for in vitro inhibitory activity against acetylcholinesterase (AChE), butylcholinesterase (BuChE), beta-secretase 1/beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), and antioxidant activities. Plants with potent activities were further characterised using a recently developed in vivo model of AD, Globodera pallida. The ability of phytoextracts to protect this organism against amyloid-beta Aβ (1-42) exposure was assessed by measuring chemosensing, survival rate, production of reactive oxygen species (ROS), and antioxidant responses. Extracts (n = 5) from Juglans regia (leaves), Ellettaria cardamomum (seeds), Cinnamomum zeylanicum (bark), Salvia officinalis (leaves/flowers), and Hypericum perforatum (flowers) exerted concentration-dependent inhibitory activities against AChE and BuChE. Three of these plant extracts (i.e., J. regia, E. cardamomum, and S. officinalis) possessed strong concentration-dependent inhibitory activity against BACE1. Furthermore, the five selected medicinal plant extracts not only enhanced significantly (p < 0.05) the nematode’s chemosensing, survival rate, and antioxidant responses (i.e., anti-ROS production, mitochondrial reductase activity, oxidized glutathione (GSSG) to reduced glutathione (GSH) ratio), but also greatly restored (p < 0.05) in a concentration-dependent manner the Aβ (1-42)-induced deleterious changes in these same parameters. In brief, this investigation highlights plant extracts with strong anti-AD activities which could be trialled as novel therapeutic supplements or undergo further biodiscovery research. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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19 pages, 4113 KiB  
Article
Synthesis of Zinc Oxide Nanoparticles with Bioflavonoid Rutin: Characterisation, Antioxidant and Antimicrobial Activities and In Vivo Cytotoxic Effects on Artemia Nauplii
by Mansab Ali Saleemi, Batoul Alallam, Yoke Keong Yong and Vuanghao Lim
Antioxidants 2022, 11(10), 1853; https://doi.org/10.3390/antiox11101853 - 20 Sep 2022
Cited by 16 | Viewed by 3173
Abstract
This study aims to synthesise zinc oxide nanoparticles with rutin (ZnO-R NPs) using a green synthesis approach and characterise the nanostructures for diverse biomedical applications. In this study, the optical and chemical properties of synthesised ZnO-R NPs were verified through Fourier transform infrared [...] Read more.
This study aims to synthesise zinc oxide nanoparticles with rutin (ZnO-R NPs) using a green synthesis approach and characterise the nanostructures for diverse biomedical applications. In this study, the optical and chemical properties of synthesised ZnO-R NPs were verified through Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy. The FTIR spectroscopy revealed a symmetric bending vibration peak of 460 cm−1 for ZnO-R NPs, whereas UV-Vis spectroscopy showed a distinct absorption band at 395 nm. Moreover, the oval-shaped morphology of ZnO-R NPs was verified through scanning electron microscopy and transmission electron microscopy. The synthesised nanoformulation revealed a wurtzite structure with a crystallite size of 13.22 nm; however, the zeta potential value was recorded as −8.50 ± 0.46 mV for ZnO-R NPs. According to an antioxidant study, ZnO-R NPs demonstrated lower free-radical scavenging activity than pure rutin. The cytotoxicity study was conducted using a human breast cancer cell line (MCF-7). In vitro analysis verified that ZnO-R NPs exhibited significantly higher anticancer and microbial growth inhibition activities than standard ZnO NPs (ZnO Std NPs) and pure rutin. In addition, ZnO-R NPs revealed a significantly lower IC50 value than the commercial ZnO Std NPs and pure rutin in MCF-7 cells (16.39 ± 6.03 μg/mL, 27 ± 0.91 μg/mL and 350 ± 30.1 μg/mL, respectively) after 48 h. However, synthesised ZnO-R NPs demonstrated no significant toxicity towards Artemia nauplii. These results highlight the synthesis of rutin-mediated ZnO NPs and their possible chemotherapeutic potential. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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13 pages, 7139 KiB  
Article
New Aspects of the Antioxidant Activity of Glycyrrhizin Revealed by the CIDNP Technique
by Aleksandra A. Ageeva, Alexander I. Kruppa, Ilya M. Magin, Simon V. Babenko, Tatyana V. Leshina and Nikolay E. Polyakov
Antioxidants 2022, 11(8), 1591; https://doi.org/10.3390/antiox11081591 - 17 Aug 2022
Cited by 7 | Viewed by 1781
Abstract
Electron transfer plays a crucial role in ROS generation in living systems. Molecular oxygen acts as the terminal electron acceptor in the respiratory chains of aerobic organisms. Two main mechanisms of antioxidant defense by exogenous antioxidants are usually considered. The first is the [...] Read more.
Electron transfer plays a crucial role in ROS generation in living systems. Molecular oxygen acts as the terminal electron acceptor in the respiratory chains of aerobic organisms. Two main mechanisms of antioxidant defense by exogenous antioxidants are usually considered. The first is the inhibition of ROS generation, and the second is the trapping of free radicals. In the present study, we have elucidated both these mechanisms of antioxidant activity of glycyrrhizin (GL), the main active component of licorice root, using the chemically induced dynamic nuclear polarization (CIDNP) technique. First, it was shown that GL is capable of capturing a solvated electron, thereby preventing its capture by molecular oxygen. Second, we studied the effect of glycyrrhizin on the behavior of free radicals generated by UV irradiation of xenobiotic, NSAID—naproxen in solution. The structure of the glycyrrhizin paramagnetic intermediates formed after the capture of a solvated electron was established from a photo-CIDNP study of the model system—the dianion of 5-sulfosalicylic acid and DFT calculations. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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16 pages, 937 KiB  
Article
Antioxidant Effects of a Polyphenol-Rich Dietary Supplement Incorporating Pinus massoniana Bark Extract in Healthy Older Adults: A Two-Arm, Parallel Group, Randomized Placebo-Controlled Trial
by Jessica J. A. Ferguson, Christopher Oldmeadow, David Bentley and Manohar L. Garg
Antioxidants 2022, 11(8), 1560; https://doi.org/10.3390/antiox11081560 - 11 Aug 2022
Cited by 2 | Viewed by 2917
Abstract
Oxidative stress is a key physiological phenomenon underpinning the ageing process and plays a major developmental role in age-associated chronic diseases. This study investigated the antioxidant effects of a polyphenol-rich dietary supplement containing Pinus massoniana bark extract (PMBE) in healthy older adults. In [...] Read more.
Oxidative stress is a key physiological phenomenon underpinning the ageing process and plays a major developmental role in age-associated chronic diseases. This study investigated the antioxidant effects of a polyphenol-rich dietary supplement containing Pinus massoniana bark extract (PMBE) in healthy older adults. In a double-blinded, placebo-controlled clinical trial, participants were randomised (in a 1:1 ratio) to receive a 50 mL/day dietary supplement containing placebo (0 mg PMBE) or PMBE (1322 mg PMBE) for 12 weeks. The primary outcome was fasting plasma malondialdehyde (MDA) concentrations and secondary outcomes were plasma inflammatory markers. MDA concentrations significantly reduced following PMBE for 6 weeks (−1.19 nmol/mL, 95%CI −1.62, −0.75, p < 0.001) and 12 weeks (−1.35 nmol/mL, 95%CI −1.74, −0.96, p < 0.001) compared to baseline. MDA did not significantly change after the placebo. MDA levels at 6 and 12 weeks were significantly lower following PMBE compared to placebo (p < 0.001). At 12 weeks in the PMBE group, fibrinogen concentrations significantly reduced (−0.25 g/L, 95%CI −0.39, −0.11; p < 0.0001) and interleukin-6 significantly increased compared to placebo (0.30 pg/mL, 95%CI 0.02, 0.59; p < 0.05). PMBE in a polyphenol-rich dietary supplement reduced oxidative stress in healthy older adults. Further studies are warranted to investigate the antioxidant capacity of PMBE in conditions with heightened oxidative stress, such as osteoarthritis, hypertension, type 2 diabetes, or other lifestyle related diseases. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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18 pages, 3802 KiB  
Article
Quercetin Attenuates Quinocetone-Induced Cell Apoptosis In Vitro by Activating the P38/Nrf2/HO-1 Pathway and Inhibiting the ROS/Mitochondrial Apoptotic Pathway
by Chongshan Dai, Qinzhi Zhang, Linjie Shen, Gaurav Sharma, Haiyang Jiang, Zhanhui Wang and Jianzhong Shen
Antioxidants 2022, 11(8), 1498; https://doi.org/10.3390/antiox11081498 - 30 Jul 2022
Cited by 12 | Viewed by 2380
Abstract
Quinocetone (QCT), a member of the quinoxaline 1,4-di-N-oxides (QdNOs) family, can cause genotoxicity and hepatotoxicity, however, the precise molecular mechanisms of QCT are unclear. This present study investigated the protective effect of quercetin on QCT-induced cytotoxicity and the underlying molecular mechanisms [...] Read more.
Quinocetone (QCT), a member of the quinoxaline 1,4-di-N-oxides (QdNOs) family, can cause genotoxicity and hepatotoxicity, however, the precise molecular mechanisms of QCT are unclear. This present study investigated the protective effect of quercetin on QCT-induced cytotoxicity and the underlying molecular mechanisms in human L02 and HepG2 cells. The results showed that quercetin treatment (at 7.5–30 μM) significantly improved QCT-induced cytotoxicity and oxidative damage in human L02 and HepG2 cells. Meanwhile, quercetin treatment at 30 μM significantly inhibited QCT-induced loss of mitochondrial membrane potential, an increase in the expression of the CytC protein and the Bax/Bcl-2 ratio, and an increase in caspases-9 and -3 activity, and finally improved cell apoptosis. Quercetin pretreatment promoted the expression of the phosphorylation of p38, Nrf2, and HO-1 proteins. Pharmacological inhibition of p38 significantly inhibited quercetin-mediated activation of the Nrf2/HO-1 pathway. Consistently, pharmacological inhibitions of the Nrf2 or p38 pathways both promoted QCT-induced cytotoxicity and partly abolished the protective effects of quercetin. In conclusion, for the first time, our results reveal that quercetin could improve QCT-induced cytotoxicity and apoptosis by activating the p38/Nrf2/HO-1 pathway and inhibiting the ROS/mitochondrial apoptotic pathway. Our study highlights that quercetin may be a promising candidate for preventing QdNOs-induced cytotoxicity in humans or animals. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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