Antioxidants

25 pages, 5222 KiB

Open AccessArticle

Signal Transducer and Activator of Transcription 3 (STAT3) Suppresses STAT1/Interferon Signaling Pathway and Inflammation in Senescent Preadipocytes

by Aisha Y. Madani, Yasser Majeed, Houari B. Abdesselem, Maha V. Agha, Muneera Vakayil, Nour K. Al Sukhun, Najeeb M. Halabi, Pankaj Kumar, Shahina Hayat, Mohamed A. Elrayess, Arash Rafii, Karsten Suhre and Nayef A. Mazloum

Antioxidants 2021, 10(2), 334; https://doi.org/10.3390/antiox10020334 - 23 Feb 2021

Cited by 24 | Viewed by 6732

Abstract

Obesity promotes premature aging and dysfunction of white adipose tissue (WAT) through the accumulation of cellular senescence. The senescent cells burden in WAT has been linked to inflammation, insulin-resistance (IR), and type 2 diabetes (T2D). There is limited knowledge about molecular mechanisms that [...] Read more.

Obesity promotes premature aging and dysfunction of white adipose tissue (WAT) through the accumulation of cellular senescence. The senescent cells burden in WAT has been linked to inflammation, insulin-resistance (IR), and type 2 diabetes (T2D). There is limited knowledge about molecular mechanisms that sustain inflammation in obese states. Here, we describe a robust and physiologically relevant in vitro system to trigger senescence in mouse 3T3-L1 preadipocytes. By employing transcriptomics analyses, we discovered up-regulation of key pro-inflammatory molecules and activation of interferon/signal transducer and activator of transcription (STAT)1/3 signaling in senescent preadipocytes, and expression of downstream targets was induced in epididymal WAT of obese mice, and obese human adipose tissue. To test the relevance of STAT1/3 signaling to preadipocyte senescence, we used Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein 9 (CRISPR/Cas9) technology to delete STAT1/3 and discovered that STAT1 promoted growth arrest and cooperated with cyclic Guanosine Monophosphate-Adenosine Monophosphate (GMP-AMP) synthase-stimulator of interferon genes (cGAS-STING) to drive the expression of interferon β (IFNβ), C-X-C motif chemokine ligand 10 (CXCL10), and interferon signaling-related genes. In contrast, we discovered that STAT3 was a negative regulator of STAT1/cGAS-STING signaling—it suppressed senescence and inflammation. These data provide insights into how STAT1/STAT3 signaling coordinates senescence and inflammation through functional interactions with the cGAS/STING pathway. Full article

(This article belongs to the Special Issue Reactive Oxygen Species as Cellular Messengers in Aging and Age-Related Diseases)

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15 pages, 25079 KiB

Open AccessArticle

NQO1 Deficiency Aggravates Renal Injury by Dysregulating Vps34/ATG14L Complex during Autophagy Initiation in Diabetic Nephropathy

by Geum-Lan Hong, Kyung-Hyun Kim, Chul-Ho Lee, Tae-Won Kim and Ju-Young Jung

Antioxidants 2021, 10(2), 333; https://doi.org/10.3390/antiox10020333 - 23 Feb 2021

Cited by 11 | Viewed by 3658

Abstract

Diabetic nephropathy (DN) is one of the causes of end-stage renal failure, featuring renal fibrosis. However, autophagy, a vital process for intracellular homeostasis, can counteract renal fibrosis. Moreover, NAD(P)H: quinone dehydrogenase 1 (NQO1) modulates the ratios of reduced/oxidized nicotinamide nucleotides, exerting a cytoprotective [...] Read more.

Diabetic nephropathy (DN) is one of the causes of end-stage renal failure, featuring renal fibrosis. However, autophagy, a vital process for intracellular homeostasis, can counteract renal fibrosis. Moreover, NAD(P)H: quinone dehydrogenase 1 (NQO1) modulates the ratios of reduced/oxidized nicotinamide nucleotides, exerting a cytoprotective function. Here, to examine the role of NQO1 genes in DN progression, the levels of autophagy-related proteins and pro-fibrotic markers were assessed in silencing or overexpression of NQO1 in human proximal tubular cells (HK2), and C57BL/6 (wild-type) and Nqo1 knockout (KO) mice injected to streptozotocin (50 mg/kg). NQO1 deficiency impaired the autophagy process by suppressing basal expression of ClassⅢ PI 3-kinase (Vps34) and autophagy-related (ATG)14L and inducing the expressions of transforming growth factor beta (TGF-β1), Smad3, and matrix metallopeptidase9 (MMP9) in high-glucose (HG) -treated HK2 cells. Meanwhile, NQO1 overexpression increased the expression of Vps34 and ATG14L, while, reducing TGF-β1, Smad3 and MMP9 expression. In vivo, the expression of Vps34 and ATG14L were suppressed in Nqo1 KO mice indicating aggravated glomerular changes and interstitial fibrosis. Therefore, NQO1 deficiency dysregulated autophagy initiation in HK2 cells, with consequent worsened renal cell damage under HG condition. Moreover, STZ-treated Nqo1 KO mice showed that NQO1 deficiency aggravated renal fibrosis by dysregulating autophagy. Full article

(This article belongs to the Special Issue Antioxidants and Their Role in the Prevention and Treatment of Chronic Kidney Disease)

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14 pages, 639 KiB

Open AccessReview

The Oxidative Paradox in Low Oxygen Stress in Plants

by Chiara Pucciariello and Pierdomenico Perata

Antioxidants 2021, 10(2), 332; https://doi.org/10.3390/antiox10020332 - 23 Feb 2021

Cited by 35 | Viewed by 5558

Abstract

Reactive oxygen species (ROS) are part of aerobic environments, and variations in the availability of oxygen (O₂) in the environment can lead to altered ROS levels. In plants, the O₂ sensing machinery guides the molecular response to low O₂ [...] Read more.

Reactive oxygen species (ROS) are part of aerobic environments, and variations in the availability of oxygen (O₂) in the environment can lead to altered ROS levels. In plants, the O₂ sensing machinery guides the molecular response to low O₂, regulating a subset of genes involved in metabolic adaptations to hypoxia, including proteins involved in ROS homeostasis and acclimation. In addition, nitric oxide (NO) participates in signaling events that modulate the low O₂ stress response. In this review, we summarize recent findings that highlight the roles of ROS and NO under environmentally or developmentally defined low O₂ conditions. We conclude that ROS and NO are emerging regulators during low O₂ signalling and key molecules in plant adaptation to flooding conditions. Full article

(This article belongs to the Special Issue Antioxidant Defenses in Plants)

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22 pages, 9268 KiB

Open AccessArticle

Oxidatively Modified LDL Suppresses Lymphangiogenesis via CD36 Signaling

by Bhupesh Singla, Hui-Ping Lin, WonMo Ahn, Joseph White and Gábor Csányi

Antioxidants 2021, 10(2), 331; https://doi.org/10.3390/antiox10020331 - 23 Feb 2021

Cited by 14 | Viewed by 4855

Abstract

Arterial accumulation of plasma-derived LDL and its subsequent oxidation contributes to atherosclerosis. Lymphatic vessel (LV)-mediated removal of arterial cholesterol has been shown to reduce atherosclerotic lesion formation. However, the precise mechanisms that regulate LV density and function in atherosclerotic vessels remain to be [...] Read more.

Arterial accumulation of plasma-derived LDL and its subsequent oxidation contributes to atherosclerosis. Lymphatic vessel (LV)-mediated removal of arterial cholesterol has been shown to reduce atherosclerotic lesion formation. However, the precise mechanisms that regulate LV density and function in atherosclerotic vessels remain to be identified. The aim of this study was to investigate the role of native LDL (nLDL) and oxidized LDL (oxLDL) in modulating lymphangiogenesis and underlying molecular mechanisms. Western blotting and immunostaining experiments demonstrated increased oxLDL expression in human atherosclerotic arteries. Furthermore, elevated oxLDL levels were detected in the adventitial layer, where LV are primarily present. Treatment of human lymphatic endothelial cells (LEC) with oxLDL inhibited in vitro tube formation, while nLDL stimulated it. Similar results were observed with Matrigel plug assay in vivo. CD36 deletion in mice and its siRNA-mediated knockdown in LEC prevented oxLDL-induced inhibition of lymphangiogenesis. In addition, oxLDL via CD36 receptor suppressed cell cycle, downregulated AKT and eNOS expression, and increased levels of p27 in LEC. Collectively, these results indicate that oxLDL inhibits lymphangiogenesis via CD36-mediated regulation of AKT/eNOS pathway and cell cycle. These findings suggest that therapeutic blockade of LEC CD36 may promote arterial lymphangiogenesis, leading to increased cholesterol removal from the arterial wall and reduced atherosclerosis. Full article

(This article belongs to the Special Issue Redox Biology and Cardiovascular Disease)

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36 pages, 6620 KiB

Open AccessFeature PaperReview

Essential Oils in Livestock: From Health to Food Quality

by Ralph Nehme, Sonia Andrés, Renato B. Pereira, Meriem Ben Jemaa, Said Bouhallab, Fabrizio Ceciliani, Secundino López, Fatma Zohra Rahali, Riadh Ksouri, David M. Pereira and Latifa Abdennebi-Najar

Antioxidants 2021, 10(2), 330; https://doi.org/10.3390/antiox10020330 - 23 Feb 2021

Cited by 99 | Viewed by 10266

Abstract

Using plant essential oils (EOs) contributes to the growing number of natural plants’ applications in livestock. Scientific data supporting the efficacy of EOs as anti-inflammatory, antibacterial and antioxidant molecules accumulates over time; however, the cumulative evidence is not always sufficient. EOs antioxidant properties [...] Read more.

Using plant essential oils (EOs) contributes to the growing number of natural plants’ applications in livestock. Scientific data supporting the efficacy of EOs as anti-inflammatory, antibacterial and antioxidant molecules accumulates over time; however, the cumulative evidence is not always sufficient. EOs antioxidant properties have been investigated mainly from human perspectives. Still, so far, our review is the first to combine the beneficial supporting properties of EOs in a One Health approach and as an animal product quality enhancer, opening new possibilities for their utilization in the livestock and nutrition sectors. We aim to compile the currently available data on the main anti-inflammatory effects of EOs, whether encapsulated or not, with a focus on mammary gland inflammation. We will also review the EOs’ antioxidant activities when given in the diet or as a food preservative to counteract oxidative stress. We emphasize EOs’ in vitro and in vivo ruminal microbiota and mechanisms of action to promote animal health and performance. Given the concept of DOHaD (Developmental Origin of Health and Diseases), supplementing animals with EOs in early life opens new perspectives in the nutrition sector. However, effective evaluation of the significant safety components is required before extending their use to livestock and veterinary medicine. Full article

(This article belongs to the Special Issue Antioxidant Micronutrients in Animal Diet: From Health to Meat Quality)

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20 pages, 2394 KiB

Open AccessArticle

Fine-Tuning the Biological Profile of Multitarget Mitochondriotropic Antioxidants for Neurodegenerative Diseases

by Daniel Chavarria, Ophelie Da Silva, Sofia Benfeito, Sandra Barreiro, Jorge Garrido, Fernando Cagide, Pedro Soares, Fernando Remião, Xavier Brazzolotto, Florian Nachon, Paulo J. Oliveira, José Dias and Fernanda Borges

Antioxidants 2021, 10(2), 329; https://doi.org/10.3390/antiox10020329 - 23 Feb 2021

Cited by 11 | Viewed by 4034

Abstract

Neurotransmitter depletion and mitochondrial dysfunction are among the multiple pathological events that lead to neurodegeneration. Following our previous studies related with the development of multitarget mitochondriotropic antioxidants, this study aims to evaluate whether the π-system extension on the chemical scaffolds of AntiOXCIN2 and [...] Read more.

Neurotransmitter depletion and mitochondrial dysfunction are among the multiple pathological events that lead to neurodegeneration. Following our previous studies related with the development of multitarget mitochondriotropic antioxidants, this study aims to evaluate whether the π-system extension on the chemical scaffolds of AntiOXCIN2 and AntiOXCIN3 affects their bioactivity and safety profiles. After the synthesis of four triphenylphosphonium (TPP⁺) conjugates (compounds 2–5), we evaluated their antioxidant properties and their effect on neurotransmitter-metabolizing enzymes. All compounds were potent equine butyrylcholinesterase (eqBChE) and moderate electric eel acetylcholinesterase (eeAChE) inhibitors, with catechols 4 and 5 presenting lower IC₅₀ values than AntiOXCIN2 and AntiOXCIN3, respectively. However, differences in the inhibition potency and selectivity of compounds 2–5 towards non-human and human cholinesterases (ChEs) were observed. Co-crystallization studies with compounds 2–5 in complex with human ChEs (hChEs) showed that these compounds exhibit different binging modes to hAChE and hBChE. Unlike AntiOXCINs, compounds 2–5 displayed moderate human monoamine oxidase (hMAO) inhibitory activity. Moreover, compounds 4 and 5 presented higher ORAC-FL indexes and lower oxidation potential values than the corresponding AntiOXCINs. Catechols 4 and 5 exhibited broader safety windows in differentiated neuroblastoma cells than benzodioxole derivatives 2 and 3. Compound 4 is highlighted as a safe mitochondria-targeted antioxidant with dual ChE/MAO inhibitory activity. Overall, this work is a contribution for the development of dual therapeutic agents addressing both mitochondrial oxidative stress and neurotransmitter depletion. Full article

(This article belongs to the Special Issue Modulators of Oxidative Stress: Chemical and Pharmacological Aspects 2021)

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24 pages, 4878 KiB

Open AccessReview

Polyphenols in the Mediterranean Diet: From Dietary Sources to microRNA Modulation

by Roberto Cannataro, Alessia Fazio, Chiara La Torre, Maria Cristina Caroleo and Erika Cione

Antioxidants 2021, 10(2), 328; https://doi.org/10.3390/antiox10020328 - 23 Feb 2021

Cited by 74 | Viewed by 8558

Abstract

It is now well established that polyphenols are a class of natural substance that offers numerous health benefits; they are present in all plants in very different quantities and types. On the other hand, their bioavailability, and efficacy is are not always well [...] Read more.

It is now well established that polyphenols are a class of natural substance that offers numerous health benefits; they are present in all plants in very different quantities and types. On the other hand, their bioavailability, and efficacy is are not always well proven. Therefore, this work aims to discuss some types of polyphenols belonging to Mediterranean foods. We chose six polyphenols—(1) Naringenin, (2) Apigenin, (3) Kaempferol, (4) Hesperidin, (5) Ellagic Acid and (6) Oleuropein—present in Mediterranean foods, describing dietary source and their chemistry, as well as their pharmacokinetic profile and their use as nutraceuticals/supplements, in addition to the relevant element of their capability in modulating microRNAs expression profile. Full article

(This article belongs to the Special Issue Antioxidants and MicroRNA Modulation)

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14 pages, 1029 KiB

Open AccessArticle

Comparative Study Regarding the Chemical Composition and Biological Activity of Pine (Pinus nigra and P. sylvestris) Bark Extracts

by Adrian Nisca, Ruxandra Ștefănescu, Diana Ionela Stegăruș, Anca Delia Mare, Lenard Farczadi and Corneliu Tanase

Antioxidants 2021, 10(2), 327; https://doi.org/10.3390/antiox10020327 - 22 Feb 2021

Cited by 34 | Viewed by 5789

Abstract

The bark resulted after the industrial processing of wood represents a byproduct of the forestry industry, used in many suboptimal ways, being considered a natural waste. Currently, it has been highlighted that the bark of different woody plants may be an important source [...] Read more.

The bark resulted after the industrial processing of wood represents a byproduct of the forestry industry, used in many suboptimal ways, being considered a natural waste. Currently, it has been highlighted that the bark of different woody plants may be an important source of several bioactive compounds, with various beneficial biological functions. The aim of this study is to evaluate and compare the chemical composition and biological activities of two different pine species (Pinus nigra and Pinus sylvestris) bark extracts. Ultrasound (UAE) and microwave (MAE) assisted extractions were performed in order to obtain the extracts. The total polyphenol (TPC) and total tannin (TTC) contents of the extracts were assessed via the Folin–Ciocâlteu method. The volatile and polyphenolic compounds were identified and quantified via a GC/MS analysis and an UPLC-PDA analysis, respectively. The antioxidant activity (AOA) was evaluated using the DPPH and ABTS assays, while the antibacterial activity was assessed using the minimum inhibitory concentration (MIC) protocol. The results showed that the Pinus sylvestris bark extracts obtained by UAE had a higher TPC, TTC and AOA, while the Pinus nigra bark extracts obtained by MAE had higher volatile compounds content (mainly α-pinene and β-pinene). Moreover, the inhibition of the bacterial growth was more efficient in the case of Pinus sylvestris extracts, Gram-positive bacteria being the most affected, while Gram-negative strains presented a relative resistance to the tested extract concentrations. These results may indicate the potential use of the pine bark extracts as antioxidant or antibacterial agents. Full article

(This article belongs to the Special Issue Antioxidant and Biological Properties of Plant Extracts)

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15 pages, 5108 KiB

Open AccessArticle

Biochemical Regulation of the Glyoxalase System in Response to Insulin Signaling

by Der-Yen Lee, Yu-Chin Lin and Geen-Dong Chang

Antioxidants 2021, 10(2), 326; https://doi.org/10.3390/antiox10020326 - 22 Feb 2021

Cited by 6 | Viewed by 2692

Abstract

Methylglyoxal (MG) is a reactive glycation metabolite and potentially induces dicarbonyl stress. The production of MG in cells is increased along with an increase in carbohydrate metabolism. The efficiency of the glyoxalase system, consisting of glyoxalase 1 (GlxI) and glyoxalase 2 (GlxII), is [...] Read more.

Methylglyoxal (MG) is a reactive glycation metabolite and potentially induces dicarbonyl stress. The production of MG in cells is increased along with an increase in carbohydrate metabolism. The efficiency of the glyoxalase system, consisting of glyoxalase 1 (GlxI) and glyoxalase 2 (GlxII), is crucial for turning the accumulated MG into nontoxic metabolites. Converting MG-glutathione hemithioacetal to S-d-lactoylglutathione by GlxI is the rate-determining step of the enzyme system. In this study, we found lactic acid accumulated during insulin stimulation in cells, however, cellular MG and S-d-lactoylglutathione also increased due to the massive flux of glycolytic intermediates. The insulin-induced accumulation of MG and S-d-lactoylglutathione were efficiently removed by the treatment of metformin, possibly via affecting the glyoxalase system. With the application of isotopic ¹³C₃-MG, the flux of MG from extracellular and intracellular origins was dissected. While insulin induced an influx of extracellular MG, metformin inhibited the trafficking of MG across the plasma membrane. Therefore, metformin could maintain the extracellular MG by means of reducing the secretion of MG rather than facilitating the scavenging. In addition, metformin may affect the glyoxalase system by controlling the cellular redox state through replenishing reduced glutathione. Overall, alternative biochemical regulation of the glyoxalase system mediated by insulin signaling or molecules like biguanides may control cellular MG homeostasis. Full article

(This article belongs to the Special Issue Redox Biology of Glyoxalases)

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17 pages, 3008 KiB

Open AccessArticle

Protective Effects of Liposomal Curcumin on Oxidative Stress/Antioxidant Imbalance, Metalloproteinases 2 and -9, Histological Changes and Renal Function in Experimental Nephrotoxicity Induced by Gentamicin

by Adriana Elena Bulboacă, Alina Porfire, Sorana D. Bolboacă, Cristina Ariadna Nicula, Dana Gabriela Feștilă, Alexandra Roman, Ruxandra Mioara Râjnoveanu, Armand Râjnoveanu, Gabriela Dogaru, Paul-Mihai Boarescu, Vasile Rus, Corneliu Angelo Bulboacă, Alexandra Ina Bulboacă and Ioana Stănescu

Antioxidants 2021, 10(2), 325; https://doi.org/10.3390/antiox10020325 - 22 Feb 2021

Cited by 18 | Viewed by 3972

Abstract

Background: Our study aimed to assess the efficiency of Curcumin nanoformulation (LCC) on experimental nephrotoxicity induced by Gentamicin in rats. Methods: Six groups of seven rats were used: C—(control group) received saline solution i.p. (i.p. = intraperitoneal), G—gentamicin (G, 80 mg/kg body weight [...] Read more.

Background: Our study aimed to assess the efficiency of Curcumin nanoformulation (LCC) on experimental nephrotoxicity induced by Gentamicin in rats. Methods: Six groups of seven rats were used: C—(control group) received saline solution i.p. (i.p. = intraperitoneal), G—gentamicin (G, 80 mg/kg body weight (b.w.)), GCC1 and GCC2—with G and CC solution (single dose of 10 mg/kg b.w.-CC1, or 20 mg/kg b.w.-CC2), GLCC1 (10 mg/kg b.w.) and GLCC2 (20 mg/kg b.w.) with G and LCC administration. Oxidative stress parameters (NOx = nitric oxide, MDA = malondialdehyde, TOS = total oxidative stress), antioxidant parameters (CAT = catalase, TAC = total antioxidant capacity), matrix metalloproteinases (MMP-2 and MMP-9), and renal function parameters (creatinine, blood urea nitrogen, and urea) were measured. Kidneys histopathologic examination was made for each group. Results: Pretreatment with CC and LCC in both doses had significantly alleviating effects on assessed parameters (NOx, MDA, TOS, CAT, TAC, MMP-2, and -9) as compared with the untreated group (p < 0.006). Histopathological aspect and renal function were significantly improved in CC and LCC groups. Liposomal formulation (LCC) showed higher efficiency on all examined parameters compared to CC (p < 0.006). Conclusions: Our results demonstrated improving renal function and kidney cytoarchitecture, oxidative stress/antioxidant/balance, and MMPs plasma concentrations with better dose-related efficacity of LCC than CC. Full article

(This article belongs to the Special Issue Nanoantioxidants)

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14 pages, 4017 KiB

Open AccessArticle

Determination of the Antioxidant Activity of Samples of Tea and Commercial Sources of Vitamin C, Using an Enzymatic Biosensor

by Danilo Braga Ribeiro, Gabriela Santos Silva, Djanira Rubim dos Santos, Andressa Rose Castro Costa, Eliane Braga Ribeiro, Mihaela Badea and Gilvanda Silva Nunes

Antioxidants 2021, 10(2), 324; https://doi.org/10.3390/antiox10020324 - 22 Feb 2021

Cited by 15 | Viewed by 4068

Abstract

Antioxidants are synthetic or natural compounds capable of preventing or delaying oxidative damage caused by chemical species that can oxidize cell biomolecules, such as proteins, membranes, and DNA, leading to the development of various pathologies, such as cancer, atherosclerosis, Parkinson, Alzheimer, and other [...] Read more.

Antioxidants are synthetic or natural compounds capable of preventing or delaying oxidative damage caused by chemical species that can oxidize cell biomolecules, such as proteins, membranes, and DNA, leading to the development of various pathologies, such as cancer, atherosclerosis, Parkinson, Alzheimer, and other diseases serious. In this study, an amperometric biosensor was used to determine the antioxidant activity of teas and effervescent products based on vitamin C, available on the market. A sensor composed of three electrodes was used. The performance of the following electrochemical mediators was evaluated: meldola blue combined with Reineck salt (MBRS), Prussian blue (PB), and cobalt phthalocyanine (CoPC), as well as the time of polymerization in the enzymatic immobilization process and the agitation process during chronoamperometric measurements. Prussian blue proved to be more efficient as a mediator for the desired purposes. After optimizing the construction stages of the biosensor, as well as the operational parameters, it presented stability for a period of 7 months. The results clearly indicate that the biosensor can be successfully used to detect fraud in products called “antioxidants” or even in drugs containing less ascorbic acid than indicated on the labels. The detection limit was set at 4.93 µmol·L⁻¹. Full article

(This article belongs to the Special Issue Dietary Polyphenols and Neuroprotection)

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14 pages, 2264 KiB

Open AccessArticle

Antioxidant Effect of a Probiotic Product on a Model of Oxidative Stress Induced by High-Intensity and Duration Physical Exercise

by Maravillas Sánchez Macarro, Vicente Ávila-Gandía, Silvia Pérez-Piñero, Fernando Cánovas, Ana María García-Muñoz, María Salud Abellán-Ruiz, Desirée Victoria-Montesinos, Antonio J. Luque-Rubia, Eric Climent, Salvador Genovés, Daniel Ramon, Empar Chenoll and Francisco Javier López-Román

Antioxidants 2021, 10(2), 323; https://doi.org/10.3390/antiox10020323 - 22 Feb 2021

Cited by 37 | Viewed by 6140

Abstract

This randomized double-blind and controlled single-center clinical trial was designed to evaluate the effect of a 6-week intake of a probiotic product (1 capsule/day) vs. a placebo on an oxidative stress model of physical exercise (high intensity and duration) in male cyclists (probiotic [...] Read more.

This randomized double-blind and controlled single-center clinical trial was designed to evaluate the effect of a 6-week intake of a probiotic product (1 capsule/day) vs. a placebo on an oxidative stress model of physical exercise (high intensity and duration) in male cyclists (probiotic group, n = 22; placebo, n = 21). This probiotic included three lyophilized strains (Bifidobacterium longum CECT 7347, Lactobacillus casei CECT 9104, and Lactobacillus rhamnosus CECT 8361). Study variables were urinary isoprostane, serum malondialdehyde (MDA), serum oxidized low-density lipoprotein (Ox-LDL), urinary 8-hydroxy-2′-deoxiguanosine (8-OHdG), serum protein carbonyl, serum glutathione peroxidase (GPx), and serum superoxide dismutase (SOD). At 6 weeks, as compared with baseline, significant differences in 8-OHdG (Δ mean difference −10.9 (95% CI −14.5 to −7.3); p < 0.001), MDA (Δ mean difference −207.6 (95% CI −349.1 to −66.1; p < 0.05), and Ox-LDL (Δ mean difference −122.5 (95% CI −240 to −4.5); p < 0.05) were found in the probiotic group only. Serum GPx did not increase in the probiotic group, whereas the mean difference was significant in the placebo group (477.8 (95% CI 112.5 to 843.2); p < 0.05). These findings suggest an antioxidant effect of this probiotic on underlying interacting oxidative stress mechanisms and their modulation in healthy subjects. The study was registered in ClinicalTrials.gov (NCT03798821). Full article

(This article belongs to the Special Issue Oxidative Stress and Exercise)

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25 pages, 7870 KiB

Open AccessArticle

Actin Cytoskeleton Regulation by the Yeast NADPH Oxidase Yno1p Impacts Processes Controlled by MAPK Pathways

by Manuela Weber, Sukanya Basu, Beatriz González, Gregor P. Greslehner, Stefanie Singer, Danusa Haskova, Jiri Hasek, Michael Breitenbach, Campbell W.Gourlay, Paul J. Cullen and Mark Rinnerthaler

Antioxidants 2021, 10(2), 322; https://doi.org/10.3390/antiox10020322 - 22 Feb 2021

Cited by 12 | Viewed by 4548

Abstract

Reactive oxygen species (ROS) that exceed the antioxidative capacity of the cell can be harmful and are termed oxidative stress. Increasing evidence suggests that ROS are not exclusively detrimental, but can fulfill important signaling functions. Recently, we have been able to demonstrate that [...] Read more.

Reactive oxygen species (ROS) that exceed the antioxidative capacity of the cell can be harmful and are termed oxidative stress. Increasing evidence suggests that ROS are not exclusively detrimental, but can fulfill important signaling functions. Recently, we have been able to demonstrate that a NADPH oxidase-like enzyme (termed Yno1p) exists in the single-celled organism Saccharomyces cerevisiae. This enzyme resides in the peripheral and perinuclear endoplasmic reticulum and functions in close proximity to the plasma membrane. Its product, hydrogen peroxide, which is also produced by the action of the superoxide dismutase, Sod1p, influences signaling of key regulatory proteins Ras2p and Yck1p/2p. In the present work, we demonstrate that Yno1p-derived H₂O₂ regulates outputs controlled by three MAP kinase pathways that can share components: the filamentous growth (filamentous growth MAPK (fMAPK)), pheromone response, and osmotic stress response (hyperosmolarity glycerol response, HOG) pathways. A key structural component and regulator in this process is the actin cytoskeleton. The nucleation and stabilization of actin are regulated by Yno1p. Cells lacking YNO1 showed reduced invasive growth, which could be reversed by stimulation of actin nucleation. Additionally, under osmotic stress, the vacuoles of a ∆yno1 strain show an enhanced fragmentation. During pheromone response induced by the addition of alpha-factor, Yno1p is responsible for a burst of ROS. Collectively, these results broaden the roles of ROS to encompass microbial differentiation responses and stress responses controlled by MAPK pathways. Full article

(This article belongs to the Special Issue Roles of NADPH Oxidase in Modulation of Signal Transduction and Cellular Metabolism)

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9 pages, 950 KiB

Open AccessPerspective

Roles of mTOR in Diabetic Kidney Disease

by Mako Yasuda-Yamahara, Shinji Kume and Hiroshi Maegawa

Antioxidants 2021, 10(2), 321; https://doi.org/10.3390/antiox10020321 - 22 Feb 2021

Cited by 42 | Viewed by 4023

Abstract

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease and the number of patients affected is increasing worldwide. Thus, there is a need to establish a new treatment for DKD to improve the renal prognosis of diabetic patients. Recently, it [...] Read more.

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease and the number of patients affected is increasing worldwide. Thus, there is a need to establish a new treatment for DKD to improve the renal prognosis of diabetic patients. Recently, it has shown that intracellular metabolic abnormalities are involved in the pathogenesis of DKD. In particular, the activity of mechanistic target of rapamycin complex 1 (mTORC1), a nutrient-sensing signaling molecule, is hyperactivated in various organs of diabetic patients, which suggests the involvement of excessive mTORC1 activation in the pathogenesis of diabetes. In DKD, hyperactivated mTORC1 may be involved in the pathogenesis of podocyte damage, which causes proteinuria, and tubular cell injury that decreases renal function. Therefore, elucidating the role of mTORC1 in DKD and developing new therapeutic agents that suppress mTORC1 hyperactivity may shed new light on DKD treatments in the future. Full article

(This article belongs to the Special Issue Oxidative Stress in Kidney Disease)

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14 pages, 1279 KiB

Open AccessArticle

Relationship between Physical Activity, Oxidative Stress, and Total Plasma Antioxidant Capacity in Spanish Children from the GENOBOX Study

by Francisco Jesús Llorente-Cantarero, Francisco Javier Aguilar-Gómez, Rosaura Leis, Gloria Bueno, Azahara I. Rupérez, Augusto Anguita-Ruiz, Rocío Vázquez-Cobela, María Dolores Mesa, Luis A. Moreno, Ángel Gil, Concepción María Aguilera and Mercedes Gil-Campos

Antioxidants 2021, 10(2), 320; https://doi.org/10.3390/antiox10020320 - 20 Feb 2021

Cited by 17 | Viewed by 3692

Abstract

The World Health Organization has recommended performing at least 60 min a day of moderate-to-vigorous physical activity (MVPA) and reducing sedentarism in children and adolescents to offer significant health benefits and mitigate health risks. Physical fitness and sports practice seem to improve oxidative [...] Read more.

The World Health Organization has recommended performing at least 60 min a day of moderate-to-vigorous physical activity (MVPA) and reducing sedentarism in children and adolescents to offer significant health benefits and mitigate health risks. Physical fitness and sports practice seem to improve oxidative stress (OS) status during childhood. However, to our knowledge, there are no data regarding the influence of objectively-measured physical activity (PA) and sedentarism on OS status in children and adolescents. The present study aimed to evaluate the influence of moderate and vigorous PA and sedentarism on OS and plasma total antioxidant capacity (TAC) in a selected Spanish population of 216 children and adolescents from the GENOBOX study. PA (light, moderate, and vigorous) and sedentarism (i.e., sedentary time (ST)) were measured by accelerometry. A Physical Activity-Sedentarism Score (PASS) was developed integrating moderate and vigorous PA and ST levels. Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and isoprostane F2α (F₂-IsoPs), as markers of OS, were determined by ELISA; and TAC was estimated by colorimetry using an antioxidant kit. A higher PASS was associated with lower plasma TAC and urinary 8-OHdG and F₂-IsoPs, showing a better redox profile. Reduced OS markers (8-OHdG and F₂-IsoPs) in children with higher PASS may diminish the need of maintaining high concentrations of antioxidants in plasma during rest to achieve redox homeostasis. Full article

(This article belongs to the Special Issue Total Antioxidant Capacity in Health and Disease)

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26 pages, 394 KiB

Open AccessReview

Recent Progress in Discovering the Role of Carotenoids and Metabolites in Prostatic Physiology and Pathology—A Review—Part II: Carotenoids in the Human Studies

by Joanna Dulińska-Litewka, Przemysław Hałubiec, Agnieszka Łazarczyk, Oskar Szafrański, Yoav Sharoni, James A. McCubrey, Bartosz Gąsiorkiewicz and Torsten Bohn

Antioxidants 2021, 10(2), 319; https://doi.org/10.3390/antiox10020319 - 20 Feb 2021

Cited by 16 | Viewed by 4120

Abstract

Among the vast variety of plant-derived phytochemicals, the group of carotenoids has continuously been investigated in order to optimize their potential application in the area of dietary intervention related to chronic diseases. One organ that has been especially targeted in many of these [...] Read more.

Among the vast variety of plant-derived phytochemicals, the group of carotenoids has continuously been investigated in order to optimize their potential application in the area of dietary intervention related to chronic diseases. One organ that has been especially targeted in many of these studies and clinical trials is the human prostate. Without doubt, carotenoids (and their endogenous derivatives—retinoids and apo-carotenoids) are involved in a plethora of intra- and intercellular signaling, cell growth, and differentiation of prostate tissue. Due to the accumulation of new data on the role of different carotenoids, such as lycopene (LYC) and β-carotene (BC), in prostatic physiology and pathology, the present review aimed to cover the past ten years of research in this regard. Data from experimental studies are presented in the first part of the review, while epidemiological studies are disclosed in this second part. The objective of this compilation was to emphasize the present state of knowledge about the most potent molecular targets of carotenoids, as well as to propose promising carotenoid agents for the prevention and possible treatment of prostatic diseases. Full article

(This article belongs to the Special Issue Carotenoids, Oxidative Stress and Disease)

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13 pages, 1442 KiB

Open AccessArticle

Health Potential of Aloe vera against Oxidative Stress Induced Corneal Damage: An “In Vitro” Study

by Ida Ceravolo, Federica Mannino, Natasha Irrera, Francesco Squadrito, Domenica Altavilla, Giorgia Ceravolo, Giovanni Pallio and Letteria Minutoli

Antioxidants 2021, 10(2), 318; https://doi.org/10.3390/antiox10020318 - 20 Feb 2021

Cited by 30 | Viewed by 4839

Abstract

Fuchs endothelial corneal dystrophy (FECD) is characterized by the gradual deterioration of corneal endothelial cells (CECs) and is the most common cause of corneal transplantation worldwide. CECs apoptosis caused by oxidative stress plays a pivotal role in the pathogenesis of FECD. Antioxidant compounds [...] Read more.

Fuchs endothelial corneal dystrophy (FECD) is characterized by the gradual deterioration of corneal endothelial cells (CECs) and is the most common cause of corneal transplantation worldwide. CECs apoptosis caused by oxidative stress plays a pivotal role in the pathogenesis of FECD. Antioxidant compounds have been of considerable significance as a candidate treatment in the management of corneal diseases. Based on these findings, the objective of this study was to evaluate the effects of an aloe extract with antioxidant properties, in an “in vitro” model of FECD. Human corneal epithelial (HCE) cells were preincubated with aloe extract 100 μg/mL, two hours before hydrogen peroxide (H₂O₂) stimulus. H₂O₂ challenge significantly reduced the cell viability, increased the generation of Reactive Oxygen Species (ROS) and malondialdehyde levels. Moreover, m-RNA expression and activity of Nrf-2, Catalase and Superoxide dismutase (SOD) were reduced together with an enhanced expression of IL-1β, tumor necrosis factor-α (TNF-α), IL-6, and cyclooxygenase 2 (COX-2). Furthermore, Bcl-2, Caspase-3 and Caspase-8 expression were down-regulated while Bax was up-regulated by H₂O₂ stimulus. Aloe extract blunted the oxidative stress-induced inflammatory cascade triggered by H₂O₂ and modulated apoptosis. Aloe extract defends HCE cells from H₂O₂-induced injury possibly due its antioxidant and anti-inflammatory activity, indicating that eye drops containing aloe extract may be used as an adjunctive treatment for FECD. Full article

(This article belongs to the Special Issue Plant-Based Diets and Their Antioxidant Role in Human Health)

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12 pages, 1790 KiB

Open AccessArticle

xCT-Driven Expression of GPX4 Determines Sensitivity of Breast Cancer Cells to Ferroptosis Inducers

by Namgyu Lee, Anne E. Carlisle, Austin Peppers, Sung Jin Park, Mihir B. Doshi, Meghan E. Spears and Dohoon Kim

Antioxidants 2021, 10(2), 317; https://doi.org/10.3390/antiox10020317 - 20 Feb 2021

Cited by 84 | Viewed by 8390

Abstract

Inducers of ferroptosis such as the glutathione depleting agent Erastin and the GPX4 inhibitor Rsl-3 are being actively explored as potential therapeutics in various cancers, but the factors that determine their sensitivity are poorly understood. Here, we show that expression levels of both [...] Read more.

Inducers of ferroptosis such as the glutathione depleting agent Erastin and the GPX4 inhibitor Rsl-3 are being actively explored as potential therapeutics in various cancers, but the factors that determine their sensitivity are poorly understood. Here, we show that expression levels of both subunits of the cystine/glutamate antiporter xCT determine the expression of GPX4 in breast cancer, and that upregulation of the xCT/selenocysteine biosynthesis/GPX4 production axis paradoxically renders the cancer cells more sensitive to certain types of ferroptotic stimuli. We find that GPX4 is strongly upregulated in a subset of breast cancer tissues compared to matched normal samples, and that this is tightly correlated with the increased expression of the xCT subunits SLC7A11 and SLC3A2. Erastin depletes levels of the antioxidant selenoproteins GPX4 and GPX1 in breast cancer cells by inhibiting xCT-dependent extracellular reduction which is required for selenium uptake and selenocysteine biosynthesis. Unexpectedly, while breast cancer cells are resistant compared to nontransformed cells against oxidative stress inducing drugs, at the same time they are hypersensitive to lipid peroxidation and ferroptosis induced by Erastin or Rsl-3, indicating that they are ‘addicted’ to the xCT/GPX4 axis. Our findings provide a strategic basis for targeting the anti-ferroptotic machinery of breast cancer cells depending on their xCT status, which can be further explored. Full article

(This article belongs to the Special Issue Antioxidants for Breast Cancer)

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15 pages, 355 KiB

Open AccessReview

Health Benefits of Antioxidative Peptides Derived from Legume Proteins with a High Amino Acid Score

by Athanasia Matemu, Soichiro Nakamura and Shigeru Katayama

Antioxidants 2021, 10(2), 316; https://doi.org/10.3390/antiox10020316 - 20 Feb 2021

Cited by 78 | Viewed by 7630

Abstract

Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources of protein with a high amino acid score and can provide bioactive peptides. This manuscript presents a review on legume-derived peptides, focusing on in vitro and in vivo studies on [...] Read more.

Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources of protein with a high amino acid score and can provide bioactive peptides. This manuscript presents a review on legume-derived peptides, focusing on in vitro and in vivo studies on the potential antioxidative activities of protein hydrolysates and their characterization, amino acid sequences, or purified/novel peptides. The health implications of legume-derived antioxidative peptides in reducing the risks of cancer and cardiovascular diseases are linked with their potent action against oxidation and inflammation. The molecular weight profiles and amino acid sequences of purified and characterized legume-derived antioxidant peptides are not well established. Therefore, further exploration of legume protein hydrolysates is necessary for assessing the potential applications of antioxidant-derived peptides in the functional food industry. Full article

(This article belongs to the Special Issue Current Trends in Food-Derived Peptidic Antioxidants)

20 pages, 2695 KiB

Open AccessArticle

Frataxins Emerge as New Players of the Intracellular Antioxidant Machinery

by Ana Belén Uceda, Josefa Donoso, Juan Frau, Bartolomé Vilanova and Miquel Adrover

Antioxidants 2021, 10(2), 315; https://doi.org/10.3390/antiox10020315 - 20 Feb 2021

Cited by 7 | Viewed by 3488

Abstract

Frataxin is a mitochondrial protein which deficiency causes Friedreich’s ataxia, a cardio-neurodegenerative disease. The lack of frataxin induces the dysregulation of mitochondrial iron homeostasis and oxidative stress, which finally causes the neuronal death. The mechanism through which frataxin regulates the oxidative stress balance [...] Read more.

Frataxin is a mitochondrial protein which deficiency causes Friedreich’s ataxia, a cardio-neurodegenerative disease. The lack of frataxin induces the dysregulation of mitochondrial iron homeostasis and oxidative stress, which finally causes the neuronal death. The mechanism through which frataxin regulates the oxidative stress balance is rather complex and poorly understood. While the absence of human (Hfra) and yeast (Yfh1) frataxins turn out cells sensitive to oxidative stress, this does not occur when the frataxin gene is knocked-out in E. coli. To better understand the biological roles of Hfra and Yfh1 as endogenous antioxidants, we have studied their ability to inhibit the formation of reactive oxygen species (ROS) from Cu²⁺- and Fe³⁺-catalyzed degradation of ascorbic acid. Both proteins drastically reduce the formation of ROS, and during this process they are not oxidized. In addition, we have also demonstrated that merely the presence of Yfh1 or Hfra is enough to protect a highly oxidation-prone protein such as α-synuclein. This unspecific intervention (without a direct binding) suggests that frataxins could act as a shield to prevent the oxidation of a broad set of intracellular proteins, and reinforces that idea that frataxin can be used to prevent neurological pathologies linked to an enhanced oxidative stress. Full article

(This article belongs to the Collection Feature Papers in ROS, RNS, RSS)

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2 pages, 185 KiB

Open AccessEditorial

Mitochondrial Oxidative and Nitrosative Stress as a Therapeutic Target in Diseases

by Montserrat Marí and Anna Colell

Antioxidants 2021, 10(2), 314; https://doi.org/10.3390/antiox10020314 - 20 Feb 2021

Cited by 9 | Viewed by 2068

Abstract

Mitochondria are fundamental to life [...] Full article

(This article belongs to the Special Issue Mitochondrial Oxidative and Nitrosative Stress as a Therapeutic Target in Diseases)

39 pages, 3901 KiB

Open AccessEditor’s ChoiceReview

Functions of ROS in Macrophages and Antimicrobial Immunity

by Marc Herb and Michael Schramm

Antioxidants 2021, 10(2), 313; https://doi.org/10.3390/antiox10020313 - 19 Feb 2021

Cited by 417 | Viewed by 38083

Abstract

Reactive oxygen species (ROS) are a chemically defined group of reactive molecules derived from molecular oxygen. ROS are involved in a plethora of processes in cells in all domains of life, ranging from bacteria, plants and animals, including humans. The importance of ROS [...] Read more.

Reactive oxygen species (ROS) are a chemically defined group of reactive molecules derived from molecular oxygen. ROS are involved in a plethora of processes in cells in all domains of life, ranging from bacteria, plants and animals, including humans. The importance of ROS for macrophage-mediated immunity is unquestioned. Their functions comprise direct antimicrobial activity against bacteria and parasites as well as redox-regulation of immune signaling and induction of inflammasome activation. However, only a few studies have performed in-depth ROS analyses and even fewer have identified the precise redox-regulated target molecules. In this review, we will give a brief introduction to ROS and their sources in macrophages, summarize the versatile roles of ROS in direct and indirect antimicrobial immune defense, and provide an overview of commonly used ROS probes, scavengers and inhibitors. Full article

(This article belongs to the Special Issue Reactive Oxygen Species in Different Biological Processes)

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16 pages, 1413 KiB

Open AccessReview

LOXL2 Inhibitors and Breast Cancer Progression

by Sandra Ferreira, Nuno Saraiva, Patrícia Rijo and Ana S. Fernandes

Antioxidants 2021, 10(2), 312; https://doi.org/10.3390/antiox10020312 - 19 Feb 2021

Cited by 80 | Viewed by 7810

Abstract

LOX (lysyl oxidase) and lysyl oxidase like-1–4 (LOXL 1–4) are amine oxidases, which catalyze cross-linking reactions of elastin and collagen in the connective tissue. These amine oxidases also allow the cross-link of collagen and elastin in the extracellular matrix of tumors, facilitating the [...] Read more.

LOX (lysyl oxidase) and lysyl oxidase like-1–4 (LOXL 1–4) are amine oxidases, which catalyze cross-linking reactions of elastin and collagen in the connective tissue. These amine oxidases also allow the cross-link of collagen and elastin in the extracellular matrix of tumors, facilitating the process of cell migration and the formation of metastases. LOXL2 is of particular interest in cancer biology as it is highly expressed in some tumors. This protein also promotes oncogenic transformation and affects the proliferation of breast cancer cells. LOX and LOXL2 inhibition have thus been suggested as a promising strategy to prevent metastasis and invasion of breast cancer. BAPN (β-aminopropionitrile) was the first compound described as a LOX inhibitor and was obtained from a natural source. However, novel synthetic compounds that act as LOX/LOXL2 selective inhibitors or as dual LOX/LOX-L inhibitors have been recently developed. In this review, we describe LOX enzymes and their role in promoting cancer development and metastases, with a special focus on LOXL2 and breast cancer progression. Moreover, the recent advances in the development of LOXL2 inhibitors are also addressed. Overall, this work contextualizes and explores the importance of LOXL2 inhibition as a promising novel complementary and effective therapeutic approach for breast cancer treatment. Full article

(This article belongs to the Special Issue Redox-Active Molecules as Therapeutic Agents)

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19 pages, 2300 KiB

Open AccessArticle

New Insights into the Antioxidant and Anti-Inflammatory Effects of Italian Salvia officinalis Leaf and Flower Extracts in Lipopolysaccharide and Tumor-Mediated Inflammation Models

by Matteo Brindisi, Chouaha Bouzidi, Luca Frattaruolo, Monica R. Loizzo, Maria Stella Cappello, Annabelle Dugay, Brigitte Deguin, Graziantonio Lauria, Anna Rita Cappello and Rosa Tundis

Antioxidants 2021, 10(2), 311; https://doi.org/10.3390/antiox10020311 - 19 Feb 2021

Cited by 38 | Viewed by 6239

Abstract

This work aimed to investigate and compare the in vitro antioxidant and anti-inflammatory effects of Salvia officinalis L. (sage) from Italy, with the aim of raising its current knowledge in this field. Leaves and flowers (S1–S8), harvested in two areas of Southern Italy, [...] Read more.

This work aimed to investigate and compare the in vitro antioxidant and anti-inflammatory effects of Salvia officinalis L. (sage) from Italy, with the aim of raising its current knowledge in this field. Leaves and flowers (S1–S8), harvested in two areas of Southern Italy, were extracted with methanol as a solvent by maceration or ultrasound-assisted extraction. Sage extracts, analysed by high pressure liquid chromatography-diode-array detection-electrospray ionization-quadrupole-mass spectroscopy (HPLC-DAD-ESI-Q-MS), exerted a promising antioxidant activity investigated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and β-carotene bleaching tests, and elicited a significant decrease in reactive oxygen species (ROS) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. The anti-inflammatory activity was analysed in the same in vitro model. All the extracts did not affect cell viability although they showed anti-inflammatory activity, as they induced a decrease in nitrite levels that was greater than 50%, when employed at 50 µg/mL. Furthermore, they elicited a decrease in nitrite levels, as well as a decline in pro-inflammatory cytokine expression. The NF-κB transcription factor proved to be involved in the mechanisms that underlie such effects. Interestingly, sage extracts were able to interfere with the inflammatory activity induced by breast cancer cell-conditioned media (nitrite levels were significantly decreased, p < 0.05; p < 0.01), highlighting for the first time the important role of S. officinalis in controlling inflammation processes related to neoplastic progression. Full article

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18 pages, 1341 KiB

Open AccessArticle

Methionine Sulfoxide Reductase B Regulates the Activity of Ascorbate Peroxidase of Banana Fruit

by Lu Xiao, Guoxiang Jiang, Huiling Yan, Hongmei Lai, Xinguo Su, Yueming Jiang and Xuewu Duan

Antioxidants 2021, 10(2), 310; https://doi.org/10.3390/antiox10020310 - 18 Feb 2021

Cited by 24 | Viewed by 3992

Abstract

Ascorbate peroxidase (APX) is a key antioxidant enzyme that is involved in diverse developmental and physiological process and stress responses by scavenging H₂O₂ in plants. APX itself is also subjected to multiple posttranslational modifications (PTMs). However, redox-mediated PTM of APX [...] Read more.

Ascorbate peroxidase (APX) is a key antioxidant enzyme that is involved in diverse developmental and physiological process and stress responses by scavenging H₂O₂ in plants. APX itself is also subjected to multiple posttranslational modifications (PTMs). However, redox-mediated PTM of APX in plants remains poorly understood. Here, we identified and confirmed that MaAPX1 interacts with methionine sulfoxide reductase B2 (MsrB2) in bananas. Ectopic overexpression of MaAPX1 delays the detached leaf senescence induced by darkness in Arabidopsis. Sulfoxidation of MaAPX1, i.e., methionine oxidation, leads to loss of the activity, which is repaired partially by MaMsrB2. Moreover, mimicking sulfoxidation by mutating Met36 to Gln also decreases its activity in vitro and in vivo, whereas substitution of Met36 with Val36 to mimic the blocking of sulfoxidation has little effect on APX activity. Spectral analysis showed that mimicking sulfoxidation of Met36 hinders the formation of compound I, the first intermediate between APX and H₂O₂. Our findings demonstrate that the redox state of methionine in MaAPX1 is critical to its activity, and MaMsrB2 can regulate the redox state and activity of MaAPX1. Our results revealed a novel post-translational redox modification of APX. Full article

(This article belongs to the Special Issue Biological Significance of Methionine Oxidation and Reduction)

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22 pages, 6930 KiB

Open AccessArticle

Exacerbation of AMD Phenotype in Lasered CNV Murine Model by Dysbiotic Oral Pathogens

by Pachiappan Arjunan, Radhika Swaminathan, Jessie Yuan, Mohamed Elashiry, Amany Tawfik, Mohamed Al-Shabrawey, Pamela M. Martin, Thangaraju Muthusamy and Christopher W. Cutler

Antioxidants 2021, 10(2), 309; https://doi.org/10.3390/antiox10020309 - 18 Feb 2021

Cited by 10 | Viewed by 4313

Abstract

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates [...] Read more.

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates characteristics of both AMD and PD has been lacking. Hence, we established a novel AMD+PD murine model to decipher the potential role of oral infection (ligature-enhanced) with the keystone periodontal pathogen Porphyromonas gingivalis, in the progression of neovasculogenesis in a laser-induced choroidal-neovascularization (Li-CNV) mouse retina. By a combination of fundus photography, optical coherence tomography, and fluorescein angiography, we documented inflammatory drusen-like lesions, reduced retinal thickness, and increased vascular leakage in AMD+PD mice retinae. H&E further confirmed a significant reduction of retinal thickness and subretinal drusen-like deposits. Immunofluorescence microscopy revealed significant induction of choroidal/retinal vasculogenesis in AMD+PD mice. qPCR identified increased expression of oxidative-stress, angiogenesis, pro-inflammatory mediators, whereas antioxidants and anti-inflammatory genes in AMD+PD mice retinae were notably decreased. Through qPCR, we detected Pg and its fimbrial 16s-RrNA gene expression in the AMD+PD mice retinae. To sum-up, this is the first in vivo study signifying a role of periodontal infection in augmentation of AMD phenotype, with the aid of a pioneering AMD+PD murine model established in our laboratory. Full article

(This article belongs to the Special Issue Oxidative Stress and Inflammation in Retinal Degeneration)

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16 pages, 1867 KiB

Open AccessReview

Natural Extracts That Stimulate Adipocyte Browning and Their Underlying Mechanisms

by Min-Kyeong Lee, Bonggi Lee and Choon Young Kim

Antioxidants 2021, 10(2), 308; https://doi.org/10.3390/antiox10020308 - 17 Feb 2021

Cited by 15 | Viewed by 10294

Abstract

Despite progress in understanding the developmental lineage and transcriptional factors regulating brown and beige adipocytes, the role of environmental modifiers, such as food components and natural extracts, remains to be elucidated. Furthermore, the undesirable pleiotropic effects produced by synthetic drugs targeting adipose tissue [...] Read more.

Despite progress in understanding the developmental lineage and transcriptional factors regulating brown and beige adipocytes, the role of environmental modifiers, such as food components and natural extracts, remains to be elucidated. Furthermore, the undesirable pleiotropic effects produced by synthetic drugs targeting adipose tissue browning and thermogenesis necessitate research into alternative natural sources to combat obesity and related metabolic disorders. The current review, therefore, focused on the effects of various extracts from foods, plants, and marine products on adipose tissue browning and obesity. In particular, the recent findings of food components and marine products on adipose tissue browning will be discussed here. Full article

(This article belongs to the Special Issue Natural and Synthetic Antioxidants as Food Additives)

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17 pages, 1957 KiB

Open AccessFeature PaperArticle

Inhibitory Effect of a Rosmarinic Acid-Enriched Fraction Prepared from Nga-Mon (Perilla frutescens) Seed Meal on Osteoclastogenesis through the RANK Signaling Pathway

by Kanokkarn Phromnoi, Maitree Suttajit, Chalermpong Saenjum and Pornngarm Limtrakul (Dejkriengkraikul)

Antioxidants 2021, 10(2), 307; https://doi.org/10.3390/antiox10020307 - 17 Feb 2021

Cited by 32 | Viewed by 4418

Abstract

The aim of this study is to determine antioxidant and anti-inflammatory activities relating to the antiosteoporosis effects of various perilla seed meal (PSM) fractions. The remaining waste of perilla seed obtained from cold oil compression was extracted with 70% ethanol and sequentially fractionated [...] Read more.

The aim of this study is to determine antioxidant and anti-inflammatory activities relating to the antiosteoporosis effects of various perilla seed meal (PSM) fractions. The remaining waste of perilla seed obtained from cold oil compression was extracted with 70% ethanol and sequentially fractionated according to solvent polarity with hexane, dichloromethane, ethyl acetate, and water. The results indicated that the seed-meal ethyl acetate fraction (SMEF) exhibited the highest antioxidant and anti-inflammatory activities, and rosmarinic acid (RA) content. The signaling pathways induced by the receptor activator of the nuclear factor kappa B (NF-κB) ligand (RANKL) that trigger reactive oxygen species (ROS) and several transcription factors, leading to the induction of osteoclastogenesis, were also investigated. The SMEF clearly showed attenuated RANKL-induced tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts and TRAP activity. A Western blot analysis showed that the SMEF significantly downregulated RANKL-induced NF-κB, AP-1 activation, and the nuclear factor of activated T-cell 1 (NFATc1) expression. SMEF also suppressed RANKL-induced osteoclast-specific marker gene-like MMP-9 using zymography. Furthermore, the SMEF showed inhibition of RANKL-induced ROS production in RAW 264.7 cells. The results suggest that the SMEF, which contained high quantities of RA, could be developed as a natural active pharmaceutical ingredient for osteoclastogenic protection and health promotion. Full article

(This article belongs to the Special Issue Antioxidant and Biological Properties of Plant Extracts)

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19 pages, 2261 KiB

Open AccessArticle

Effect on the Antioxidant, Lipoperoxyl Radical Scavenger Capacity, Nutritional, Sensory and Microbiological Traits of an Ovine Stretched Cheese Produced with Grape Pomace Powder Addition

by Raimondo Gaglio, Ignazio Restivo, Marcella Barbera, Pietro Barbaccia, Marialetizia Ponte, Luisa Tesoriere, Adriana Bonanno, Alessandro Attanzio, Antonino Di Grigoli, Nicola Francesca, Giancarlo Moschetti and Luca Settanni

Antioxidants 2021, 10(2), 306; https://doi.org/10.3390/antiox10020306 - 17 Feb 2021

Cited by 25 | Viewed by 3474

Abstract

An innovative ovine cheese enriched with red grape pomace powder (GPP) was produced to improve the functional properties of Vastedda cheese typology. Vastedda cheese making was performed adding GPP and four selected Lactococcus lactis strains (Mise36, Mise94, Mise169 and Mise190). For each strain, [...] Read more.

An innovative ovine cheese enriched with red grape pomace powder (GPP) was produced to improve the functional properties of Vastedda cheese typology. Vastedda cheese making was performed adding GPP and four selected Lactococcus lactis strains (Mise36, Mise94, Mise169 and Mise190). For each strain, 40 L of pasteurized ewe’s milk was divided into two aliquots representing control and experimental trials. Control cheese (CC) production did not contain GPP, while the experimental cheese (EC) production was enriched with 1% (w/w) GPP. GPP did not slow down starter development and acid generation. Plate counts and randomly amplified polymorphic DNA (RAPD)-PCR analysis confirmed the dominance of the starters in all trials. The evolution of the physicochemical parameters showed that EC productions were characterized by lower fat content, higher protein content, and higher values of secondary lipid oxidation. Sensory evaluation indicated that the cheeses produced with the strain Mise94 were those more appreciated by the judges. Thus, the last cheeses were investigated for some functional aspects: GPP enrichment significantly increased antioxidant activity and lipoperoxyl radical scavenger capacity, confirming that grape polyphenol inclusion in cheese represents an optimal strategy for the valorization of ovine cheeses as well as winemaking industry by-products. Full article

(This article belongs to the Special Issue Lipid Oxidation and Antioxidants in Food)

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18 pages, 5542 KiB

Open AccessArticle

Methylene Blue Bridges the Inhibition and Produces Unusual Respiratory Changes in Complex III-Inhibited Mitochondria. Studies on Rats, Mice and Guinea Pigs

by Gergely Sváb, Márton Kokas, Ildikó Sipos, Attila Ambrus and László Tretter

Antioxidants 2021, 10(2), 305; https://doi.org/10.3390/antiox10020305 - 16 Feb 2021

Cited by 11 | Viewed by 6586

Abstract

Methylene blue (MB) is used in human therapy in various pathological conditions. Its effects in neurodegenerative disease models are promising. MB acts on multiple cellular targets and mechanisms, but many of its potential beneficial effects are ascribed to be mitochondrial. According to the [...] Read more.

Methylene blue (MB) is used in human therapy in various pathological conditions. Its effects in neurodegenerative disease models are promising. MB acts on multiple cellular targets and mechanisms, but many of its potential beneficial effects are ascribed to be mitochondrial. According to the “alternative electron transport” hypothesis, MB is capable of donating electrons to cytochrome c bypassing complex I and III. As a consequence of this, the deleterious effects of the inhibitors of complex I and III can be ameliorated by MB. Recently, the beneficial effects of MB exerted on complex III-inhibited mitochondria were debated. In the present contribution, several pieces of evidence are provided towards that MB is able to reduce cytochrome c and improve bioenergetic parameters, like respiration and membrane potential, in mitochondria treated with complex III inhibitors, either antimycin or myxothiazol. These conclusions were drawn from measurements for mitochondrial oxygen consumption, membrane potential, NAD(P)H steady state, MB uptake and MB-cytochrome c oxidoreduction. In the presence of MB and complex III inhibitors, unusual respiratory reactions, like decreased oxygen consumption as a response to ADP addition as well as stimulation of respiration upon administration of inhibitors of ATP synthase or ANT, were observed. Qualitatively identical results were obtained in three rodent species. The actual metabolic status of mitochondria is well reflected in the distribution of MB amongst various compartments of this organelle. Full article

(This article belongs to the Special Issue Mitochondrial Reactive Oxygen Species)

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