Antioxidants

18 pages, 3407 KB

Open AccessArticle

NADK Governs Ferroptosis Susceptibility by Orchestrating NADPH Homeostasis

by Xinyi Chen, Yingying Zhang, Dandan Song, Fei Gui, Yuejia Cao, Yu Hong, Rong Chen, Yang Song, Chunhong Di, Jun Yang and Xiaohua Tan

Antioxidants 2025, 14(12), 1396; https://doi.org/10.3390/antiox14121396 - 24 Nov 2025

Abstract

Ferroptosis, a regulated cell death pathway driven by iron-dependent lipid peroxidation, is modulated by cellular antioxidant systems, particularly the glutathione (GSH)–glutathione peroxidase 4 (GPX4) axis. NAD kinase (NADK), the only enzyme converting NAD⁺ to NADP⁺ located in cytoplasm, fuels NADPH-dependent antioxidant [...] Read more.

Ferroptosis, a regulated cell death pathway driven by iron-dependent lipid peroxidation, is modulated by cellular antioxidant systems, particularly the glutathione (GSH)–glutathione peroxidase 4 (GPX4) axis. NAD kinase (NADK), the only enzyme converting NAD⁺ to NADP⁺ located in cytoplasm, fuels NADPH-dependent antioxidant defenses. However, its role in ferroptosis regulation remains not fully explored. Using ferroptosis-sensitive HT1080 cells, we employed pharmacological inhibition (thioNAM), siRNA-mediated knockdown, and plasmid-driven overexpression of NADK to dissect its impact on ferroptosis. Complementary interventions with nicotinamide mononucleotide (NMN), glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme 1 (ME1) were used to map metabolic interactions. Cell viability, redox metabolites (NADPH and GSH), oxidative stress markers (ROS, MDA), and protein expression were quantified. ThioNAM depleted NADP(H) and sensitized cells to RSL-3-induced ferroptosis, which was reversible with Ferrostatin-1. NADK knockdown produced similar results, reducing NADP(H) levels and amplifying lipid peroxidation. Conversely, NADK overexpression restored NADPH/GSH levels and rescued ferroptosis. NADK was essential for G6PD- and ME1-mediated NADPH production and ferroptosis resistance. Administration of ThioNAM or knockdown of NADK abolished the ferroptosis-rescuing effects of NMN, whereas NADK overexpression enhanced NMN’s ability to rescue ferroptosis by maintaining redox homeostasis. NADK is a metabolic hub in ferroptosis regulation, bridging NMN-driven NAD⁺ salvage to NADPH synthesis via G6PD/ME1. Targeting NADK offers novel strategies for diseases associated with ferroptosis. Full article

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15 pages, 3959 KB

Open AccessArticle

ROS-Driven STAT1 S-Glutathionylation Sustains IFNγ Signaling and Pro-Inflammatory Microglial Polarization

by Martina Brattini, Alessandra Carcereri de Prati, Carlotta Passarini, Marta Menegazzi, Alessandra Fiore, Maria Mosaico, Michelle D’Urso, Sofia Mariotto and Elena Butturini

Antioxidants 2025, 14(12), 1395; https://doi.org/10.3390/antiox14121395 - 23 Nov 2025

Abstract

Oxidative stress is a major driver of neuroinflammation, yet the molecular redox mechanisms that shape microglial activation remain incompletely defined. Among reversible redox modifications, protein S-glutathionylation has emerged as a key regulator of signaling cascades under conditions of elevated Reactive Oxygen Species (ROS). [...] Read more.

Oxidative stress is a major driver of neuroinflammation, yet the molecular redox mechanisms that shape microglial activation remain incompletely defined. Among reversible redox modifications, protein S-glutathionylation has emerged as a key regulator of signaling cascades under conditions of elevated Reactive Oxygen Species (ROS). While IFNγ is known to activate STAT1 and promote a pro-inflammatory microglial phenotype, the contribution of oxidative stress to this process is poorly understood. Here, we investigated the interplay between ROS and STAT1 signaling in IFNγ-stimulated microglial cells. We demonstrate that ROS not only enhance STAT1 phosphorylation but also promote its S-glutathionylation, a modification that sustains STAT1 transcriptional activity. This dual regulation leads to prolonged expression of pro-inflammatory mediators, including iNOS, COX2, TNFα, and IL-6. Importantly, STAT1-deficient cells fail to mount these responses, confirming STAT1 as a central redox-sensitive hub in microglial polarization. Our findings identify S-glutathionylation as a molecular switch that links oxidative stress to persistent STAT1 activation and M1 polarization. These results suggest that targeting STAT1 redox regulation could help control microglial overactivation and may offer new opportunities for therapeutic intervention in neuroinflammatory and neurodegenerative diseases. Full article

(This article belongs to the Special Issue Redox Regulation in Inflammation and Disease—3rd Edition)

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20 pages, 2441 KB

Open AccessArticle

Magnesium Promotes Growth–Metabolism Balance in Juvenile Largemouth Bass (Micropterus salmoides) and Modulates Antioxidant–Inflammatory–Apoptotic Responses Under Heat Stress

by Junjie Qin, Dongyu Huang, Hualiang Liang, Xiaoru Chen, Jiaze Gu, Mingchun Ren and Lu Zhang

Antioxidants 2025, 14(12), 1394; https://doi.org/10.3390/antiox14121394 - 23 Nov 2025

Abstract

This study addressed the optimal magnesium (Mg) requirement for juvenile largemouth bass (Micropterus salmoides) and assessed the effects of dietary Mg supplementation on growth performance, nutrient metabolism, and alleviation of heat stress in it. In this study, six diets with varying [...] Read more.

This study addressed the optimal magnesium (Mg) requirement for juvenile largemouth bass (Micropterus salmoides) and assessed the effects of dietary Mg supplementation on growth performance, nutrient metabolism, and alleviation of heat stress in it. In this study, six diets with varying Mg levels (1.01, 1.26, 1.78, 2.24, 2.35, and 2.51 g/kg), designated as MG1, MG2, MG3, MG4, MG5, and MG6, respectively, were formulated using MgSO₄·7H₂O as the Mg source. These diets were fed to juvenile M. salmoides (initial body weight 2.27 ± 0.02 g) for 8 weeks. The growth performance of the MG4 group was significantly improved. In addition, Plasma GLU, LDL-C, and TG levels were significantly reduced in the MG4 group, while plasma HDL-C levels were increased. In terms of gene expression, glut2, g6pdh, ppar-γ, fas, elovl2, acc, and igf-1 were significantly upregulated in the MG4 and MG5 groups, while g6pase and ppar-α were significantly downregulated in the MG5 group. In the heat stress test, MG4 group exhibited enhanced antioxidant capacity, as evidenced by decreased plasma MDA levels and increased CAT activity, coupled with enhanced gill Na⁺/K⁺-ATPase activity. Gene expression results also showed that il-10 and bcl-2 were significantly upregulated in the MG4 group, while nf-κb, ifn-γ, il-8, tnf-α, casp3, casp8, bax, jnk2 and ask1 were significantly downregulated. Furthermore, the results of TUNEL immunofluorescence labeling analysis showed that the apoptotic index was significantly decreased in the MG2-MG6 groups. Overall, appropriate dietary Mg levels promoted growth performance, improved glucose metabolism, and induced lipid deposition in juvenile M. salmoides. Notably, Mg reduced oxidative damage by enhancing antioxidant enzyme activity, thereby modulating heat stress-induced Antioxidant–Inflammatory–Apoptotic of juvenile M. salmoides. Based on quadratic regression analysis of SGR and FCR, the optimal Mg requirement for juvenile M. salmoides was 2.04, and 2.15 g/kg, respectively. Full article

(This article belongs to the Special Issue Antioxidant Defenses Against Stress Caused by Physical or Chemical Environmental Changes)

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21 pages, 1310 KB

Open AccessReview

Nuclear Factor Erythroid 2-Related Factor 2 (NRF2) as a Biomarker for Radiation Dosimetry and Health Risk Assessment: A Review

by Kave Moloudi, Traimate Sangsuwan, Satoru Monzen, Yohei Fujishima, Donovan Anderson, Benjamin Frey, Tomisato Miura, Samayeh Azariasl, Hiroshi Yasuda and Siamak Haghdoost

Antioxidants 2025, 14(12), 1393; https://doi.org/10.3390/antiox14121393 - 22 Nov 2025

Abstract

Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor that controls the antioxidant response to oxidative stress, especially after exposure to ionizing radiation (IR). This review examines NRF2’s emerging role as a complementary biomarker in radiobiological dosimetry for assessing radiation [...] Read more.

Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor that controls the antioxidant response to oxidative stress, especially after exposure to ionizing radiation (IR). This review examines NRF2’s emerging role as a complementary biomarker in radiobiological dosimetry for assessing radiation exposure and its potential health effects. When cells encounter IR, the resulting reactive oxygen species (ROS) interfere with the NRF2 repressor KEAP1, leading to NRF2 activation and the expression of cytoprotective genes such as HO-1, NQO1, and GCLC. Evidence suggests that NRF2 levels increase in a dose- and time-dependent manner, primarily at low to moderate radiation doses, highlighting its potential for early detection of radiation exposure. However, at high doses (>8 Gy), NRF2 activation may be suppressed due to apoptosis or irreversible damage, which limits its reliability in those situations. The review also compares NRF2 with other biomarkers used in biodosimetry, discussing its advantages, such as sensitivity and early response, along with its limitations, including variability in activation at high doses and expression influenced by other oxidative factors. The authors introduce a comprehensive radiobiological model that illustrates how low-dose IR exposure affects NRF2 expression patterns, thereby improving the understanding of dose-dependent oxidative stress mechanisms. Additionally, the role of NRF2 in inflammation and general health risk assessment is emphasized, suggesting broader applications beyond biodosimetry. Overall, NRF2 holds significant promise for use in evaluating radiation exposure, developing radioprotection strategies, and informing future radiobiological research frameworks. Full article

(This article belongs to the Special Issue Radiation Exposure and Health: The Role of Oxidative Stress and Inflammatory Response)

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15 pages, 8882 KB

Open AccessArticle

Ovatifolin Isolated from Leptocarpha rivularis Induces the Death of A375 and A2958 Cells in Breast Cancer

by Viviana Burgos, Nicole Cortez, Rocío Aguilera-Paillán, Sofía Bravo-Bouchat, Bernd Schmidt, Eric Sperlich, Rebeca Pérez, Nelia M. Rodriguez, Leandro Ortiz, Jaime R. Cabrera-Pardo, Cecilia Villegas and Cristian Paz

Antioxidants 2025, 14(12), 1392; https://doi.org/10.3390/antiox14121392 - 21 Nov 2025

Abstract

Skin cancer is increasing worldwide, with melanoma being its most aggressive and lethal form due to its high metastatic potential. Despite therapeutic advances, drug resistance remains a challenge, highlighting the need to explore new anticancer agents. Leptocarpha rivularis is a native plant of [...] Read more.

Skin cancer is increasing worldwide, with melanoma being its most aggressive and lethal form due to its high metastatic potential. Despite therapeutic advances, drug resistance remains a challenge, highlighting the need to explore new anticancer agents. Leptocarpha rivularis is a native plant of Chile, locally called “Palo negro”, and is traditionally used in medicine by the Mapuche people. L. rivularis produces bioactive germacrene sesquiterpenoids with cytotoxic, antioxidant, anti-inflammatory and anti-angiogenic properties. This study reports for the first time the isolation of ovatifolin from aerial parts of L. rivularis and its identification by NMR and X-ray diffraction, together with its antiproliferative activity against two melanoma cell lines. The results show that ovatifolin has cytotoxic activity against the cell lines A2058 and A375, with an IC₅₀ of 27.6 (90.2 µM) and 18.4 µg/mL (60.1 µM), respectively, evaluated by live-cell IncuCyte^® analysis. Moreover, ovatifolin arrests colony formation in a clonogenic assay, with an IC₅₀ of 3.26 (10.6 μM) and 3.65 µg/mL (11.9 μM) in these same cell lines. Therefore, ovatifolin increased intracellular ROS and decreased the mitochondrial membrane potential (ΔΨ m). Cell death studies using Annexin V showed that its cytotoxic activity is partially caused by non-specific apoptosis, which was corroborated by the caspase inhibitor Z-VAD with an incomplete recovery of the cell death process. Full article

(This article belongs to the Special Issue Bioactive Compounds from Natural Sources with Antioxidant and Anti-Inflammatory Potential)

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18 pages, 4660 KB

Open AccessArticle

Lycopene and SKQ1 Improve Boar Sperm Quality During 17 °C Storage via the AMPK/Nrf2 Pathway

by Miaolian Peng, Pengyao Wang, Yongchang Lu, Xiaoliang Wang, Xianwei Zhang, Ruhai Xu, Ting Gu, Gengyuan Cai, Zhenfang Wu, Lihe Dai and Linjun Hong

Antioxidants 2025, 14(12), 1391; https://doi.org/10.3390/antiox14121391 - 21 Nov 2025

Abstract

During the storage of boar sperm at 17 °C, reactive oxygen species (ROS) are continuously generated. Excessive ROS can disrupt the mitochondrial redox balance and cause sperm damage. In this study, boar semen was diluted with solutions containing different concentrations of the natural [...] Read more.

During the storage of boar sperm at 17 °C, reactive oxygen species (ROS) are continuously generated. Excessive ROS can disrupt the mitochondrial redox balance and cause sperm damage. In this study, boar semen was diluted with solutions containing different concentrations of the natural antioxidant lycopene (1, 5, 10, 20, 40, 80 μM) or the mitochondria-targeted antioxidant SKQ1 (1, 5, 10, 25, 50, 70 nM), and sperm vitality was assessed throughout storage at 17 °C. Based on the screening results, the optimal concentrations were selected for combined application to investigate their effects on sperm quality and potential synergistic interactions. The results demonstrated that sperm motility was significantly higher in the 20 μM lycopene and 50 nM SKQ1 treatment groups compared to the control (p < 0.05). The combined treatment of 20 μM lycopene and 25 nM SKQ1 exhibited a synergistic effect, significantly improving sperm vitality, acrosome and membrane integrity, superoxide dismutase (SOD), glutathione peroxidase (GSP), adenosine triphosphate (ATP) levels (p < 0.05). Meanwhile, ROS and malondialdehyde (MDA) levels were significantly reduced (p < 0.05). Metabolomics analysis identified 52 differential metabolites (p < 0.05), including ABC transporters, corticosterone, and palmitic acid. KEGG pathway enrichment analysis revealed that these metabolites were mainly associated with steroid hormone biosynthesis, ABC transporters, and AMPK signaling pathways (p < 0.05), most of which were related to sperm cell energy metabolism and signal transduction. Furthermore, treatment with antioxidants significantly increased p-AMPK and Nrf2 expression in sperm cells (p < 0.05). These findings suggest that the combination of lycopene and SKQ1 improves boar sperm quality during 17 °C storage by enhancing energy metabolism and mitigating oxidative stress, potentially through the activation of the AMPK/Nrf2 pathway. Full article

(This article belongs to the Section Health Outcomes of Antioxidants and Oxidative Stress)

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19 pages, 2943 KB

Open AccessArticle

Ginseng Oligopeptides Promote Longevity and Enhance Stress Resistance in Caenorhabditis elegans via the DAF-16/FOXO Pathway

by Qian Du, Yiping Zhang, Xiaoyu Guo, Meng Cai, Yong Li and Meihong Xu

Antioxidants 2025, 14(12), 1390; https://doi.org/10.3390/antiox14121390 - 21 Nov 2025

Abstract

Background: Ginseng oligopeptides (GOPs), small bioactive peptides with potent antioxidant capacity and high bioavailability, have shown promise in promoting healthy aging; however, their underlying molecular mechanisms remain largely unexplored. Methods: Using the model organism Caenorhabditis elegans (C. elegans), we comprehensively evaluated [...] Read more.

Background: Ginseng oligopeptides (GOPs), small bioactive peptides with potent antioxidant capacity and high bioavailability, have shown promise in promoting healthy aging; however, their underlying molecular mechanisms remain largely unexplored. Methods: Using the model organism Caenorhabditis elegans (C. elegans), we comprehensively evaluated the anti-aging effects of GOPs on lifespan, locomotion, oxidative stress, and gene expression. Integrated phenotypic assays and transcriptomic analyses were conducted to elucidate GOP-mediated molecular mechanisms. The transgenic strain TJ356 (DAF-16::GFP) and the loss-of-function mutant CF1038 [daf-16(mu86)] were employed to functionally validate the role of the DAF-16/FOXO pathway. Results: GOP supplementation significantly extended median lifespan by approximately 11.5% and improved age-related locomotion decline in C. elegans. Transcriptomic profiling identified 1928 differentially expressed genes (DEGs) enriched in metabolic, antioxidant defense, and longevity-regulating pathways. GOPs upregulated key antioxidant and stress-response genes (gst-4, sod-5, mtl-1) and longevity-related regulators (daf-16, lin-31, Y51B9A.9, and daf-12), while downregulating ins-7, an insulin-like peptide. Moreover, GOPs enhanced cytochrome P450–related detoxification and vitamin-dependent (retinol, ascorbate, and riboflavin) metabolic pathways, establishing a multidimensional antioxidant defense network. Phenotypic validation confirmed that GOPs markedly reduced reactive oxygen species (ROS) levels and lipofuscin accumulation (p < 0.001). Notably, GOPs promoted DAF-16 nuclear translocation in TJ356 worms, whereas the lifespan-extending effects were abolished in CF1038 mutants, highlighting the essential role of DAF-16/FOXO in mediating GOP effects. Conclusions: GOPs delay aging in C. elegans by activating the DAF-16/FOXO signaling cascade and reinforcing antioxidant networks, thereby maintaining redox and metabolic homeostasis. These findings provide novel mechanistic evidence supporting GOPs as promising dietary antioxidants for promoting healthy aging through modulation of conserved redox and longevity pathways. Full article

(This article belongs to the Section Health Outcomes of Antioxidants and Oxidative Stress)

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15 pages, 426 KB

Open AccessReview

Oxidant Stress, Hyperoxia/Hypoxia and Neonatal Respiratory Disorders

by Ourania Kaltsogianni, Theodore Dassios and Anne Greenough

Antioxidants 2025, 14(12), 1389; https://doi.org/10.3390/antiox14121389 - 21 Nov 2025

Abstract

Neonates, especially those born prematurely, have low antioxidant capacity and are highly exposed to oxidant stress during the perinatal period. Oxidant stress damage has been associated with several diseases of prematurity, including respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and pulmonary hypertension. In [...] Read more.

Neonates, especially those born prematurely, have low antioxidant capacity and are highly exposed to oxidant stress during the perinatal period. Oxidant stress damage has been associated with several diseases of prematurity, including respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and pulmonary hypertension. In addition, preterm infants are frequently exposed to hypoxia or hyperoxia, which further increases oxidant stress and morbidity. This narrative review describes the relationship between oxidant stress, hyperoxia/hypoxia, and neonatal respiratory disorders. Preterm infants with respiratory distress syndrome and BPD have higher levels of oxidative stress biomarkers in plasma and in tracheal aspirates and reduced activity of antioxidant enzymes. Early, prolonged, and frequent intermittent hypoxaemic episodes are related to BPD development. Exposure to hyperoxia is linked to longer duration of respiratory support and higher BPD rates. Preclinical data showed that intermittent hypoxia and hyperoxia are associated with pulmonary hypertension (PH) and that hyperoxia can negatively affect the response to pulmonary vasodilators. Antioxidant treatments are not routinely implemented into clinical care due to their modest effect on clinical outcomes, associated complications, and limited clinical data. Optimisation of oxygen delivery and monitoring with closed-loop automated oxygen control systems could potentially reduce oxidant stress in the neonatal environment. Full article

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

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29 pages, 3761 KB

Open AccessReview

SHP2: A Redox-Sensitive Regulator Linking Immune Checkpoint Inhibitor Therapy to Cancer Treatment and Vascular Risk

by Silvia Fernanda López Moreno, Stefania Assunto Lenz, Bernardo Casso-Chapa, Angelica Paniagua-Bojorges, Jung Hyun Kim, Nicolas L. Palaskas, Kevin T. Nead, Venkata S. K. Samanthapudi, Gilbert Mejia, Oanh Hoang, Jonghae Lee, Steven H. Lin, Joerg Herrmann, Guangyu Wang, Syed Wamique Yusuf, Cezar A. Iliescu, Noah I. Beinart, Charlotte Manisty, Masuko Ushio-Fukai, Tohru Fukai, Pietro Ameri, Roza I. Nurieva, Michelle A. T. Hildebrandt, Keri Schadler, Efstratios Koutroumpakis, Sivareddy Kotla, Nhat-Tu Le and Jun-ichi Abe Show full author list Hide full author list

Antioxidants 2025, 14(12), 1388; https://doi.org/10.3390/antiox14121388 - 21 Nov 2025

Abstract

Src homology 2-domain containing protein tyrosine phosphatase 2 (SHP2), encoded by the Ptpn11 gene (Tyrosine-protein phosphatase non-receptor type 11), is a key downstream effector of PD-1/PD-L1 signaling and is likely important, in addition to immune modulation, in tumor development and vascular homeostasis. SHP2 [...] Read more.

Src homology 2-domain containing protein tyrosine phosphatase 2 (SHP2), encoded by the Ptpn11 gene (Tyrosine-protein phosphatase non-receptor type 11), is a key downstream effector of PD-1/PD-L1 signaling and is likely important, in addition to immune modulation, in tumor development and vascular homeostasis. SHP2 conveys PD-1 mediated inhibitory signaling in T cells, and is emerging as a therapeutic target. Importantly, there is an association between immune checkpoint inhibitors (ICIs), immune-related adverse events (irAEs), and cardiovascular complications, underscoring the need to understand SHP2’s role in these processes. This review aims to summarize current knowledge on SHP2/PTPN11 biology, its role in immune regulation, cancer progression, and vascular homeostasis, and to discuss emerging therapeutic strategies targeting this pathway. The concept of using SHP2 inhibitors with immune checkpoint inhibitors (ICIs) is being investigated to address ICI resistance and to improve anti-tumor efficacy substantially. SHP2 is also being studied in non-cancer cell contexts, and signaling responses can differ by large magnitudes depending on the biological context and stimuli. Under normal circumstances, SHP2 promotes vascular homeostasis in endothelial cells (ECs) and myeloid cells and inhibits inflammation, and the reduction in SHP2 activity by oxidative stress, such as in atherosclerosis or diabetes, upregulates inflammation. In contrast, in response to radiation, the fibrotic response and subsequent lung injury were increased by endothelial SHP2 induction via Notch-Jag1 signaling. Vascular smooth muscle cells SHP2 act as a pro-atherogenic effector by enhancing ERK/MAPK signaling, and the upregulation of mitochondria localized SHP2 can also induce cellular senescence-associated inflammation by upregulating mitochondrial reactive oxygen species. Taken together, the two opposite signaling effects of SHP2 suggest that both the immune and vascular system responses appear to be more modulated by the redox, cell, and compartment-specific signaling of SHP2. More studies are needed for mitigating cardiovascular toxicity to patients, particularly with ICI-based treatment regimens. Full article

(This article belongs to the Special Issue Modulation of Biochemical, Cellular and Physiological Mechanisms in Response to Oxidative Stress in Animals)

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16 pages, 4417 KB

Open AccessArticle

Sprouting Enhances Submergence Tolerance in Rice by Promoting Glutathione Biosynthesis and Turnover

by Mei Wang, Na Kuang, Ziyi Mao, Shangfeng Zhou, Zhixuan Liu, Ke Chen, Licheng Liu, Jingbo Xu, Lifeng Wang and Haoyu Lu

Antioxidants 2025, 14(12), 1387; https://doi.org/10.3390/antiox14121387 - 21 Nov 2025

Abstract

Submergence stress is a major constraint in direct-seeded rice production. This study investigated the effect and biochemical mechanism of sprouting, a traditional agronomic practice, on improving submergence tolerance in rice. Our findings demonstrate that sprouting is an effective seed treatment that significantly enhances [...] Read more.

Submergence stress is a major constraint in direct-seeded rice production. This study investigated the effect and biochemical mechanism of sprouting, a traditional agronomic practice, on improving submergence tolerance in rice. Our findings demonstrate that sprouting is an effective seed treatment that significantly enhances the plant’s ability to withstand flooding. Specifically, 48 h sprouting increased shoot height and root length by 163% and 423%, respectively, in the YLYJ48 variety under 6-day submergence. Sprouting upregulated the activity of glutathione reductase (GR) and the expression of its related genes, thereby significantly promoting the biosynthesis of glutathione (GSH). GSH content in seeds increased from 64.86 µg g⁻¹ FW (0 h) to 83.00 µg g⁻¹ FW (48 h) in HZ, and from 82.14 to 92.52 µg g⁻¹ FW in YLYJ48. This process provides critical antioxidant protection for seedlings to implement a rapid “escape strategy,” ultimately enhancing their submergence tolerance. Functional verification showed that seed soaking with exogenous GSH (0.1%) effectively improved submergence tolerance by increasing antioxidant reserves. Exogenous GSH treatment elevated shoot height by approximately 50% in both HZ and YLYJ48 varieties under submergence. Field trials further demonstrated that exogenous GSH application significantly enhanced seedling establishment rates by 30–35% and improved seedling growth traits under submergence tolerance stress across multiple rice varieties. This study reveals part of the mechanism by which sprouting enhances submergence tolerance by influencing glutathione metabolism, offering practical strategies for flood-resilient direct-seeded rice cultivation. Full article

(This article belongs to the Special Issue Antioxidant Defense in Mitigating Abiotic Stresses in Plants: Mechanisms, Innovations, and Applications)

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22 pages, 3109 KB

Open AccessArticle

Chlorogenic Acid Alleviates the Detrimental Effects of Concurrent Hyperglycemia and Chronic Stress on Brain Homeostasis by Modulating Antioxidative Defense in Adult Zebrafish

by Rhea Subba, Gianluca Fasciolo, Adriana Petito, Eugenio Geremia, Maria Teresa Muscari Tomajoli, Amal Chandra Mondal, Gaetana Napolitano and Paola Venditti

Antioxidants 2025, 14(12), 1386; https://doi.org/10.3390/antiox14121386 - 21 Nov 2025

Abstract

Oxidative stress is a key contributor to diabetes-related cognitive decline and is intensified by diabetes distress (DD), the psychological burden of disease management. DD lowers brain levels of nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that regulates antioxidant defense. This [...] Read more.

Oxidative stress is a key contributor to diabetes-related cognitive decline and is intensified by diabetes distress (DD), the psychological burden of disease management. DD lowers brain levels of nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that regulates antioxidant defense. This study examined whether chlorogenic acid (CGA), a polyphenolic NRF2 activator, could counteract oxidative and astroglial dysfunctions in adult zebrafish subjected to chronic unpredictable mild stress (CUMS) combined with dextrose, a model mimicking DD. Zebrafish were treated with CGA (50, 100, or 200 mg/kg), and the levels of NRF2 protein and mRNA, along with its regulator keap1, were quantified. Expression levels of key downstream antioxidant genes (sod1, sod2, catalase, glutathione peroxidase, and glutamate-cysteine ligase catalytic subunit) were assessed alongside glutathione (GSH) content and superoxide dismutase (SOD) and catalase activities. Astroglial integrity was evaluated via glial fibrillary acidic protein (GFAP) levels in the whole brain and stress-sensitive regions. CGA increased total brain NRF2 protein, its mRNA, and those of its downstream effectors. At 200 mg/kg, CGA restored GSH levels, boosted antioxidant enzyme activities, and mitigated DD-associated reductions in GFAP and NRF2 in stress-vulnerable areas. These findings identify NRF2 as a promising target to protect brain health under diabetic conditions. Full article

(This article belongs to the Special Issue Role of Mitochondria and ROS in Health and Disease—2nd Edition)

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20 pages, 1368 KB

Open AccessArticle

Phytochemistry and Biological Effects of the Juglans regia “Sorrento” Walnut Husk Extract on Human Keratinocyte Cells

by Giulia Vergine, Michela Ottolini, Giuseppe E. De Benedetto, Simona Bettini, Francesca Baldassarre, Daniele Vergara and Giuseppe Ciccarella

Antioxidants 2025, 14(12), 1385; https://doi.org/10.3390/antiox14121385 - 21 Nov 2025

Abstract

Plants are a valuable source of natural compounds with diverse applications. Recently, increased attention has focused on waste products from the agricultural industry, including walnut husk. Given its potential as a sustainable source of bioactives, this work characterizes the alcoholic Juglans regia “ [...] Read more.

Plants are a valuable source of natural compounds with diverse applications. Recently, increased attention has focused on waste products from the agricultural industry, including walnut husk. Given its potential as a sustainable source of bioactives, this work characterizes the alcoholic Juglans regia “Sorrento” walnut husk extract (WHE). The extract’s phenolic content, antioxidant activity, and phytochemical composition were evaluated using spectrophotometry and UHPLC-HRMS-based untargeted metabolomics analysis. WHE exhibited a high total phenolic content (TPC = 1.45 ± 0.03 mg GAE/g dry extract) and a rich profile of phenolic acids, flavonoids, and tannins. Given this composition, WHE’s biological activity was further tested in an in vitro human keratinocyte (HaCaT) model. At the concentration of 10 μg/mL, WHE showed no cytotoxicity and displayed significant antioxidant properties by modulating detoxifying proteins such as Nrf2. WHE also influenced mitochondrial metabolism, increased maximum respiration, preserved barrier integrity, and activated pathways for epithelial homeostasis. Overall, this study highlights the bioactivity of the J. regia “Sorrento” walnut husk extract. These findings support the valorization of walnut husk as a sustainable source of bioactives for dermatological and cosmetic products. Full article

(This article belongs to the Special Issue Antioxidant Phytochemicals for Promoting Human Health and Well-Being)

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21 pages, 3548 KB

Open AccessArticle

Anti-Inflammatory and Antioxidant Mechanisms of Dendrobium moschatum Polysaccharide in Intestinal Epithelial Cells via TLR4-NF-κB and Nrf2 Signaling Pathways

by Ji Chen, Chunyan Ma, Xu Mo, Linhong Li, Lijuan Wu, Chaowen Zhang, Rui Li, Yuanfeng Zou, Fan Liu and Mengliang Tian

Antioxidants 2025, 14(11), 1384; https://doi.org/10.3390/antiox14111384 - 20 Nov 2025

Abstract

Dendrobium moschatum neutral polysaccharide (DMP-NP) was isolated using a water extraction–ethanol precipitation method, followed by purification with DEAE-cellulose anion-exchange resin and a dextran gel column. The resulting DMP-NP1 exhibited a weight-average molecular weight of 16.23 kDa. The molar ratio of monosaccharides was as [...] Read more.

Dendrobium moschatum neutral polysaccharide (DMP-NP) was isolated using a water extraction–ethanol precipitation method, followed by purification with DEAE-cellulose anion-exchange resin and a dextran gel column. The resulting DMP-NP1 exhibited a weight-average molecular weight of 16.23 kDa. The molar ratio of monosaccharides was as follows: glucose–mannose–galactose–fucose–rhamnose = 78.54:19.11:1.59:0.53:0.23, with a glucose-to-mannose ratio of 4.1:1. Infrared spectroscopic analysis revealed characteristic carbohydrate absorption peaks and confirmed the presence of pyranosidic linkages. NMR analysis revealed that DMP-NP1 possesses a backbone mainly formed by 1→4 glycosidic linkages, a small number of 1→6 branches, and O-acetyl substitutions at the C2 and C3 positions of mannose residues. In vitro experiments demonstrated that treatment with 0–20 μg/mL (0–1.23 μM) DMP-NP significantly enhanced the activities of catalase (CAT) and superoxide dismutase (SOD) in IPEC-J2 cells, along with upregulation of the corresponding antioxidant genes. Concurrently, DMP-NP reduced the secretion of key pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, and downregulated the expression of genes associated with both antioxidant and inflammatory signaling pathways. Collectively, these findings indicate that DMP-NP not only prevents but also ameliorates LPS-induced inflammatory injury in intestinal epithelial cells, thereby providing a basis for the application of DMP-NP in intestinal inflammation mitigation. Full article

(This article belongs to the Section Health Outcomes of Antioxidants and Oxidative Stress)

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19 pages, 6628 KB

Open AccessArticle

Ammonia Stress Disrupts Intestinal Health in Litopenaeus vannamei Under Seawater and Low-Salinity Environments by Impairing Mucosal Integrity, Antioxidant Capability, Immunity, Energy Metabolism, and Microbial Community

by Yafei Duan, Yuxiu Nan, Jitao Li, Meng Xiao, Yun Wang and Ruijie Zhu

Antioxidants 2025, 14(11), 1383; https://doi.org/10.3390/antiox14111383 - 20 Nov 2025

Abstract

Ammonia is a key water quality factor limiting shrimp aquaculture. Intestinal health is closely associated with the nutrition, metabolism and immunity of shrimp. However, the response characteristics of the shrimp intestine to ammonia stress under seawater and low-salinity environments remain unclear. In this [...] Read more.

Ammonia is a key water quality factor limiting shrimp aquaculture. Intestinal health is closely associated with the nutrition, metabolism and immunity of shrimp. However, the response characteristics of the shrimp intestine to ammonia stress under seawater and low-salinity environments remain unclear. In this study, the shrimp Litopenaeus vannamei reared in seawater (salinity 30) or low-salinity (salinity 3) water were subjected to ammonia stress for 14 days, respectively. The changes in intestinal morphology, antioxidant capacity, immune response, energy metabolism, and microbial community were systematically investigated. The results showed that ammonia stress induced intestinal tissue damage in both seawater and low-salinity cultured shrimp, characterized by epithelial cell detachment and mucosal structural disruption. At the molecular level, ammonia stress triggered intestinal stress responses by interfering with key physiological processes such as antioxidant defense and endoplasmic reticulum stress. This process further led to varying degrees of disorders in physiological functions, including immune regulation, inflammatory response, and autophagic activity. In addition, ammonia stress disrupted the homeostatic balance of intestinal energy metabolism by affecting the expression of genes related to glucose metabolism, the tricarboxylic acid (TCA) cycle, and mitochondrial respiratory chain. In addition, ammonia stress increased the diversity of intestinal microbiota and caused microbial dysbiosis by increasing harmful bacteria (e.g., Vibrio) and decreasing beneficial bacterial groups (e.g., Bacillus). Ammonia stress generally enhanced intestinal microbiota chemotaxis. Specifically, predicted functions of microbiota in seawater-cultured shrimp showed increased carbohydrate, linoleic acid, and cofactor/vitamin metabolism; in low-salinity-cultured shrimp, functions including protein digestion/absorption, flavonoid/steroid hormone biosynthesis, and glycosaminoglycan degradation were reduced. These results revealed that ammonia stress compromised shrimp intestinal health by disrupting mucosal structure, triggering stress responses, and disturbing immune function, energy metabolism, and microbial homeostasis. Notably, low-salinity cultured shrimp exhibited more pronounced intestinal stress responses and greater physiological vulnerability than seawater-cultured counterparts. Full article

(This article belongs to the Special Issue Antioxidant Defenses and Oxidative Stress Management in Aquaculture)

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16 pages, 3413 KB

Open AccessArticle

Evaluation of Dexamethasone and Swimming Exercise as Complementary Interventions in a Rat Sciatic Nerve Injury Model

by Meral Karakoç, Hayat Ayaz, Ferhat Çelik and Fırat Aşır

Antioxidants 2025, 14(11), 1382; https://doi.org/10.3390/antiox14111382 - 20 Nov 2025

Abstract

Background: Peripheral nerve injuries frequently result in incomplete recovery despite advances in microsurgical repair. Both pharmacological and rehabilitative strategies have been investigated to enhance regeneration. Dexamethasone, a potent anti-inflammatory corticosteroid, and aerobic exercise, such as swimming, may promote repair through distinct but complementary [...] Read more.

Background: Peripheral nerve injuries frequently result in incomplete recovery despite advances in microsurgical repair. Both pharmacological and rehabilitative strategies have been investigated to enhance regeneration. Dexamethasone, a potent anti-inflammatory corticosteroid, and aerobic exercise, such as swimming, may promote repair through distinct but complementary mechanisms. Methods: A standardized rat sciatic nerve crush model was used to evaluate the effects of local dexamethasone administration (2 mg/kg/day, perineural for 10 days), swimming exercise (20 min/session, three times per week for 21 days), and their combination. Functional recovery was assessed by the Sciatic Functional Index (SFI), oxidative stress by MDA, GPX, and MPO assays, and structural recovery by histological, MBP immunohistochemical, and TEM analyses. Results: The injury group exhibited markedly elevated MDA and MPO levels and reduced GPX activity, indicating oxidative stress. Both dexamethasone and swimming exercise significantly improved these parameters, while the combination group showed values approaching controls (p < 0.001 for all comparisons vs. injury). Histological and immunohistochemical findings confirmed greater myelin preservation and higher MBP expression in treated groups, particularly in the combination group, whose g-ratio and myelin thickness were statistically indistinguishable from controls. SFI analysis revealed progressive motor improvement, with the combination therapy achieving near-normal function by day 28. Conclusions: This study demonstrates that dexamethasone and swimming exercise each contribute to peripheral nerve recovery and that their combined application provides additive benefits in terms of functional, biochemical, and structural regeneration. These results are limited to the specific dose and exercise regimen tested but support the potential of integrating anti-inflammatory pharmacotherapy with controlled physical exercise as a multimodal approach to enhance peripheral nerve repair. Full article

(This article belongs to the Special Issue Antioxidant Capacity of Natural Products—2nd Edition)

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22 pages, 5849 KB

Open AccessArticle

Hyperosmolarity-Induced Oxidative Stress Leads to Senescence in Human Corneal Epithelial Cells (HCEPC) via DNA Damage, Metabolic Disturbance and Mitophagy Decline

by Yongjie Zhang and Tingjun Fan

Antioxidants 2025, 14(11), 1381; https://doi.org/10.3390/antiox14111381 - 19 Nov 2025

Abstract

Background: Dry eye disease (DED), characterized by tear film hyperosmolarity, can lead to corneal epithelial damage. The mechanisms linking hyperosmotic stress to human corneal epithelial cell (HCEPC) damage are not fully understood. Methods: A DED model was established by exposing HCEPCs to sustained [...] Read more.

Background: Dry eye disease (DED), characterized by tear film hyperosmolarity, can lead to corneal epithelial damage. The mechanisms linking hyperosmotic stress to human corneal epithelial cell (HCEPC) damage are not fully understood. Methods: A DED model was established by exposing HCEPCs to sustained hyperosmotic stress (400 mOsm/L) over multiple passages in vitro. Senescence was assessed using senescence-associated-β-galactosidase (SA-β-gal) staining, 5-ethynyl-2′-deoxyuridine (EdU) assays, p16^INK4A and senescence-associated secretory phenotypes (SASP) analysis. Mechanisms were investigated by measuring reactive oxygen species (ROS), mitochondrial function, energy metabolism, DNA damage, and inflammatory signaling. The role of autophagy was probed pharmacologically. Results: Hyperosmotic stress induced HCEPC senescence, driven by mitochondrial dysfunction, oxidative stress, DNA damage, bioenergetic crisis, and compromised autophagy (especially mitophagy). Autophagy and mitophagy play a key role in regulating senescence progression. Enhancing autophagy with LYN-1604 ameliorated oxidative stress, improved energy homeostasis, and attenuated senescence. Inhibiting autophagy exacerbated these states. Conclusion: Hyperosmolarity promotes HCEPC senescence via mitochondrial dysfunction and oxidative damage. Autophagy serves a critical protective role, and its enhancement represents a promising therapeutic strategy for DED. Full article

(This article belongs to the Special Issue Oxidative Stress in Cell Senescence)

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23 pages, 1362 KB

Open AccessArticle

Functional and Metabolomic Analyses of Chamomile Jelly Derived from Gelatin Capsule Waste with Inulin and Polydextrose as Prebiotic Sugar Substitutes

by Sasina Sanprasert, Anurak Uchuwittayakul, Pudthaya Kumnerdsiri, Lalitphan Kitsanayanyong, Anusorn Seubsai, Jaksuma Pongsetkul, Kantiya Petsong, Supatra Karnjanapratum, Chalalai Jaisan, Samart Sai-ut, Saroat Rawdkuen and Passakorn Kingwascharapong

Antioxidants 2025, 14(11), 1380; https://doi.org/10.3390/antiox14111380 - 19 Nov 2025

Abstract

Jelly is a popular confectionery, and research increasingly focuses on nutritionally enhanced formulations. In this study, gelatin capsule waste was valorized as a natural gelling base for chamomile jelly, providing an innovative approach to upcycling food-grade waste into functional products. The effects of [...] Read more.

Jelly is a popular confectionery, and research increasingly focuses on nutritionally enhanced formulations. In this study, gelatin capsule waste was valorized as a natural gelling base for chamomile jelly, providing an innovative approach to upcycling food-grade waste into functional products. The effects of replacing sugar with inulin (INU) or polydextrose (PDX) (25–100%) on chemical, physical, and sensory properties were investigated. Sugar replacement decreased carbohydrate content while increasing ash and fat, slightly increased turbidity, and reduced lightness (L*) and yellowness (b*). Gels with inulin and polydextrose exhibited higher gel strength (55.97–81.45 g) and hardness (9.77–10.20 N) than the control, whereas antioxidant activity remained largely unaffected. Among the formulations, 50% inulin (INU-50) received the highest consumer acceptance score (6.88 ± 1.05) and maintained stable quality during 21 days at 4 °C, with decreased free water content and increased gel strength. INU-50 jelly supplied essential nutrients, was cholesterol-free, and promoted Lactobacillus plantarum growth, supported by metabolomic analysis. Overall, this study demonstrates the potential of chamomile jelly with inulin substitution as a functional, health-promoting product and highlights a novel, sustainable approach to valorize gelatin capsule waste for modern health-conscious consumers. Full article

(This article belongs to the Special Issue From Waste to Health: Upcycling Agrifood By-Products into Functional Antioxidant-Rich Ingredients and Products)

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17 pages, 1029 KB

Open AccessArticle

Effect of Long-Term Storage Temperature on the Quality of Extra-Virgin Olive Oil (Coratina cv.): A Multivariate Discriminant Approach

by Pasquale Crupi, Maria Lisa Clodoveo, Addolorata Desantis, Roberta Zupo and Filomena Corbo

Antioxidants 2025, 14(11), 1379; https://doi.org/10.3390/antiox14111379 - 19 Nov 2025

Abstract

Kinetic evolution of quality parameters in 21 extra-virgin olive oils (EVOOs) from Coratina cultivar was evaluated during 18 months of dark storage at room temperature (RT) and 4 °C (LT). The aim was to identify the most discriminating variables—fatty acids, peroxide value, spectrophotometric [...] Read more.

Kinetic evolution of quality parameters in 21 extra-virgin olive oils (EVOOs) from Coratina cultivar was evaluated during 18 months of dark storage at room temperature (RT) and 4 °C (LT). The aim was to identify the most discriminating variables—fatty acids, peroxide value, spectrophotometric indices, and phenolic compounds—using kinetic analysis and multivariate statistics. Fatty acids remained stable, while peroxide value and ultraviolet absorbance indices increased significantly at RT, following zero-order kinetics. Polyphenols declined markedly after 6 months, especially at RT, with degradation rates influenced by initial concentrations. Hydroxytyrosol and tyrosol followed pseudo-zero-order kinetics, whereas secoiridoids and lignans followed second-order kinetics. Discriminant analysis achieved 90% accuracy (p = 0.000012) in classifying oils by storage condition. The most relevant discriminants were associated with phenolic degradation and oxidative changes. These findings support the importance of low-temperature storage in preserving the biochemical quality and shelf life of EVOOs. Full article

(This article belongs to the Topic Natural Bioactive Compounds as a Promising Approach to Mitigating Oxidative Stress)

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15 pages, 1384 KB

Open AccessArticle

Superoxide Dismutase 3 Deficiency Disrupts the Regulation of Oxidative Stress Caused by Polystyrene Nanoplastics

by Yugyeong Sim, Jin-Hyoung Kim, Jeong-Soo Lee, Jinyoung Jeong and Hyun-Ju Cho

Antioxidants 2025, 14(11), 1378; https://doi.org/10.3390/antiox14111378 - 19 Nov 2025

Abstract

Nanoplastics have been recognized as emerging pollutants posing potential risks to ecosystems and human health. They are now detected ubiquitously in the environment and even human tissues, where their small size allows for tissue accumulation and cellular penetration. Growing evidence links nanoplastics to [...] Read more.

Nanoplastics have been recognized as emerging pollutants posing potential risks to ecosystems and human health. They are now detected ubiquitously in the environment and even human tissues, where their small size allows for tissue accumulation and cellular penetration. Growing evidence links nanoplastics to oxidative stress, yet the specific contribution of extracellular accumulation to toxicity remains poorly understood. To address this, we used zebrafish, a transparent vertebrate model suitable for toxicological studies, to explore the role of extracellular antioxidant defenses in polystyrene nanoplastic (PSNP)-induced oxidative stress. In particular, we focused on superoxide dismutase 3 (SOD3), which is an enzyme that regulates extracellular reactive oxygen species by catalyzing the detoxification of superoxide radicals. Zebrafish Sod3a is a homolog of human SOD3, preserving conserved metal-binding sites critical for enzymatic function. We established sod3a mutant zebrafish and examined their responses following PSNP exposure. In sod3a mutant larvae, tissue accumulation of PSNPs was higher than in wild-type (WT), and this was associated with elevated oxidative stress, enhanced cell death, and abnormalities in intestinal function and immune responses. Collectively, these observations reveal the functional importance of SOD3 during PSNP-induced oxidative stress and provide new insight into extracellular antioxidant mechanisms that mitigate PSNP-induced toxicity. Full article

(This article belongs to the Special Issue Oxidative Stress Induced by Micro(Nano)plastics)

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