Search Results (833)

Background/Objectives: Oats and oat bran are rich in polyphenols and soluble fiber, which are metabolized by gut microbiota into bioactive compounds. Previous studies identified ursodeoxycholic acid (UDCA), 3-(3-hydroxyphenyl)propionic acid (3-HPP), and avenanthramide C (AVC) as key microbial metabolites with protective effects against colitis. Methods: This study aimed to elucidate their antioxidant and anti-inflammatory activities and underlying mechanisms using LPS-induced RAW 264.7 macrophages and AAPH-induced oxidative stress in zebrafish embryos. All three metabolites significantly reduced intracellular reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA), and pro-inflammatory cytokines (IL-6, TNF-α). They also restored mitochondrial membrane potential and enhanced superoxide dismutase (SOD) activity. Results:In vivo, treatment improved zebrafish survival, normalized SOD activity to 76–89% of control levels, and decreased ROS and MDA by 2.4 to 3.8 fold, with UDCA showing the greatest efficacy. Molecular docking revealed strong binding affinities to Keap1, particularly UDCA, which interacted with residues Met577, Ala440, Val532, and Val486. qRT-PCR further demonstrated downregulation of Keap1 and upregulation of Nrf2 and SOD, indicating activation of the Keap1-Nrf2 pathway. Conclusions: Collectively, these findings show that oats and bran-derived microbial metabolites exert potent antioxidant and anti-inflammatory effects via modulation of the Keap1-Nrf2 axis. Among the metabolites, UDCA exhibited the strongest biological activity at equivalent concentrations. This study provides mechanistic insight into how microbiota-derived oat metabolites contribute to redox balance and immune regulation, supporting their potential as functional components in dietary strategies for managing oxidative stress-related inflammatory diseases. Full article

The Keap1-Nrf2 signaling pathway is a central regulator of transcriptional responses to oxidative stress and is strongly linked to diverse pathologies, particularly cancer. In the cytoplasm, Keap1 (Kelch-like ECH-associated protein 1) promotes proteasomal degradation of Nrf2 (NF-E2–related factor 2). Oxidative stimuli disrupt the Keap1-Nrf2 interaction, facilitating Nrf2 nuclear accumulation and activation of antioxidant and detoxifying genes. Recent evidence suggests that Keap1 family proteins also enter the nucleus, bind chromatin, and regulate transcription, but the underlying mechanisms remain less understood. Here, we show that the Drosophila Keap1 ortholog, dKeap1, accumulates in the nucleus and gradually assembles stable nuclear foci in cells following oxidative treatment. FRAP analyses revealed reduced mobility of dKeap1 within these foci. Both the N-terminal (NTD) and C-terminal (CTD) domains of dKeap1 were required for foci formation. Two intrinsically disordered regions (IDRs) were identified within the CTD, and CTD-YFP fusion proteins readily formed condensates in vitro. Conversely, deletion of the Kelch domain resulted in robust cytoplasmic foci even under basal conditions, and in vitro assays also indicated that the Kelch domain suppresses dKeap1 condensate formation. Together, these findings reveal a novel molecular mechanism for the nuclear function of dKeap1, providing new insight into the broader roles of Keap1 factors in oxidative response, development, and disease. Full article

Oxidative stress (OS) is a major cause of defective sperm function. During laboratory handling, gametes are exposed to OS, potentially mitigated by in vitro antioxidant supplementation. This study evaluates the protective role of caffeic acid (CAF) on basal human semen and under induced OS. First, six semen samples from normozoospermic donors were incubated with CAF concentrations ranging from 50 to 500 µM at 37 °C for 2 h. Sperm motility and DNA integrity (acridine orange) were evaluated. Then, ten semen samples were divided into four aliquots and incubated, respectively, with CAF at 100 µM, H₂O₂ at 2 mM, or H₂O₂ at 2 mM + CAF at 100 µM, or untreated. Motility, DNA integrity, acrosome status (Pisum sativum agglutinin), OS quantified by F₂-isoprostanes (ELISA), and expression of Nrf2, Keap1, and HO-1 (qRT-PCR) were assessed. CAF at 100 µM improved progressive motility without damaging DNA and was selected for subsequent experiments. CAF showed protective effects on sperm damage induced by H₂O₂ treatment, restoring motility, DNA integrity, and acrosome status and reducing F₂-isoprostane levels. Nrf2 and HO-1 expression were upregulated by CAF, downregulated by H₂O₂, and restored by the co-treatment. CAF supplementation may protect human spermatozoa during in vitro handling by reducing OS, improving several sperm parameters, with a possible mechanism of action involving the Nrf2 pathway. Full article

Adipose tissue thermogenesis is a promising strategy to counter obesity and metabolic disease, but sustained activation of thermogenic adipocytes elevates oxidative and lipid-peroxidation stress, increasing susceptibility to ferroptotic cell death. Existing models often treat redox buffering, hypoxia signaling and ferroptosis as separate processes, which cannot explain why similar interventions—such as antioxidants, β-adrenergic agonists or iron modulators—alternately enhance thermogenesis or precipitate tissue failure. Here, we propose the Redox–Thermogenesis–Ferroptosis Compass (RTF-Compass) as a framework that maps adipose depots within a space defined by ferroptosis resistance capacity (FRC), ferroptosis signaling intensity (FSI) and HIF-1α-dependent hypoxic tone. Within this space, thermogenic output follows a hormetic, inverted-U trajectory, with a Thermogenic Ferroptosis Window (TFW) bounded by two failure states: a Reductive-Blunted state with excessive antioxidant buffering and weak signaling, and a Cytotoxic state with high ferroptotic pressure and inadequate defense. We use this model to reinterpret genetic, nutritional and pharmacological studies as state-dependent vectors that move depots through FRC–FSI–HIF space and to outline principles for precision redox medicine. Although the TFW is represented as coordinates in FRC–FSI–HIF space, we use ‘Compass’ to denote a coordinate framework in which perturbations act as vectors that orient depots toward thermogenic or cytotoxic outcomes. Finally, we highlight priorities for testing the model in vivo, including defining lipid species that encode ferroptotic tone, resolving spatial heterogeneity within depots and determining how metabolic memory constrains reversibility of pathological states. Full article

This review summarizes the role of nuclear factor erythroid 2–related factor 2 (Nrf2) as a common link between aging, neurodegeneration, and neuropathic pain. Aging is characterized by oxidative stress and constant inflammation, which coincides with reduced Nrf2 activity and weaker antioxidant responses, increasing vulnerability to diseases. In neurodegenerative disorders—including Alzheimer’s, Parkinson’s, Huntington’s disease, and amyotrophic lateral sclerosis—evidence indicates that impaired Nrf2 signaling contributes to oxidative damage, neuroinflammation, and mitochondrial dysfunction. Furthermore, in neuropathic pain, similar mechanisms are involved, and Nrf2 could play a role as a potential analgesic target because of its role in regulating cellular defense pathways. We also review natural Nrf2 modulators (e.g., flavonoids, other polyphenols, terpenoids, alkaloids), discussing their benefits alongside common translational limitations such as poor solubility, low oral bioavailability, rapid metabolism, and potential safety issues, including possible pro-oxidant effects and chemoresistance. We also outline future directions that should prioritize improving delivery systems, addressing NRF2/KEAP1 gene variations, evaluating combinations with standard therapies, exploring preventive applications, and defining dosing, treatment duration, and long-term safety. Overall, current evidence indicates that Nrf2 modulation is a practical, cross-cutting approach relevant to healthy aging and disease management. Full article

Background: Acacetin, a naturally occurring flavone present in various plants, is known as a promising drug candidate for cardiovascular disorders. Our previous study demonstrated that acacetin ameliorates atherosclerosis through endothelial cell protection; however, its pharmacological effects on vascular smooth muscle cells (VSMCs) remain unexplored. This study investigates the therapeutic potential of acacetin against lysophosphatidylcholine (LysoPC)-induced VSMC injury and elucidates the underlying molecular mechanisms. Methods and Results: Multiple biochemical techniques were employed in the present study. The results showed that acacetin significantly attenuated LysoPC-induced apoptosis and reactive oxygen species (ROS) generation in cultured VSMCs. Western blot analysis revealed that the cytoprotection of acacetin was associated with upregulated expression of antioxidant defense proteins, including nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), NADPH quinone oxidoreductase 1 (NQO-1), and superoxide dismutase 1 (SOD1). Nrf2 silencing completely abolished these protective effects. Mechanistically, siRNA-silencing of Sirtuin 1 (Sirt1) abrogated acacetin-induced modulation of the Nrf2/Keap1/p62 signaling. In vivo validation using aortic tissues from high-fat-diet-fed ApoE^−/− mice confirmed that acacetin effectively suppressed VSMC apoptosis and ROS overproduction associated with restoring the downregulated Sirt1 expression levels. Conclusions: These findings establish a novel mechanistic paradigm wherein acacetin confers protection against LysoPC-induced VSMC apoptosis and oxidative stress through Sirt1-dependent activation of the Nrf2/p62 signaling pathway, suggesting that acacetin is a promising therapeutic drug candidate for atherosclerotic plaque stabilization. Full article

In today’s world, unhealthy living habits have contributed to the rise in metabolic disorders like hyperlipidemia. Recognized as a popular edible and medicinal mushroom in China and various eastern nations, Ganoderma lucidum is a promising high-value functional and medicinal food with multiple biological activities. Our earlier research has demonstrated that G. lucidum polysaccharides (GLP) showed distinct lipid-lowering abilities by enhancing the response to oxidative stress and inflammation, adjusting bile acid production and lipid regulation factors, and facilitating reverse cholesterol transport through Nrf2-Keap1, NF-κB, LXRα-ABCA1/ABCG1, CYP7A1-CYP27A1, and FXR-FGF15 pathways, hence we delved deeper into the effects of GLP on hyperlipidemia, focusing on its structural characterization, gut microbiota, and fecal metabolites. Our findings showed that GLP changed the composition and structure of gut microbiota, and 10 key biomarker strains screened by LEfSe analysis markedly increased the abundance of energy metabolism, and cell growth and death pathways which were found by PICRUSt2. In addition, GLP intervention significantly altered the fecal metabolites, which enriched in amino acid metabolism and lipid metabolism pathways. The results of structural characterization showed that GLP, with the molecular weight of 12.53 kDa, consisted of pyranose rings and was linked by α-type and β-type glycosidic bonds, and its overall morphology appeared as an irregular flaky structure with some flecks and holes in the surface. Collectively, our study highlighted that the protective effects of GLP were closely associated with the modification of gut microbiota and the regulation of metabolites profiles, thus ameliorating dyslipidemia. Full article

Periodontitis is a chronic non-communicable inflammatory disease in which oxidative stress plays an important role in tissue destruction and alveolar bone loss. Excessive production of reactive oxygen species disrupts redox homeostasis, activates inflammatory signaling pathways, and promotes regulated cell death processes such as pyroptosis and ferroptosis. The Nrf2/Keap1 pathway is a key regulator of antioxidant defense and cellular adaptation to redox imbalance. Impaired Nrf2 signaling has been associated with enhanced oxidative injury, NF-κB and NLRP3 inflammasome activation, osteoclast-driven bone resorption, and reduced regenerative capacity in periodontal tissues. Experimental studies suggest that Nrf2 activation can restore the redox balance and attenuate inflammation and bone destructive responses in a periodontal model. Moreover, therapeutic approaches involving phytochemicals, microbial-derived metabolites, and redox-responsive biomaterials have been reported to influence Nrf2-related signaling in experimental settings. However, the majority of the available evidence is derived from in vitro or animal studies, and the relevance of these findings to clinical periodontitis remains to be established. This review summarizes the current advances linking oxidative stress, redox signaling, cell death pathways, and bone remodeling with Nrf2 dysfunction in periodontitis and outlines the key mechanistic insights while highlighting the existing knowledge gaps. Full article

Alcoholic liver injury (ALI) is a major global public health issue, with oxidative stress imbalance as its core pathological mechanism. The Kelch-like ECH-associated protein 1–nuclear factor erythroid 2-related factor 2–heme oxygenase-1/glutathione peroxidase 4 signaling pathway (Keap1–Nrf2–HO-1/GPX4) signaling pathway is a key target for regulating hepatic antioxidant defense. This study integrated Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS), Global Natural Products Social Molecular Networking (GNPS) molecular networking, network pharmacology, and animal experiments to systematically explore the hepatoprotective effect and mechanism of Cornus officinalis yeast-fermentation (COF). Component characterization identified 25 bioactive components, including flavonoids, triterpenic acids, and other fermentation-derived metabolites. Network pharmacology identified 441 common targets and 36 core targets of COF and ALI, which were enriched in oxidative stress regulation, inflammatory response, and the Keap1–Nrf2 pathway via Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Molecular docking showed that icariin and other components had stable interactions with Keap1 and Nrf2 (binding energy < −5 kcal/mol). Animal experiments confirmed that COF reduced the liver index of ALI mice, downregulated serum Alanine Aminotransferase (ALT)/Aspartate Aminotransferase (AST) activities, and ameliorated liver pathological damage. Western blot verified that COF inhibited Keap1 expression, promoted Nrf2 nuclear translocation, and upregulated HO-1/GPX4 expression. In conclusion, COF alleviates hepatic oxidative stress by regulating the Keap1–Nrf2–HO-1/GPX4 pathway, providing a scientific basis for its development as a functional food or candidate drug against ALI and a technical paradigm for fermentation-enhanced medicinal plant research. Full article

Oxidative stress contributes to brain aging processes and is implicated in related functional decline. Developing strategies to mitigate oxidative stress is therefore of significant interest. In this study, a neutral polysaccharide (GBPN) was isolated from ginseng berry. Structural analysis revealed that GBPN (molecular weight 1.52 × 10⁴ Da) is primarily composed of glucose (53.18%), arabinose (24.3%), and galactose (16.75%). Glucose exists in the forms of →4)-Glcp-(1→ (32.95%), →6)-Glcp-(1→ (13.81%), and →4,6)-Glcp-(1→ (3.70%), while arabinose exists as →1)-Araf (9.73%), →1)-Arap (5.82%), →2)-Arap-(1→ (0.66%), →5)-Araf-(1→ (7.62%), and →3,5)-Araf-(1→ (1.69%) forms, while galactose exists in the forms of →1)-Galp (3.58%), →3)-Galp-(1→ (1.59%), and →3,6)-Galp-(1→ (12.67%). GBPN adopts a triple-helix conformation and exhibits a curled lamellar appearance. Functionally, GBPN exhibited strong 2,2-diphenyl-1-picrylhydrazyl radical, hydroxyl radical scavenging activity, and iron ion chelation capacity. It can activate the antioxidant system in D-galactose-induced aging-like mice, and simultaneously enhance their learning and memory abilities. Mechanistic analysis revealed that these effects are associated with the kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 pathway. These findings suggest that ginseng berry polysaccharides like GBPN hold promise as potential agents for alleviating oxidative stress and cognitive deficits in aging-related contexts. Full article

The microglia, first identified by Pío del Río-Hortega, are resident macrophages in the CNS that aid in immune monitoring, synaptic remodeling, and tissue repair. Microglial biology’s dual functions in maintaining homeostasis and contributing to neurodegeneration are examined in this review, with a focus on neurodegenerative disease treatment targets. Methods: We reviewed microglial research using single-cell transcriptomics, molecular genetics, and neuroimmunology to analyze heterogeneity and activation states beyond the M1/M2 paradigm. Results: Microglia maintains homeostasis through phagocytosis, trophic factor production, and synaptic pruning. They acquire activated morphologies in pathological conditions, releasing proinflammatory cytokines and reactive oxygen species via NF-κB, MAPK, and NLRP3 signaling. Single-cell investigations show TREM2 and APOE-expressing disease-associated microglia (DAM) in neurodegenerative lesions. Microglial senescence, mitochondrial failure, and chronic inflammation result from Nrf2/Keap1 redox pathway malfunction in ageing. Microglial interactions with astrocytes via IL-1α, TNF-α, and C1q result in neurotoxic or neuroprotective A2 astrocytes, demonstrating linked glial responses. Microglial inflammatory or reparative responses are influenced by epigenetic and metabolic reprogramming, such as regulation of PGC-1α, SIRT1, and glycolytic flux. Microglia are essential to neuroprotection and neurodegeneration. TREM2 agonists, NLRP3 inhibitors, and epigenetic modulators can treat chronic neuroinflammation and restore CNS homeostasis in neurodegenerative illnesses by targeting microglial signaling pathways. Full article

Oxidative stress is a defining feature of stroke pathology, but the magnitude, timing and impact of redox imbalance are not static. Emerging evidence indicates that physiological contexts, such as aging, metabolic stress, and circadian disruption, continuously reshape oxidative status and determine the brain’s vulnerability to ischemic and reperfusion injury. This review integrates recent insights into how these intrinsic modulators govern the transition from adaptive physiological redox signaling to pathological oxidative stress during stroke. Aging compromises mitochondrial quality control and blunts NRF2-driven antioxidant responses, heightening susceptibility to ROS-driven damage. Metabolic dysfunction, as seen in obesity and diabetes, amplifies oxidative burden through NADPH oxidase activation, lipid peroxidation, and impaired glutathione recycling, further aggravating post-ischemic inflammation. Circadian misalignment, meanwhile, disrupts the rhythmic expression of antioxidant enzymes and metabolic regulators such as BMAL1, REV-ERBα, and SIRT1, constricting the brain’s temporal window of resilience. We highlight convergent signaling hubs, NRF2/KEAP1, SIRT–PGC1α, and AMPK pathways, as integrators of these physiological inputs that collectively calibrate redox homeostasis. Recognizing oxidative stress as a dynamic, context-dependent process reframes it from a static pathological state to a dynamic outcome of systemic and temporal imbalance, offering new opportunities for time-sensitive and metabolism-informed redox interventions in stroke. Full article

Oxidative stress arises from an imbalance between reactive oxygen species (ROS) and antioxidant defense mechanisms and disrupts the structural integrity of macromolecules such as lipids, proteins, and DNA. This biochemical imbalance triggers the pathogenesis of cardiovascular and neurodegenerative diseases and leads to lipid oxidation and quality degradation in food systems. Plant-derived bioactive compounds (BACs) such as polyphenols and terpenes develop versatile molecular strategies to mitigate this oxidative damage. In addition to their direct radical scavenging effects, polyphenols stimulate the synthesis of endogenous antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) by activating the Nrf2–Keap1 signaling pathway. Terpenes, on the other hand, create a specialized protective shield in lipid-based matrices through “chain-breaking” reactions and a “slingshot” mechanism that externally halts the oxidation of γ-terpinene. In food engineering applications, these compounds meet the demand for “clean-label” products by providing alternatives to synthetic antioxidants such as BHA and BHT. Specific terpenes, such as carnosic acid, demonstrate higher performance in inhibiting lipid oxidation compared to their synthetic counterparts. Although BAC use extends the shelf life of products while maintaining color and flavor stability, potential interactions with protein digestibility necessitate dosage management. From a clinical perspective, these compounds suppress inflammatory responses by inhibiting the NF-κB pathway and contribute to the prevention of chronic diseases by modulating the gut microbiota. This review evaluates the capacity of BACs to manage oxidative stress in food preservation technologies and human health through a mechanistic and application-based approach. Full article

Essential oils (EOs) are complex volatile mixtures that exhibit antioxidant activity through both chemical and biological pathways. Phenolic constituents act as efficient chain-breaking radical-trapping antioxidants, whereas some non-phenolic terpenes operate through distinct mechanisms. Notably, γ-terpinene functions via a “radical export” pathway, generating hydroperoxyl radicals that intercept lipid peroxyl radicals and accelerate chain termination. Recent methodological advances, such as inhibited autoxidation kinetics, oxygen-consumption assays, and fluorescence-based lipid peroxidation probes, have enabled more quantitative evaluation of these activities. Beyond direct radical chemistry, EOs also regulate redox homeostasis by modulating signaling networks such as Nrf2/Keap1, thereby activating antioxidant response element–driven enzymatic defenses in cell and animal models. Phenolic constituents and electrophilic compounds bearing an α,β-unsaturated carbonyl structure may directly activate Nrf2 by modifying Keap1 cysteine residues, whereas non-phenolic terpenes likely depend on oxidative metabolism to form active electrophilic species. Despite broad evidence of antioxidant efficacy, molecular characterization of EO–protein interactions remains limited. This review integrates radical-chain dynamics with redox signaling biology to clarify the mechanistic basis of EO antioxidant activity and to provide a framework for future research. Full article

Skin aging is driven largely by oxidative stress, chronic inflammation, and mitochondrial dysfunction, processes closely linked to cellular senescence and declining NRF2 activity. Numerous dietary phytochemicals—such as curcumin (from turmeric), resveratrol (from grapes), sulforaphane (from cruciferous vegetables), zerumbone, and salvianolic acid B—abundant in fruits, vegetables, herbs, and traditional food sources, exhibit potent antioxidant and anti-inflammatory properties. This review systematically elucidates the molecular mechanisms by which these compounds mitigate skin aging, primarily through modulating the NRF2 signaling pathway. We further integrate insights from clinical trials of NRF2-targeting agents to inform the translational potential of these dietary bioactives. Molecular docking analyses confirm that these food-derived compounds interact directly with the KEAP1-NRF2 complex, promoting NRF2 activation. Transcriptomic analyses of skin-related datasets (GSE35160, GSE71910, GSE185129) further validate the downregulation of key NRF2-regulated cytoprotective genes (e.g., FTH1, FTL, HMOX1, SLC7A11) involved in antioxidant defense and the suppression of pro-inflammatory mediators. Based on this mechanistic foundation, we discuss the translational potential of these food-derived bioactives and the rationale for their future incorporation into skin-health-promoting nutraceuticals. We highlight how these food-derived phenolics and other bioactives may be incorporated into functional foods or nutraceuticals to support skin health from within, offering a dietary strategy to delay aging. We acknowledge that key translational challenges, such as oral bioavailability and optimal formulation, require further investigation. Further research is warranted to bridge these mechanistic insights into effective human applications. Full article