Search Results (465)

Red blood cells (RBCs) are uniquely vulnerable to oxidative stress due to their role in O₂ transport and their high content of heme iron and polyunsaturated fatty acids (PUFAs). Despite lacking nuclei and organelles, RBC homeostasis relies on a finely tuned redox system to preserve membrane integrity, cytoskeletal organization, and metabolic function. Impairment of this delicate balance results in a series of oxidative events that ultimately leads to the premature clearance of RBCs from the bloodstream. This review outlines the main oxidative mechanisms that affect RBC at different levels, such as membrane, cytoskeleton, and intracellular environment, with a focus on the molecular targets of reactive species. The role of major antioxidant systems in preventing or reversing redox damage will also be examined, revealing their multiple mechanisms of action ranging from direct ROS scavenging to the enhancement of endogenous antioxidant defense pathways. Redox regulatory mechanisms in RBCs are required to maintain membrane integrity, cytoskeletal organization, and metabolic function. Disruption of these processes causes several oxidative processes that trigger premature RBC removal. Cumulative evidence places oxidative stress at the core of RBC dysfunction in both physiological aging and pathological conditions, including diabetes, inflammatory conditions, and hemolytic disorders. Antioxidant-based strategies, rather than providing generalized protection, should aim to selectively target the specific molecular pathways affected in distinct clinical settings. Full article

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought to light unexpected complications beyond respiratory illness, including effects on kidney function and a potential link to kidney stone disease (KSD). This review proposes a novel framework connecting COVID-19-induced epigenetic reprogramming to disruptions in mitochondrial sulfur metabolism and the pathogenesis of kidney stones. We examine how SARS-CoV-2 interferes with host methylation processes, leading to elevated homocysteine (Hcy) levels and impairment of the trans-sulfuration pathway mechanisms particularly relevant in metabolic disorders such as homocystinuria. These epigenetic and metabolic alterations may promote specific kidney stone subtypes through disrupted sulfur and oxalate handling. Additionally, we explore the role of COVID-19-associated gut dysbiosis in increasing oxalate production and driving calcium oxalate stone formation. Together, these pathways may accelerate the transition from acute kidney injury (AKI) to chronic KSD, linking viral methylation interference, sulfur amino acid imbalance, mitochondrial dysfunction, and microbiota changes. Unlike earlier reviews that address these mechanisms separately, this work offers an integrated hypothesis to explain post-viral renal lithogenesis and highlights the potential of targeting sulfur metabolism and redox pathways as therapeutic strategies for KSD triggered or aggravated by viral infections such as COVID-19. Full article

Cellular senescence, a state of permanent cell cycle arrest, represents a double-edged sword in biology—providing tumor-suppressive functions while contributing to tissue degeneration, chronic inflammation, and age-related diseases when senescent cells persist. A key driver of senescence is oxidative stress, primarily mediated by excessive reactive oxygen species that damage mitochondrial DNA, modulate redox-sensitive signaling pathways, and trigger the senescence-associated secretory phenotype. Emerging evidence highlights the pathogenic role of SASP in promoting local inflammation, immune evasion, and senescence propagation. This review explores the intricate interplay between redox imbalance and cellular senescence, emphasizing mitochondrial dysfunction, SASP dynamics, and their implications in aging and cancer. We discuss current senotherapeutic strategies—including senolytics, senomorphics, antioxidants, gene therapy, and immunotherapy—that aim to eliminate or modulate senescent cells to restore tissue homeostasis. Understanding the heterogeneity and context-specific behavior of senescent cells remains crucial for optimizing these therapies. Future research should focus on addressing key knowledge gaps, including the standardization of senescence biomarkers such as circulating miRNAs, refinement of predictive preclinical models, and development of composite clinical endpoints. These efforts are essential to translate mechanistic insights into effective senotherapeutic interventions and enable the safe integration of senescence-targeting strategies into routine clinical practice. Full article

Eriobotrya japonica (Thunb.) Lindl. leaves are rich in polyphenolic compounds, yet their toxicological effects in aquatic models remain poorly understood. This study evaluated the impact of a hydroethanolic E. japonica leaf extract on zebrafish embryos through the use of morphological, behavioral, and biochemical parameters. The 96 h LC₅₀ was determined as 189.8 ± 4.5 mg/L, classifying the extract as practically non-toxic, according to OECD guidelines. Thereby, embryos were exposed for 90 h to 75 and 150 mg/L concentrations of the E. japonica leaf extract. While no significant effects were noted at the lowest concentration of 150 mg/L, significant developmental effects were observed, including reduced survival, delayed hatching, underdevelopment of the swim bladder, and retention of the yolk sac. These malformations were accompanied by marked behavioral impairments. Biochemical analysis revealed a concentration-dependent increase in superoxide dismutase (SOD) and catalase (CAT) activity, suggesting the activation of antioxidant defenses, despite no significant change in reactive oxygen species (ROS) levels. This indicates a potential compensatory redox response to a pro-oxidant signal. Additionally, the acetylcholinesterase (AChE) activity was significantly reduced at the highest concentration, which may have contributed to the observed neurobehavioral changes. While AChE inhibition is commonly associated with neurotoxicity, it is also a known therapeutic target in neurodegenerative diseases, suggesting concentration-dependent dual effects. In summary, the E. japonica leaf extract induced concentration-dependent developmental and behavioral effects in zebrafish embryos, while activating antioxidant responses without triggering oxidative damage. These findings highlight the extract’s potential bioactivity and underscore the need for further studies to explore its safety and therapeutic relevance. Full article

This study investigated the effects of six cap management protocols targeting contrasting oxidation-reduction potential (ORP) evolutions during alcoholic fermentation of Pinot noir wines. Treatments included twice-daily punch-downs (PD) and pump-overs (PO), 1 h air or N₂ injections (AirMix, N₂Mix), air injections triggered by ORP ≤ −40 mV (RedoxConAir), and equal N₂ injections concurrent to RedoxConAir wines (RedoxConN₂). AirMix wines maintained ORP values above 0 mV throughout fermentation, showed an oxidatively favored glutathione-to-glutathione disulfide ratio (GSH:GSSG) of 0.3:1, and had 21% lower total phenolics and 24% lower anthocyanins than PD wines. In contrast, N₂Mix wines maintained the lowest ORP, near −100 mV, and showed a reductively favored GSH:GSSG ratio (7:1). PD wines extracted 48% more flavan-3-ols than PO wines, consistent with greater berry integrity disruption and seed submersion. Volatile composition was also impacted: ethyl n-octanoate showed the highest OAV among esters, ranging from 147 in PO wines to 116 in AirMix wines. Results suggest the GSH:GSSG ratio served as an indicator of redox history, with potential implications for color and aroma preservation during aging. Inert gas mixings resulted in equal or greater total phenolic content, while excessive air injections may provide a tool to soften astringency. Full article

The increasing threat of antimicrobial resistance (AMR), along with the limited availability of new lead compounds in the drug development pipeline, highlights the urgent need to discover antimicrobial agents with innovative mechanisms of action. In this regard, metal complexes offer a unique opportunity to access mechanisms distinct from those of conventional antibiotics. Although iron (Fe) is an essential element for all forms of life, including pathogenic bacteria, it also poses a serious risk of cytotoxicity due to its redox activity, which can trigger the production of reactive oxygen species (ROS) via the Fenton reaction. This review highlights recent advances in the development of iron-based antimicrobial agents that harness the toxicity resulting from dysregulated iron uptake, thereby inducing bacterial cell death through oxidative stress. These findings may guide the development of effective treatments for pathogenic infections and offer new perspectives on leveraging redox chemistry of iron to combat the growing threat of global bacterial resistance. Full article

Oxysterols such as 7-ketocholesterol (7KCh) contribute to the pathogenesis of autoimmune and chronic inflammatory diseases by inducing oxidative stress and promoting pro-inflammatory immune cell activation. Dendritic cells (DCs) play a central role in maintaining immune tolerance, and their dysregulation is a key driver of autoimmunity. Targeting DCs by using natural compounds offers a promising strategy to restore redox balance and suppress aberrant immune responses. This study investigated the immunomodulatory and antioxidant properties of Lupeol, a natural triterpenoid, in human monocyte-derived DCs exposed to 7KCh. Flow cytometry and cytokine profiling demonstrated that Lupeol preserved the immature, tolerogenic phenotype of DCs by promoting a dose-dependent increase in the anti-inflammatory cytokine IL-10. Lupeol also inhibited the 7KCh-induced upregulation of maturation markers (CD83, CD86) and suppressed the release of pro-inflammatory cytokines IL-1β and IL-12p70. Functionally, Lupeol-treated DCs directed T cell polarization toward an anti-inflammatory and regulatory profile while dampening the inflammatory responses triggered by 7KCh. This immunoregulatory effect was further supported by the decreased secretion of the pro-inflammatory cytokines IL-1β and IL-12p70 in DC culture supernatants. Mechanistic analyses using immunofluorescence showed that Lupeol alone significantly increased nuclear NRF2 levels and upregulated HO-1 expression. Western blot analysis further confirmed Lupeol’s ability to activate the KEAP1-NRF2 signaling pathway, as evidenced by increased expression of NRF2 and its downstream target, NQO1. The use of ML385, a selective NRF2 inhibitor, in ROS and cytokine assays supported the involvement of NRF2 in mediating the Lupeol antioxidant and anti-inflammatory effects in DCs. Notably, the oxidative burden induced by 7KCh limited the full activation of NRF2 signaling triggered by Lupeol. Furthermore, docking and MM/PBSA analyses revealed the specific interactions of Lupeol with the kelch domain of KEAP1. These findings suggest that Lupeol may serve as a promising orally available immunomodulatory agent capable of promoting tolerogenic DCs, offering potential applications in autoimmune and other chronic inflammatory diseases. Full article

Thermodynamic simulations of fluid–rock interactions provide valuable insights into mineral deposit formation mechanisms. This study investigates the Pulang porphyry Cu-Au deposit in the Sanjiang Tethys Orogen, employing both Gibbs energy minimization (GEM) and the Law of mass action (LMA) method to understand alteration overprinting and metal precipitation. The modeling results suggest that the ore-forming fluid related to potassic alteration was initially oxidized (ΔFMQ = +3.54~+3.26) with a near-neutral pH (pH = 5.0~7.0). Continued fluid–rock interactions, combined with the input of reduced groundwater, resulted in a decrease in both pH (4.8~6.1) and redox potential (ΔFMQ~+1), leading to the precipitation of propylitic alteration minerals and pyrrhotite. As temperature further decreased, fluids associated with phyllic alteration showed a slight increase in pH (5.8~6.0) and redox potential (ΔFMQ = +2). The intense superposition of propylitic and phyllic alteration on the potassic alteration zone is attributed to the rapid temperature decline in the magmatic–hydrothermal system, triggering fluid collapse and reflux. Mo, mainly transported as HMoO₄⁻ and MoO₄⁻², precipitated in the high-temperature range; Cu, carried primarily by CuCl complexes (CuCl₄⁻³, CuCl₂⁻, CuCl), precipitated over intermediate to high temperatures; and Au, transported as Au-S complexes (Au(HS)₂⁻, AuHS), precipitated from intermediate to low temperatures. This study demonstrates that fluid–rock interactions alone can account for the observed sequence of alteration and mineralization in porphyry systems. Full article

Plants are constantly exposed to environmental stressors such as drought, salinity, and extreme temperatures, which threaten their growth and productivity. To counter these challenges, they employ complex molecular defense systems, including epigenetic modifications that regulate gene expression without altering the underlying DNA sequence. This review comprehensively examines the emerging roles of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as central signaling molecules orchestrating epigenetic changes in response to abiotic stress. In addition, biotic factors such as pathogen infection and microbial interactions are considered for their ability to trigger ROS/RNS generation and epigenetic remodeling. It explores how ROS and RNS influence DNA methylation, histone modifications, and small RNA pathways, thereby modulating chromatin structure and stress-responsive gene expression. Mechanistic insights into redox-mediated regulation of DNA methyltransferases, histone acetyltransferases, and microRNA expression are discussed in the context of plant stress resilience. The review also highlights cutting-edge epigenomic technologies such as whole-genome bisulfite sequencing (WGBS), chromatin immunoprecipitation sequencing (ChIP-seq), and small RNA sequencing, which are enabling precise mapping of stress-induced epigenetic landscapes. By integrating redox biology with epigenetics, this work provides a novel framework for engineering climate-resilient crops through the targeted manipulation of stress-responsive epigenomic signatures. Full article

Air pollution acts as a pervasive oxidative stressor, disrupting global crop production and ecosystem health through the overproduction of reactive oxygen species (ROS). Hazardous pollutants impair critical physiological processes—photosynthesis, respiration, and nutrient uptake—triggering oxidative damage and yield losses. This review synthesizes current knowledge on plant defense mechanisms, emphasizing the integration of enzymatic (SOD, POD, CAT, APX, GPX, GR) and non-enzymatic (polyphenols, glutathione, ascorbate, phytochelatins) antioxidant systems to scavenge ROS and maintain redox homeostasis. We highlight the pivotal roles of transcription factors (MYB, WRKY, NAC) in orchestrating stress-responsive gene networks, alongside MAPK and phytohormone signaling (salicylic acid, jasmonic acid, ethylene), in mitigating oxidative stress. Secondary metabolites (flavonoids, lignin, terpenoids) are examined as biochemical shields against ROS and pollutant toxicity, with evidence from transcriptomic and metabolomic studies revealing their biosynthetic regulation. Furthermore, we explore biotechnological strategies to enhance antioxidant capacity, including overexpression of ROS-scavenging genes (e.g., TaCAT3) and engineering of phenolic pathways. By addressing gaps in understanding combined stress responses, this review provides a roadmap for developing resilient crops through antioxidant-focused interventions, ensuring sustainability in polluted environments. Full article

The present study aimed to evaluate the therapeutic benefits of a hybrid material based on gold nanoparticles and natural extracts on an experimental model of thioacetamide-induced (TAA) liver injury in rats. The nanomaterials were synthesized using a green method, with Cornus sanguinea L. extract as a reducing and capping agent (NPCS), and were then mixed with Vaccinium myrtillus L. (VL) extract in order to achieve a final mixture with enhanced properties (NPCS-VL). NPCSs were characterized using UV–vis spectrophotometry and transmission electron microscopy (TEM), which demonstrated the formation of spherical, stable gold nanoparticles with an average diameter of 20 nm. NPCS-VL’s hepatoprotective effects were evaluated through an analysis of oxidative stress, inflammation, hepatic cytolysis, histology assays, and TEM in comparison to silymarin on an animal model of thioacetamide (TAA)-induced toxic hepatitis. TAA administration determined hepatotoxicity, as it triggered redox imbalance, increased proinflammatory cytokine levels and alanine aminotransferase (ALAT) activity, and induced morphological and ultrastructural changes characteristic of liver fibrosis. In rats treated with NPCS-VL, all these pathological processes were attenuated, suggesting a potential antifibrotic effect of this hybrid bionanomaterial. Full article

The fermentation of Actinobacillus succinogenes in bioelectrochemical systems offers a promising approach to enhance biotechnological succinate production by shifting the redox balance towards succinate and simultaneously enabling CO₂ utilization. Key process parameters include the applied electric potential, electrode material, and reactor design. This study investigates the influence of various carbon fabric electrodes and applied potentials on product distribution during fermentation of A. succinogenes. Building on prior findings that potentials between −600 mV and –800 mV increase succinate production, recent data reveal that more negative potentials, beyond the water electrolysis threshold, trigger electrochemical side reactions, altering product yields. Specifically, succinate decreased from 19.76 ± 0.41 g∙L⁻¹ to 14.1 ± 1.6 g∙L⁻¹, while lactate rose from 0.59 ± 0.12 g∙L⁻¹ to 3.12 ± 0.21 g∙L⁻¹. Contrary to common assumptions, the shift is not primarily driven by oxygen formation. Instead, the results indicate that the intracellular redox potential is affected by both the applied potential and hydrogen evolution, which alters metabolic pathways to maintain redox balance. These findings demonstrate that more negative applied potentials in electro-fermentation processes can impair succinate yields, emphasizing the importance of fine-tuning electrochemical conditions in the system for optimized biotechnological succinate production. Full article

Progression of aortic stenosis (AS) is aggravated by type 2 Diabetes Mellitus (T2DM) and kidney dysfunction (KD). Oxidative stress is one of the main mechanisms that triggers AS and is also disturbed among subjects with T2DM and KD. Consequently, we studied the redox homeostasis in four groups of patients, also classifying each patient based on their kidney function: control subjects, T2DM, AS, and AS+T2DM. Free reduced thiols in plasma were analyzed using a colorimetric assay, and the redox state of human serum albumin (HSA) was assessed by immunodetection and PEG-PCMal labeling. Lower levels of thiols were evident in patients with AS and AS+T2DM, while reduced and mildly oxidized HSA was more abundant in T2DM and AS+T2DM patients, reflecting less protection against oxidation. Moreover, the thiol levels decreased as KD increased in patients with AS and AS+T2DM. Differences also exist in reduced and mildly oxidized HSA between patients with normal and severely impaired kidney function, whereas AS patients with severe KD had more strongly oxidized HSA. Our results confirm an imbalance in oxidative stress associated with AS that is aggravated by the coexistence of T2DM and KD. Moreover, T2DM treatment might mitigate this dysfunction, opening the door to new therapeutic approaches for these patients. Full article

Crustins are a family of cysteine-rich antimicrobial peptides (AMPs), predominantly found in crustaceans, and play important roles in innate immunity. However, among the many reported crustins, few studies have explored their immunomodulatory functions. In this study, we investigated the immune function of a type I crustin (LvCrustinIa-2) in Litopenaeus vannamei, with particular emphasis on comparing the roles of its different domains. LvCrustinIa-2 possesses cationic patchy surface and amphipathic structure, and its expression was significantly induced in hemocytes after pathogen challenge. Both the recombinant LvCrustinIa-2 (rLvCrustinIa-2) and its whey acidic protein (WAP) domain (rLvCrustinIa-2-WAP) exhibited significant inhibitory activities against the tested Gram-positive bacteria. They also showed binding affinity not only for Gram-positive bacteria but also for Gram-negative bacteria. Furthermore, rLvCrustinIa-2 induced membrane leakage and structure damage in the target bacteria. Notably, chemotaxis assays revealed that rLvCrustinIa-2 and the synthetic cysteine-rich region (LvCrustinIa-2-CR) significantly enhanced the chemotactic activity of shrimp hemocytes in vitro. Knockdown of LvCrustinIa-2 triggered significant transcriptional activation of genes involved in calcium transport, inflammation, redox regulation, and NF-κB pathway. Taken together, these findings elucidate the distinct roles of the cysteine-rich region and WAP domain in type Ia crustin and provide the first evidence of a crustacean AMP with chemotactic and immunomodulatory activities. Full article

Pancreatic cancer is one of the most lethal malignancies, in part due to its profound metabolic adaptability, which underlies drug resistance and therapeutic failure. This study explores the metabolic rewiring associated with resistance to treatment using a systems metabolomics approach. Exposure to the redox-disrupting agent erastin revealed key metabolic vulnerabilities but failed to produce lasting growth suppression. Combinatorial treatments with methotrexate or alpelisib significantly impaired proliferation and triggered marked metabolic shifts. Systems-level analyses identified serine metabolism as a central adaptive pathway in resilient cells. Metabolic tracing and gene expression profiling showed increased de novo serine biosynthesis and uptake, supporting redox homeostasis, biosynthetic activity, and epigenetic regulation. Notably, cells that resumed growth after drug withdrawal exhibited transcriptional reprogramming involving serine-driven pathways, along with elevated expression of genes linked to survival, proliferation, and migration. These findings establish serine metabolism as a functional biomarker of metabolic plasticity and adaptive resilience in pancreatic cancer, suggesting that targeting this adaptive axis may enhance therapeutic efficacy. Full article