Search Results (795)

The potency of urate, an abundant human plasma antioxidant, in preventing oxidative damage caused by the carbonate radical anion CO₃^•−, was studied using quantum chemical calculations. The influence of microhydration of CO₃^•−/CO₃²⁻ and urate⁻/urate^• couples on the thermodynamic and kinetics of the one-electron oxidation process was investigated. Depending on the degree of microhydration, the estimated rate constant for one-electron transfer is in the range of 2.0–7.3 × 10⁹ M⁻¹ s⁻¹, in good agreement with the experimental value of 1.3 × 10⁹ M⁻¹ s⁻¹. Modeling using vertical detachment energy and electron affinity, the driving forces of single electron transfer revealed urate(H₂O)₆⁻ and CO₃(H₂O)₉^•− clusters as the most likely existing species in water. Molecular docking revealed a favorable interaction of urate with the catalytic pocket of SOD1. Urate binds more strongly to the anionic active center of SOD1 than the reference inhibitor LSC-1, indicating its potency to prevent HCO₃⁻-supported CO₃^•− formation. In contrast, the known OGG1 inhibitor TH13264 shows substantially stronger binding than urate, indicating urate’s weaker affinity toward the DNA repair enzyme catalytic pocket. The molecular dynamics data indicate that urate binding does not destabilize either SOD1 or OGG1. In light of increasing evidence that the major source of oxidative stress could be CO₃^•−, rather than the commonly assumed hydroxyl radical HO^•, the obtained results indicate the inherent ability of plasma to combat oxidative stress induced by this selective, milder oxidant. Such an ability with respect to the non-selective, highly reactive HO^• does not exist in vivo. Full article

Diabetic wounds remain a major clinical challenge due to impaired healing associated with persistent inflammation, oxidative stress, and microvascular dysfunction. Plasma-based therapies have emerged as promising approaches for promoting tissue repair; however, comparative evidence regarding different plasma modalities remains limited. In this study, we evaluated and compared the effects of atmospheric pressure cold plasma (APCP) and plasma-activated water (PAW) on wound healing in a streptozotocin-induced diabetic rat model. Forty Wistar albino rats were randomly assigned to five groups: isotonic wet dressing, hydrocolloid dressing, APCP treatment, PAW application, and a non-diabetic control group. Wound healing was assessed using macroscopic evaluation, histopathological analysis, and biochemical measurements of systemic oxidative status. PAW treatment significantly accelerated wound closure during the early healing phase compared with conventional dressing methods (p < 0.05). Histological findings demonstrated enhanced re-epithelialization, increased collagen deposition, and improved follicular regeneration in the PAW group. Although total oxidant status (TOS) did not differ significantly among groups (p = 0.996), total antioxidant status (TAS) was significantly increased following PAW treatment (p < 0.05), indicating a more favorable systemic antioxidant profile. These findings suggest an association between improved wound healing and a more favorable systemic antioxidant profile following PAW treatment. However, because local wound-level redox parameters and molecular markers were not assessed, the contribution of redox-related mechanisms remains to be clarified. Moreover, PAW demonstrated superior therapeutic efficacy compared with direct plasma application, highlighting its potential as a non-invasive approach for diabetic wound management. Full article

Many rhizobia use quorum sensing (QS) systems to detect their population density and modify their symbiotic behavior with the legume host. There are three LuxRI-type QS systems in Rhizobium etli CFN42, and CinR plays a key role in symbiotic performance. However, the details of how CinR regulates the symbiotic process remain unknown. In this study, we employed the RNA-Seq method to screen differentially expressed genes between the wild-type strain and the ΔcinR mutant of R. etli CFN42. We found that most of the genes related to reactive oxygen species (ROS) were expressed at lower levels in the ΔcinR mutant than in CFN42. We also found that the ΔcinR mutant was more sensitive to H₂O₂ than to CFN42. We then showed that CinR positively regulated katG expression and possessed an affinity to bind the katG promoter in the absence of the AHL ligand. The addition of AHLs promoted CinR binding to the katG promoter and enhanced katG expression. Accumulation of H₂O₂ and O₂^•− was observed in root nodules formed by the ΔcinR mutant. Crucially, katG overexpression rescued the H₂O₂-sensitive phenotype in vitro and partially restored defective symbiotic performance in nodules formed by the ΔcinR mutant on the common bean. These results suggest that CinR globally regulates ROS scavenging gene expression in order to balance oxidative stress within root nodules, promoting nitrogenase activity of R. etli CFN42. Full article

Chronic kidney disease (CKD) affects approximately 700 million people worldwide and is a major contributor to end-stage renal disease (ESRD), cardiovascular morbidity, and premature mortality. Although oxidative stress has long been considered central to CKD progression, conventional antioxidant strategies have not consistently improved clinical outcomes, suggesting that excess reactive oxygen species (ROS) alone cannot fully account for the underlying disease pathophysiology. Emerging evidence supports a broader paradigm of redox network failure, characterized by the disruption of coordinated signaling among ROS, nitric oxide (NO), and reactive sulfur species (RSS). Within this framework, hydrogen sulfide (H₂S), a major endogenous RSS, functions as a key regulator of renal redox homeostasis. CKD is consistently associated with systemic and renal H₂S deficiency, accompanied by downregulation of cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST), as well as impaired transsulfuration and disrupted mitochondrial sulfide oxidation. Importantly, this deficiency cannot be explained solely by reduced renal function but instead reflects active suppression of H₂S biosynthesis. Uremic toxins, particularly indoxyl sulfate (IS), contribute to this process through activation of the aryl hydrocarbon receptor (AhR), which inhibits specificity protein 1 (Sp1)-dependent transcription of H₂S-producing enzymes. This IS–AhR–Sp1 axis provides a mechanistic link between toxin accumulation and disruption of the sulfur arm of the redox network, amplifying oxidative stress, endothelial dysfunction, mitochondrial impairment, ferroptotic vulnerability, and fibrotic remodeling. Beyond H₂S itself, downstream RSS, including persulfides, polysulfides, and thiosulfate, may represent the principal bioactive mediators of sulfur-dependent redox signaling, and their coordinated depletion in CKD may impair redox buffering capacity beyond what H₂S measurement alone reflects. This review integrates current evidence to propose a conceptual model in which CKD progression involves failure of coordinated redox signaling—characterized by feed-forward network collapse and threshold-dependent transition to a self-sustaining high-ROS state—with H₂S deficiency representing one mechanistically supported component of this broader network disruption. This framework highlights the therapeutic potential of targeting redox network restoration rather than isolated oxidative pathways in CKD. Full article

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited targeted therapeutic options, underscoring the urgent need for novel treatment strategies. Feilike (FLK), a Traditional Chinese Medicine formula with heat-clearing and detoxifying properties, aligns with key pathological features implicated in breast cancer progression. In addition, several of its components have demonstrated anti-tumor activity, positioning FLK as a potential therapeutic candidate for TNBC. In this study, we employed an integrated approach combining network pharmacology, transcriptomic analysis, and experimental validation to investigate the anti-TNBC effects of FLK. Our results demonstrate that FLK significantly inhibits the proliferation of TNBC cell lines and patient-derived organoids and induces typical pyroptotic features, including cell swelling and increased lactate dehydrogenase (LDH) release. Mechanistically, FLK triggers a mutant p53 signaling cascade involving calcium dysregulation, endoplasmic reticulum stress (ERS) activation, mitochondrial dysfunction, and reactive oxygen species (ROS) accumulation, which collectively activate the P38/JNK–Caspase-3/GSDME pathway to induce pyroptosis. In vivo, FLK markedly suppresses tumor growth in a 4T1 orthotopic mouse model and enhances the anti-tumor efficacy of Cyclophosphamide. Furthermore, Licochalcone B (LCB) is identified as a key bioactive constituent that recapitulates the pyroptosis-inducing effects of FLK. Collectively, our findings uncover a previously unrecognized mutant p53–ERS–ROS–MAPK signaling axis underlying FLK-induced pyroptosis and provide mechanistic insight and experimental evidence supporting the repurposing of FLK as a potential therapeutic strategy for TNBC. Full article

Background: The beet moth, Scrobipalpa ocellatella Boyd, 1858 (Lep.: Gelechiidae), is an increasingly important pest whose climate-driven expansion threatens sugar beet (Beta vulgaris L.) production in Europe. This study aimed to characterize the structural, physiological, biochemical, and molecular responses of sugar beet to infestation. Methods: Plants were analysed using computed tomography (CT), SPAD and NDVI measurements, HPLC-based sugar analysis, FRAP and MDA assays, and RT-qPCR of antioxidant-related genes. Results: CT imaging enabled non-destructive detection of larvae (mean length: 7.32 ± 0.73 mm) and pest-induced cavities (982.20 ± 316.04 mm³). SPAD did not differ significantly among treatments, whereas NDVI was consistently reduced in infested plants, declining from 0.648 ± 0.031 in non-infested plants to 0.593 ± 0.038 in infested-treated plants and 0.611 ± 0.021 in infested-untreated plants at the first sampling. Infestation induced pronounced oxidative stress, with FRAP increasing from 14.102 ± 0.943 to 25.471 ± 0.922 µg AA eq g⁻¹ FW and MDA from 558.065 ± 21.819 to 1325.806 ± 16.762 nmol g⁻¹ FW in untreated infested plants. Antioxidant gene expression was significantly upregulated, particularly for SOD, CAT, APX, DHAR, MDAR, and GPX. Conclusions: S. ocellatella infestation triggered coordinated oxidative stress responses in sugar beet, while CT and NDVI proved useful for early damage detection. Full article

Chronic low-grade inflammation, a key driver of diabetes and fatty liver disease, is present in obesity, which affects 2.1 billion adults as of 2021. Plant-derived bioactive peptides have emerged as promising alternatives to treat inflammation in these pathological processes. This study evaluated the effect of pre- and post-ultrasound-assisted enzymatic hydrolysis on bioactive peptide production and antioxidant activity from common bean (Phaseolus vulgaris L.) and pumpkin (Cucurbita argyoesperma) seed proteins. Pre-treated hydrolysates were fractionated by molecular weight (<3 kDa and 3–10 kDa) and evaluated for their anti-inflammatory properties by measuring nitric oxide and reactive oxygen species in three treatment schemes (pre-, co-, and post-treatment) in an obesity/inflammatory macrophage model. Ultrasound pre-treatment achieved a higher degree of hydrolysis (peptide production) compared to post-treatment, with corresponding increases in antioxidant activity as measured by the ABTS and ORAC assays. All hydrolysate fractions demonstrated dose-dependent inhibition of pro-inflammatory markers. Fractions administered as a co-treatment showed the strongest anti-inflammatory effect, reducing Nos-2 and Cox-2 mRNA expression, as well as secreted levels of pro-inflammatory cytokines (TNF-α, IL-6, MCP-1). These findings indicate that ultrasound treatment, mainly as pre-treatment, represents an effective strategy for producing bioactive peptide hydrolysates with anti-inflammatory properties in vitro that warrant deeper investigation. Full article

Staphylococcus aureus biofilms formed on titanium surfaces are highly relevant to orthopedic implant-associated infection and remain difficult to control after maturation. This study aimed to evaluate whether ultraviolet A (UVA, 365 nm) combined with cinnamaldehyde (CA) could improve antibiofilm activity against titanium-associated S. aureus biofilms in a stage-resolved in vitro model and to examine whether the observed responses were associated with reactive oxygen species (ROS). Early stage (8 h) and 24 h biofilm models were established on total hip arthroplasty (THA)-derived titanium discs. After condition screening, 0.5 mM CA combined with 5 min UVA exposure was selected for subsequent experiments. Biofilm biomass was assessed by crystal violet staining, bacterial viability by live/dead staining and colony-forming unit (CFU) enumeration, ROS-associated fluorescence by dihydroethidium (DHE) imaging, and biofilm-associated gene expression by quantitative real-time PCR (qRT-PCR). Chondrocyte viability was also evaluated under the selected antibiofilm-effective conditions. The combined treatment showed stage-dependent antibiofilm effects, with greater biomass reduction in the 8 h biofilm model and marked impairment of bacterial viability and culturability in both models. ROS-associated fluorescence increased under combined exposure and was partially attenuated by N-acetyl-L-cysteine (NAC) in the 24 h biofilm model. In parallel, CA + UVA was associated with lower expression levels of clfA, icaA, and icaD in the 8 h biofilm model and of icaA, icaB, and icaD in the 24 h biofilm model, with partial NAC attenuation in the latter. Chondrocyte viability was lower in all treatment groups than in the untreated control, although the combined treatment did not show an obvious additional decrease compared with the single-treatment groups. These findings indicate that UVA combined with CA exerts stage-dependent antibiofilm effects in an in vitro titanium-associated S. aureus biofilm model. The observed ROS-associated responses were consistent with, but do not establish, mechanistic involvement. The current treatment setting also requires further optimization before translational applicability can be more confidently considered. Full article

Non-heading Chinese cabbage (NHCC) is a highly economically valuable leafy vegetable widely grown in Asian regions. However, it undergoes rapid leaf yellowing and wilting during postharvest storage, which subsequently cause rapid quality decline and loss of nutritional components. Abscisic acid (ABA) promotes postharvest leaf senescence, while hydrogen-rich water (HRW) is widely used in postharvest preservation due to its excellent antioxidant properties; yet, the mechanism through which they interact to regulate postharvest senescence in NHCC remains unclear. Herein we found that exogenous HRW effectively delayed dark- and ABA-induced postharvest leaf senescence in NHCC, significantly maintained chlorophyll content, inhibited oxidative damage, and preserve nutritional components such as soluble sugars and vitamin C. The underlying mechanism was HRW inhibiting chlorophyll degradation by repressing the expression of chlorophyll catabolic genes like NYC1, NYE1, and PPH1. Meanwhile, HRW effectively lowered the accumulation of MDA and H₂O₂, elevated both the enzymatic activities and transcript abundance of SOD and CAT, and downregulated the transcript levels of RbohB, RbohC, RbohD, and RbohE, thereby maintaining reactive oxygen species (ROS) homeostasis. In addition, HRW negatively regulated ABA biosynthesis by inhibiting the transcript levels of ABA1, ABA2 and ABA3, while promoting the transcription of CYP707A1, CYP707A2 and CYP707A3. It also dampened the transcript abundance of ABA signaling components including PYL5, ABI1, and ABF3, thus blocking ABA signal transduction and alleviating its senescence-promoting effect. Collectively, this study confirms that HRW mitigates leaf senescence induced under dark and ABA conditions in NHCC via multiple synergistic pathways. Full article

Onion peel represents a valuable food by-product rich in bioactive phenolic compounds. Building on previous phytochemical investigations, an onion peel extract from the Rossadi Tropea variety was developed as a standardized bioactive ingredient (OPI-T), defined by flavonol (quercetin and its glycosylated and oxidized derivatives) and anthocyanin (cyanidin derivatives) markers, ensuring batch-to-batch consistency, and evaluated for its potential against hepatic steatosis. The present study aimed to assess the protective effects of OPI-T against palmitate-induced steatosis and oxidative stress in HepG2 cells, a widely used in vitro model of hepatic lipid accumulation. An onion peel extract derived from the Ramata di Montoro variety was included as a natural negative reference to account for varietal variability. HepG2 cells were co-treated with palmitate (500 µM) and OPI-T (25 or 50 µg/mL). Lipid accumulation was evaluated by Oil Red O and BODIPY staining, while oxidative stress was assessed by the DCF assay. Mitochondrial dynamics and autophagy were investigated through the analysis of key protein markers, including MFN2, DRP1, SQSTM1/p62 and LC3 II/I. OPI-T significantly attenuated palmitate-induced lipid accumulation (−18%) and reduced intracellular ROS production (−75%), while modulating mitochondrial dynamics toward a reduced fission phenotype with a marked increase in the MFN2/DRP1 ratio (1.66) and improving autophagy flux. In contrast, the Ramata di Montoro variety showed weaker or inconsistent effects under the same experimental conditions. Overall, these findings support the functional validation of a standardized onion peel-derived ingredient, highlighting its potential application as a bioactive component for functional food or nutraceutical development targeting hepatic steatosis and oxidative stress. Full article

Since its discovery in higher plants, melatonin has attracted considerable attention for its antioxidant properties and its diverse roles in plant physiology and stress responses. However, its biosynthetic pathway remains only partially elucidated, particularly in horticultural crops of economic and nutritional importance, such as pepper (Capsicum annuum L.) fruits. In our previous work, we identified five genes encoding tryptophan decarboxylase (TDC), the first enzyme in the melatonin biosynthetic pathway in pepper. The present study expands on this by identifying and characterizing additional genes encoding enzymes involved in subsequent steps of the pathway, including four tryptamine 5-hydroxylase (T5H) genes, two serotonin N-acetyltransferase (SNAT) genes, three N-acetylserotonin O-methyltransferase (ASMT) genes, two caffeic acid O-methyltransferase (COMT) genes, and one N-acetylserotonin deacetylase (ASDAC) gene, representing a total of twelve newly identified genes. We further examined their expression in sweet pepper fruits and found that only nine of the identified genes are expressed in the fruit, with generally higher transcript levels during the unripe stages. Melatonin quantification in the California-type ‘Masami’ cultivar using UPLC with fluorescence detection (FD) revealed concentrations of 623 ng melatonin·g⁻¹ dry weight (DW) in green fruits and 431 ng melatonin·g⁻¹ DW in red fruits, consistent with the higher expression of melatonin biosynthetic genes in unripe fruit. Expression analysis of these genes by means of RNA-seq revealed differential modulation in response to exogenous melatonin treatments (20, 50, and 100 µM). To our knowledge, this is the first report demonstrating that exogenous melatonin regulates the expression of genes involved in its own biosynthetic pathway in sweet pepper fruits. Notably, treatment with 100 µM melatonin delayed ripening in these non-climacteric fruits, highlighting its potential biotechnological application for controlling fruit ripening and improving postharvest management. Full article

Cadmium (Cd) is a potentially toxic element that impairs plant growth and threatens food safety and human health. This study aimed to investigate the effects of sulfur (S) supplementation on Cd uptake and tolerance in rice under hydroponic conditions. Rice seedlings were exposed to Cd stress and treated with S at different concentrations. Physiological traits, oxidative damage markers, thiol compounds, and ionomic profiles in rice plants were assessed. S supplementation reduced Cd-induced growth inhibition, restoring plant biomass. Although Cd accumulation increased with S treatment, it was accompanied by enhanced antioxidant responses, scavenging reactive oxygen species (ROS) and malondialdehyde. S application increased the production of thiol-containing compounds, including γ-glutamylcysteine, glutathione, and phytochelatins, which helped chelate Cd and sequester it in vacuoles, particularly in roots. Additionally, S supplementation altered the essential nutrient composition in rice tissues, particularly the uptake of N, P, and K, while influencing levels of Ca, Mg, and other essential elements. S supplementation enhanced rice tolerance to Cd stress by reestablishing ROS balance, activating thiol-based detoxification pathways, and regulating mineral nutrient balance. Furthermore, sulfur (S) exhibited a dual effect in plants, enhancing cadmium (Cd) uptake while also promoting its detoxification, underscoring its role in improving crop resilience in contaminated soils. Full article

This study evaluated the protective effects of lipid emulsion (LE) against bupivacaine-induced cytotoxicity in human rotator cuff fibroblasts (hRCFs). hRCFs were divided into control, bupivacaine alone (Bupivacaine), LE alone (LE), LE-pretreated bupivacaine (LE + Bupivacaine), N-acetylcysteine alone (NAC), and NAC-pretreated bupivacaine (NAC + Bupivacaine). Cell viability was assessed by MTT and Live/Dead assays; ROS production by DCF-DA; apoptosis by Annexin V/PI staining and TUNEL assay; cleaved caspase-3 and PARP expression by Western blot; cell cycle by FACS; cell proliferation by Ki-67 staining; and wound healing. Cell viability decreased in a bupivacaine concentration-dependent manner (p < 0.001). Pretreatment with LE or NAC improved cell viability compared with bupivacaine alone (p < 0.001). ROS levels were elevated by bupivacaine, whereas LE and NAC pretreatments significantly reduced ROS (p < 0.001). Bupivacaine-induced apoptosis was significantly attenuated by LE and NAC, as evidenced by reductions in apoptosis rate, expression levels of cleaved caspase-3 and PARP-1, TUNEL-positive nuclei, and the subG1 population (p < 0.05). Cell proliferation and wound healing were suppressed by bupivacaine but restored by LE and NAC pretreatment. This study demonstrates bupivacaine-induced cytotoxicity in hRCFs and suggests that LE and NAC mitigate these effects by reducing oxidative stress and promoting cell survival and wound healing. Full article

Hydroxyurea (HU) is a ribonucleotide reductase inhibitor widely used for the treatment of sickle cell disease and myeloproliferative disorders, yet a precise nitric oxide (NO) synthase (NOS)-dependent mechanism remains incompletely defined. The role of NOS3 in HU-mediated proliferation, cell cycle, and apoptosis was analyzed in HEL92.1.7 erythroleukemic cells and primary mouse erythroid progenitors upon genetic knockdown/knockout and pharmacological NOS2/NOS3 inhibition. NOS3 expression, phosphorylation, NO and citrulline production, and protein nitrosylation were assessed via immunoblotting and biochemical assays. Computational docking and molecular dynamics simulations were performed to examine the interaction between HU and NOS3. HU enhanced NOS3 expression and phosphorylation, leading to increased NO and citrulline production. Computational analysis predicted HU binding within the NOS3 active site, whereas functional activation was AKT1-dependent. A biotin switch assay revealed cooperative NOS2-/NOS3-mediated protein nitrosylation under HU treatment. NOS3 depletion or inhibition abrogated HU-induced S-phase accumulation and restored cell proliferation. NOS3 protein depletion increased late apoptosis in erythroleukemic cells, while in murine erythroid cells, both Nos3 deficiency and inhibition decreased early and increased late apoptosis. NOS2 and NOS3 act as complementary mediators of proliferation and apoptosis, with NOS3 playing a distinct role in HU-induced proliferation arrest in erythroid cells. These findings highlight the therapeutic potential of NOS targeting to enhance the efficacy of HU and overcome resistance in hematologic malignancies. Full article

Oxidative stress is no longer viewed as a random imbalance between reactive oxygen species and antioxidants, but as a failure of an integrated redox network that connects metabolism, immunity, and metal homeostasis. Classical markers such as malondialdehyde and 4-hydroxynonenal define oxidative damage, yet they cannot explain how redox adaptation occurs or fails. Over the past decade, the discovery of regulated cell-death pathways (ferroptosis, cuproptosis) and emerging metabolic signals has revealed a new generation of adaptive redox mediators—including itaconate, nitro-fatty acids, reactive sulfur species and succinate—that act as electrophilic or persulfidating regulators rather than passive by-products of oxidation. This review integrates mechanistic, biochemical and clinical evidence to define how these mediators remodel the nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1, nuclear factor kappa-light-chain-enhancer of activated B cells, and hypoxia-inducible factor 1-alpha axes, coordinate lipid–metal–sulfur cross-talk, and shape vulnerability or resistance to ferroptosis and cuproptosis. By combining deep molecular research with translational perspectives, we propose a unifying framework for predictive redox medicine based on composite biomarker panels and AI-assisted phenotyping. Understanding and quantifying these next-generation mediators will open new avenues for precision nutrition, drug development, and disease prevention—transforming oxidative-stress biology from a descriptive field into an actionable platform for human health. Full article