Search Results (349)

Several studies have demonstrated that methionine supplementation in fish diets enhances immune status, inflammatory response, and resistance to bacterial infections by modulating for DNA methylation, aminopropylation, and transsulfuration pathways. However, the immunomodulatory effects of methionine in viral infections remain unexplored. This study aimed to evaluate the effect of methionine supplementation on immune modulation and resistance to the viral haemorrhagic septicaemia virus (VHSV) in rainbow trout (Oncorhynchus mykiss). Two diets were formulated and fed to juvenile rainbow trout for four weeks: a control diet (CTRL) with all nutritional requirements, including the amino acid profile required for the species, and a methionine-supplemented diet (MET), containing twice the normal requirement of DL-methionine. After feeding, fish were bath-infected with VHSV, while control fish were exposed to a virus-free bath. Samples were collected at 0 (after feeding trial), 24, 72, and 120 h post-infection for the haematological profile, humoral immune response, oxidative stress, viral load, RNAseq, and gene expression analysis. In both diets, results showed a peak in viral activity at 72 h, followed by a reduction in viral load at 120 h, indicating immune recovery. During the peak of infection, leukocytes, thrombocytes, and monocytes migrated to the infection site, while oxidative stress biomarkers (superoxide dismutase glutathione S-transferase, and glutathione redox ratio) suggested a compromised ability to manage cellular imbalance due to intense viral activity. At 120 h, immune recovery and homeostasis were observed due to an increase in the amount of nitric oxide, GSH/GSSG levels, leukocyte replacement, monocyte influx, and a reduction in the viral load. When focusing on the infection peak, gene ontology (GO) analysis showed several exclusively enriched pathways in the skin and gills of MET-fed fish, driven by the upregulation of several key genes. Genes involved in recognition/signalling, inflammatory response, and other genes with direct antiviral activity, such as TLR3, MYD88, TRAF2, NF-κB, STING, IRF3, -7, VIG1, caspases, cathepsins, and TNF, were observed. Notably, VIG1 (viperin), a key antiviral protein, was significantly upregulated in gills, confirming the modulatory role of methionine in inducing its transcription. Viperin, which harbours an S-adenosyl-L-methionine (SAM) radical domain, is directly related to methionine biosynthesis and plays a critical role in the innate immune response to VHSV infection in rainbow trout. In summary, this study suggests that dietary methionine supplementation can enhance a more robust fish immune response to viral infections, with viperin as a crucial mediator. The improved antiviral readiness observed in MET-fed fish underscores the potential of targeted nutritional adjustments to sustain fish health and welfare in aquaculture. Full article

Emerging research indicates that neuronal activity is maintained by an architectural system of protons in a multi-scale fashion. Proton architecture is formed when organelles (such as mitochondria, endoplasmic reticulum, lysosomes, synaptic vesicles, etc.) are coupled together to produce dynamic energy domains. Techniques have been developed to visualize protons in neurons; recent advances include near-atomic structural imaging of organelle interfaces using cryo-tomography and nanoscale resolution imaging of organelle interfaces and proton tracking using ultra-fast spectroscopy. Results of these studies indicate that protons in neurons do not diffuse randomly throughout the neuron but instead exist in organized geometric configurations. The cristae of mitochondrial cells create oscillating proton micro-domains that are influenced by the curvature of the cristae, hydrogen bonding between molecules, and localized changes in dielectric properties that result in time-patterned proton signals that can be used to determine the metabolic load of the cell and the redox state of its mitochondria. These proton patterns also communicate to the rest of the cell via hydrated aligned proton-conductive pathways at the mitochon-dria-endoplasmic reticulum junctions, through acidic lipid regions, and through nano-tethered contact sites between mitochondria and other organelles, which are typically spaced approximately 10–25 nm apart. Other proton architectures exist in lysosomes, endosomes, and synaptic vesicles. In each of these organelles, the V-ATPase generates steep concentration gradients across their membranes, controlling the rate of cargo removal from the lumen of the organelle, recycling receptors from the surface of the membrane, and loading neurotransmitters into the vesicles. Recent super-resolution pH mapping has indicated that populations of synaptic vesicles contain significant heterogeneity in the amount of protons they contain, thereby influencing the amount of neurotransmitter released per vesicle, the probability of vesicle release, and the degree of post-synaptic receptor protonation. Additionally, proton gradients in each organelle interact with the cytoskeleton: the protonation status of actin and microtubules influences filament stiffness, protein–protein interactions, and organelle movement, resulting in the formation of localized spatial structures that may possess some type of computational significance. At multiple scales, it appears that neurons integrate the proton micro-domains with mechanical tension fields, dielectric nanodomains, and phase-state transitions to form distributed computing elements whose behavior is determined by the integration of energy flow, organelle geometry, and the organization of soft materials. Alterations to the proton landscape in neurons (e.g., due to alterations in cristae structure, drift in luminal pH, disruption in the hydration-structure of the cell, or imbalance in the protonation of cytoskeletal components) could disrupt the intracellular signaling network well before the onset of measurable electrical or biochemical pathologies. This article will summarize evidence indicating that proton–organelle interaction provides a previously unknown source of energetic substrate for neural computation. Using an integrated approach combining nanoscale proton energy, organelle interface geometry, cytoskeletal mechanics, and AI-based multiscale models, this article outlines current principles and unresolved questions related to the subject area as well as possible new approaches to early detection and precise intervention of pathological conditions related to altered intracellular energy flow. Full article

Beneficial effects of the microbiota-derived metabolite butyrate at the colonic level are well established, particularly through its relevance in colorectal cancer (CRC) and inflammatory bowel disease (IBD), two major intestinal pathologies. Therefore, the mechanisms involved in butyrate transport across colonic epithelial cell membranes (uptake transporters: monocarboxylate transporter 1 (MCT1) and sodium-coupled monocarboxylate transporter 1 (SMCT1); efflux transporters: breast cancer resistance protein (BCRP) and MCT1/monocarboxylate transporter 4 (MCT4)), which are determinant for its intracellular levels, are of primary importance for its beneficial effects at the colonic level. The available data suggest that all these butyrate transporters can be modulated by redox and inflammatory status, but the evidence is scarce and rather inconsistent. Nevertheless, a role of nuclear factor erythroid 2-related factor 2 (Nrf2) and of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in mediating the effect of oxidative stress and inflammation, respectively, on MCT1 and SMCT1 is suggested. So, more investigation on this subject is needed, given the fact that increased oxidative stress levels and inflammatory status are present in a series of intestinal conditions and pathologies, including CRC and IBD, which could help to establish these transporters as potential cellular targets in these diseases. Full article

Redox unbalance, a molecular trait common to neurodegenerative conditions and para-physiological processes like aging, is a critical factor in disease development and in exacerbating progression. The mechanism by which redox imbalance perturbs cellular homeostasis is strongly linked to the activity and function of the ubiquitin–proteasome system (UPS). The UPS, along with autophagy, is the primary intracellular proteolytic system, regulating targeted proteolysis and removing damaged proteins. Consequently, the UPS serves also as the first line of defense for cellular recovery following exposure to redox stressors. Paradoxically, the composition and function of the UPS can also be negatively targeted by redox unbalance through a vicious cycle. The alterations in redox balance and UPS biological mechanisms are involved in the etiopathogenesis of chronic eye disorders. These disorders encompass a diverse repertoire of pathologies affecting the retinal layers (e.g., age-related macular degeneration, diabetic retinopathy) and the optic nerve (e.g., glaucoma). Nowadays, the comprehension of the interplay between proteostasis and oxidative redox status remains pivotal for identifying new therapeutic approaches. Encouragingly, a number of anti-oxidant compounds have been reported to modulate proteasome activity against redox insults in vitro and in vivo. Furthermore, these compounds provide cytoprotective roles in both in vitro and animal models of eye diseases. Therefore, this review highlights recent research on the interplay of the UPS with oxidative stress in physio-pathological conditions, focusing on the onset and progression of ocular diseases, thereby providing new insights into UPS-oxidative stress interaction. Full article

The present study aimed to evaluate blood redox status and acute phase protein profile throughout two pharmacological treatment protocols for pyometra bitches, employing aglepristone either as a monotherapy or in combination with prostaglandin. A prospective study was conducted in 10 open-cervix pyometra bitches assigned to two groups: aglepristone (n = 5; subcutaneous injections of aglepristone on days 1, 2, and 8 after diagnosis) and aglepristone + prostaglandin (n = 5, aglepristone coupled with daily injections of cloprostenol from days 1 to 7). Blood samples were collected daily for the liver profile (alanine aminotransferase—ALT, alkaline phosphatase, and albumin), acute phase proteins (C-reactive protein-CRP, haptoglobin, and serum amyloid-A), and redox analysis [antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH), oxidative stress (TBARS), and protein oxidation]. In the aglepristone group, there was increase in albumin concentration and SOD, while protein oxidation and GSH decreased progressively throughout treatment. The aglepristone + prostaglandin group had lower ALT levels but higher lipid peroxidation, GPx, and CRP. In conclusion, the combined use of prostaglandin modified the profile of oxidative markers, antioxidant enzymes, and C-reactive protein, thereby preventing the assessment of treatment efficacy. Conversely, albumin concentration proved a sensitive marker of therapeutic effectiveness in both treatment protocols for pyometra bitches. Full article

S-nitrosoglutathione (GSNO) reductase (GSNOR) is a major and conserved enzyme in prokaryotes and eukaryotes. It reduces a stable nitric oxide (NO) reservoir, GSNO, to balance the organisms’ redox status through S-nitrosylation. Over the last few decades, much of our understanding of GSNOR’s roles in plant biology has been updated. Here, therefore, we review the current knowledge of GSNOR in plant physiology and signaling under abiotic and biotic stresses. We observe that the role of GSNOR in plant abiotic stress is widely studied in both model and crop plants, whereas studies on its role in biotic stress have mainly focused on model plants. Under abiotic stresses, GSNOR plays a pleiotropic role in terms of plant tolerance and sensitivity. The presence or absence of GSNOR activity modulates the endogenous NO pool that balances plant reactive nitrogen species (RNS) and reactive oxygen species (ROS) under stress conditions. Moreover, GSNOR regulates hormonal levels, like ethylene, abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA), in response to abiotic and biotic stress conditions. Although GSNOR is important in plant physiology, its regulation of the redox switch is directly influenced by the extent of S-nitrosylation, where S-nitrosylated proteins generally enhance plant tolerance to abiotic stress but simultaneously suppress plant immunity. We further highlight a new perspective on NO-based nanotechnology in agriculture, focusing on GSNO encapsulated in nanocarriers. This technology improves NO stability and opens new avenues by allowing an evaluation of GSNOR’s role for sustainable crop production. Intriguingly, we discuss knowledge gaps, which are crucial to understanding the role of GSNOR in plant stress tolerance. Overall, this review accumulates a comprehensive understanding of the GSNOR enzyme in crop biology, which could aid in harnessing its function to address the impacts of climate change. Full article

Diabetes mellitus and chronic venous disease (CVD) are multifactorial, long-lasting diseases. Although usually considered separately, they often coexist, and individuals with diabetes are more prone to CVD development. Despite different etiology, CVD and diabetic vascular complications share several pathomechanisms, and oxidative stress is one of them. In this study the antioxidative potential of two venoactive flavonoids—diosmin and hesperidin—in the course of type 1 diabetes was compared for the first time. Type 1 diabetic rats were treated with diosmin or hesperidin, each at two doses, 50 and 100 mg/kg, for four weeks. In order to evaluate the antioxidative potential of tested compounds, the antioxidative enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), thiols homeostasis, oxidative status markers (total antioxidative response—TAR, total oxidative status and oxidative stress index—OSI), and oxidative damage markers (advanced oxidation protein products and malondialdehyde) in the serum were measured. Diabetes caused disturbance in the serological redox homeostasis, especially by decreasing enzyme activity and TAR while increasing levels of oxidative damage markers and OSI, increasing advanced glycation end products (AGEs) levels, as well as altering carbohydrate and lipid metabolism. Flavonoids improved the majority of lipid metabolism markers and reduced AGEs with no effect on glycemia. In the context of oxidative stress, their effect was moderate and dose-dependent, and better potency of hesperidin over diosmin was noted, both in individual and multivariate analyses of the parameters. The collective analysis of all parameters led to the conclusion that both diosmin and hesperidin can be considered complementary agents averting negative impact of diabetes due to their multi-faceted actions, including antioxidative properties. Full article

The hitherto unknown thiol-disulfide redox potential (E₀′) of the β93Cys residue in the HbS (β^6Glu→Val) variant of human hemoglobin was calculated by MALDI-ToF mass spectrometry, which analyzes blood from a heterozygous carrier. To calculate the (E₀′) value, a redox equilibrium model was adopted, and the previously calculated value for wild-type β-Hb chain (E₀′ −121 mV) was used. An E₀′ value of −130.5 ± 1.7 mV for the β93Cys residue of HbS was obtained, thus a more reducing value than E₀′ in the wild-type isoform. Glutathionylation from this residue in the HbS tetramer lowers the extent of protein aggregation in fibrils and the clinical consequences, such as painful capillary occlusion and hemolysis. This finding confirmed the peculiar property of HbS as a more reactive scavenger of glutathione sulphinic acid (E₀′ = −264 mV), which forms in the cytoplasm of red blood cells and reacts with structural and regulatory proteins, including hemoglobin. The ability to assess the erythrocyte oxidative status in sickle cell carriers can be developed into an additional functional test to rationally assess the effect of drug treatment and antioxidant dietary interventions on improving disease control. Full article

Background: Sepsis is a leading cause of mortality in intensive care units, with liver dysfunction representing a critical determinant of poor outcome, mainly associated with excessive inflammation and oxidative stress. Lycopene, a carotenoid with potent antioxidant and anti-inflammatory properties, has been proposed as a potential therapeutic agent. This study investigated whether lycopene supplementation mitigates lipopolysaccharide-induced oxidative and inflammatory liver injury in rats. Methods: Male Wistar rats, divided into four groups, were exposed to either lipopolysaccharide or a combination of lipopolysaccharide (10 mg/kg) and lycopene (6 mg/kg). In order to assess liver damage induced by lipopolysaccharide, hepatocellular injury markers, oxidative stress indices, nitric oxide metabolism, glutathione redox status, apoptotic enzyme activity, and inflammatory mediators were assessed in serum and liver tissue. Results: Lipopolysaccharide induced marked hepatocellular damage, characterized by elevated serum liver-cell damage parameters, and liver tissue xanthine oxidase, myeloperoxidase, thiobrabituric reactive substances, protein carbonyl content, deoxyribonuclease I/II activity, nuclear factor kappa B, tumor necrosis factor-α, and interleukin-6, alongside depletion of reduced glutathione and reduced glutathione reductase and glutathione peroxidase activities. Lyc pretreatment significantly attenuated liver enzyme leakage, oxidative damage, and cytokine release while restoring reduced glutathione and glutathione reductase activity. In contrast, lycopene had limited effects on glutathione peroxidase activity, nitric oxide/inducible nitric oxide synthase signaling, and nuclear factor erythroid 2-related factor 2 expression. Conclusions: These findings demonstrate that lycopene confers partial hepatoprotection in endotoxemic rats, primarily through suppression of oxidative damage and nuclear factor kappa B-mediated inflammation. Further studies are needed to clarify tissue-specific mechanisms and optimize dosing strategies in order to increase the efficacy of this carotenoid. Full article

Hepatitis C represents a critical global health crisis, causing approximately 1.4 million deaths annually. Although 98% of cases are treatable, only about 20% of infected individuals know their hepatitis C virus (HCV) status, highlighting the urgent need for rapid and more efficient diagnostic management. Viral genetic material can be detected in serum or plasma within just one week of exposure, making it the most reliable marker and the gold standard for active HCV infection diagnosis. In this study, a biosensor was developed to detect conserved nucleotide sequences of HCV using a 3D surface electrode composed of poly-L-lysine (PLL) and carbon nanotubes (CNTs). PLL is a positively charged biocompatible polymer rich in amine groups, attractive for the immobilization of proteins, DNA, and other biomolecules. PLL was employed to construct a 3D surface with vertically aligned CNTs, achieving a high electron transfer rate. Cyclic voltammetry technique and scanning electron microscopy (SEM) were used to characterize the sensor platform, and analytical responses were measured by differential pulse voltammetry. This HCV biosensor detected the hybridization event by a significant reduction in DPV peaks in the presence of the ferri/ferrocyanide redox probe, without any intercalator agents. DNA responses were observed in phosphate-buffered saline (PBS) and cDNA-spiked serum samples, demonstrating its analytical specificity. These findings represent advances in analytical tools that can effectively address the challenges of timely diagnosis for asymptomatic HCV carriers. Full article

Chronic rhinosinusitis without nasal polyps (CRSsNP) is a chronic inflammatory disease that lacks a clear pathogenesis/pathophysiology. While large studies focused on elucidating the pathophysiology of CRS with NPs (CRSwNP), this study aimed to use a systemic evaluation approach to identify the redox gene expression profile, its association with oxidative damage in CRSsNP, and the differences between CRSsNP and -wNP. The expression of 84 redox genes was analyzed using real-time PCR array in control and CRSsNP nasal mucosae. Changes in the mRNA and protein levels of these redox differentially expressed genes (DEGs) were verified using a customized real-time PCR array, RT-PCR, and Western blotting in an additional 18 patients. 4-Hydroxynonenal (lipid peroxidation) and 3-nitrotyrosine (protein nitrosylation) expression, representing oxidative stress (OxS) and nitrosative stress (NsS) status, were examined using immunohistochemistry. We found 27 DEGs (24 upregulated and 3 downregulated) in CRSsNP. AKR1C2, GCLM, GPX2, NOS2, and NQO1 were upregulated and LPO was downregulated more than 4-fold. These changes led to a substantial increase in OxS in CRSsNP nasal mucosa. In a comparison of the currently identified 27 DEGs with the 23 previously reported CRSwNP genes, there were 16 unique redox DEGs expressed between CRSsNP and -wNP. A String protein interaction network analysis revealed that CRSsNP possessed “an adaptive antioxidant defense signature”, while CRSwNP showed “a pro-inflammatory and -oxidant pathway”. Collectively, we systemically performed transcriptomic analysis to profile OxS-related genes in CRSsNP and highlighted the unique redox gene sets and pathway differences between CRSsNP and -wNP. Full article

Tempol, a synthetic nitroxide, exhibits dual antioxidant and pro-oxidant activity, requiring millimolar concentrations to induce oxidative stress, which limits its therapeutic use. Glutathione Peroxidase 4 (GPX4) is a critical lipid peroxidase that prevents ferroptosis, and its inhibition has emerged as a strategy to sensitize cancer cells to oxidative stress. To enhance Tempol’s efficacy, we investigated its interaction with ML210, a GPX4 inhibitor, in human colon (HT29) and gastric (CRL-1739) cancer cell lines. We quantified cell viability, oxidative stress markers (H₂O₂, Total Oxidant Status (TOS), and Total Antioxidant Status (TAS)) and endoplasmic reticulum (ER) stress proteins (ATF6, GRP78, and IRE1α) in in vitro assays. Synergy was assessed using Bliss independence analysis. The combination of Tempol (2 mM) and ML210 (0.05 μM) markedly reduced viability in both cell lines. Bliss analysis revealed slight/moderate synergy for cytotoxicity (Δ = +0.15 in HT29; Δ = +0.26 in CRL-1739) and strong synergy for H₂O₂ accumulation (Δ = +1.92–2.23 across replicates). In contrast, TOS showed moderate-to-strong antagonism across both cell lines, and TAS demonstrated slight synergistic or antagonistic effects. ER stress markers exhibited marker and cell line specific synergy: ATF6 showed strong synergy, IRE1α slight synergy in both lines, and GRP78 activation was highly variable, showing strong synergy in CRL-1739 cells but moderate antagonism in HT29 cells. These findings indicate that the cooperative action of Tempol and ML210 is ROS-pool–specific and pathway-selective in the ER. These findings demonstrate that ML210 potentiates Tempol’s pro-oxidant pressure by targeting GPX4, selectively amplifying H₂O₂ accumulation and ER stress engagement without collapsing global redox balance. This study provides mechanistic rationale for redox–proteostasis co-targeting in gastric and colon cancers and establishes a foundation for in vivo validation. Full article

Background: Gallic acid (GA) is a dietary polyphenol widely found in walnuts, tea leaves, and grapes, and it is recognized for its potent antioxidant and anti-inflammatory properties. Chronic sleep deprivation (CSD) is known to disrupt redox balance, promote neuroinflammation, and impair cognition, while effective nutritional strategies to mitigate these effects remain scarce. This study was designed to evaluate the protective potential of GA against CSD-induced cognitive deficits in mice and to elucidate the underlying mechanisms. Methods: Seventy-two male ICR mice were randomly allocated to six groups, including control, CSD model, Ginkgo biloba extract, and GA at three doses (50, 100, and 200 mg/kg). After 28 days of treatment, cognitive performance was assessed using the open field test (OFT), novel object recognition (NOR), step-through passive avoidance (ST), and Morris water maze (MWM). Redox status and inflammatory mediators were determined by ELISA, while the hippocampal expression of proteins related to antioxidant defense and NF-κB signaling was analyzed by Western blotting. Results: GA supplementation improved exploratory activity, recognition memory, and spatial learning in the CSD mice. Biochemical evaluation revealed that total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity were restored, while malondialdehyde (MDA) levels, an indicator of lipid peroxidation, were reduced. These changes were accompanied by decreased circulating concentrations of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). At the molecular level, GA enhanced the expression of Nrf2, HO-1, and NQO1, while inhibiting p-p65, iNOS, and COX2 in the hippocampus. Conclusions: These findings demonstrate that GA alleviates CSD-induced cognitive deficits through the activation of the Nrf2/HO-1 antioxidant pathway and inhibition of NF-κB–mediated inflammatory responses. Thus, GA may represent a promising nutraceutical candidate for maintaining cognitive health under chronic sleep loss. Full article

Introduction: Chronic spontaneous urticaria (CSU), vitiligo, and Hashimoto’s thyroiditis (HT) frequently co-occur in the same patients, suggesting a shared autoimmune pathogenesis. These conditions are increasingly recognized as components of polyautoimmunity, with overlapping clinical, immunological, and pathogenetic features. Among the proposed common mechanisms, vitamin D deficiency and oxidative stress (OS) have emerged as key contributors. We aimed to explore the shared immunopathogenic pathways linking these conditions, with a focus on the interplay between vitamin D status and redox imbalance. Methods: An extensive narrative review of the current literature regarding the associations among CSU, vitiligo, and HT, focusing on the role of vitamin D status, OS, and nitrosative stress, and shared immunological pathways was conducted. Discussion: Vitamin D deficiency was consistently observed across all three conditions and is associated with increased disease activity and poorer clinical outcomes. Several polymorphisms in the vitamin D receptor (VDR) and binding protein genes correlate with disease susceptibility. OS and nitrosative stress markers, such as malondialdehyde (MDA) and nitric oxide (NO) metabolites, are elevated in patients with CSU, vitiligo, and HT, and are linked to tissue-specific immune activation, apoptosis, and loss of self-tolerance. Evidence suggests that vitamin D and antioxidant supplementation may provide clinical benefit. In vitiligo, narrowband ultraviolet B (NB-UVB) phototherapy not only promotes repigmentation through melanocyte stimulation but also reduces ROS production and modulates local immune responses. Conclusions: The coexistence of CSU, vitiligo, and HT reflects a broader systemic autoimmune tendency, with vitamin D deficiency and redox imbalance serving as potential unifying mechanisms. Routine assessment of vitamin D levels and OS parameters may enhance diagnostic precision and inform therapeutic strategies. Antioxidant-based interventions represent promising avenues in the integrated management of autoimmune skin and endocrine disorders. Full article

Liver transplantation is commonly used for end-stage liver disease, but the demand for organs exceeds the supply, leading to the use of expanded criteria donors (ECDs). Organs from ECDs, especially from donors after circulatory death (DCD), encounter challenges like increased ischemia damage. Biomarkers, especially oxidative stress markers, may provide valuable insights for understanding and monitoring post-transplant events. Here, we highlight the unique value of organ preservation solution (OPS) as a non-invasive and early source of redox biomarkers, directly reflecting graft status during critical cold storage. This study investigated oxidative stress in 74 donated livers using OPS samples collected after cold storage, and also liver biopsies obtained before and after storage. We measured lipid peroxidation, protein carbonylation, DNA oxidation, and total antioxidant capacity from OPS, and performed gene expression analysis of liver biopsies. Oxidative stress markers differed based on donation type, with higher lipid peroxidation in DCD samples compared with donation after brain death (18.51 ± 2.77 vs. 11.03 ± 1.31 nmoles malondialdehyde (MDA)/mg protein; p = 0.049). Likewise, oxidative damage markers were associated with clinical outcomes: lipid peroxidation was increased in patients who developed biliary complications (21.86 ± 5.91 vs. 11.97 ± 1.12 nmol MDA/mg protein; p = 0.05), and protein carbonylation was elevated in those experiencing acute rejection (199.6 ± 22.02 vs. 141.6 ± 15.94 nmol carbonyl/mg protein; p = 0.005). Moreover, higher protein carbonylation levels showed a trend toward reduced survival (p = 0.091). Transcriptomic analysis revealed overexpression of genes associated with reactive oxygen species production in DCD livers. A predictive model for acute rejection integrating OPS biomarkers with clinical variables achieved 83% accuracy. Hence, this study underscores the importance of assessing oxidative stress status in preservation fluid as a biomarker for evaluating liver transplant outcomes and highlights the need for validation in larger, independent cohorts. Full article