Search Results (2,033)

Plant-derived compounds have recently attracted considerable scientific attention due to their potential therapeutic applications, which are largely attributed to their antioxidant properties. Tert-butyl hydroperoxide (t-BHP) is a potent inducer of intracellular oxidative stress, generating reactive free radicals, which significantly contribute to hepatic and renal damage. Micromeria frivaldszkyana (M. frivaldszkyana), a Bulgarian endemic species, contains high levels of phenolic compounds, including linarin, rosmarinic acid (RA), chlorogenic acid, rutin, quercetin, naringenin, and apigenin. In this study, male Wistar rats received oral treatment for 5 days comprising saline, 250, 400, or 500 mg/kg of M. frivaldszkyana methanolic extract, 100 mg/kg RA, or 125 mg/kg silymarin. On the final day, 0.5 mmol/kg of t-BHP was injected intraperitoneally, and blood and liver tissue samples were collected 18 h later for biochemical and histological analysis. Liver and kidney function was evaluated using biochemical markers (alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine (Cr), uric acid (UA)), indicators of oxidative stress (malondialdehyde (MDA), 8-hydroxy-2′-deoxyguanosine (8-OHdG), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT)), and histopathology. Exposure to t-BHP resulted in significant hepatic and renal damage, including elevated serum markers, increased lipid peroxidation, and deoxyribonucleic acid (DNA) damage. Administration of 500 mg/kg M. frivaldszkyana markedly lowered elevated serum ALT and AST levels. The extract also significantly mitigated t-BHP-induced increases in serum Cr and UA. However, no significant increase in the levels of the antioxidant enzymes SOD and CAT or in GSH was observed at all tested doses. Malondialdehyde and 8-OHdG levels increased markedly following t-BHP exposure, whereas pretreatment with M. frivaldszkyana at all tested doses significantly ameliorated these oxidative alterations. These findings suggest that the methanolic extract of M. frivaldszkyana confers protective effects against t-BHP-induced toxicity, potentially through stabilisation of cell membranes, inhibition of lipid peroxidation, and reduction in DNA damage. The extract may therefore serve as a potential natural therapeutic agent against injuries caused by oxidative stress. Full article

Introduction: Aquatic chemical pollution is among the most worrying threats to ecosystem health. There is an ever-increasing variety of pollutant substances detected across the source-to-sea continuum, causing loss of biodiversity and ecological disequilibrium. Achieving cleaner and healthier systems relies on carrying out sustained, cost-effective, diagnosis and aquatic effects monitoring, within the adaptive management cycle. The available methods are, however, cumbersome, which creates a clear need for innovative expeditious approaches for low-cost surveillance monitoring. In the last decade, Raman Spectroscopy (RS) has gained wide recognition for application to biological questions, for its ability to uncover the complexity of molecules and their interactions. Various fields, from pharmacology to disease diagnosis and prognosis, have suffered an innovation revolution through the application of RS. In this technique inelastic light scattering of a small part of photons of an incident electromagnetic monochromatic light beam (ranging from near-infrared to visible or ultraviolet) is caused by the molecular vibration of chemical bonds. This results in shifts in energy, which indicate discrete vibrational modes of polarisable molecules, providing qualitative and quantitative assessments of the chemical composition and molecular structure of the sample. The technique shows high sensitivity, no need for sample preparation and the possibility of use in non-invasive and label-free analysis. Objective: The aim of this work is to present and discuss evidence about the application of Raman Spectroscopy (RS) to environmental diagnosis and aquatic effect monitoring of pollution. Methodology: The technique was applied to different biological models, i.e., diatoms, zebrafish embryos and larvae and freshwater snails. Quality assessments with diatoms were tested in environmental monitoring, while assessments with other models were done upon exposure to metals and organic contaminants. Results and conclusions: The Raman spectra obtained from the samples analysed comprised bands detected within the 800 to 2000 cm⁻¹ wavenumber range. These were related to bond vibrations of carbohydrates, DNA phosphate groups, proteins or CH, NH and OH stretching in lipids and proteins. Data analysis using chemometric methods clearly distinguished pollutant exposure from control sites or treatments, pointing out the potential for surveyance monitoring. The next steps include the comparison with other sensitive methods (e.g., locomotion and avoidance behaviours, omics methods) to assess efficiency and bring further mechanistic understanding. Full article

Leishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania. Curcumin (CUR) is a polyphenol with several biological properties, including antimicrobial effects. However, its low bioavailability remains a challenge, and nanoencapsulation may represent a useful strategy to overcome this limitation. This study aimed to evaluate, in vitro, the antipromastigote activity of free CUR and the antiamastigote effect of CUR nanoparticles and their association with antimoniate, as well as to elucidate possible mechanisms of action. Free CUR directly inhibited promastigote proliferation, with an IC₅₀ of 25 µM at 24 h. CUR induced mitochondrial hyperpolarization, increased the production of reactive oxygen species (ROS) and nitric oxide (NO), and enhanced lipid peroxidation and the accumulation of lipid droplets in promastigotes. These alterations were associated with autophagic and apoptotic processes, morphological and ultrastructural changes, DNA fragmentation, and cell cycle arrest. Free CUR also reduced the viability of BALB/c peritoneal macrophages, and this effect was attenuated after nanoencapsulation. Free CUR, CUR nanoparticles, and their association with antimoniate (AM) reduced both the percentage of infected macrophages and the number of intracellular amastigotes at all tested concentrations, with increased NO production observed at the highest concentrations of free CUR. Altogether, our findings suggest that CUR exerts leishmanicidal activity against promastigotes by disrupting oxidative metabolism and triggering autophagic and apoptotic pathways, while amastigote elimination appears to occur through mechanisms independent of oxidative stress. Full article

Background: Obesity is a chronic endocrine–metabolic disorder. The risk of comorbidities increases with a higher body mass index (BMI), particularly when BMI ≥ 35.0 kg/m². Common complications include insulin resistance, type 2 diabetes, dyslipidemia, and chronic low-grade inflammation, which collectively impair DNA stability by promoting the formation of genotoxic species. Methods: This non-randomised, quasi-experimental clinical intervention study included 53 participants (both sexes) with a BMI ≥ 35.0 kg/m², who were assigned to parallel experimental or control streams based on clinical needs and institutional eligibility. During a three-week intervention, the experimental group received a hospital-supervised very-low-calorie diet (VLCD; ~600 kcal/day) under continuous medical monitoring. Conversely, the control group followed a standard reduced-calorie diet (SRD) of 1500 kcal/day in a free-living home environment. Before and after the intervention, primary, oxidative, and permanent DNA damage were measured using alkaline, FPG-modified comet (peripheral blood mononuclear cells), and cytokinesis-block micronucleus cytome assays (phytohaemagglutinin-stimulated binucleated lymphocytes), alongside anthropometric and biochemical tracking. Results: Within-group evaluations revealed that both dietary regimens improved several metabolic health indicators, notably modulating insulin resistance, lipid profiles, and leukocyte counts. However, participants in the VLCD stream experienced significantly greater downward changes in body weight, BMI, and absolute lipid values. Crucially, the VLCD intervention was associated with a highly significant within-group reduction in parameters of permanent chromosomal damage, effectively halving the frequencies of micronuclei and nuclear buds, independent of baseline variations, in adjusted multivariate regression models. Conversely, the home-based SRD regimen demonstrated no measurable impact on permanent genomic damage. Neither diet induced a significant change in repairable primary or oxidative DNA lesions over this short timeframe. Conclusions: These exploratory findings suggest that strict calorie restriction can rapidly stabilise genome stability in advanced clinical settings, warranting future randomised controlled trials with long-term longitudinal follow-up to assess permanent risk reductions. Due to structural baseline variations in age, chronic comorbidities, and compliance environments between the cohorts, direct comparative superiority cannot be definitively established. Full article

Microplastics and nanoplastics (MNPLs) are increasingly recognized as dynamic vectors capable of transporting a wide range of environmental contaminants, as well as acting as physical particulates. Their small size, high surface reactivity and strong sorption capacity allow them to carry metals, pesticides, pharmaceuticals and endocrine-active compounds into biological systems. This narrative review examines how these particle-contaminant complexes influence oxidative stress, inflammatory signaling and endocrine function during early development. Relevant literature was identified through structured searches of PubMed, Scopus, Web of Science and Google Scholar, with a focus on the physicochemical properties of plastics, sorption mechanisms, gut barrier physiology and developmental toxicology. Early developmental stages are particularly sensitive, as immature mucus layers, permeable epithelial junctions and underdeveloped detoxification pathways facilitate the uptake and systemic distribution of MNPLs. Once internalized, these particles and their chemical cargo promote the generation of reactive oxygen species through redox-active contaminants, surface-catalysed reactions and mitochondrial dysfunction. The resulting oxidative imbalance activates stress-responsive pathways, including Nrf2–Keap1 signaling, and promotes lipid peroxidation, DNA damage and cellular dysfunction. MNPLs also stimulate inflammatory cascades by activating pattern-recognition receptors, altering cytokine profiles and disrupting epithelial homeostasis. These responses are intensified in the presence of sorbed pollutants, leading to sustained inflammatory states that can be particularly detrimental during organogenesis and immune maturation. Endocrine function is likewise affected, as MNPLs transport hormonally active chemicals and can interfere with hormone-responsive pathways through oxidative and inflammatory mechanisms. These interactions may disrupt thyroid signaling, metabolic regulation and the development of the reproductive axis, with potential long-term physiological consequences. Integrating evidence from polymer chemistry, contaminant behavior and developmental physiology, this review shows that MNPLs act as biologically active vectors that may increase oxidative, inflammatory and endocrine disturbances during early development. These findings highlight the importance of considering particle–contaminant interactions as a critical component of early-life risk assessment. Full article

Effective hand washing takes time and hand sanitizers that contain alcohol have a number of drawbacks, and frequent use of alcohol may cause skin damage. The objective of this study is to formulate nanostructured lipid carrier systems containing chlorhexidine digluconate to be applied topically for hand hygiene, especially for people sensitive to alcohol. A cytotoxicity experiment was conducted to ascertain the safe dosage for each of the three nano-cream formulas (F1, F2 and F3). Following each treatment, the viral titer was assessed using tissue culture infectious dose₅₀ and standard plaque assays. The selected formulation was characterized rheologically. Furthermore, fifteen volunteers of various ages and genders participated in the vivo antimicrobial test of the selected formulation as a hand sanitizer. All of the formulas were found to be safe. Using the disc diffusion method, the three formulations exhibited in vitro antimicrobial effects against different microbes. F1 showed biphasic release, reasonable skin deposition and spherical droplets under a microscope. F1 exhibited a non-Newtonian shear thinning flow behavior. After 30 min, the reduction values for rotavirus and Phix-174 were 21 and 4%, respectively. Additionally, the impact of F1 was assessed on the infectivity of simian rotavirus sa-11 (ds RNA) and Phix-174 (ss DNA) bacteriophage. According to the findings of the in vivo study, the percentage of total bacterial counts that were removed varied from 91 to 100%. Moreover, the range of the removal percentage of total fungi was 95.38 to 100%. In summary, F1 can be used as an economic, safe, and effective hand antiseptic. It can also completely replace alcohol in the market. Full article

DMG, including DIPG, is a highly aggressive pediatric brain tumor with dismal clinical outcomes. Radiotherapy remains the cornerstone of treatment, yet responses are transient and resistance is nearly universal. Emerging evidence indicates that EVs are key mediators of radiation response, facilitating intercellular communication and the propagation of radioresistant phenotypes within the tumor microenvironment. EVs carry diverse molecular cargo, including RNAs, proteins, and lipids, that can dynamically influence tumor behavior and treatment response. In this review, we focus on the role of EVs in shaping radiation response in DMG, while also examining their broader functions in tumor biology, biomarker development, and therapeutic delivery. We summarize evidence for EV-mediated regulation of tumor growth, invasion, microenvironmental interactions, and immune modulation. We further discuss the potential of EVs as minimally invasive biomarkers for liquid biopsy, highlighting both their advantages and current limitations relative to circulating tumor DNA (ctDNA) approaches. In addition, we review emerging strategies utilizing EVs as therapeutic delivery platforms capable of crossing the blood–brain barrier (BBB) and delivering small molecules and nucleic acid-based therapies. Finally, we explore the role of EVs in modulating radiation response, including their contribution to radioresistance and their potential as biomarkers of treatment efficacy. Although EV-based approaches hold significant promise in DMG, challenges related to standardization, specificity, and clinical validation remain. Continued investigation into EV biology and translational applications may provide new opportunities for improving diagnosis, monitoring, and treatment of this devastating disease. Full article

Fatty liver disease represents a major metabolic disorder affecting domestic animals worldwide, with significant implications for animal health, welfare, and agricultural productivity. Disrupted communication between mitochondria and other organelles—particularly the endoplasmic reticulum, lipid droplets, and lysosomes—plays a critical role in disease pathogenesis. This review synthesizes knowledge on inter-organellar communication across domestic animals, with emphasis on species-specific adaptations. We address the “Dairy Cow Paradox”—periparturient dairy cows develop severe hepatic steatosis (>30% liver fat), yet under sterile conditions, they have a higher threshold for progressing to sterile steatohepatitis compared to rodents and humans. However, it is critical to note that severe fatty liver in dairy cows is indeed associated with impaired autophagy, inflammation, and liver damage, particularly when accompanied by ketosis or concurrent infections, and 39% of transition cows exhibit moderate to severe lymphocytic hepatitis. We propose that the tolerance to severe steatosis in dairy cows arises from three adaptations: (1) attenuated innate immune sensing via the cGAS-STING pathway; (2) enhanced lipid buffering from perilipin 5 (PLIN5) with a hypothesized ruminant-specific Val152 substitution that may stabilize lipid droplet–mitochondria contacts; and (3) dampened calcium signaling due to ER–mitochondria membrane lipid raft rigidity, elevated inositol 1,4,5-trisphosphate receptor 2 (IP₃R2) expression, and reduced mitochondrial calcium uniporter (MCU) conductance. We contrast this with the inflammatory steatohepatitis common in rodent models driven by calcium overload and mitochondrial DNA (mtDNA) release, and glucocorticoid-mediated mitofusin 1 (MFN1) suppression, causing mitochondrial fragmentation in poultry. We identify critical knowledge gaps, including the need to define bovine and avian mitochondria-associated endoplasmic reticulum membrane (MAM) proteomes and spatially resolve hepatic zonal communication patterns. Targeting organellar communication hubs with nutraceuticals or pharmacological agents offers promising therapeutic strategies. Full article

Background: Atopic dermatitis is a chronic inflammatory skin disease characterized by epidermal barrier dysfunction and immune dysregulation, whereas major depressive disorder is a common psychiatric condition with a substantial impact on quality of life; increasing attention has been given to oxidative and nitrosative stress as a potential biological link between these disorders. Methods: This narrative review synthesizes current evidence on molecular biomarkers of oxidative and nitrosative stress in AD and MDD and examines shared mechanisms within the skin–brain axis. Results: Across both conditions, studies consistently report increased markers of lipid peroxidation (e.g., malondialdehyde, 4-hydroxynonenal), oxidative DNA damage (8-hydroxy-2′-deoxyguanosine), and nitrosative stress, alongside impaired antioxidant defenses, particularly involving glutathione; these alterations are closely associated with chronic inflammation, cytokine signaling, mitochondrial dysfunction, and dysregulation of neuroimmune and hypothalamic–pituitary–adrenal axis pathways. Conclusions: Although the available evidence is heterogeneous and largely based on cross-sectional studies, limiting causal inference, the findings support a biologically plausible link between AD and depression mediated by shared redox pathways and highlight the need for further longitudinal and mechanistic research. Full article

Background/Objectives: Hepatocellular carcinoma (HCC) is challenging to treat with chemotherapy. Immunotherapy has shown moderate responses in inflammatory and immunosuppressive tumor environments. Hepatic cytochrome P450 monooxygenases (CYPs) play a crucial role in xenobiotic and drug metabolism, as well as lipid and steroid metabolism. We aimed to investigate whether CYP expression and various parameters of the innate and adaptive immune system are prognostic factors for the survival of HCC patients. Methods: HCC biopsies (n = 370) from The Cancer Genome Atlas (TCGA) database were analyzed using Kaplan–Meier statistics and the KMPlotter algorithm. Parameters such as immune cell infiltration, DNA mutation rates, and neoantigen load were selected for survival analysis and subjected to hierarchical cluster analysis. The expression of candidate CYP genes in tumors was compared to that in normal liver tissues. Furthermore, tumor infiltration of innate immune cells (basophilic and eosinophilic granulocytes, natural killer cells), adaptive immune cells (CD4+ memory and CD8+ cytotoxic T cells, regulatory T cells, type 1 and type 2 helper T cells), and mesenchymal stem cells was examined. Results: High expression of CYP19A1 and CYP26B1 was associated with shorter survival, whereas high expression of CYP3A5, CYP3A43, CYP7A1, and CYP27A1 was linked to longer survival. Mutation rates combined with CYP expression showed a correlation with five out of six CYP genes, while a high neoantigen load produced less definitive results. A specific cluster exhibiting high CYP expression and immune cell counts or mutation/neoantigen rates was associated with shorter survival, while another cluster was linked to longer survival. Conclusions: CYPs involved in the metabolic regulation of HCC, including CYP3A5, CYP3A43, CYP7A1, CYP19A1, CYP26B1, and CYP27A1, were found to have prognostic value for patient survival. Combined signatures that include CYP expression, mutational rates, and immune cell infiltration into tumors further enhanced the prognostic value for patient survival. This suggests that CYPs may influence the creation of a tumor-specific metabolic microenvironment that impacts immune functions. These combined signatures could be utilized for patient stratification to personalize tumor treatment and develop novel combination therapies aimed at optimizing treatment outcomes, such as combining transarterial chemoembolization (TACE) with immune checkpoint inhibitors. Full article

Micro- and nanoplastics (MNPs) are emerging environmental contaminants of increasing relevance to human health. Growing evidence suggests that, following ingestion, inhalation, or, less convincingly, dermal exposure, MNPs may cross biological barriers, enter lymphatic and vascular compartments, and reach the liver. Owing to portal blood flow, sinusoidal architecture and Kupffer cell activity, the liver appears to be one of the principal sites of early particle sequestration. Human biomonitoring, ex vivo and postmortem studies have detected MNPs in blood and multiple organs, including the liver, although the currently available evidence remains limited and methodologically heterogeneous. Their identification relies on multistep analytical procedures that integrate sample pretreatment with FTIR, Raman spectroscopy, LD-IR, Py-GC-MS and supplementary imaging methods. However, each of these techniques presents significant limitations, particularly in the analysis of nanoplastics. Experimental studies indicate that MNPs may induce hepatic injury through oxidative stress, mitochondrial impairment, endoplasmic reticulum stress, inflammation, DNA damage, dysregulated lipid metabolism and disruption of the gut–liver axis, consequently contributing to steatosis, cholestatic anomalies and fibrosis. Consequently, MNPs should be considered potential contributors to liver pathology, although more comprehensive human data are still required. Full article

Ischemic heart disease (IHD) is a chronic and progressive condition characterized by reduced blood flow, mainly due to atherosclerosis. It is currently the leading cause of mortality among cardiovascular diseases. In recent years, per- and polyfluoroalkyl substances (PFAS), a group of ubiquitous and highly persistent environmental contaminants, have emerged as potential risk factors for IHD. PFAS are well-established endocrine disruptors and have been associated with hypercholesterolemia, hypertriglyceridemia, and insulin resistance. Despite the limited number of epidemiological studies and inconsistent findings from occupational settings, accumulating evidence suggests that elevated exposure to certain PFAS compounds may increase the risk of IHD and vascular dysfunction, including processes related to atherosclerosis development, sometimes with dose–response relationships and sex-specific patterns. Mechanistic evidence supports this link, indicating that PFAS exposure induces molecular and cellular alterations relevant to cardiovascular pathophysiology, including increased oxidative stress and vascular inflammation, and disruption of lipid metabolism. In addition, PFAS may affect epigenetic regulation, telomere length, and mitochondrial DNA copy number, which are emerging biomarkers associated with atherosclerosis and IHD and may indicate early cardiovascular vulnerability. Future research integrating innovative approaches and advanced analytical techniques may help address current knowledge gaps and clarify the mechanistic pathways linking PFAS exposure to clinical cardiovascular outcomes. Full article

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in older adults and is characterized by progressive dysfunction of the retinal pigment epithelium (RPE). Although genetic susceptibility and environmental exposure both contribute to disease risk, the mechanisms through which chronic metabolic and oxidative stress are integrated into sustained RPE dysfunction remain incompletely understood. Increasing evidence from human AMD donor tissue and experimental RPE models indicates that epigenetic regulation operates at the interface between mitochondrial dysfunction, redox imbalance, and transcriptional remodeling. This review synthesizes current findings on DNA methylation, chromatin accessibility, histone modification, and RNA-based regulation in AMD, with emphasis on their metabolic and mitochondrial context. Studies in human AMD-RPE demonstrate that epigenetic alterations are generally selective rather than global and frequently involve pathways related to mitochondrial maintenance, lipid metabolism, oxidative stress responses, and cellular homeostasis. Mechanistically, mitochondrial dysfunction and reactive oxygen species (ROS) may influence epigenetic regulation through altered Nicotinamide adenine dinucleotide (NAD⁺) availability, acetyl-CoA metabolism, redox-sensitive chromatin regulation, and modulation of DNA methyltransferase and histone deacetylase activity. Redox-sensitive pathways, including antioxidant signaling, further connect mitochondrial stress to adaptive or maladaptive transcriptional responses in the RPE. Importantly, while several interactions discussed are supported by findings in human AMD tissue, other components of the proposed epigenetic–mitochondrial–redox framework remain inferential or model-based and require further validation. Rather than acting as isolated disease triggers, epigenetic changes are more likely to function as stress-responsive regulatory layers that stabilize transcriptional states over time in a long-lived post-mitotic tissue. We further discuss unresolved questions regarding causality, reversibility, therapeutic feasibility, and stage-specific intervention strategies. Collectively, this framework positions the epigenetic–mitochondrial–redox axis as a unifying model for understanding RPE vulnerability and AMD progression. Full article

The seeds of Impatiens balsamina L. have been traditionally used in East Asian medicine and are known to contain bioactive compounds with antioxidant properties. However, studies focusing on seed-derived callus remain limited. This study aimed to comparatively evaluate the antioxidant activities and lipid accumulation-inhibitory effects of 70% ethanol extracts from seeds (IB) and seed-derived callus (IBC) of I. balsamina. Callus was induced on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D). Antioxidant activities were evaluated using DPPH radical scavenging, superoxide anion scavenging, deoxyribose-based hydroxyl radical scavenging, DNA nicking, lipid peroxidation, and relative electrophoretic mobility (REM) assays, along with the determination of total phenolic, flavonoid, and tannin contents. Cell viability and lipid accumulation were assessed in FFA-treated HepG2 cells. In silico network and transcription factor (TF) enrichment analyses were performed to explore underlying mechanisms. Callus induction was most effective at 1 mg/L 2,4-D. Both IB and IBC exhibited antioxidant activities across all assays, with IB showing higher activity and greater phytochemical content than IBC. Both extracts reduced lipid accumulation in FFA-treated HepG2 cells at non-cytotoxic concentrations. Network analysis identified enrichment in pathways related to oxidative stress, inflammation, and lipid metabolism, and TF enrichment analysis identified NFKB1 and ATF3 as major upstream regulators. Both IB and IBC exhibited antioxidant activities across multiple in vitro assays, with IB showing higher activity attributable to its more complex phytochemical content. The lipid accumulation-inhibitory effects observed in FFA-treated HepG2 cells suggest a potential association between antioxidant capacity and lipid regulation, although the underlying mechanisms remain to be experimentally validated. Seed-derived callus may serve as a useful in vitro model for studying plant-derived bioactive compounds, pending further optimization. Full article

Hypoxia-induced radioresistance remains a major obstacle in non-small cell lung cancer (NSCLC) radiotherapy. This study investigates whether artificially activating mitochondrial reverse electron transfer (RET) can enhance radiosensitivity in NSCLC by triggering oxidative stress. An in vitro hypoxia/reoxygenation (H/R) model was established in A549 cells to assess reactive oxygen species (ROS) levels, mitochondrial function, and metabolic alterations using fluorescence probes, flow cytometry, confocal microscopy, and targeted metabolomics. Mitochondrial complex inhibitors and dimethyl succinate (DM-S) were employed to validate the RET mechanism, and radiosensitivity was evaluated through clonogenic survival, apoptosis assays, and γ-H2AX staining. In vivo, A549 tumor-bearing mice received high oxygen (95% O₂) combined with DM-S and localized irradiation (4 Gy); tumor growth, histopathology, and immunohistochemistry were examined. H/R triggered substantial mitochondrial ROS production via complex I-mediated RET, dependent on a high mitochondrial membrane potential and electron transport chain imbalance, with succinate accumulation serving as a key metabolic switch. Exogenous DM-S exacerbated H/R-induced oxidative damage, DNA fragmentation (8-OHdG elevation, mtDNA integrity loss), and mitochondrial network disruption. H/R combined with DM-S significantly enhanced in vitro radiosensitivity, reducing clonogenic survival and increasing apoptosis to 53.4% ± 1.9% versus 10.3% ± 1.2% with irradiation alone. In vivo, the combination therapy markedly suppressed tumor growth, induced apoptosis and oxidative lipid damage (4-HNE), alleviated hypoxia (reduced HIF-1α), and showed no overt toxicity. These findings demonstrate that activating mitochondrial RET effectively enhances radiosensitivity in NSCLC. Succinate metabolism is a critical therapeutic target, and combining high oxygen with a succinate analog represents a promising radiosensitization strategy for hypoxic tumors. Full article