Search Results (290)

Background: Endometriosis is a chronic inflammatory and estrogen-dependent disease in which oxidative stress, immune dysregulation, and lesion-supportive microenvironmental signaling contribute to lesion development. N-acetylcysteine (NAC), a glutathione-replenishing and redox-modulating agent, has been studied as a possible non-hormonal intervention. Methods: Following preregistration in the Open Science Framework (OSF), we performed a PRISMA-compliant systematic review of studies evaluating NAC in endometriosis-related clinical, in vivo, ex vivo, or in vitro settings. We searched PubMed/MEDLINE, EBSCOhost, and the Bielefeld Academic Search Engine (BASE) from inception to 24 May 2026. Risk of bias was assessed with design-specific instruments. Results: Twenty-two studies were included. Clinical evidence comprised six studies and suggested that the findings vary by clinical context. In non-postoperative settings, NAC was associated with reduced pain, decreased NSAID use, and endometrioma shrinkage or stabilization. In contrast, the only postoperative randomized comparison found no added benefit of NAC over continuous oral contraceptive therapy for recurrence or pain. Fertility-related clinical findings were suggestive but preliminary. Across nonclinical models, NAC reduced proliferation, lesion burden, oxidative stress, inflammatory mediators, and, in selected systems, migration-related behavior. Mechanistic studies linked NAC to modulation of ROS-dependent proliferation, TNF-α, COX-2, MMP-2/-9, autophagy-related signaling, oxidation-sensitive nociception, and partial protection of oocyte and embryo competence under endometriosis-associated oxidative conditions. Conclusions: NAC shows biological plausibility and preclinical activity in endometriosis, but clinical evidence is heterogeneous and methodologically limited. Full article

Background/Objectives: Drug repurposing has emerged as a promising strategy for identifying novel anticancer agents among clinically established drugs. Fexofenadine, a second-generation H1 antihistamine, has been proposed as a candidate for repurposing in oncology; however, the molecular mechanisms underlying its biological activity remain insufficiently characterized. This study investigated the effects of fexofenadine on oxidative stress, mitochondrial function, apoptosis, and pro-survival signaling pathways in cervical and lung cancer cells. Methods: HeLa and A549 cancer cells, as well as non-tumorigenic Beas-2B epithelial cells, were exposed to fexofenadine under in vitro conditions. Cell viability, apoptosis, reactive oxygen species generation, mitochondrial membrane potential, DNA damage, autophagy-associated responses, and PI3K/AKT and MAPK/ERK pathway activation were assessed using flow cytometry, fluorescence microscopy, electron microscopy, and biochemical assays. Three-dimensional spheroid cultures and N-acetyl-L-cysteine rescue experiments were additionally employed to evaluate biological relevance and the contribution of oxidative stress. Results: Fexofenadine induced concentration-dependent accumulation of reactive oxygen species, mitochondrial membrane depolarization, Bcl-2 inactivation, caspase-3/7 activation, DNA damage, and apoptotic cell death in HeLa and A549 cells. Antioxidant pretreatment with N-acetyl-L-cysteine significantly reduced oxidative stress, attenuated mitochondrial dysfunction, and partially suppressed apoptosis. Fexofenadine was associated with reduced PI3K/AKT and MAPK/ERK pathway activation and promoted autophagy-associated responses. In three-dimensional spheroid cultures, treatment disrupted spheroid integrity and increased apoptotic cell death. Non-tumorigenic Beas-2B cells exhibited lower sensitivity to treatment than malignant cells. Conclusions: Fexofenadine disrupts redox homeostasis and is associated with reduced activation of pro-survival signaling pathways, resulting in oxidative stress-associated mitochondrial dysfunction and apoptosis in cancer cells. These findings provide mechanistic support for further evaluation of fexofenadine as a candidate for anticancer drug repurposing, while additional pharmacokinetic and in vivo studies are required to determine its translational relevance. Full article

Shiga toxin-producing Escherichia coli (STEC) infections are a major cause of hemolytic uremic syndrome (HUS), a thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The pathogenesis of STEC-HUS is primarily driven by Shiga toxins (Stx), which induce endothelial injury, inflammation, platelet activation, and microvascular thrombosis. Hemolysis associated with thrombotic microangiopathy leads to the release of hemoglobin and free heme into the circulation. Free heme, an iron-containing molecule with potent pro-oxidative, pro-inflammatory, and cytotoxic properties, contributes to oxidative stress, endothelial dysfunction, complement activation, and further tissue injury. Oxidative stress plays a crucial role in both host and bacterial cells, influencing disease progression and the expression of bacterial virulence factors, including Shiga toxin. N-acetyl-L-cysteine (NAC), a precursor of glutathione (GSH) and a well-established antioxidant, has attracted attention as a potential adjunctive therapeutic agent due to its antioxidant, anti-inflammatory, antiplatelet, and cytoprotective properties. In addition, NAC may influence iron- and heme-mediated oxidative damage and improve erythrocyte resistance to oxidative stress. This review summarizes current knowledge regarding the roles of oxidative stress and free heme in STEC-HUS and examines the mechanistic rationale and current evidence supporting NAC as a potential adjunctive strategy. The available evidence remains largely indirect and preclinical; therefore, the potential role of NAC in STEC-HUS should be considered hypothesis-generating and requires further investigation in clinical studies. Full article

Background/Objectives: The toxic side effects and resistance-associated limitations of conventional chemotherapeutic agents necessitate the development of more effective and selective combination strategies incorporating naturally derived compounds. In this study, the cytotoxic, apoptotic, oxidative stress-associated, and immunomodulatory effects of thymoquinone (TQ), a bioactive compound derived from Nigella sativa, and docetaxel (Dos), a taxane-based chemotherapeutic agent, were investigated alone and in combination in OVCAR3 ovarian cancer cells using integrated two-dimensional (2D) and three-dimensional (3D) experimental models. Materials and Methods: Cell viability was evaluated following treatment with TQ (10–500 µM), Dos (1–500 nM), and the TQ + Dos combination, and synergistic interactions were assessed by IC₅₀⁻ and combination index-based analyses. Apoptosis and cell cycle distribution were analyzed by flow cytometry. Cytokine levels were determined using ELISA, whereas apoptosis- and cell cycle-associated gene expression profiles were evaluated by RT-qPCR. Active caspase-3 expression was assessed by immunocytochemistry. Intracellular reactive oxygen species (ROS) accumulation was examined using DCFH-DA-based fluorescence imaging and antioxidant rescue experiments using N-acetyl-L-cysteine (NAC). In addition, the antitumor activity of the combination was further evaluated in OVCAR3-derived 3D tumor spheroid models using spheroid morphology, ATP-based viability, and live/dead fluorescence imaging analyses. Results: The TQ + Dos combination demonstrated enhanced cytotoxic and apoptotic activity in OVCAR3 cells compared with single-agent treatments and induced marked G2/M cell cycle arrest. Combination treatment increased pro-apoptotic gene expression and was associated with reduced expression of anti-apoptotic markers and modulated inflammatory cytokine profiles. Fluorescence-based analyses demonstrated marked intracellular ROS accumulation following TQ + Dos treatment, whereas NAC pretreatment partially attenuated oxidative stress and restored viability, suggesting partial involvement of ROS-associated mechanisms in treatment-induced cytotoxicity. Importantly, the combination maintained stronger cytotoxic and growth-inhibitory effects than either monotherapy in 3D ovarian cancer spheroids, where combination treatment induced pronounced spheroid shrinkage, viability loss, and structural disruption. Relatively lower toxicity observed in HaCaT cells suggested partial selectivity toward cancer cells. Conclusions: Collectively, these in vitro findings suggest that the TQ + Dos combination produces greater cytotoxic, apoptotic, and growth-inhibitory effects than either agent alone in ovarian cancer models and is associated with alterations in apoptosis-, cell cycle-, and oxidative stress-related responses. The observation of these effects in 3D spheroid models supports further investigation of this combination in more advanced preclinical systems. Full article

Methylmercury (MeHg) is a potent environmental contaminant primarily ingested through seafood consumption. Gestational exposure induces profound neurological and developmental deficits in the fetus that often persist throughout childhood. This developmental vulnerability arises from the immature state of the blood–brain barrier and a limited endogenous antioxidant capacity in the developing CNS. Postnatal exposure via breastfeeding further compromises neurodevelopment, specifically impairing visuospatial processing and memory. While fetal and placental mercury accumulation correlates with gestational age, the specific mechanisms of transplacental transport remain poorly defined. Mechanistically, MeHg predominantly accumulates in fetal renal tissue, followed by the brain and liver. This review aims to elucidate MeHg-induced oxidative stress and autophagic collapse mediated by the PI3K/AKT/mTOR and AMPK/TSC2/mTOR pathways. Furthermore, we evaluate neuroprotective candidates, specifically N-acetyl-L-cysteine (NAC) and CCL chemokine modulation, as strategies to mitigate fetal impairment and the associated cellular damage. Full article

Chattonella marina is an ichthyotoxic, bloom-forming raphidophyte known for its hemolytic activity. However, the mechanisms by which nitrogen (N) and phosphorus (P) limitation influence this hemolytic toxicity remain poorly understood. In this study, both N and P limitation reduced growth, photosynthetic efficiency (F_v/F_m, Y_II, rETR_max), and the expression of nutrient-uptake, tetrapyrrole/chlorophyll biosynthesis genes. Nevertheless, the two nutrients produced opposite effects on toxicity: N limitation lowered hemolytic activity and ROS levels to near zero, whereas P limitation kept both relatively high, similar to nutrient-replete controls. The addition of the antioxidant NAC (N-Acetyl-L-cysteine) reduced hemolytic activity, confirming that ROS contributes to toxicity. Transcriptome data showed that under N limitation, genes for nitrogen uptake and initial reduction (NRT, NR, glnA) were upregulated, while downstream assimilation genes (nirA, GLT1) were downregulated. In contrast, under P limitation, all the nitrogen-metabolism-related genes (NRT, NR, glnA, nirA, GLT1) were downregulated. In the tetrapyrrole pathway, most genes were downregulated under both nutrient-limited conditions, except for HemD, suggesting a bottleneck that may result in the accumulation of porphyrin intermediates within the tetrapyrrole/chlorophyll biosynthesis pathway. Together, the secondary products derived primarily from the reaction of ROS with tetrapyrrole-based compounds appear to be the main contributors to hemolytic toxicity. Consequently, high levels of both ROS and porphyrin intermediates under P-limited conditions, as well as high ROS levels but low porphyrin intermediates under nutrient-sufficient conditions, may both contribute to the high hemolytic toxicity of C. marina. In contrast, under N limitation, despite the accumulation of porphyrin intermediates, the strong suppression of photosynthetic electron transport limits both ROS production and the synthesis of nitrogen-containing toxins, resulting in low hemolytic activity. These findings demonstrate that nutrient conditions regulate hemolytic activity in C. marina in a nutrient-specific manner. 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

A two-year field experiment was conducted in Tengchong, Yunnan, to evaluate the effects of tobacco monoculture (TM) and maize relay intercropping with tobacco (TIM) on subsequent tobacco growth and the rhizosphere microenvironment. Results showed that TIM significantly increased plant height by 11.8% and maximum leaf length by 12.4% at the vigorous growth stage without reducing yield. Although leaf chloride content increased and the potassium-to-chloride ratio decreased, both remained within high-quality ranges. Relay-cropped silage maize yielded 4.86 t·hm⁻², adding 1.70 × 10⁴ CNY·hm⁻². TIM reduced nitrogen accumulation in aboveground tobacco and temporarily lowered soil organic matter and available potassium, while increasing acid phosphatase, peroxidase, and urease activities. Soil bacterial α-diversity increased, with enrichment of beneficial genera, including Candidatus Solibacter, Talaromyces, and Penicillium. Metabolomics identified 1043 metabolites, with upregulation of galactinol, N-acetyl-L-tryptophan, and 3-dehydroshikimic acid, enriched in cyanogenic amino acid and cysteine–methionine pathways. PLS-PM and Mantel analyses indicated that relay-cropped maize indirectly regulates nutrient availability via microbial and metabolic pathways. These results show that maize relay intercropping creates a soil “legacy effect,” shifting the system from direct nutrient competition to microbially mediated nutrient buffering. Full article

Background/Objectives: Retinoblastoma treatment remains limited by therapeutic resistance and toxicity. While melphalan is a key chemotherapeutic agent, its efficacy is constrained by adverse effects. Curcumin has emerged as a potential adjunct owing to its capacity to regulate oxidative stress and oncogenic signaling pathways, including STAT3. This study aimed to assess the synergistic tumor-inhibitory effects of melphalan–curcumin combined treatment and to investigate the roles of ROS, apoptosis, and STAT3-associated signaling, including validation in a three-dimensional (3D) tumor spheroid model. Materials and Methods: Human retinoblastoma (WERI-Rb-1) and normal keratinocyte (HaCaT) cells were exposed to melphalan, curcumin and the combined treatment regimen. Cell viability was analyzed by MTT assay, and drug interactions were analyzed using the Chou–Talalay method. Migration was evaluated by scratch assay. Intracellular ROS levels were quantified using the DCFH-DA assay and confirmed by flow cytometry. Apoptosis was quantified by Annexin V/PI staining, and caspase activity was assessed colorimetrically and by immunocytochemistry. Cytokine levels were determined by ELISA, and gene expression profiling of STAT3 and apoptosis-associated genes were performed using qRT-PCR. Three-dimensional tumor spheroids were established to evaluate treatment responses in a physiologically relevant model. The contribution of ROS was further investigated using N-acetyl-L-cysteine (NAC) pretreatment. Results: The combination of melphalan and curcumin notably reduced WERI-Rb-1 cell viability in a synergistic manner (CI < 1) while exhibiting lower cytotoxicity in HaCaT cells, indicating selective antitumor activity. Co-treatment markedly inhibited cell migration and increased intracellular ROS levels. Cells pretreated with NAC significantly reduced ROS levels accumulation and moderately restored cellular viability, supporting a contributory role of oxidative stress. The combination treatment induced pronounced apoptosis, with increased early and late apoptotic cell populations, enhanced caspase-7 and caspase-9 activity, and elevated caspase-9 protein expression. These effects were associated with upregulation of pro-apoptotic genes (BAX, CASP3, CASP7, CASP9), downregulation of anti-apoptotic genes (BCL2, SURVIVIN), and reduction in STAT3 mRNA expression. In addition, the combination reduced pro-inflammatory cytokine levels. Importantly, these effects were recapitulated in 3D tumor spheroids, where the combination treatment reduced spheroid size and viability and induced structural disruption. NAC-mediated rescue experiments in 3D models further supported the notion that ROS contributes to, but is not solely responsible for, the observed effects. Conclusions: Overall, these results suggest that melphalan and curcumin exert synergistic and selective antitumor effects in retinoblastoma cells, associated with changes consistent with ROS-related effects, mitochondrial apoptotic processes, and STAT3-related transcriptional alterations rather than definitive pathway activation. The validation of these effects in a 3D tumor spheroid model provides additional support for the potential clinical significance of this combined treatment; however, additional protein-level and functional validation is required. Full article

Quercetin, a naturally occurring flavonoid, exhibits antiproliferative and pro-apoptotic effects across various cancer models. Topotecan, a topoisomerase I inhibitor, is used in the treatment of retinoblastoma; however, its clinical utility is limited by dose-dependent toxicity. This study aimed to investigate whether quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma and to explore the underlying mechanisms under both two-dimensional (2D) and three-dimensional (3D) conditions. Cell viability was assessed using the MTT assay, and drug interactions were evaluated using the combination index (CI) based on the Chou–Talalay method. Apoptosis was analyzed by Annexin V-FITC/PI staining and flow cytometry. Reactive oxygen species (ROS) levels and mitochondrial membrane potential were evaluated using fluorometric methods, and N-acetyl-L-cysteine (NAC) was used for functional modulation of oxidative stress. Three-dimensional tumor spheroid models were used to assess treatment effects under conditions that partially recapitulate tumor architecture. Gene expression levels of apoptosis-related markers and PI3K/Akt/mTOR pathway components were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The combination of quercetin and topotecan was associated with synergistic cytotoxic effects in Y79 cells (CI < 1), accompanied by increased ROS levels, mitochondrial membrane depolarization, and elevated apoptotic cell death. NAC co-treatment partially attenuated ROS levels and restored cell viability. In 3D spheroid models, combination treatment induced structural disruption, reduced viability, and increased cell death, effects that were partially reversed by NAC. Gene expression analysis revealed upregulation of pro-apoptotic genes and downregulation of survival-related genes, along with increased PTEN expression. Quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma cells under both 2D and 3D conditions. These effects were associated with ROS-associated cellular stress, mitochondrial dysfunction, and modulation of apoptotic and survival-related pathways. The partial rescue by NAC supports a contributory, but not exclusive, role of oxidative stress. These findings should be interpreted within a preclinical context and suggest that quercetin may represent a potential adjunct strategy warranting further validation in translational and in vivo models. Full article

Oral mucosal ulcers sustain a persistent inflammatory and oxidative microenvironment that interferes with epithelial repair and delays healing. Although hyaluronic acid (HA) is used in oral wound management due to its biocompatibility and hydrating properties, its biological activity is highly context-dependent and can be compromised under inflammatory conditions. In contrast, N-acetyl-L-cysteine (NAC) is a well-established antioxidant with documented anti-inflammatory effects, yet its rapid clearance limits its effectiveness when applied locally. In this study, the effects of HA and NAC, individually and in combination, on metabolic activity and inflammatory responses of TNF-α–stimulated human gingival keratinocytes were evaluated. In parallel, the individual immobilization of HA or NAC onto plasma-activated decellularized extracellular matrix (dECM) films was investigated as a materials-oriented approach for potential localized intraoral applications. NAC significantly attenuated TNF-α-induced IL-6 and IL-8 secretion, reducing both cytokines by approximately 99%, while preserving keratinocyte metabolic activity. HA displayed limited immunomodulatory effects. The combined HA + NAC condition did not improve the response compared with NAC alone. Plasma treatment enabled stable individual grafting of HA and NAC onto dECM films, and both functionalized surfaces retained chemical stability under saliva-like conditions. Collectively, these findings identify NAC as the most effective anti-inflammatory candidate under the tested cellular conditions and support plasma-functionalized dECM films as a feasible platform for future biological evaluation in intraoral applications. Full article

Background/Objectives: Retinoblastoma represents the most common intraocular malignancy in childhood; however, the clinical applicability of mitomycin C (MMC) is restricted by dose-dependent ocular toxicity. Consequently, the development of pharmacological strategies that sensitize tumor cells to MMC while allowing dose reduction remains an unmet therapeutic objective. In this context, quercetin, a bioactive flavonoid with pleiotropic anticancer properties, has emerged as a potential chemosensitizing agent. Methods: Human retinoblastoma cell lines Y79 and WERI-Rb1 were exposed to MMC and quercetin, administered either individually or in fixed-ratio combinations. Cytotoxic responses were quantified through dose–response modeling and IC₅₀ determination following 24 and 48 h of treatment. Drug–drug interactions were quantitatively characterized using the Chou–Talalay combination index (CI) approach and isobologram analysis. Cell cycle distribution was assessed by propidium iodide (PI)-based flow cytometric analysis to evaluate treatment-associated alterations in cell cycle progression. Apoptotic cell death was assessed by Annexin V-FITC/PI flow cytometry, while transcriptional modulation of genes associated with apoptosis, cell cycle regulation, and oxidative stress (BAX, BCL-2, TP53, CASP3, CDKN1A, and HMOX1) was evaluated by qRT-PCR. Modulation of tumor-supportive signaling was examined by measuring VEGF and IL-6 secretion. Translational relevance was further investigated using a three-dimensional (3D) tumor spheroid model, and the functional contribution of reactive oxygen species (ROS) was interrogated through N-acetyl-L-cysteine (NAC) rescue experiments. Results: Quercetin significantly enhanced the cytotoxic activity of MMC in both retinoblastoma cell lines, with CI values below 1 across IC₅₀–IC₉₀ effect levels, indicating a synergistic pharmacological interaction. PI–FACS analysis revealed that combined MMC and quercetin treatment induced a pronounced accumulation of cells in the G2/M phase, consistent with cell cycle arrest, with a more marked effect observed in Y79 cells compared with WERI-Rb1 cells. Combination treatment resulted in a pronounced increase in apoptotic cell populations compared with single-agent exposure and triggered a coordinated pro-apoptotic transcriptional response, characterized by increased expression of BAX, TP53, CASP3, CDKN1A, and HMOX1, alongside suppression of BCL-2 and a marked shift in the BAX/BCL-2 ratio. Concurrently, VEGF and IL-6 secretion were significantly reduced, reflecting attenuation of pro-angiogenic and pro-inflammatory signaling. Notably, synergistic cytotoxicity was maintained in 3D tumor spheroids, where combined treatment induced spheroid shrinkage, architectural disruption, and reduced viability. NAC pretreatment diminished ROS accumulation and partially restored cell viability, indicating that oxidative stress contributes to, but does not solely account for, the observed synergistic cytotoxic effect. Conclusions: Collectively, these findings indicate that quercetin appears to function as an effective chemosensitizing adjuvant to MMC in retinoblastoma models, through transcriptional changes consistent with p53-associated apoptotic signaling at the transcriptional level, G2/M cell cycle arrest, and partial involvement of ROS-related cellular stress responses, along with suppression of tumor-supportive signaling pathways. The preservation of synergistic activity in 3D tumor spheroids supports the potential preclinical relevance of this combination. However, these findings are based on transcriptional and phenotypic analyses and should be interpreted as hypothesis-generating, requiring further validation through protein-level and in vivo studies before translational application. Full article

Background: Cryopreservation induces oxidative stress, membrane disruption, and mitochondrial injury in spermatozoa, leading to impaired motility and fertility. Selenium, as an essential trace element, protects cells from oxidative damage through selenoproteins such as glutathione peroxidase 4 (GPX4), a critical enzyme that detoxifies lipid hydroperoxides and inhibits ferroptosis. This study investigated whether supplementation with L-selenomethionine (L-SeMet), an organic selenium source with superior bioavailability and lower toxicity than inorganic forms, could alleviate cryo-induced sperm injury by suppressing ferroptosis. Methods & Results: Dairy goat sperm were cryopreserved with 0, 2, 4, 6, 8, 10 μM L-SeMet. Supplementation with 6 μM L-SeMet significantly improved motility, membrane and acrosome integrity, and mitochondrial membrane potential. Biochemical assays showed reduced iron, ROS, and MDA levels, alongside increased ATP, SOD, and GSH contents. Proteomic analysis identified 148 differentially expressed proteins, including up-regulation of GPX4, FTH1, VDAC2, and VDAC3—core ferroptosis regulators. Metabolomic profiling further revealed enrichment in unsaturated fatty acid biosynthesis, amino acid metabolism, and the TCA cycle, pathways closely linked to ferroptosis regulation. Transmission electron microscopy confirmed that L-SeMet preserved mitochondrial ultrastructure. Mechanistically, L-SeMet mirrored the ferroptosis inhibitor N-acetyl-L-cysteine and reversed RSL3-induced oxidative damage. Western blotting verified activation of the NRF2–SLC7A11–GPX4 antioxidant axis and inhibition of KEAP1 expression. Conclusions: Collectively, these findings demonstrate that L-SeMet protects spermatozoa from cryo-induced injury by stabilizing redox homeostasis, maintaining mitochondrial function, and inhibiting ferroptosis. The results highlight ferroptosis as a critical mechanism of sperm cryodamage and identify L-SeMet as a promising metabolic intervention to enhance post-thaw sperm quality and fertility. Full article

Excessive oxidative stress can cause irreversible cytotoxic damage to both healthy and cancer cells through the induction of reactive oxygen species (ROS) mediated lipid peroxidation. Ferroptosis has recently been shown to promote lipid peroxidation due to the over-accumulation of iron. Although cancer cells possess elevated antioxidant capacity to neutralize chemotherapy-induced oxidative stress, the co-delivery of polyphenol compounds such as curcumin (CUR) can overwhelm these defenses by elevating intracellular ROS levels to a toxic threshold, thereby increasing anticancer efficacy. In this study, we evaluated the potential of CUR to chemosensitize doxorubicin (DOX) towards the DOX-resistant lung cell line (H69AR). Our results demonstrated that the combination of DOX and CUR resulted in a concentration-dependent behavior, where low-dose concentrations exhibited antagonistic effects, while high-dose IC₅₀-equivalent concentrations shifted towards synergism. The combination induced significantly greater mitochondrial dysfunction, ATP depletion, cytochrome C release, and caspase-3 activation. This also resulted in excessive ROS generation, intracellular iron overload, and lipid peroxidation, accompanied by a reduction in antioxidant enzymatic activities. Pretreatment with N-acetyl-L-cysteine (ROS inhibitor) and ferrostatin-1 (ferroptosis inhibitor) further supported the involvement of oxidative stress and ferroptosis in modulating apoptosis and DNA fragmentation. Molecular docking analyses supported the binding of CUR and DOX to key ferroptosis regulators. This study shows the potential of CUR to sensitize DOX-resistant cancer cells through ferroptosis-linked-oxidative stress targeting. Full article

This study addresses the thermodynamic aspects of galactose oxidase (GAOx) adsorption and redox behavior on gold electrodes modified with self-assembled monolayers (SAMs) derived from thiocarboxylic acids, namely N-acetyl-L-cysteine (NAC), mercaptosuccinic acid (MSA), mercaptoacetic acid (MAA), and L-cysteine (Cys). The electrochemical response of GAOx immobilized on these SAM-modified surfaces was analyzed to extract key thermodynamic parameters governing enzyme–electrode interactions, including the formal redox potential (E°), surface excess (Γ), potential of zero charge (E_zc), adsorption free energy (∆G_add), differential capacitance (C_dl), and surface tension (γ). The results demonstrate that the nature of the terminal functional group of the SAM significantly influences the thermodynamic stabilization of GAOx at the gold interface. Shifts in the redox potential are attributed to specific coordination and electrostatic interactions between the SAM functional groups and the GAOx metal center, leading to distinct interfacial energy landscapes. Overall, the SAM-modified electrodes provide a well-defined thermodynamic framework to probe enzyme orientation, interfacial charge distribution, and stabilization of the redox-active state of GAOx during direct electron transfer. These results offer guidelines based on thermodynamic and kinetic principles for customizing enzyme–electrode interfaces, which can enhance the efficiency, stability, and consistency of third-generation electrochemical biosensors. Full article