Search Results (3,913)

Mitochondria play a vital role in fundamental cellular processes, serving as key regulators of energy metabolism, apoptosis, oxidative stress, calcium homeostasis. Mitochondrial dysfunction is widely regarded as a common pathogenic pathway in the development of widespread chronic diseases, such as metabolic disorders, cardiovascular disease, neurodegeneration, and malignancies. Modern research examines mitochondrial dynamics, mitophagy, mitochondrial biogenesis, mtDNA damage, and the role of reactive oxygen species not only for in-depth understanding of disease pathogenesis but also for identifying diagnostic markers and therapeutic targets. Determining mitochondrial dysfunction is a significant challenge and should involve a comprehensive approach with reliable assessment methods that take into account the dynamic state, number, and localization of mitochondria. The review summarizes the results of the studies exploring the pathogenetic role of mitochondrial dysfunction in the development of widespread chronic diseases and current methods of its evaluation for the integration of mitochondrial dysfunction biomarkers into modern diagnostic strategies and development of mitochondria-target treatment approaches. Full article

Lipopolysaccharide (LPS) impairs the function of ovine follicular granulosa cells (GCs), representing a primary cause of follicular atresia. Selenium (Se), an essential trace element, possesses anti-inflammatory and cytoprotective properties; however, its effects on GC ultrastructure remain largely unknown. In this study, primary ovine GCs were exposed to LPS (10 µg/mL) and treated with sodium selenite (25 nM). Transmission electron microscopy (TEM), JC-1 staining, enzyme-linked immunosorbent assay (ELISA), reactive oxygen species (ROS) detection, flow cytometry, and quantitative real-time PCR (qRT-PCR) were employed to evaluate cellular ultrastructure, mitochondrial membrane potential (ΔΨm), and downstream physiological processes. LPS induced severe mitochondrial pyknosis, cristae loss, and reduced ΔΨm, accompanied by inflammation, oxidative stress, apoptosis, and impaired steroidogenesis. Se intervention markedly ameliorated these ultrastructural injuries, preserving mitochondrial morphology and ΔΨm. Functionally, Se suppressed the release of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β); enhanced the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) while attenuating ROS accumulation; inhibited apoptosis by upregulating BCL-2 and downregulating BAX and CASPASE-3; and restored E₂ and P₄ secretion via upregulation of STAR and NR5A1. This study provides direct morphological evidence that Se protects ovine GCs from LPS-induced damage by repairing mitochondrial ultrastructure. This structural restoration is central to its integrated anti-inflammatory, antioxidant, anti-apoptotic, and steroidogenic effects. These in vitro findings suggest that Se may serve as a promising nutritional strategy for mitigating inflammation-driven follicular atresia, pending further in vivo validation. Full article

Inflammatory bowel disease (IBD) is characterized by chronic intestinal inflammation in which excessive cell death and the release of damage-associated molecular patterns (DAMPs) such as high-mobility group box 1 (HMGB1) amplify mucosal injury. Although necrosis—particularly regulated forms including necroptosis and ferroptosis—has emerged as a contributor to IBD pathogenesis, the therapeutic potential of targeting necrotic cell death remains incompletely explored. We investigated whether MIT-001 (previously known as NecroX-7), a mitochondria-targeted reactive oxygen species (ROS) scavenger with anti-necrotic activity, ameliorates intestinal inflammation in an acute dextran sulfate sodium (DSS)-induced colitis model. In vitro, MIT-001 reduced hydrogen peroxide-induced necrotic cell death in IEC-18 intestinal epithelial cells and was associated with a qualitative reduction in the 55-kDa cleaved poly(ADP-ribose) polymerase-1 (PARP-1) fragment (a marker of necrosis), with no apparent change in the apoptosis-related 89-kDa fragment. In vivo, oral administration of MIT-001 to C57BL/6 mice with DSS-induced colitis was associated with preservation of colon length, reduced histological injury, and a marked decrease in HMGB1-positive cells in colonic tissue. Among pro-inflammatory cytokines, IL-1β expression was significantly reduced, while IL-12, monocyte chemoattractant protein-1 (MCP-1), and TNF-α showed non-significant downward trends. These findings indicate that MIT-001 ameliorates DSS-induced colitis in association with reduced HMGB1 and IL-1β expression, supporting further investigation of mitochondria-targeted anti-necrotic strategies as a potential adjunctive approach in IBD. 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

Carrot processing for juice generates substantial pomace residues rich in bioactive compounds, which represent both an environmental challenge and an unexploited resource. This study investigated the protective effects of a polyphenolic extract derived from carrot pomace (CP) against Escherichia coli lipopolysaccharide (LPS)-induced damage. For that, we used IPEC-1 (Intestinal Porcine Epithelial Cells) as an in vitro model of the intestinal epithelium. The total phenolic content of the CP polyphenolic extract (CPE) was 1.017 mg GAE/mL, with flavan-3-ols (epicatechin, catechin, epigallocatechin) accounting for 71.3% of that value. Before being exposed to LPS (10 μg/mL) for 24 h, the cells were pre-treated with CP extract (20.34 µg and 10.17 µg polyphenols/mL of extract corresponding to 1/50 and 1/100 dilution) for 4 h. Epithelial renewal (cell viability, cell proliferation and apoptosis), monolayer/barrier integrity (TEER, FD4 permeability, LDH release), as well as epithelial functionality (synthesis of pro-inflammatory cytokines: TNF-α, IL-1β, IL-6, reactive oxygen species (ROS), nitric oxide (NO) production), MAPK signalling and mitochondrial morphology and function were assessed. The results showed that CP extract had no cytotoxic effects and successfully counteracted LPS-induced loss of cell viability and proliferation. The pre-treatment with CPE at both dilutions significantly reduced LPS-induced apoptosis and cell death. Barrier integrity was preserved with TEER values maintained near baseline: −0.43% and −0.24% for 1/50 and 1/100 dilutions of CPE vs. −53.47% at 72 h for LPS alone, and paracellular FD4 passage was restored to control levels. At the molecular level, CP extract reduced pro-inflammatory cytokine gene expression (IL-6 by 40%, TNF-α by 50–56%) and suppressed LPS-induced MAPK activation by 62.9% and 46.5%, for 1/50 and 1/100 dilutions of CPE, respectively. The pre-treatment of cells with CP extract normalised LPS-induced ROS production and protected mitochondrial morphology and function. These in vitro findings demonstrate that CP extract exerts a protective effect on intestinal epithelial cells, acting through anti-inflammatory, antioxidant and barrier-preserving mechanisms. This supports the hypothesis for valorisation of carrot agro-industrial by-products as functional feed additives for promoting intestinal health. Further in vivo studies are needed to validate this hypothesis and to establish the concentration/rate of inclusion of carrot by-products to achieve the maximal positive effects. Full article

Mitochondria-targeting metal complexes (MTMCs) are a mechanistically distinct class of metallopharmaceuticals. Unlike first-generation platinum drugs that form nuclear DNA adducts, MTMCs exploit organelle-specific vulnerabilities such as hyperpolarised mitochondrial membrane potential (ΔΨm), elevated reactive oxygen species (ROS), limited mitochondrial DNA (mtDNA) repair capacity, and redox-dependent enzymes such as thioredoxin reductase (TrxR). We systematically searched PubMed, Web of Science, Scopus, and Google Scholar databases for studies published between 2016 and 2026, applying predefined inclusion criteria that included subcellular localization evidence and functional bioenergetic endpoints. The search identified 147 studies covering Pt(II/IV), Ru(II/III), Au(I/III), Ir(III), Os(II), Re(I), and V(IV/V) complexes and metal–organic framework nanoplatforms. Mechanistic evidence converges on four intramitochondrial target categories: inhibition of ETC (Electron Transport Chain) Complexes I/III with consequent ATP depletion; ROS overproduction, coupled with glutathione and TrxR depletion; outer mitochondrial membrane permeabilization and intrinsic apoptotic cascade activation; and mtDNA damage within a compartment limited to base excision repair. Multi-modal cell death—the co-occurrence of apoptosis, ferroptosis, necroptosis, and autophagic cell death—was a recurrent finding across the reviewed studies. This review thoroughly surveys the latest trends in MTMC drug design (metals, ligand structures, and mechanisms of action) and summarises analytical techniques for speciation, pharmacokinetics, safe monitoring, and resistance, while critically analysing translational barriers and clinical failures. To address the field’s inconsistent terminology, we introduce an explicit localization evidence hierarchy that distinguishes mitochondria-targeting complexes (through quantitative ICP-MS fractionation or co-localization with defined Pearson/Manders coefficients) from simply mitochondria-localising or mitochondria-perturbing agents, and we apply it throughout. We also point out that the idea of selectivity being purely driven by membrane voltage (ΔΨm) and thermodynamics is constrained by membrane and protein binding, as well as the transmembrane pH gradient, kinetic limitations, and demonstrated heterogeneity of cancer-cell membrane potential, and, as such, the functional mitochondrial effects must not be equated with mitochondrial accumulation. Since elemental quantification cannot distinguish intact complex from protein adducts and decomposition products, speciation-aware pharmacokinetics emerges as a prerequisite for a credible exposure–response interpretation. The translational progress will depend less on new chemotypes than on this analytical and pharmacokinetic rigour, together with organelle-level safety monitoring and biomarker-guided patient selection. Full article

Chronic hyperglycemia and excessive reactive oxygen species (ROS) production are defining features of endothelial dysfunction, a key driver of diabetic vascular complications such as diabetic nephropathy. Microvesicles (MV-enriched fraction), a subtype of extracellular vesicles, and the stress-responsive antioxidant protein Sestrin2 (SESN2) have emerged as important contributors to these processes. This study investigated the role of the MV-enriched fraction in endothelial cell communication under diabetic conditions, with a particular focus on oxidative stress signaling. To model diabetic injury, EA.hy926 endothelial cells were treated with methylglyoxal (MGO), and the resulting MV-enriched fraction was isolated and then applied to two recipient models: naïve endothelial cells and SESN2 knockdown (KD) cells. Protein expression of key antioxidant markers, including endothelial nitric oxide synthase (eNOS), was assessed by Western blot. Nitric oxide (NO) bioavailability was quantified via nitrite measurement using 2,3-diaminonaphthalene (DAN), while mitochondrial and cytosolic ROS levels were evaluated using MitoSOX and dihydroethidium (DHE), respectively. Results demonstrated that the MV-enriched fraction derived from diabetic conditions triggers a complex antioxidant response in healthy endothelial cells, characterized by upregulation of SESN2, superoxide dismutase 1 (SOD1), and heme oxygenase-1 (HO-1). This suggests a compensatory mechanism that mitigates oxidative stress. Notably, SESN2 KD cells exhibited increased ROS production and reduced NO levels upon MV treatment, underscoring the essential role of SESN2 in maintaining redox homeostasis. Overall, this study highlights the dual role of the MV-enriched fraction as a mediator of both protective and detrimental redox signaling in diabetic endothelial dysfunction and suggests potential therapeutic targets for managing diabetic vascular complications. Full article

Chronic ultraviolet B (UVB) radiation drives cutaneous photoaging—clinically manifesting as erythema, edema, scaling, deep wrinkling, loss of elasticity, and barrier disruption—through mitochondrial reactive oxygen species (mtROS) overproduction and quality-control failure. Here we identify α-ketoglutarate (AKG; also known as 2-oxoglutarate), a TCA-cycle intermediate and essential co-substrate for α-ketoglutarate-dependent dioxygenases (α-KGDDs), as a metabolic corrector of mitochondrial redox homeostasis in UVB-induced photoaging. In a 10-week chronic UVB SKH1 hairless mouse model, microneedle-assisted transdermal delivery of AKG dose-dependently attenuated macroscopic erythema, scaling, and erosive lesions, restored skin barrier function and dermal elasticity, preserved epidermal–dermal architecture, and protected collagen and elastic fiber integrity, with efficacy comparable to all-trans retinoic acid. Mechanistically, AKG reactivated α-KGDD/prolyl hydroxylase (PHD) catalytic function and promoted proteasomal clearance of aberrantly stabilized HIF-1α under normoxia; this was accompanied by restored AMPK Thr172 phosphorylation downstream of constitutive LKB1 and recovery of PGC-1α-driven mitochondrial biogenesis. AKG preferentially attenuated mitochondrial superoxide over total cellular ROS through a co-substrate-mediated mechanism distinct from direct radical scavenging, and its protective effects were largely abrogated by DMOG (an α-KGDD inhibitor) or compound C (an AMPK inhibitor). These findings position AKG, delivered via microneedle-assisted topical application, as a candidate metabolite-based intervention targeting the α-KGDD/HIF-1α/AMPK axis for photoaging. Full article

Layer chickens have dual physiological demands for rapid growth and continuous egg production. The maintenance of skeletal homeostasis in layer chickens relies on the precise coordination among OCs, osteoblasts (OBs), and osteocytes. The imbalances in the supply of nutrients such as calcium (Ca) and phosphorus (P), as well as dysfunction of the “gut–bone” axis, can disrupt normal bone development in layer chickens, leading to bone diseases such as tibial dyschondroplasia (TD) and osteoporosis (OP), seriously damaging the production performance of layer chickens. This review systematically summarizes the knowledge background of the metabolic reprogramming of OCs in layer chickens, especially mitochondria-mediated biological processes, including oxidative phosphorylation (OXPHOS), glycolysis, reactive oxygen species (ROS) signaling, mitophagy, etc. Notably, the co-culture system of OCs derived from the bone marrow cavity of embryos in vitro has been established in laying chickens. However, there are few reports on the study of mitochondrial metabolism of OCs using this model. Therefore, this review particular focuses on the bone metabolism mediated by OCs in layer chickens and proposes future research priorities, including the application of gene editing and multi-omics methods to ultimately achieve targeted nutritional or pharmacological interventions for optimizing mitochondrial function and promoting bone health. Full article

Neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, and Amyotrophic lateral sclerosis, are distinguished by progressive neuronal dysfunction caused primarily by oxidative stress, mitochondrial impairment, neuroinflammation, and redox imbalance. Growing evidence suggests that indole-derived compounds have significant neuroprotective potential due to their antioxidant, anti-inflammatory, and redox-modulating properties. This review summarizes the structural and biological significance of indole scaffolds, focusing on the mechanisms by which natural, endogenous, microbiota-derived, and synthetic indole compounds protect neuronal networks. Indole-3-carbinol, 3,3′-diindolylmethane, indole-3-propionic acid, and melatonin are major indole derivatives that control important neuroprotective pathways like Nrf2/ARE signaling, mitochondrial bioenergetics, neurotrophic factor expression, apoptotic regulation, and suppression of proinflammatory mediators. These compounds also maintain synaptic plasticity, reduce reactive oxygen species production, and improve neuronal survival in neurodegenerative disease models. Additionally, updated information from translational and clinical research indicates that indole-based compounds may have promising therapeutic applications; however, obstacles like low bioavailability, metabolic instability, and blood–brain barrier penetration continue to be major obstacles to clinical application. Development in nanoparticle delivery systems, microbiome-targeted interventions, and rational structural optimization may improve therapeutic efficacy and translational potential. Overall, indole-derived compounds are a versatile class of redox modulators with potential applications in the prevention and treatment of neurodegenerative diseases via integrated antioxidant and neuroprotective mechanisms. Full article

Neuroinflammation, driven by microglial activation and oxidative stress, is a key pathological feature of various neurodegenerative diseases. Dendropanax morbifera Léveille (DM) is a medicinal plant known for its diverse pharmacological activities; however, the influence of leaf developmental stage on its neuroprotective potential remains poorly understood. In this study, we compared the phytochemical profiles of young DM (YDM) and mature DM leaves and evaluated their effects on neuronal metabolism and microglia-mediated neuroinflammation. HPLC analysis revealed that YDM contained approximately 2.4-fold higher levels of chlorogenic acid than DM, while DM exhibited higher quercetin content. In differentiated N2A neuronal cells, YDM treatment significantly upregulated the expression of key metabolic and mitochondrial regulators, including PGC-1α, PPARγ, and CPT2, suggesting enhanced mitochondrial and metabolic regulatory signaling related to biogenesis and fatty acid β-oxidation. Under inflammatory conditions, YDM more potently suppressed the secretion of pro-inflammatory cytokines (IL-6 and TNF-α) in LPS-stimulated BV2 microglia compared to DM. Furthermore, in N2A cells treated with BV2-conditioned medium, both extracts effectively mitigated reactive oxygen species production and restored brain-derived neurotrophic factor expression. These findings demonstrate that leaf age is a critical determinant of the phytochemical composition and biological activity of DM. Our results suggest that chlorogenic acid-rich YDM preparations may offer superior therapeutic advantages in targeting neuroinflammatory and metabolic dysregulation in the central nervous system. Full article

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia and is increasingly driven by cardiometabolic disease, including type 2 diabetes mellitus (T2DM), obesity, and insulin resistance. These conditions promote atrial electrical instability and a permissive substrate through mitochondrial dysfunction, oxidative stress, inflammation, calcium-handling abnormalities, and profibrotic signaling, culminating in atrial fibrosis and conduction heterogeneity. Metformin, the foundational glucose-lowering therapy for T2DM, exerts pleiotropic actions that intersect with these upstream pathways. Beyond glycemic control, metformin induces mild mitochondrial complex I modulation with reduction of reverse electron transfer-derived reactive oxygen species, activates adenosine monophosphate (AMP) activated protein kinase, and attenuates nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-mediated cytokine signaling; experimental data further suggest favorable effects on adiponectin–sarcoendoplasmic reticulum calcium adenosine triphosphatase (SERCA) 2a-dependent calcium cycling, connexin expression, small-conductance Ca²⁺-activated K+ channel remodeling, lipid handling, and transforming growth factor-β (TGF)-β-associated fibrotic remodeling. Observational cohort studies have reported associations between metformin exposure and a modest reduction in incident AF, particularly with longer treatment duration and in higher-risk metabolic phenotypes; device-based surveillance cohorts support a preventive association for new-onset AF rather than reduction of established AF burden. Data after catheter ablation suggest improved freedom from recurrence in metformin-treated patients, whereas evidence in postoperative AF is largely neutral, likely reflecting distinct acute mechanisms. Collectively, metformin may be best conceptualized as a potential substrate-modifying, upstream therapy candidate; however, confounding, exposure misclassification, and heterogeneity in comparators limit causal inference, underscoring the need for prospective randomized trials with AF endpoints. In practice, integration with comprehensive risk-factor modification (blood pressure, weight, sleep apnea, and glycemic optimization) remains essential when considering AF prevention strategies. Full article

Pancreatic cancer remains a highly lethal malignancy, with standard therapies offering limited benefits in advanced stages; thus, novel strategies that exploit specific cancer cell vulnerabilities are urgently needed. Building on our previous findings that nanosecond pulsed electric fields (nsPEF) combined with cold atmospheric plasma (CAP) produce enhanced cytotoxicity, this study investigates the molecular mechanisms underlying this synergy. Pan02 pancreatic cancer cells were subjected to nsPEF, CAP, or a combination of both. We assessed cell viability, reactive oxygen species (ROS) production, and mitochondrial integrity using metabolic assays, flow cytometry, and fluorescence microscopy. Apoptotic markers were evaluated via Western blotting and caspase activity assays. Combined nsPEF–CAP treatment significantly outperformed either modality alone in inducing cell death. Mechanistically, dual treatment triggered a surge in intracellular ROS, particularly mitochondrial superoxide, indicating severe oxidative stress. Distinct mitochondrial responses were observed: nsPEF reduced mitochondrial membrane potential, whereas CAP alone caused a slight elevation. Notably, while CAP induced apoptosis (evidenced by increased cleaved caspase-3 and caspase-3/7 activity), lethal nsPEF (100 pulses) caused cell death without triggering apoptotic signaling. However, mild nsPEF (20 pulses) significantly potentiated CAP-induced apoptosis. These findings suggest that nsPEF sensitizes cells to CAP treatment by amplifying oxidative stress and mitochondrial dysfunction. This synergistic combination represents a promising therapeutic approach for managing pancreatic cancer cells resistant to conventional therapies. Full article

Mitochondrial diseases have traditionally been viewed as energy deficiencies, but current evidence positions mitochondria as central regulators of multiple cell death pathways. This review systematically analyzes the molecular mechanisms of apoptosis and ferroptosis in the context of both primary mitochondrial diseases—caused by mutations in mtDNA or nuclear DNA directly affecting oxidative phosphorylation—and secondary mitochondrial dysfunction associated with broader pathological conditions. Apoptosis is an energy-dependent process characterized by mitochondrial outer membrane permeabilization, cytochrome c release, and caspase cascade activation, whereas ferroptosis involves iron-dependent lipid peroxidation, glutathione depletion, and inactivation of glutathione peroxidase 4 (GPX4), leading to accumulation of oxidized phospholipids predominantly in endoplasmic reticulum and plasma membranes; mitochondrial ultrastructural changes—including volume reduction and cristae loss—represent characteristic morphological features of ferroptosis rather than its primary site of initiation. Key findings reveal that reactive oxygen species overproduction, disruption of reducing equivalent metabolism, iron dyshomeostasis, and calcium overload simultaneously prime cells for both death pathways. Cytochrome c, p53, and BCL-2 family proteins serve as integration hubs, with cardiolipin peroxidation and phospholipid composition influencing pathway switching. Tissue specificity is pronounced in primary mitochondrial diseases: retinal ganglion cells in Leber’s hereditary optic neuropathy, cardiomyocytes in mtDNA-associated cardiomyopathies, and hepatocytes in mtDNA depletion syndromes exhibit distinct dominant death pathways. It should be noted, however, that for many conditions discussed, the evidence for ferroptosis involvement relies on indirect markers—such as lipid peroxidation products, decreased GPX4, and iron deposition—rather than on pharmacological rescue with ferrostatin-1 or liproxstatin-1 and rigorous exclusion of alternative death modalities; this limitation is discussed critically throughout the review. Diagnostic criteria combining morphological, biochemical, and pharmacological tools enable differentiation of death pathways. The review concludes that combined inhibition—using mitochondria-targeted antioxidants, GPX4 modulators, iron chelators, and mPTP blockers—together with personalized diagnostic algorithms offers the most promising therapeutic strategy. Understanding the apoptosis–ferroptosis crosstalk is essential for developing targeted interventions in mitochondrial diseases. Full article

Carnosine is a naturally occurring endogenous dipeptide with great potential to improve reproductive function and fertility. In this study, supplementation of 1 μg/mL carnosine during in vitro maturation (IVM) significantly enhanced the developmental competence and quality of the resulting bovine embryos. Carnosine treatment effectively elevated mitochondrial membrane potential, mitochondrial activity, and ATP content in oocytes. Moreover, it strengthened the antioxidant and anti-apoptotic capacities of oocytes, as evidenced by reduced intracellular reactive oxygen species (ROS) levels, lowered DNA damage and an early apoptosis rate, alongside increased glutathione (GSH) content, an elevated BCL2/BAX mRNA ratio, and upregulation of antioxidant genes SOD1, CAT, GPx1, and GPx4. Notably, combined application of 1 μg/mL carnosine during IVM and 10⁻⁷ M melatonin during in vitro culture (IVC) synergistically improved both blastocyst development and quality. Collectively, these findings provide novel evidence supporting the therapeutic potential of carnosine in optimizing in vitro embryo production in bovine, and highlight the value of stage-specific supplementation strategies to further improve embryonic development efficiency. Full article