Search Results (256)

Lactococcus lactis (L. lactis) is a pathogenic Gram-positive, catalase-negative coccobacillus (GPCN) associated with bovine mastitis. In this study, nine strains of L. lactis were successfully isolated and characterized from 457 milk samples from cows with clinical mastitis in China. All isolates exhibited a high degree of susceptibility to marbofloxacin and vancomycin. A series of molecular and cell biological techniques were used to explore the biological characteristics and pathogenicity of these isolates. The virulence gene profiles of the isolates were analyzed using whole genome resequencing combined with polymerase chain reaction (PCR) to elucidate the differences in virulence gene expression between isolates. To provide a more visual demonstration of the pathogenic effect of L. lactis on bovine mammary epithelial cells, an in vitro infection model was established using MAC-T cells. The results showed that L. lactis rapidly adhered to the surface of bovine mammary epithelial cells and significantly induced the release of lactate dehydrogenase, suggesting that the cell membranes might be damaged. Ultrastructural observations showed that L. lactis not only adhered to MAC-T cells, but also invaded the cells through a perforation mechanism, leading to a cascade of organelle damage, including mitochondrial swelling and ribosome detachment from the endoplasmic reticulum. The objective of this study was to provide strong evidence for the cytotoxic effects of L. lactis on bovine mammary epithelial cells. Based on this research, a prevention and treatment strategy for L. lactis as well as major pathogenic mastitis bacteria should be established, and there is a need for continuous monitoring. Full article

Background/Objectives: Epicardial adipose tissue (EAT) is metabolically active and is in dynamic crosstalk with the surrounding cardiomyocytes, modulating their function and metabolism. Oxidative stress is a key contributor to cell death and cardiac remodeling, is a hallmark of diabetes (DM) and cardiovascular disease, such as coronary artery disease (CAD). However, little is known about these processes in EAT from patients undergoing cardiac surgery. This study investigates changes in mitochondrial dynamics, reactive oxygen species (ROS) production, and antioxidant defense levels in EAT compared to subcutaneous adipose tissue (SAT) in patients undergoing cardiac surgery, with a focus on the impact of DM and CAD. Methods: Adipose tissue biopsies were collected from 128 patients undergoing surgical cardiac intervention. Mitochondrial dynamics and oxidative stress markers were analyzed. Results: EAT exhibited increased expression of mitochondrial fusion markers [mitofusin 1 (p ≤ 0.001), mitofusin 2 (p = 0.038), and optic atrophy 1 (p ≤ 0.001)], as well as fission markers [fission 1 (p ≤ 0.001) and dynamin-related protein 1 (p ≤ 0.001)] relative to SAT. Additionally, ROS levels (dihydroethidium, p = 0.004) were elevated, while lipid peroxidation (malondialdehyde, p ≤ 0.001) was reduced in EAT compared to SAT. Reduced glutathione (GSH) levels (p ≤ 0.001) and the redox buffer ratio between reduced and oxidized glutathione (GSH/GSSG, p ≤ 0.001) were significantly increased in EAT. Interestingly, glutathione peroxidase activity (p ≤ 0.001) and the antioxidant defense markers catalase (p ≤ 0.001) and superoxide dismutase 2 (p = 0.001) were significantly reduced in EAT compared to SAT. Conclusions: The findings provide a unique molecular insight into the mitochondrial dynamics and oxidative stress profiles of EAT, highlighting potential avenues for a novel diagnostic method and therapeutic strategies for cardiac disease. Full article

The regulation of oxidative stress is an effective strategy for treating cancers. Therapeutic strategies for modulating an undesirable redox balance against cancers have included the enhancement of oxidative components, reducing the action of antioxidant systems, and the combined application of radiation and redox-modulating drugs. A precise understanding of redox regulation is required to treat different kinds of cancer. This review focuses on the redox regulation and oxidative stress defense systems of lung cancers. Thus, we highlighted several enzymatic antioxidant components, such as superoxide dismutase, catalase, heme oxygenase-1, peroxiredoxin, glutaredoxin, thioredoxin, thioredoxin reductase, glutathione peroxidase, and antioxidant components, including glutathione, nuclear factor erythroid 2–related factor 2, 8-oxo-7,8-dihydro-2′-deoxyguanosine, and mitochondrial citrate carrier SLC25A1, based on PubMed and Scopus-indexed literature. Understanding the oxidative stress defense system in lung cancer would be beneficial for developing and expanding therapeutic strategies, such as drug development, drug design, and advanced delivery platforms. Full article

Alzheimer’s disease (AD), the most prevalent form of neurodegenerative dementia, is characterized by progressive cognitive decline and neuronal loss. Despite advances in pharmacological treatments, current therapies remain limited in efficacy and often induce adverse effects. Increasing evidence highlights oxidative stress, mitochondrial dysfunction, and disrupted neurotrophic signaling as key contributors to AD pathogenesis. Pulsed electromagnetic fields (PEMFs) are emerging as a non-invasive, multifactorial approach with promising biological effects. In this study, we investigated the neuroprotective potential of PEMFs in NGF-differentiated PC12 cells exposed to hydrogen peroxide (H₂O₂) or amyloid-β peptide (Aβ), both of which model pathological features of AD. PEMF treatment significantly counteracted H₂O₂- and Aβ-induced cytotoxicity by restoring cell viability, reducing reactive oxygen species production, and improving catalase activity. Furthermore, PEMFs preserved the mitochondrial membrane potential and decreased caspase-3 activation and chromatin condensation. Mechanistically, PEMFs inhibited ERK phosphorylation and enhanced cAMP levels, CREB phosphorylation, and BDNF expression, pathways known to support neuronal survival and plasticity. In conclusion, these findings suggest that PEMFs modulate multiple stress response systems, promoting neuroprotection under oxidative and amyloidogenic conditions. Full article

Background: Under oxidative stress conditions, the increased levels of reactive oxygen species (ROS) within cells disrupt the intracellular homeostasis. Tartary buckwheat peptides exert their effects by scavenging oxidative free radicals, such as superoxide anion and hydrogen peroxide, thereby reducing oxidative damage within cells. Meanwhile, these peptides safeguard mitochondria by maintaining the mitochondrial membrane potential, decreasing the production of mitochondrial oxygen free radicals, and regulating mitochondrial biogenesis and autophagy to preserve mitochondrial homeostasis. Through these mechanisms, Tartary buckwheat peptides restore the intracellular redox balance, sustain cellular energy metabolism and biosynthesis, and ensure normal cellular physiological functions, which is of great significance for cell survival and adaptation under oxidative stress conditions. Objectives: In this experiment, a classical cellular oxidative stress model was established. Indicators related to antioxidant capacity and mitochondrial membrane potential changes, as well as pathways associated with oxidative stress, were selected for detection. The aim was to elucidate the effects of Tartary buckwheat oligopeptides on the metabolism of cells in response to oxidative stress. Methods: In this study, we established an oxidative damage model of mouse skeletal muscle myoblast (SOL8) cells using hydrogen peroxide (H₂O₂), investigated the pre-protective effects of Tartary buckwheat oligopeptides on H₂O₂-induced oxidative stress damage in SOL8 cells at the cellular level, and explored the possible mechanisms. The CCK-8 method is a colorimetric assay based on WST-8-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodiumsalt], which is used to detect cell proliferation and cytotoxicity. Results: The value of CCK-8 showed that, when the cells were exposed to 0.01 mmol/L H₂O₂ for 1 h and 10 mg/mL Tartary buckwheat oligopeptides intervention for 48 h, these were the optimal conditions. Compared with the H₂O₂ group, the intervention group (KB/H₂O₂ group) showed that the production of ROS was significantly reduced (p < 0.001), the malondialdehyde (MDA) content was significantly decreased (p < 0.05), and the activity of catalase (CAT) was significantly increased (p < 0.01); the mitochondrial membrane potential in the KB/H₂O₂ group tended to return to the level of the control group, and they all showed dose-dependent effects. Compared with the H₂O₂ group, the mRNA expression of KEAP1 in the KB/H₂O₂ group decreased, while the mRNA expression of NRF2α, HO-1, nrf1, PGC-1, P62, and PINK increased. Conclusions: Therefore, Tartary buckwheat oligopeptides have a significant pre-protective effect on H₂O₂-induced SOL8 cells, possibly by enhancing the activity of superoxide dismutase, reducing ROS attack, balancing mitochondrial membrane potential, and maintaining intracellular homeostasis. Full article

Citral, an organic compound found in lemongrass (Cymbopogon citratus) oil and Litsea cubeba essential oil, has been reported to exhibit notable antifungal activity against Magnaporthe oryzae (M. oryzae), the pathogen of rice blast, which causes significant economic losses in rice production. However, the role of citral in inducing oxidative stress related to antifungal ability and its underlying regulatory networks in M. oryzae remain unclear. In this study, we investigated the oxidative effects of citral on M. oryzae and conducted transcriptomic and widely targeted metabolomic (WTM) analyses on the mycelia. The results showed that citral induced superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activities but reduced glutathione S-transferase (GST) activity with 25% maximal effective concentration (EC₂₅) and 75% maximal effective concentration (EC₇₅). Importantly, citral at EC₇₅ reduced the activities of mitochondrial respiratory chain complex I, complex III and ATP content, while increasing the activity of mitochondrial respiratory chain complex II. In addition, citral triggered a burst of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP) through the observation of fluorescence. Furthermore, RNA-seq analysis and metabolomics analysis identified a total of 466 differentially expression genes (DEGs) and 32 differential metabolites (DAMs) after the mycelia were treated with citral. The following multi-omics analysis revealed that the metabolic pathways centered on AsA, GSH and melatonin were obviously suppressed by citral, indicating a disrupted redox equilibrium in the cell. These findings provide further evidences supporting the antifungal activity of citral and offer new insights into the response of M. oryzae under oxidative stress induced by citral. Full article

Dry eye is an ophthalmic disease with an intricate pathomechanism, and there are no effective interventions or medications available. We investigated the effects of a peptide, DFCPPGFNTK (DFC), screened from tilapia skin hydrolysate on dry eye and its underlying mechanisms. In vitro, human corneal epithelial cells (HCECs) were challenged by 100 mM NaCl in a hyperosmotic environment. DFC restored the cell viability of HCECs induced by NaCl, reduced the transition of mitochondrial membrane potential, delayed the apoptosis of damaged cells, reduced the production of reactive oxygen (ROS) and malondialdehyde (MDA), increased the activities of superoxide dismutase (SOD) and catalase (CAT), and increased the expression rate of Bcl-2/Bax. Compared to the model group, the protein expression levels of COX-2 and iNOS were down-regulated, the mRNA expression of Tnf-α and Il-6 were decreased, the protein expression levels of Nrf2 and HO-1 were increased, and the levels of autophagy-related proteins p62 and LC3B were regulated. In vivo, the dry eye model was developed by administering eye drops of 0.2% BAC to mice for 14 days. DFC increased tear secretion, changed the morphology of tear fern crystals, prevented corneal epithelial thinning, reduced the loss of conjunctival goblet cells (GCs), and inhibited the apoptosis of mice corneal epithelial cells. In summary, DFC improved dry eye by inhibiting oxidative stress, apoptosis, inflammation, and autophagy. Full article

This study examined branched-chain fatty acids (BCFAs)’ effects on oxidative stress, energy metabolism, inflammation, tight junction disruption, apoptosis, and Toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) signaling in lipopolysaccharide (LPS)-induced calf small intestinal epithelial cells (CSIECs). Eight groups were used: a control group, an LPS-induced group, and six BCFA treatment groups (12-methyltridecanoic acid (iso-C14:0), 13-methyltetradecanoic acid (iso-C15:0), 14-methylpentadecanoic acid (iso-C16:0), 15-methylhexadecanoic acid (iso-C17:0), 12-methyltetradecanoic acid (anteiso-C15:0), and 14-methylhexadecanoic acid (anteiso-C17:0)) with LPS. The BCFA pretreatments significantly increased CSIEC activity compared to the LPS-induced group, with iso-C14:0 showing the highest activity (89.73%). BCFA reduced Reactive Oxygen Species (ROS) generation and malondialdehyde (MDA) levels and improved the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities and glutathione (GSH) levels. Iso-C16:0 optimized total antioxidant capacity (T-AOC). BCFA enhanced the mitochondrial membrane potential, Adenosine Triphosphate (ATP) enzyme activity, and ATP content, with iso-C14:0 increasing ATP by 27.01%. BCFA downregulated interleukin (IL)-1β, IL-8, tumor necrosis factor (TNF)-α, and interferon (INF)-γ gene expression, reduced IL-6 levels, and increased IL-10 expression. Myeloid differentiation factor 88 (MyD88) mRNA levels were reduced. BCFA alleviated Zonula Occludin (ZO-1), Claudin-1, and Claudin-4 decrease and increased Occludin levels. BCFA mitigated LPS-induced increases in Caspase-3 and BCL2-Associated X (BAX) mRNA levels, reduced Caspase-8 and Caspase-9 expression, and increased B-Cell Lymphoma-2 (BCL-2) mRNA levels. The Entropy Weight-TOPSIS method was adopted, and it was discovered that iso-C15:0 has the best effect. In summary, BCFA supplementation mitigated oxidative stress and enhanced mitochondrial function. BCFA inhibited TLR4/NF-κB signaling pathway overactivation, regulated inflammatory cytokine gene expression, reduced cellular apoptosis, preserved tight junction integrity, and supported barrier function. Full article

Type 2 diabetes mellitus represents a major global health burden and is often preceded by a prediabetic state characterized by insulin resistance and metabolic dysfunction. Mitochondrial alterations, oxidative stress, and disturbances in lipid metabolism are central to the prediabetes pathophysiology. Melatonin, a pleiotropic indolamine, is known to regulate metabolic and mitochondrial processes; however, its therapeutic potential in prediabetes remains poorly understood. This study investigated the effects of melatonin on energy metabolism, oxidative stress, and mitochondrial function in a rat model of prediabetes induced by chronic sucrose intake and low-dose streptozotocin administration. Following prediabetes induction, animals were treated with melatonin (20 mg/kg) for four weeks. Biochemical analyses were conducted to evaluate glucose and lipid metabolism, and mitochondrial function was assessed via gene expression, enzymatic activity, and oxidative stress markers. Additionally, hepatic mitochondrial dynamics were examined by quantifying key regulators genes associated with biogenesis, fusion, and fission. Prediabetic animals exhibited dyslipidemia, hepatic lipid accumulation, increased fat depots, and impaired glucose metabolism. Melatonin significantly reduced serum glucose, triglycerides, and total cholesterol levels, while enhancing the hepatic high-density lipoprotein content. It also stimulated β-oxidation by upregulating hydroxyacyl-CoA dehydrogenase and citrate synthase activity. Mitochondrial dysfunction in prediabetic animals was evidenced by the reduced expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha and mitochondrial transcription factor A, both of which were markedly upregulated by melatonin. The indolamine also modulated mithocondrial dynamics by regulating fusion and fission markers, including mitosuin 1 and 2, optic atrophy protein, and dynamin-related protein. Additionally, melatonin mitigated oxidative stress by enhancing the activity of superoxide dismutase and catalase while reducing lipid peroxidation. These findings highlight melatonin’s protective role in prediabetes by improving lipid and energy metabolism, alleviating oxidative stress, and restoring mitochondrial homeostasis. This study provides novel insights into the therapeutic potential of melatonin in addressing metabolic disorders, particularly in mitigating mitochondrial dysfunction associated with prediabetes. Full article

Endometrial cancer (EC) is classified into two main subtypes with distinct molecular profiles. Sphingolipids, particularly ceramide and sphingosine-1-phosphate (S1P), are crucial regulators of cell survival, apoptosis, and oxidative stress. This study examined the impact of sphingolipid metabolism in Ishikawa (type 1) and HEC-1A (type 2) EC cells following the silencing of Sptlc1 and Sptlc2, which encode subunits of serine palmitoyltransferase (SPT), a key enzyme in de novo sphingolipid synthesis. Gene silencing was confirmed by RT-PCR and Western blot, while sphingolipid levels were quantified using UHPLC/MS/MS and the sphingolipid rheostat (S1P/ceramide ratio) was calculated. Cell viability (MTT assay), cell death, ROS levels (ELISA), total antioxidant capacity (TAC), catalase and caspase-3 activity, and mitochondrial membrane potential were also assessed. The obtained data showed higher ceramide levels in Ishikawa_(CON) cells and higher S1P levels in HEC-1A_(CON) cells, resulting in a higher sphingolipid rheostat in HEC-1A cells. SPT knockdown reduced sphingolipid levels, increased cell viability, elevated ROS levels, and decreased cell death, particularly in Ishikawa cells. Furthermore, after gene silencing, these cells exhibited reduced catalase activity and diminished TAC, indicating an impaired redox balance. These findings reveal subtype-specific responses to disrupted sphingolipid synthesis and highlight the importance of sphingolipid homeostasis in the behavior of EC cells. Full article

Schizothorax prenanti is an economically important cold-water fish in China. Lipopolysaccharide (LPS) can induce an immune response in S. prenanti; however, little is known about the effects of LPS on oxidative stress (OS) and apoptosis in S. prenanti. In this study, S. prenanti fish were stimulated with LPS at a dose of 10 mg/kg of body weight. After 0 h, 12 h and 24 h, the tissue samples were collected. The OS- and apoptosis-related genes and enzymatic activities in the liver, head kidney (HK), and spleen of S. prenanti were analyzed by a two-way repeated-measures analysis of variance (ANOVA). Hematoxylin and eosin and terminal transferase uridyl nick end labeling staining were also performed. In S. prenanti, LPS administration downregulated the catalase (CAT) and B-cell lymphoma/Leukemia-2 (Bcl-2) expression levels, and upregulated BCL2-associated X (Bax) and cysteine-aspartic-specific protease-3 (caspase-3) expression levels. Meanwhile, superoxide dismutase and CAT enzymatic activities were inhibited and malondialdehyde (MDA) content was increased by LPS treatment. Additionally, LPS treatment induced OS damage and apoptosis in tissue sections. These results indicated that apoptosis in the liver, HK, and spleen of LPS-administered S. prenanti may be mediated by OS via the mitochondrial apoptotic signaling pathway. Our findings are expected to contribute to a better understanding of the responses of different tissues to bacterial challenges. In addition, we can increase the tolerance of fish to the OS through dietary manipulation in the future. Full article

Oxidative stress is involved in pathophysiological mechanisms associated with a myriad of liver diseases. Bergamot (Citrus bergamia) leaves yield a high level of antioxidant polyphenolic compounds that may hinder the development of liver diseases, while their potential is yet to be fully explored. Thus, the aim of the study was to test the effects of bergamot leaf extract (BLE) on hepatic and mitochondrial oxidative stress in different models. In vivo study: Wistar rats were distributed into two groups: control diet (C) and high-sugar–fat diet (HSF) for twenty weeks. Afterward, the animals were redivided to initiate a ten-week treatment with BLE: C, HSF, and HSF+BLE. In vitro study: Rat hepatic mitochondria were isolated by differential centrifugation and used to assess safety and efficacy of the BLE. Hepatocyte monolayer and spheroids were applied to evaluate the safety of physiologically plausible BLE concentrations and their effects on hydrogen peroxide-induced cytotoxicity. The results showed that BLE improved metabolic parameters, reduced hepatic triglyceride levels, malondialdehyde, and increased catalase activity in vivo. In vitro, BLE decreased lipid peroxidation and increased the ratio of reduced and oxidized glutathione in chemically challenged mitochondria. BLE did not exert cytotoxicity in the hepatocyte monolayer and spheroids, while attenuated oxidative stress-induced cytotoxicity. Data indicate that in vivo and in vitro hepatic oxidative stress is modulated by BLE, reinforcing that BLE may act as an agent against chronic liver diseases. Full article

The present study aimed to investigate the effects of exogenous carnitine treatments on maize seed germination by stimulating lipid metabolism and regulating the mitochondrial respiratory pathway. Maize seeds were grown as control, 5, 7.5, and 10 μM carnitine treatment groups in a germination chamber at 25 °C under dark conditions for 5 d. It was determined that carnitine treatments increased the germination rate (GR), germination index (GI), germination potential (GP), vigor index (VI), root and hypocotyl length, fresh weight (FW), and content of total soluble protein but decreased the total carbohydrate content. It was also found that it increased the activities of α-amylase, isocitrate lyase (ICL), and malate synthase (MS) enzymes, which are critical in the germination process, and upregulated the expression of ICL and MS genes. To clarify the potential of carnitine treatments to promote the participation of lipids in respiration in roots and hypocotyls, lipase, carnitine acyltransferases (CATI and CATII), and citrate synthase (CS) enzyme activities were examined, and significant increases in these activities were detected. It was also found that gene levels of respiratory enzymes cytochrome oxidase (COX), pyruvate dehydrogenase (PDH), and Atp synthase, lipase, and CS proteins were upregulated by carnitine treatment. In support of the enzyme and gene change findings, significant changes were determined in fatty acid contents, free carnitine, and long-chain acylcarnitine levels in seeds, roots, and hypocotyls depending on carnitine application. In roots and hypocotyls, carnitine treatments significantly increased glutamine synthase (GS) and glutamate dehydrogenase (NADH-GDH) activities and gene expression levels, which are closely related to the tricarboxylic acid cycle (TCA). It was also noted that all proteins analyzed at the gene expression level were upregulated by carnitine applications in seeds. In addition, significant increases were recorded in antioxidant enzyme ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities and total ascorbate (AsA) and glutathione (GSH) contents in roots and hypocotyls, while decreases were determined in guaiacol peroxidase (GPX) and catalase activities. Significant changes were recorded in all parameters examined, especially with 7.5 µM carnitine application. The findings suggest that carnitine may promote the transport of fatty acids to mitochondrial respiration by accelerating lipid catabolism in five-day-old maize and contribute to seed germination and growth and development processes by activating other metabolic pathways associated with respiration in this process. Full article

The aim of this study is to investigate the alleviating effect of lipoic acid on oxidative stress and tissue damage induced by aflatoxin B₁ (AFB₁) in young laying hens. The experiment was divided into a control group, an AFB₁ group, and three lipoic acid treatment groups. The AFB₁ group and three lipoic acid treatment groups were given diets supplemented with 90 μg/kg of AFB₁. The additional amounts of lipoic acid were 20, 100, and 500 mg/kg, respectively, with a feeding period of 4 weeks. The experimental results showed that AFB₁ significantly increased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and malondialdehyde (MDA) in the serum and significantly decreased the levels of total protein (TP), albumin (ALB), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) (p < 0.05). In addition, AFB₁ damaged the structure of the liver, spleen, and ovarian tissues. Lipoic acid reduced the levels of ALT, AST, ALP, and MDA in the serum and increased the levels of TP, ALB, T-SOD, GSH-Px, and CAT (p < 0.05). Meanwhile, lipoic acid also protected mitochondrial structure and alleviated liver, spleen, and ovarian tissue damage caused by AFB₁. In summary, lipoic acid can alleviate oxidative stress and tissue damage caused by AFB₁ in young laying hens. Full article

Background: The egg-laying performance of hens is primarily regulated by ovarian follicle growth and development; these follicles are susceptible to oxidative damage caused by excessive reactive oxygen species (ROS). Oxidative damage can lead to follicular atresia and impaired reproductive performance. Melatonin (MT), a known endogenous antioxidant, plays a role in regulating oxidative damage, but its precise mechanisms in mitigating H₂O₂-induced oxidative damage via mitophagy regulation in granulosa cells remain unclear. Methods: An in vitro oxidative damage model was established by determining the optimal H₂O₂ concentration using CCK-8 fluorescence quantification. The optimal MT concentration was identified through fluorescence quantification and catalase (CAT) activity assays. The protective effects of MT against H₂O₂-induced oxidative damage in follicular granulosa cells were investigated using flow cytometry, Western blotting, ELISA, and quantitative fluorescence analysis. Results: An in vitro oxidative damage model was established using H₂O₂-induced granulosa cells, characterized by P53 and LC3-II upregulation and LC3-I and BCL-2 downregulation. The optimal MT concentration for reducing cellular injury was determined. MT co-treatment enhanced CAT, GSH, and SOD activities, decreased LC3-II/LC3-I conversion, and increased P62 expression. Furthermore, MT reduced autophagic vesicle formation and restored mitochondrial membrane potential, demonstrating its protective effect against H₂O₂-induced oxidative damage. Conclusions: Melatonin alleviates H₂O₂-induced oxidative damage in chicken follicular granulosa cells by modulating antioxidant defense, autophagy, and mitochondrial function. These findings provide newer insights to our understanding of the regulatory mechanisms underlying the alleviation of the H₂O₂-induced oxidative damage in granulosa cells during ovarian follicle development in chickens. Full article