Search Results (126)

Despite the recognized role of oxidative stress (OS) in sperm function, limited data exist on Nuclear factor-E2-related factor 2 (Nrf2) pathway modulation in relation to reliable oxidative damage markers in human semen. In this study, 79 semen samples were collected from men undergoing semen analysis and grouped as varicocele (V, no. 22), urogenital infections (UI, no. 23), unknown fertility status without pathologies (UFS, no. 15), and fertile controls (F, no. 19). After semen analysis, ELISA were used to quantify F₂-Isoprostane (F₂-IsoPs) level, a marker of lipid peroxidation, and Nrf2 in seminal plasma and spermatozoa. The Nrf2 pathway (Keap1, Nrf2, Bach1, HO-1) was assessed in spermatozoa by qRT-PCR. Seminal plasma and sperm Nrf2 positively correlated with F₂-IsoPs (p < 0.001) and negatively with sperm vitality. Sperm Nrf2 also inversely correlated with progressive motility (p < 0.05). Seminal F₂-IsoP levels were lower in F than in the other groups. Sperm Nrf2 was significantly lower in F versus V and UI (p < 0.001) and UFS (p < 0.05), while seminal plasma Nrf2 levels did not differ among groups. qRT-PCR suggested Nrf2 pathway activation mainly in V and UI, consistent with increased OS. Elevated F₂-IsoPs, a marker of poor sperm quality, and sperm Nrf2 could suggest OS-driven Nrf2 activation, providing complementary biomarkers of oxidative status in male reproductive health. Full article

(1) Background: Oxidative stress (OS) has been extensively associated with male infertility, contributing to its pathophysiology in approximately 30–80% of affected individuals. Excessive reactive oxygen species (ROS) levels trigger a cascade of interconnected processes, including lipid peroxidation, DNA damage, and mitochondrial dysfunction, ultimately impairing sperm quality. (2) Methods: The present study was designed to examine the relationship between seminal oxidative stress biomarkers such as superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) and sperm DNA integrity in men with unexplained (UMI) and idiopathic (IMI) male infertility. The study population comprised 235 participants, who were divided into three groups: fertile controls (n = 78), UMI (n = 88), and IMI (n = 69). Semen analysis was performed according to WHO criteria. Sperm DNA fragmentation index (DFI) was assessed using the TUNEL assay, while sperm decondensation index (SDI) was evaluated by aniline blue staining. Seminal OS biomarkers were measured in seminal plasma using spectrophotometric methods. (3) Results: DFI and SDI were significantly increased in infertile groups compared with fertile controls (p < 0.001), exceeding the clinical thresholds of 30% and 15%, respectively. Antioxidant enzyme activities (SOD and CAT) were significantly reduced, whereas MDA levels were significantly elevated, particularly in the IMI group (p < 0.001). Correlation analysis revealed strong positive associations between MDA and both DFI (r = 0.76, p < 0.001) and SDI (r = 0.80, p < 0.001). Additionally, MDA, DFI, and SDI were negatively correlated with semen parameters, whereas SOD and CAT were positively correlated with sperm quality (p < 0.001). (4) Conclusions: Our findings emphasize the critical role of oxidative stress and sperm DNA integrity as potential biomarkers for the diagnosis and evaluation of UMI and IMI. Full article

The advent of breast cancer molecular subtyping has transformed management, enabling treatment personalisation and de-escalation beyond traditional stage-based approaches. Established biomarkers, such as Ki-67 in luminal disease, HER2 amplification, and PD-L1 expression in triple-negative breast cancer, underpin seminal clinical trials yet remain imperfect predictors of response and long-term outcome. MicroRNAs have emerged as promising next-generation biomarkers and therapeutic tools. As master regulators of gene expression, both tumour-derived and circulating microRNAs can refine diagnosis and molecular subclassification, inform prognosis and therapeutic selection, act as treatment sensitisers, and potentially serve as direct therapeutic targets. Well-characterised miRNAs such as miR-221 have been implicated in endocrine resistance, while recent liquid-biopsy approaches have enabled the identification of circulating miR-145 and exosomal miR-155 as predictors of pathological complete response in HER2-positive disease. Their detectability in tissue, blood and other biofluids offers a minimally invasive means to dynamically monitor cancer behaviour and response, supporting more precise therapeutic decision-making. This review synthesises the current evidence for miRNA-based biomarkers across oestrogen-receptor positive, HER2-positive and triple-negative breast cancer and outlines their potential integration into biomarker-driven clinical trial designs and personalised treatment strategies. Full article

Purpose: Neuroinflammation and oxidative stress are increasingly recognized as central, interconnected drivers of neurodegeneration in the visual system. This review examines the pathogenic mechanisms shared across glaucoma, age-related macular degeneration (AMD), diabetic retinopathy (DR), and Alzheimer’s disease (AD), and evaluates the therapeutic rationale for targeting both pathways simultaneously. Methods: A narrative review of peer-reviewed literature was conducted using PubMed. Searches combined the following MeSH terms: neuroinflammation, oxidative stress, retinal neurodegeneration, microglia, Müller glia, mitochondrial dysfunction, glaucoma, age-related macular degeneration, diabetic retinopathy, and Alzheimer’s disease. Priority was given to original research, systematic reviews, and high-impact publications from 2000 through 2025. However, seminal foundational works were included regardless of publication date. Studies were selected based on relevance to glial activation, mitochondrial dysfunction, reactive oxygen and nitrogen species, and disease-specific neuronal outcomes. Results: Across all four diseases, persistent microglial and Müller glial activation, mitochondrial electron transport chain dysfunction, and excess reactive oxygen species (ROS) and reactive nitrogen species (RNS) production form a self-amplifying feed-forward loop that accelerates neuronal injury. In glaucoma, these mechanisms drive intraocular pressure-independent retinal ganglion cell loss. In AMD and DR, lipid dysregulation, complement activation, and chronic hyperglycemia sustain oxidative-inflammatory injury to the retinal pigment epithelium, photoreceptors, and neurovasculature. In AD, retinal amyloid deposition and oxidative stress mirror cortical pathology, positioning the retina as a noninvasive biomarker site. Conclusions: Neuroinflammation and oxidative stress constitute unifying upstream mechanisms across major vision-threatening neurodegenerative diseases. Combination therapeutic strategies that simultaneously modulate glial activation and restore redox homeostasis may offer superior neuroprotective efficacy compared to approaches targeting isolated downstream mediators. Full article

Background: The early detection of prostate and testicular tumors remains challenging as standard diagnostic tools often lack sensitivity and produce ambiguous results. Seminal fluid is a biologically rich medium that closely reflects the state of male reproductive tissues and has therefore emerged as a promising source of non-invasive molecular biomarkers. Objective: This study aimed to critically evaluate the evidence regarding cell-free DNA, RNA, proteins and metabolites in seminal fluid, and to assess their potential for improving the early detection of male reproductive cancers. Methods: A systematic review was performed according to PRISMA guidelines. Comprehensive searches of the PubMed and Scopus databases were conducted to identify original clinical studies analyzing molecular biomarkers in seminal fluid from patients with prostate or testicular tumors. For each study, data were extracted on biomarker types, cohort characteristics, analytical methods and diagnostic performance. Results: Forty-two eligible studies were included, covering multiple biomarker classes. Most were observational, single-center investigations classified as level 3b evidence. Across the different types of biomarkers, seminal fluid was associated with tumor-associated molecular changes. Alterations in the concentration, fragmentation and methylation patterns of cell-free DNA (e.g., GSTP1, RARβ2, LGALS3 and OCT3/4) distinguished malignant from benign conditions with sensitivities of up to 80–100%. RNA-based markers, including microRNAs, small non-coding RNAs, and tRNA fragments, showed improved performance in several studies, with multimarker models achieving areas under the curve (AUCs) of 0.85–0.93. Proteomic analyses identified high-specificity candidates such as TGM4, AMACR, PROS1 and DKK3. Metabolomic profiling further strengthened the diagnostic potential; reduced seminal citrate outperformed prostate-specific antigen (AUC 0.748 vs. 0.548), and reproducible shifts in amino acid and lipid profiles were observed in testicular tumors. However, substantial heterogeneity in study design, patient selection, and analytical platforms was observed. Risk of bias varied, and large prospective validation cohorts were lacking. Conclusions: Current evidence suggests that seminal fluid contains molecular signals associated with tumors that could be used for diagnosis. However, the available data are predominantly exploratory and methodologically heterogeneous. Before seminal fluid-based biomarkers can be considered for routine clinical implementation, robust prospective studies with standardized protocols are required. Full article

Chronic pain is increasingly understood as a neuroimmune disorder rather than a purely neuronal condition, in which immune mediators and immune-like signaling within the nervous system regulate nociceptive gain across peripheral tissues, dorsal root ganglia (DRG), spinal cord, and supraspinal networks. Seminal and recent syntheses show that microglia, macrophages, cytokines/chemokines, and innate immune sensors can initiate and maintain maladaptive plasticity and central sensitization, helping explain the frequent clinical dissociation between structural pathology, systemic inflammatory markers, and pain severity. However, immune biology is bidirectional: alongside pronociceptive pathways, a growing literature describes active “pain-resolving” programs that terminate sensitization and restore homeostasis, including regulatory T cell (Treg)–IL-10 signaling and specialized pro-resolving mediators (SPMs). A structured search of PubMed/MEDLINE, supplemented by Europe PMC and PubMed Central, was performed, and citation chasing through broad scholarly indices was used to identify high-impact reviews, meta-analyses, and translational mechanistic studies. Systematic biomarker syntheses in low back pain, neck pain, and fibromyalgia indicate modest and heterogeneous systemic inflammatory signals, underscoring the need for mechanistic endotyping and stage-specific interventions. Based on this evidence, a clinically oriented framework is presented that distinguishes immune-driven pain amplification from impaired resolution and outlines practical implications for assessment, biomarker interpretation, and precision-oriented trial design. Full article

Ambient heat exposure reduces male fertility in mammals with scrotal testes. Our previous work has demonstrated that some stallions are more susceptible to ambient heat-related subfertility than others, yet the mechanism for heat-induced subfertility remains uncertain, limiting both diagnosis and preventative measures. This study sought to define how the phenotype of stallions susceptible to heat-induced subfertility differs from that of more resilient animals, by measuring the systemic (blood plasma) and localized (reproductive tract) inflammatory and oxidative stress markers of sperm concentration, sperm motility assessments, total antioxidant capacity (TAC; in blood and seminal plasma), malondialdehyde (MDA; in blood and seminal plasma), oxidized guanine species (8-OH-2dG; in blood plasma and spermatozoa DNA), sperm DNA damage (assessed via Halo, SCSA (Sperm Chromatin Structure Assay) and CMA3 (Chromomycin A3)), and c-reactive protein (CRP; in blood plasma). Post-breeding dismount semen samples (n = 357) and blood plasma samples (n = 97) were collected from 31 stallions at commercial thoroughbred studs throughout one breeding season (NSW, Australia). A subset of stallions (16%) was deemed heat-induced subfertility-susceptible (HISS) stallions. These animals showed reduced seminal plasma antioxidant capacity, increased systemic and localized lipid peroxidation, and distinct systemic inflammatory response. Seminal antioxidant capacity was found to be strongly associated with impaired sperm motility (r = 0.739 * vs. r = −0.059). The plasma c-reactive protein of heat-susceptible stallions correlated to heat exposure (r = 0.597 *) and affected sperm motilities (r = −0.527 **, r = −0.434 *). Systemic oxidative DNA damage (8-OH-2dG) also increased following heat events (r = 0.862 ***) and correlated with fertility losses (FCP: r = −0.740 **, PCP: r = −0.603 *). Non-HISS stallions displayed greater variability in systemic antioxidant status and robust response following heat exposure (r = 0.307 *) and localized antioxidant capacity was more strongly correlated to systemic antioxidant capacity than in the heat-susceptible group (r = 0.897 *** vs. r = 0.482 **). We demonstrate that impaired antioxidant responses, altered redox balance and suppressed acute-phase inflammatory signalling are key features associated with heat-induced subfertility in stallions and highlight biomarkers that could be used to identify animals with heat-susceptible fertility. Full article

To evaluate seminal oxidative stress, antioxidant defense, apoptosis-related activity, and Sertoli cell biomarkers in infertile men with grade 3 varicocele versus normozoospermic controls, and to assess postoperative changes after varicocelectomy. This prospective observational case–control study included 39 infertile men with grade 3 clinical varicocele and 44 normozoospermic controls. Seminal plasma levels of Malondialdehyde (MDA), 8-hydroxy-2′-deoxyguanosine (8-OHdG), superoxide dismutase (SOD), glutathione peroxidase-1 (GPx-1), reduced glutathione (GSH), nuclear factor erythroid 2–related factor 2 (NRF2), Kelch-like ECH-associated protein 1 (KEAP1), caspase-3, anti-Müllerian hormone (AMH), and inhibin B were measured by ELISA. Testicular volume, semen parameters, and diagnostic performance were also evaluated. Compared with controls, patients with varicocele had lower testicular volumes and impaired semen parameters. Seminal 8-OHdG and caspase-3 levels were higher, whereas SOD and inhibin B levels were lower. Baseline MDA, GPx-1, GSH, NRF2, KEAP1, and AMH levels did not differ significantly. After varicocelectomy, sperm concentration, total sperm count, progressive and total motility, total motile sperm count, morphology, and round cell count improved significantly. Postoperatively, caspase-3, MDA, and KEAP1 decreased, whereas SOD, GPx-1, GSH, NRF2, and inhibin B increased significantly. 8-OHdG showed a borderline decrease, and AMH remained unchanged. SOD showed the best diagnostic performance. Grade 3 varicocele is associated with oxidative DNA damage, impaired antioxidant defense, increased apoptotic signaling, and altered Sertoli cell-related seminal biomarkers. Varicocelectomy partially restores redox homeostasis, which may contribute to improved spermatogenic function. Full article

At the dawn of the 20th century, seminal studies revealed that muscle fibers produce less heat and generate greater force during elongation than during shortening actions, laying the foundation for contemporary research on eccentric exercise. Today, eccentric exercise is widely used by athletes to enhance strength and by older adults to maintain functional capacity, yet it may cause muscle damage, particularly in unaccustomed muscles. Despite more than a century of investigation, the precise mechanisms of eccentric exercise-induced muscle damage remain incompletely resolved. Nevertheless, eccentric exercise serves as a valuable model for studying muscle injury and repair and adaptation. This review organizes current evidence into nine key themes: (1) eccentric exercise-induced muscle damage and flawed biomarkers, (2) satellite cell-mediated and alternative repair pathways, (3) high-force, low-cost contractions and metabolic impact, (4) repeated bout effect and protective adaptations, (5) architectural remodeling of fascicles, sarcomeres and tendon, (6) distinct neural control, proprioception, and cross-education adaptations, (7) mitochondrial, sarcoplasmic reticulum, and cytoskeletal stress remodeling, (8) connective tissue perturbation, remodeling, and joint stability, and (9) targeted, cautious use of antioxidant supplementation. Rather than offering a comprehensive overview, this review highlights pivotal experiments, concepts, and controversies within these themes to guide readers to the most impactful discoveries in eccentric exercise and muscle damage. Full article

Male fertility is declining worldwide, with notable reductions in sperm counts, emphasizing the need for new therapeutic interventions. Atranorin (ATR), a lichen-derived secondary metabolite, exhibits strong antioxidant and anti-inflammatory activities. This study assessed the protective effects of ATR on type 1 diabetes (T1D)-induced reproductive dysfunction in rats. T1D was induced in male Wistar rats via a single intraperitoneal injection of alloxan at 150 mg/kg body weight (bw). ATR significantly ameliorated T1D-related reproductive damage. At 170 mg/kg bw, ATR reduced hyperglycemia by 66% and attenuated seminal inflammation, decreasing leukocyte infiltration (−51%) and myeloperoxidase (MPO) activity (−68%). Oxidative balance improved, as evidenced by increased total antioxidant status (TAS) (+203%) and decreased thiobarbituric acid reactive substances (TBARS) (−73%), hydrogen peroxide (H₂O₂) (−45%), and total oxidant status (TOS) (−70%). Steroidogenesis was restored through enhanced 3β-hydroxysteroid dehydrogenase (3β-HSD) (+65%) and 17β-hydroxysteroid dehydrogenase (17β-HSD) (+102%) activities, resulting in a 90% recovery of testosterone levels. Seminal plasma function improved, with increased fructose levels (+71%), normalized pH (7.4), and enhanced hyaluronidase (HYAL) (+71%), adenosine triphosphatase (ATPase) (+71%), and prostatic acid phosphatase (PAP) (+79%) activities. Fertility biomarkers, such as adenosine deaminase (ADA) (+148%) and lactate dehydrogenase-C4 (LDH-C4) (+62%), increased, and essential minerals Zn²⁺ (+72%), Ca²⁺ (+96%), Mg²⁺ (+84%), and Se (+57%) were restored. Consequently, sperm density (+87%), viability (+69%), and motility (+189%) improved, while abnormalities declined (−46%). Histological findings confirmed the restoration of spermatogenesis and epididymal maturation. ATR effectively counteracts diabetes-induced reproductive dysfunction by reducing oxidative and inflammatory stress while improving hormonal and seminal parameters. Full article

Cancer metabolism is a cornerstone of tumor biology, characterized by profound alterations in cellular energy production and biosynthetic pathways that drive malignancy. The seminal discovery of the “Warburg effect”, the preference of cancer cells for aerobic glycolysis even under oxygen-rich conditions, provided the first major insight into this field. Historically, this observation was attributed to defective mitochondria, but modern research has revealed a far more complex picture of metabolic reprogramming that is actively driven by oncogenes, tumor suppressor genes, and the tumor microenvironment (TME). This review advances a unifying framework for understanding cancer metabolism as a dynamic ecosystem defined by three interconnected adaptations: metabolic plasticity, oncometabolite-driven epigenetic remodeling, and immune-metabolic crosstalk. These adaptations extend beyond glycolysis to encompass glutamine metabolism, lipid synthesis, amino acid utilization, and mitochondrial dynamics, all coordinated to fuel rapid proliferation, promote survival, and enable metastasis. By examining the drivers, consequences, and therapeutic barriers within this framework, we highlight emerging strategies for precision intervention. Although understanding the mechanistic basis of these pathways has unveiled new therapeutic avenues, clinical translation has been limited by metabolic redundancy, microenvironmental buffering, and patient heterogeneity. Strategies such as metabolic inhibitors, dietary interventions, and immuno-metabolic combinations offer promising prospects for disrupting tumor growth when guided by biomarker-driven patient selection and emerging technologies, including spatial metabolomics and AI-driven network modeling. Full article

Prostatitis includes infectious and noninfectious inflammatory phenotypes that can impair male reproductive potential and may influence couple-level reproduction via seminal inflammatory and microbial exposure. This review summarizes mechanisms linking prostatic inflammation and dysbiosis to semen dysfunction and sperm DNA damage and proposes an infertility-oriented diagnostic and management framework. This is a narrative review of clinical and translational evidence addressing semen inflammation, oxidative stress, sperm DNA fragmentation (SDF), microbiome signatures, and reproductive outcomes in prostatitis (National Institutes of Health (NIH) categories I-IV). Across prostatitis phenotypes, leukocytospermia and elevated seminal cytokines (especially interleukin-8) are associated with impaired motility, altered viscosity and liquefaction, oxidative stress, and higher SDF. Persistent infection or dysbiosis may sustain immune activation and redox injury, while ductal remodeling and pain-related sexual dysfunction can further reduce natural conception. Seminal cytokines and microbes may affect female reproductive tract biology, although clinical outcome data remain limited. Prostatitis-related infertility requires evaluation beyond routine semen analysis. A biomarker-guided workup integrating inflammatory markers, oxidative stress testing, targeted microbiology (culture plus nucleic acid amplification tests when indicated), SDF testing in selected men, and imaging when obstruction is suspected can identify treatable drivers and guide timing and selection of assisted reproduction strategies. Future studies should standardize fertility endpoints and validate biomarker-guided and microbiome-directed interventions. Full article

Background/Objectives: Cervical cancer remains a leading cause of cancer morbidity and mortality worldwide. Although chemoradiation followed by brachytherapy is the curative-intent standard for locally advanced disease, outcomes remain heterogeneous and recurrence and distant metastasis persist. In parallel, immune checkpoint inhibitors (ICIs) and antibody–drug conjugates (ADCs) have expanded systemic options in recurrent or metastatic settings and created new opportunities for multimodality. This review aims to integrate treatment-relevant cervical cancer biology and biomarkers to clarify how chemoradiation, immunotherapy, and ADCs can be optimally selected, sequenced, and combined across disease states. Methods: We conducted a structured narrative, evidence-based literature synthesis focusing on cervical cancer management. The review encompassed: (i) the molecular and immune mechanisms underlying human papillomavirus (HPV)-driven carcinogenesis; (ii) contemporary diagnostic and staging approaches, including advanced imaging modalities and histopathological evaluation; and (iii) clinical and translational evidence supporting the optimization of chemoradiation, immune checkpoint inhibition, and antibody–drug conjugates, with emphasis on clinically validated or emerging biomarkers that are relevant to patient stratification and mechanistically rational combination or sequencing strategies. A systematic search of PubMed/MEDLINE, Embase, and major oncology conference proceedings was performed. Priority was given to peer-reviewed original research articles, high-impact clinical trials (Phase II–III), meta-analyses, and consensus guidelines published within the past 10 years to ensure contemporary relevance. Articles published prior to this period were generally excluded to maintain clinical currency; however, seminal studies that established foundational therapeutic standards, mechanistic paradigms, or landmark treatment milestones were intentionally retained due to their enduring influence on current practice. Exclusion criteria included non-peer-reviewed sources, case reports with limited generalizability, non-English publications, and studies lacking methodological rigor or clinical relevance to cervical cancer management. Preclinical studies were included selectively when directly informing therapeutic mechanisms, biomarker development, or translational rationale. This approach was designed to balance historical context with up-to-date clinical applicability, ensuring both scientific rigor and contemporary relevance. Results: Chemoradiation and brachytherapy remain essential for local control, while ICIs can restore antitumor T-cell activity in biomarker-enriched contexts. ADCs enable target-directed delivery of potent cytotoxins and may promote immunogenic cell death, supporting immunotherapy and radiation. However, key challenges include resistance mechanisms, toxicity management, and patient identification for the most beneficial combined multimodality. Conclusions: A biology- and biomarker-informed framework can guide more rational integration of multimodality therapy in cervical cancer. Future progress will depend on validated predictive biomarkers, optimized sequencing/combination strategies, and trials that balance efficacy with short- and long-term toxicity. Full article

Oxidative stress (OS) and sperm DNA fragmentation (SDF) are complementary contributors to male infertility. OS characterizes a compromised seminal redox status, whereas SDF quantifies downstream genomic damage. Human sperm are highly susceptible to redox damage due to lipid-rich membranes and disrupted post-meiotic DNA-repair capacity. Excess reactive oxygen species (ROS) can cause lipid peroxidation, oxidative base lesions, and DNA strand breaks that impair fertilization, embryo development, and pregnancy outcomes. This review explains how OS promotes genomic instability and summarizes the main laboratory assays that assess redox status and SDF in semen. These include direct ROS chemiluminescence assay, oxidation–reduction potential, total antioxidant capacity/ferric reducing antioxidant power, and lipid peroxidation biomarkers, alongside SDF platforms (Sperm Chromatin Structure Assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling, alkaline/neutral Comet, and sperm chromatin dispersion). Additionally, guideline-aligned indications are highlighted to clarify the conditions for testing OS and SDF. OS testing is most relevant in men with leukocytospermia or suspected genital tract infection or inflammation, including dysbiosis; in cases of major modifiable exposures such as smoking or heat; and for early monitoring after treatment. SDF testing is particularly informative in couples with recurrent pregnancy loss and in unexplained infertility with normal semen parameters. Combined OS and SDF testing is recommended in clinical varicocele, repeated in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) failure, poor embryo development, and follow-up after targeted therapy. Management centers on treating infection and inflammation, improving lifestyle and environmental factors, considering varicocelectomy when indicated, using targeted antioxidant therapy in men with documented OS, and selectively applying sperm selection technologies or testicular sperm for ICSI when SDF remains high. Priorities include assay standardization, etiologic attribution of DNA damage, and trials testing OS/SDF-guided pathways with live birth as the primary endpoint. When used selectively and in the appropriate context, OS and SDF testing can help refine diagnosis, improve counseling, and help personalize care of infertile couples. Full article

Background/Objectives: Cryptorchidism is a common cause of male infertility and often results in azoospermia. However, the metabolic perturbations underlying cryptorchidism complicated with azoospermia and their association with surgical sperm retrieval outcomes remain poorly defined. Methods: A total of 35 patients with cryptorchidism and azoospermia, as well as 40 controls with normal semen parameters, were enrolled in the study. Seminal plasma samples from all participants were subjected to metabolomic analysis. Additionally, some patients underwent micro-TESE; the association between metabolomic features and the success or failure of surgical sperm retrieval was further analyzed. Results: A total of 931 differential metabolites were identified between patients and controls, primarily enriched in lipid metabolism and amino acid metabolism pathways. Lipid metabolites were broadly downregulated in patients, while several inflammation-related metabolites, including Prostaglandin E2, were upregulated. Routine clinical parameters showed no significant differences between patients with successful and failed micro-TESE. However, metabolomic profiles effectively distinguished these two subgroups. These differential metabolites between the two subgroups were mainly involved in three key pathways: phenylalanine–tyrosine–tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, and folate biosynthesis. Most metabolites in the first two pathways were downregulated in the successful retrieval group, while those in the folate biosynthesis pathway showed the opposite regulatory trend. Four metabolites, including Leucine, 7,8-Dihydroneopterin, L-Tyrosine and Pterin, exhibited robust predictive value for micro-TESE outcomes. Conclusions: This study reveals distinct metabolic signatures in patients of cryptorchidism with azoospermia. The identified metabolic biomarkers provide valuable references for clinical decision-making regarding micro-TESE, facilitating a personalized assessment of sperm retrieval feasibility. Full article