Search Results (3,246)

Objectives: Doxorubicin (DOX) is an effective chemotherapeutic agent, but its clinical use is limited by hepatotoxicity associated with oxidative stress and inflammatory signaling. This study aimed to investigate the potential protective effects of melatonin and agomelatine on DOX-induced hepatic injury using scintigraphic, biochemical, and molecular parameters. Methods: Twenty-eight rats were randomly divided into four groups: Control, DOX, DOX + Melatonin, and DOX + Agomelatine. Melatonin and agomelatine were administered as a one-week pretreatment, and DOX was injected during the experimental period (total dose: 18 mg/kg). Hepatic injury was evaluated using 99mTc-PYP scintigraphic imaging, serum liver enzymes (AST, ALT, and LDH), oxidative stress markers (MDA, GSH, Nrf2, and SIRT1), and inflammatory cytokines (TNF-α, IL-6, and IL-10). Results: DOX administration significantly increased hepatic 99mTc-PYP uptake, as well as serum AST, ALT, and LDH levels, indicating hepatocellular necrosis and membrane damage. DOX also increased MDA, TNF-α, and IL-6 levels while reducing GSH, Nrf2, SIRT1, and IL-10, demonstrating pronounced oxidative stress and inflammatory activation. Treatment with melatonin or agomelatine significantly reduced tracer uptake and liver enzyme levels compared with the DOX group. Both treatments improved antioxidant status by decreasing MDA and restoring GSH, Nrf2, and SIRT1 levels, while simultaneously attenuating inflammatory cytokine responses through reduction in TNF-α and IL-6 and partial restoration of IL-10. Conclusions: Melatonin and agomelatine attenuated DOX-induced hepatotoxicity by reducing oxidative stress, modulating inflammatory responses, and restoring hepatic SIRT1 and Nrf2 levels. These findings suggest that melatonergic interventions may represent promising protective strategies against doxorubicin-induced liver injury. Full article

Background: Obesity is a chronic, relapsing disease that often proves resistant to lifestyle measures alone. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), are reshaping treatment, yet prospective real-world data remain limited. Objective: To prospectively assess the effects of once-weekly Semaglutide on weight, body composition, and metabolic health in obesity. Methods: An exploratory observational study of 37 patients initiating Semaglutide (mean age 31 years; 11 children and adolescents; 22 females) was conducted. All met obesity criteria (baseline BMI 34.7 kg/m²). Anthropometry, bioimpedance body composition, and fasting biochemistry were obtained at baseline and 3 months. Variables were reported as mean ± SD or median (IQR) according to normal/non-normal distribution, whether a parametric test or a Wilcoxon one was used. Parametric or non-parametric paired tests (two-sided α = 0.05) were applied. We also explored tri-ponderal mass index (TMI, kg/m³) and its correlations with metabolic markers. Results: At 3 months, body weight decreased by a median 8.0 kg (p < 0.001), BMI by 1.6 kg/m² (p < 0.001). Body fat percentage declined: 43.4% to 42.8% (p = 0.009), with a small reduction in skeletal muscle mass (−0.6 kg; p = 0.035). Fasting glucose improved (p = 0.030) and HOMA-IR fell significantly. HbA1c changes were minimal, consistent with near-normal baseline values. Triglycerides decreased, while total cholesterol, LDL-C, HDL-C, liver enzymes, creatinine, uric acid, and 25-OH vitamin D remained stable. Baseline TMI (median 20.13 kg/m³; IQR 3.80) correlated strongly with HOMA-IR (r = 0.766, p < 0.001) and moderately-to-strongly with body fat percentage (r = 0.621, p < 0.001). Conclusions: In this real-world cohort, Semaglutide produced rapid, clinically meaningful improvements in weight, adiposity, and insulin resistance within 3 months. Findings suggest that Semaglutide may represent a promising adjunct to lifestyle therapy in obesity management. Full article

Nicotinamide (NAM), a precursor of nicotinamide adenine dinucleotide (NAD⁺), and NAD⁺ are integral to a variety of cellular processes. NAM supplementation has been shown to have benefits for cellular senescence. However, the mechanism by which NAM improves skin photoaging remains unclear. In this study, the multi-omics analysis revealed that insufficient nicotinamide metabolism may be associated with a decrease in NAD⁺ synthesis during skin aging. Importantly, we found that NAM has an ameliorating effect on the skin photoaging in mice. Supplementation with NAM restored the expression of the salvage-pathway enzymes and NAD⁺ consumers. In addition, the supplementation with NAM was shown to restore the expression of skin barrier-related proteins (ZO1 and E-cadherin) and collagen I, while reducing the expression of senescence markers (γ-H2AX, p53, and p21). Furthermore, we found that NAM effectively suppresses the senescence-associated secretory phenotype (SASP) factors’ expression in skin photoaging. Our research reveals the dual role of NAM in attenuating skin photoaging, acting not only to delay cellular senescence but also to suppress the SASP. Full article

Background/Objectives: Spinosin, a flavone glycoside derived from medicinal plants, has been widely studied for its neuroactive properties; however, its effects on gastric injury remain unclear. Therefore, this study investigated the potential protective role of spinosin against HCl/ethanol-induced gastric lesions and its association with Nrf2/HO-1-related antioxidant responses. Methods: Gastric ulceration was experimentally induced in male Swiss albino mice by intragastric administration of 0.3 M HCl in 70% ethanol. Spinosin was administered orally at doses of 10 and 20 mg/kg, while omeprazole (20 mg/kg) was used as a reference treatment. Results: HCl/ethanol exposure led to pronounced oxidative stress and inflammatory responses, as reflected by increased levels of MDA, NFκB, IL-6, TNF-α, Cox-2, iNOS, IL-1β, Bax, and Cas-3, along with reduced antioxidant enzyme activities (GSH, SOD, CAT), decreased PGE2 and NO levels, and downregulation of Nrf2, HO-1, and Bcl-2 expression. Spinosin administration significantly attenuated gastric injury, suppressed pro-inflammatory mediators, reduced markers of lipid peroxidation and apoptosis, and enhanced antioxidant defenses. In parallel, spinosin treatment was associated with increased expression of Nrf2, HO-1, and Bcl-2. Conclusions: These findings suggest that spinosin mitigates gastric damage and is associated with attenuation of oxidative stress, inflammatory responses, and apoptosis, suggesting a possible contribution of Nrf2/HO-1-related antioxidant responses. Full article

Objective: Diabetes mellitus (DM) is a major metabolic disorder associated with hyper-glycemia and oxidative stress. Traditional medicinal plants remain important sources of bioactive compounds with potential antidiabetic activity. Salacia reticulata and Caralluma tuberculata are two important medicinal plants that have been reported to have antidiabetic effects. The growing burden of type 2 diabetes and the need for therapies that address both hyperglycemia and oxidative stress underscore the necessity to investigate these two medicinal plants. Therefore, the current study evaluated the antihyperglycemic, antioxidant, and protective effects of Salacia reticulata and Caralluma tuberculata in an alloxan-induced diabetic female rat model. Methods: Ethanolic extracts of S. reticulata and C. tuberculata were characterized by total phenolic content (TPC), total flavonoid content (TFC), DPPH radical-scavenging assay, and UPLC–MS/MS metabolite profiling. Female Wistar rats (n = 42) were randomly assigned to seven groups (n = 6/group), including normal control, diabetic control, extract-treated non-diabetic groups, diabetic extract-treated groups, and a metformin-treated diabetic group. Diabetes was induced by alloxan (130 mg/kg), followed by oral treatment for 8 days with extracts or metformin (500 mg/kg/day). Fasting blood glucose, oral glucose tolerance, serum malondialdehyde (MDA), antioxidant markers (SOD1, GSH, and CAT), and liver and kidney histopathology were assessed. Results: Both plant extracts significantly reduced fasting blood glucose compared with baseline, with S. reticulata showing a greater reduction (22.8%) than C. tuberculata (12.3%), and a response comparable to metformin (27.4%). Diabetic rats exhibited increased MDA and reduced antioxidant enzyme activities. C. tuberculata significantly lowered MDA levels and increased SOD1 activity, suggesting moderate antioxidant effects, whereas S. reticulata showed higher phenolic and flavonoid contents and the highest DPPH scavenging activity. UPLC–MS/MS identified 33 compounds in S. reticulata and 24 in C. tuberculata. Histopathological findings supported improvement of diabetes-associated renal and hepatic damage. Conclusions: Within the eight-day experimental period, both extracts demonstrated significant acute antidiabetic and antioxidant effects with distinct redox–metabolic profiles. However, further long-term studies are recommended to evaluate their sustained efficacy, safety, and potential as complementary therapeutic agents for diabetes management. Full article

Osteoarthritis (OA) is a chronic, debilitating degenerative joint disease whose prevalence is rising markedly with the rapid aging of the global population. In this study, we investigated the chondroprotective efficacy of NP-2007, an enzymatically hydrolyzed low-molecular-weight collagen from Cervi cornu, using IL-1β-stimulated SW1353 human chondrocyte cells and a medial meniscal transection (MMT)-induced OA rat model. In SW1353 cells, NP-2007 considerably suppressed the expression of inflammatory mediators (iNOS, COX-2) and cytokines (TNF-α, IL-6) without cytotoxicity. Crucially, it restored matrix homeostasis by downregulating catabolic enzymes (MMP-3, MMP-13, and ADAMTS-5) and upregulating anabolic markers (COL2A1, aggrecan), a process associated with the modulation of the Wnt/β-catenin and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathways and the recovery of the master chondrogenic factor SOX9. These in vitro findings were consistent with the in vivo results from the MMT model, where oral administration of NP-2007 (50 and 200 mg/kg) for 8 weeks effectively preserved articular cartilage structure and proteoglycan content while markedly reducing serum levels of catabolic biomarkers, including MMP-13 and COMP. Collectively, our findings demonstrate that NP-2007 exerts potent chondroprotective effects by modulating the balance between cartilage degradation and synthesis, suggesting its potential as a therapeutic candidate for the management of OA. Full article

Although praziquantel (PZQ) is the main antischistosomal drug currently in use, concerns remain regarding incomplete reversal of schistosomiasis-induced pathology and the emergence of drug resistance. This study evaluates the combined effect of PZQ with safranal, a bioactive saffron constituent, on Schistosoma mansoni-induced pathology in mice. Male CD1 Swiss albino mice were exposed to 60 S. mansoni cercariae and, at week 9 post-infection, were treated with PZQ (500 mg/kg orally for two consecutive days), safranal (50 mg/kg/day), or both, for three weeks. The animals were sacrificed at week 11 post-infection. Worm and egg burdens, liver histopathology, fibrotic markers, oxidative stress, and inflammatory cytokines were assessed. Combined PZQ + safranal therapy significantly reduced adult worm counts and hepatic and intestinal egg loads compared to PZQ alone. All treatments decreased liver index (hepatomegaly), with the combination treatment providing the best intervention. Histological analyses revealed significantly reduced granuloma size and hepatic necrosis post-treatment, particularly in the combination group. The levels of proinflammatory cytokines (TNF-α, IL-1β) and Th2 cytokines (IL-4, IL-5, IL-6, IL-10) were significantly lowered in treated mice, most notably with the combination treatment. Oxidative stress was also markedly attenuated, and infected mice exhibited elevated malondialdehyde and depleted antioxidant enzymes (SOD, CAT, GSH). Interestingly, PZQ and/or safranal restored antioxidant status and reduced lipid peroxidation, with the combination being most effective. Furthermore, collagen deposition and expression of hepatic fibrotic markers α-smooth muscle actin (α-SMA), TGF-β1, and matrix metalloproteinase-9 were most effectively suppressed by combined therapy. To conclude, safranal enhances PZQ’s antischistosomal efficacy and confers additive protection against Schistosoma-induced liver fibrosis. Full article

Sinotaia angularis is a freshwater viviparid snail with limited genomic resources. Here, we report a chromosome-level reference genome generated using PacBio HiFi sequencing and Hi-C scaffolding, with mitochondrial marker -based screening (16S rRNA and COI (cox1)) and phylogenetic analysis supporting the taxonomic assignment. A total of 74.08 Gb of HiFi reads were obtained, providing approximately 65.7-fold genome coverage. The final assembly spans 1.127 Gb, with a scaffold N50 of 141.87 Mb and a GC content of 34.47%. Hi-C scaffolding anchored 978.89 Mb (86.85% of the assembly) onto eight chromosome-level scaffolds. BUSCO analysis using the mollusca_odb10 dataset recovered 86.9% complete orthologs from the genome assembly. Repeat annotation identified 378.75 Mb of repetitive sequences (33.60% of the genome), with unclassified repeats and LTR elements as the dominant components. Gene annotation predicted 22,232 protein-coding genes, 209 tRNAs, 72 rRNAs, 88 snRNAs, and 10 snoRNAs. Functional annotation assigned database support to 155,611 predicted proteins or isoforms, corresponding to 98% of the total protein set. CAZy annotation identified 5371 carbohydrate-active enzyme entries, suggesting broad carbohydrate-processing potential. This genome provides a reference resource for comparative genomics, chromosome evolution, repeat dynamics, gene-family evolution, and freshwater adaptation studies in Viviparidae. Full article

High-fat diet (HFD)-induced hyperlipidemia is an experimental metabolic condition characterized primarily by dysregulated serum lipid levels and hepatic lipid accumulation, with associated oxidative, inflammatory, mitochondrial, and cardiovascular alterations. This study investigated the therapeutic efficacy of epigallocatechin gallate (EGCG)-functionalized selenium nanoparticles (EGCG-SeNPs) against HFD-induced metabolic and hepatic injury, in comparison with free EGCG, sodium selenite (Na₂SeO₃), and Lipanthyl. EGCG-SeNPs were characterized by dynamic light scattering, zeta potential analysis, transmission electron microscopy, X-ray diffraction, and UV–visible spectrophotometry. Forty-two adult male rats were allocated into six groups: control, HFD, HFD/Lipanthyl, HFD/EGCG, HFD/Na₂SeO₃, and HFD/EGCG-SeNPs. High-fat diet (HFD) feeding induced pronounced dyslipidemia, elevated hepatic enzymes, increased cardiac injury biomarkers, enhanced lipid peroxidation and nitrosative stress, depletion of antioxidant defenses, and disruption of the Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) regulatory axis. HFD also increased nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), while altering mitochondrial apoptotic markers, including B-cell lymphoma 2 (Bcl-2), cytochrome c, and caspase-3. At the transcriptional level, HFD increased lipogenic gene expression and reduced the expression of genes related to fatty-acid oxidation, metabolic regulation, and mitochondrial homeostasis. EGCG-SeNPs showed the greatest overall improvement among the tested interventions, as indicated by an improved lipid profile, hepato-cardiac injury biomarkers, antioxidant status, inflammatory markers, apoptotic markers, hepatic architecture, and Nrf2 immunoreactivity. Collectively, EGCG-SeNPs may mitigate HFD-induced hepatic lipotoxicity and associated cardiac stress through coordinated modulation of lipid metabolism, redox balance, inflammation, and mitochondrial homeostasis. Full article

Background: Vitamin D has traditionally been recognized for its role in calcium homeostasis and skeletal health, but vitamin D receptor expression and vitamin D-metabolizing enzymes have also been identified in extra-skeletal tissues, including components of the male reproductive tract. Observational evidence has suggested associations between vitamin D status and androgen-related markers; however, whether vitamin D supplementation has a measurable effect on androgen bioavailability remains uncertain. Objective: This systematic review and meta-analysis evaluated the effects of vitamin D supplementation on total testosterone (TT) and androgen bioavailability markers in adult men, including sex hormone-binding globulin (SHBG), free androgen index (FAI), calculated free testosterone (calculated FT), and bioactive testosterone (BAT) where methodologically compatible. Methods: The review was registered in PROSPERO (CRD420261365005) and conducted according to PRISMA 2020 and Cochrane methodological guidance. Searches were conducted from database inception to April 2026 in PubMed, Web of Science, Scopus, ClinicalTrials.gov, and the WHO ICTRP. Embase was initially planned but was not searched because institutional access was unavailable; this amendment was made before screening, extraction, risk-of-bias assessment, and synthesis. Records were deduplicated in Zotero, screened in a structured matrix, and converted from report-level records into independent comparison-level datasets where appropriate. Meta-analyses used random-effects REML models with Hartung–Knapp adjustment. Results: The official search set comprised 2854 records, of which 703 duplicates were removed, leaving 2151 records for title and abstract screening. The full-text screening file was reconciled to 162 PRISMA-countable reports/records: 135 reports were assessed, 27 reports could not be assessed because the full text was unavailable or had not been obtained for review, and 27 reports/studies were retained for qualitative synthesis. Eighteen reports were considered candidate sources for quantitative synthesis and were operationalized into 21 comparison-level records. The primary TT model included 11 comparisons and showed no clear effect of vitamin D supplementation on final TT (MD 0.47 nmol/L, 95% CI −0.50 to 1.44; I² = 24.1%). No clear effects were observed for SHBG (MD 0.27 nmol/L, 95% CI −2.14 to 2.68), FAI (MD −0.37, 95% CI −4.28 to 3.55), calculated FT sensitivity evidence (MD −0.0096 nmol/L, 95% CI −0.0525 to 0.0332), or BAT exploratory evidence (MD −0.47 nmol/L, 95% CI −1.77 to 0.83). GRADE certainty was low for TT, SHBG, and FAI, and very low for calculated FT and BAT. Conclusions: Current randomized evidence does not demonstrate a statistically clear or reproducible effect of vitamin D supplementation on total testosterone or androgen bioavailability markers in adult men. GRADE certainty was low for total testosterone, SHBG, and FAI, and very low for calculated free testosterone and bioactive testosterone. Because directly measured and calculated free testosterone are not analytically equivalent, free testosterone was not pooled as a primary outcome; method-compatible calculated FT was handled as sensitivity evidence and BAT as exploratory evidence. Full article

As one of the most economically important cucurbit crops, melon (Cucumis melo L.) is extensively cultivated in semi-arid and tropical regions where high evaporative demand frequently intensifies salt accumulation. These conditions promote the evaporative concentration of salt, leading to salt accumulation in soil and irrigation water, which can impair crop development. Therefore, identifying approaches capable of maintaining seedling establishment under saline conditions is crucial for sustainable melon production. This study evaluated tolerance and antioxidant responses in different melon cultivars using seed treatments to mitigate salt stress effects. The experiment was conducted in two stages under a completely randomized design with four replicates of 50 seeds. In the first stage, a 3 × 5 factorial design tested three salinity levels (0, 60, and 120 mM NaCl) and five cultivars (‘Dali’, ‘Premier’, ‘Supreme’, ‘Imperial 45’, and ‘Asturia’), assessing morphological, physiological, and biochemical traits. In the second stage, two contrasting cultivars (‘Imperial 45’ (sensitive) and ‘Asturia’ (tolerant)) were exposed to salinity combined with stress attenuators, including hydropriming, gibberellic acid, ascorbic acid, salicylic acid, and hydrogen peroxide. Additional biochemical markers and antioxidant enzyme activities were analyzed. Results showed that gibberellic acid and ascorbic acid enhanced antioxidant activity and reduced oxidative damage, particularly in Imperial 45, whereas hydrogen peroxide was more effective in Asturia. Based on their physiological and biochemical responses during germination and early seedling development, Asturia and Imperial 45 were identified as tolerant and sensitive to salt stress, respectively. These findings indicate that the effectiveness of seed treatments depends on cultivar-specific physiological characteristics at the seedling stage. Full article

Background: Menopause represents a critical physiological transition associated with hormonal changes that influence both metabolic health and quality of life (QoL). Metabolic dysfunction-associated steatotic liver disease (MASLD), a common metabolic condition, is closely linked to menopause; however, its independent contribution to QoL impairment remains unclear. This study aimed to investigate the interplay between menopausal status, metabolic dysfunction, MASLD, and QoL in midlife women. Methods: A cross-sectional observational study was conducted including 80 women aged 45–55 years, comprising both premenopausal and menopausal participants. Clinical, anthropometric, biochemical, and imaging data were collected. MASLD was diagnosed using magnetic resonance imaging in the presence of metabolic dysfunction. Metabolic assessment included glucose, insulin, liver enzymes, C-reactive protein, and indices of insulin resistance (HOMA-IR) and sensitivity (QUICKI). QoL was evaluated using the Utian Quality of Life (UQOL) scale. Associations were examined using univariate and multivariable linear regression models. Results: MASLD prevalence was significantly higher in menopausal women compared with non-menopausal women (61.9% vs. 15.8%, p < 0.001). Metabolic parameters, particularly insulin resistance and body mass index, were strongly associated with MASLD. The mean total UQOL score indicated moderate QoL. In multivariable analysis, menopausal status was the only independent predictor of reduced total QoL (b = −4.93, p = 0.01) and occupational health domain (b = −4.60, p = 0.001). MASLD and metabolic parameters were not independently associated with overall QoL. Correlation analyses revealed modest associations between metabolic markers and specific QoL domains, particularly occupational and physical health. Conclusions: Menopause is the primary determinant of reduced QoL in midlife women, particularly affecting functional domains, while MASLD does not independently impact QoL despite its strong association with metabolic dysfunction. These findings suggest that menopausal status may play a more prominent role in quality-of-life outcomes than MASLD in women undergoing the menopausal transition. However, the cross-sectional design does not allow conclusions regarding causal or mechanistic relationships. Full article

Background: The kidney is an organ rich in peroxisomes, which play a pivotal role in fatty acid oxidation and ROS decomposition. Importantly, peroxisomal dysfunction contributes to the development and progression of various renal diseases. Therefore, we aimed to elucidate whether peroxisomes affect renal damage and fibrosis over time using a unilateral ureteral obstruction (UUO) mouse model. Methods: Expression levels of peroxisome-related factors and ROS- and hypoxia-related genes in UUO mice were measured in a time-dependent manner. Results: UUO led to renal damage and fibrosis progression over time; it significantly increased the protein expression levels of ATG5 and ATG7, while it decreased PMP70 and PEX14 protein expression. In particular, UUO increased the protein expression level of pexophagy receptor NBR1. Although the number of peroxisomes decreased, the protein expression levels of peroxisomal biogenesis-related proteins such as PEX11b, PEX16, and PEX19 remained constant. Decreased lipid metabolism due to reductions in ACOX1, DBP, and catalase caused by UUO and increased ROS production through peroxisomal degradation and mitochondrial antioxidant enzyme dysfunction were observed. Additionally, HIF-1α protein levels gradually increased in the UUO mice, whereas those of HIF-2α initially increased and then decreased. Conclusions: UUO is characterized by a progressive, chronological reduction in peroxisomal markers. Our findings indicate that peroxisomal degradation and associated metabolic dysfunction are tightly correlated with the progression of kidney injury and fibrosis, suggesting a potential involvement of compromised peroxisomal homeostasis in renal pathogenesis rather than proving a direct causal mechanism. Maintaining peroxisomal quality control may nevertheless represent a potential therapeutic avenue for chronic kidney disease. Full article

Thai shallot (Allium cepa L. var. aggregatum) is rich in quercetin glycosides, which can be enzymatically hydrolyzed into aglycone forms with potentially higher bioavailability. However, whether this structural modification enhances metabolic efficacy in vivo remains unclear. This study aimed to compare the metabolic and histopathological effects of enzymatic (ESE) and non-enzymatic (NES) Thai shallot extracts in a high-fat diet (HFD)-induced obese mouse model. Male C57BL/6 mice were fed HFD for 12 weeks to induce obesity, followed by a 12-week treatment with NES or ESE (1000 and 2000 mg/kg/day). Metabolic parameters, lipid profiles, oxidative stress markers, hepatic enzyme activities, and histopathological changes were evaluated. Enzymatic hydrolysis significantly increased the proportion of quercetin aglycone without altering total quercetin content. Both NES and ESE improved fasting glucose, insulin resistance, lipid profiles, and oxidative stress markers compared with HFD controls. Histological examination showed attenuation of hepatic steatosis and preservation of tissue architecture in treated groups. However, no consistent superiority of ESE over NES was observed across metabolic or histopathological outcomes. Despite substantial modification of flavonoid composition, enzymatic processing did not enhance the measured metabolic efficacy of Thai shallot extract under the conditions tested. Because circulating quercetin and metabolite levels were not assessed, this finding should be interpreted as comparable metabolic efficacy rather than evidence of equivalent bioavailability. These findings suggest that factors beyond aglycone content may play a key role in determining biological activity, with implications for the development and cost-effectiveness of functional food products. Full article

Myxomatous mitral valve disease (MMVD) is the most common acquired cardiac disease in small-breed dogs and shows particularly high prevalence and early onset in Cavalier King Charles Spaniels (CKCS). Although MMVD is considered a complex, polygenic disease, the clinical relevance of individual genetic variants remains incompletely understood. The angiotensin-converting enzyme (ACE) gene variant rs850683722 has previously been associated with altered ACE activity and differences in renin–angiotensin–aldosterone system-related responses in dogs with MMVD. The aim of this study was to determine the prevalence of rs850683722 in a Polish population of CKCS dogs and to assess whether this variant is associated with the clinical course of MMVD. A total of 105 CKCS dogs were included in the study. All dogs underwent standardized cardiovascular evaluation, including echocardiography, electrocardiography, and systolic blood pressure measurement. MMVD diagnosis and staging were performed according to current ACVIM consensus criteria. Genotyping of the rs850683722 variant was performed using Sanger sequencing for 95 dogs, while next-generation sequencing data was obtained for 10 dogs. Genotype distribution, allele frequencies, conformity with the Hardy–Weinberg equilibrium (HWE), sex-related differences, and associations between genotype and age at progression to selected MMVD stages or the primary clinical endpoint were assessed statistically. The most frequent genotype was AA, detected in fifty-nine dogs, followed by GG in thirty-seven dogs and AG in nine dogs. When dogs carrying at least one A allele were considered variant-positive, the overall prevalence of the variant-positive genotype was 64.8%. The calculated allele frequencies were 0.605 for the A allele and 0.395 for the G allele. The observed genotype distribution deviated markedly from the Hardy–Weinberg equilibrium, mainly because of a pronounced deficit of heterozygous dogs. No significant association was detected between genotype and sex. Genotype was also not significantly associated with age at progression to stage B2 or stage C. A statistically significant difference in age of death was demonstrated by genotype, but this difference was not reflected in the survival analysis. The rs850683722 variant was highly prevalent in the studied Polish CKCS population, with a frequency comparable to previously reported data for this breed. Despite its documented biological association with ACE activity and RAAS-related responses, the variant was not significantly associated with the clinical progression of MMVD in this cohort. These findings suggest that rs850683722 alone seems unlikely to be a reliable marker for predicting the severity or rate of MMVD progression in Polish CKCS dogs. Further studies including larger cohorts, longer follow-up, pedigree information, and the direct assessment of RAAS activity may help clarify whether this variant has stage-dependent or treatment-related clinical relevance. Full article