Search Results (1,682)

Background and Objectives: Nintedanib is indicated for progressive pulmonary fibrosis (PPF) based on clinical trial results. The primary objectives of this study were to evaluate the effectiveness of nintedanib on forced vital capacity (FVC) and diffusing lung capacity for CO (DLCO) after one year of treatment, and to compare the annual rate of decline (“slope”) for FVC, DLCO and 6 minute walking distance (6MWD) with the year prior to treatment. The secondary objectives were antifibrotic safety, tolerability, adverse events, immunosuppressant use, dyspnoea and survival. Materials and Methods: This study was a single-centre, retrospective, observational cohort study that included consecutive patients with PPF treated with nintedanib. Results: Fifty-five patients with non-IPF fibrotic ILD initiated nintedanib due to fibrosis progression. Most patients (63.4%) stabilised/improved FVC after 1 year of treatment, and 82.5% stabilised/improved DLCO. The “slope” of FVC and DLCO was reduced after 1 year of treatment compared to the year before initiation, although the difference was not statistically significant: FVC slope was +0.61% in the year after initiation vs. −2.3% in the year prior (mean change: 2.94%, 95%CI [−4.74, 10.62]); DLCO slope was −3.8% after treatment vs. −7% before initiation (mean change: 3.24%, 95%CI [−7.43, 13.92]). Dyspnoea improved in 23.2% of patients. A reduction in immunosuppressant use was observed after nintedanib initiation. Forty-one patients (74.5%) experienced at least one side effect: diarrhoea (60%), hepatotoxicity (23.6%), or asthenia (12.7%). Fifteen patients required permanent or temporary treatment discontinuation. Conclusions: In our real-world PPF cohort, most patients showed FVC and/or DLCO stabilisation or improvement after one year of nintedanib treatment. A non-significant reduction in the rate of FVC decline after one year of treatment was also observed, as was a reduction in symptom severity in our real-life PPF cohort. Full article

Per- and polyfluoroalkyl substances (PFASs) present a critical challenge to global public health and environmental integrity due to the exceptional stability of the carbon–fluorine (C–F) bond. This review synthesizes current knowledge on PFAS physicochemical properties, exposure pathways, and toxicological outcomes, while evaluating global regulatory efficacy. A central problem addressed in this review is the widening discrepancy between rigid, yet deeply fragmented, international regulatory frameworks and the increasingly complex, non-linear epidemiological data regarding PFAS health risks. While historical paradigms focused heavily on direct carcinogenicity, recent high-resolution data reveal significant heterogeneity and methodological inconsistencies in cancer links. Instead, robust evidence points to severe systemic toxicities—including hepatotoxicity, immunotoxicity, and maternal–fetal disruptions—frequently driven by mixture co-exposures and sex-specific metabolic dimorphisms. Furthermore, the industrial transition to short-chain substitutes has inadvertently compounded the crisis due to their high environmental mobility and resistance to conventional water treatment. By critically evaluating these toxicological and regulatory contradictions, this review demonstrates that current substance-by-substance legislative models fail to mitigate real-world pollution trends. Ultimately, we emphasize the urgent need to transition to holistic mixture modeling, implement unified class-based global regulations, and accelerate advanced destructive remediation technologies to mineralize the resilient C–F bond. Full article

Background and Aims: TDF is a first-line antiviral for CHB with pleiotropic effects including immunomodulation and fibrosis regression, but its virus-independent mechanisms are unclear. This study delineates TDF’s direct molecular and metabolic landscape in vivo using multi-omics. Methods: Wild-type mice received TDF or vehicle for 4 months. Liver tissues underwent RNA-seq and targeted metabolomics, followed by integrative systems biology. Results: TDF caused no hepatotoxicity but induced transcriptomic reprogramming: broad upregulation of immune/inflammatory pathways and suppression of metabolic pathways. Metabolomics confirmed perturbations in amino acid and fatty acid homeostasis. Multi-omics revealed coordinated downregulation of arginine/proline, alanine/aspartate/glutamate, and phenylalanine metabolism, restricting fibrogenic amino acids. TDF also suppressed the TCA cycle (downregulating Idh, Sdh, and Mdh), suggesting a metabolic bottleneck that was associated with paradoxically accumulated succinate and oxoglutarate—immunomodulatory danger signals. Conclusions: This first integrated atlas shows TDF actively remodels the hepatic microenvironment independent of viral infection, bridging metabolic suppression with immune activation. These findings provide an immunometabolic framework that offers new perspectives for understanding the clinical application of TDF and identifies potential biomarkers for CHB therapy. explaining TDF’s clinical superiority and identifying potential biomarkers for CHB therapy. Full article

Background: Acetaminophen (APAP) overdose remains a major cause of acute liver injury. Although N-acetylcysteine (NAC) is the clinically established antidote for APAP toxicity, its efficacy is greatest when administered early, and additional therapeutic strategies are still needed for patients with delayed presentation or progressive injury. Because APAP hepatotoxicity involves coupled disturbances in redox control, mitochondrial performance, and cellular metabolism, metabolic enzymes that sustain NADPH availability may critically influence disease severity. Malic enzyme 1 (ME1), a cytosolic NADPH-generating enzyme, has not been functionally defined in this context. Methods: To determine the contribution of ME1 to APAP-induced liver injury (AILI), we used hepatocyte-specific ME1 knockout mice, hepatic overexpression and reconstitution approaches, primary mouse hepatocytes, and an enzymatically inactive ME1 mutant. Liver injury and associated changes in oxidative stress, mitochondrial function, energy metabolism, autophagic flux, and endoplasmic reticulum (ER) stress were evaluated using biochemical, histological, molecular, and ultrastructural analyses, together with pharmacological interventions. Results: Genetic loss of ME1 did not substantially alter early APAP metabolic activation-related indices, including APAP-protein adduct formation, but markedly increased hepatocellular metabolic vulnerability after APAP challenge. This phenotype was characterized by enhanced lipid peroxidation, impaired mitochondrial polarization, reduced ATP availability, defective autophagic flux, and amplified ER stress, leading to more severe liver damage. In contrast, ME1 overexpression or reconstitution promoted a more adaptive metabolic response and limited tissue injury. These effects depended largely on ME1 catalytic activity, as protection was markedly weakened with the mutant enzyme. Pharmacological analyses further supported the involvement of AMPK/mTOR-associated autophagy regulation and ER stress adaptation in the downstream actions of ME1. Malic acid also partially attenuated APAP-induced hepatotoxicity in vivo and in vitro. Conclusions: ME1 functions as an endogenous metabolic factor that influences the outcome of APAP-induced liver injury. Its catalytic activity supports hepatocyte survival primarily by preserving reductive capacity, bioenergetic balance, and adaptive stress responses, rather than by altering APAP metabolic activation. Full article

Background/Objectives: Atrasentan is a selective endothelin A receptor antagonist (SERA) developed as a potential therapy for chronic renal diseases, including diabetic nephropathy and immunoglobulin A nephropathy. Despite this potential, understanding its metabolic bioactivation is essential for assessing the risks of drug-induced liver injury (DILI). However, the metabolic profile of atrasentan remains poorly characterized, and the mechanisms underlying its potential hepatotoxicity remain underexplored. Therefore, this study aims to investigate the metabolic pathways of atrasentan in human liver microsomes (HLMs) in the presence of nicotinamide adenine dinucleotide phosphate (NADP⁺), uridine diphosphate glucuronic acid (UDPGA), or glutathione (GSH). Methods: A liquid chromatography–high resolution mass spectrometry (LC-HRMS) coupled with a feature-based molecular networking approach was used to characterize metabolites. Characterization of the major metabolites was achieved through cytochrome P450 (P450) phenotyping with human recombinant P450 isoforms. Results: A total of eighteen metabolites were characterized through phase I and II metabolic reactions, including demethylenation, N-dealkylation, O-demethylation, hydroxylation, dehydrogenation, and glucuronidation. Atrasentan acyl glucuronide (M8) was confirmed as the predominant metabolite, and we also putatively annotated a catechol intermediate (M5) and its corresponding GSH conjugate (M15). Characterizing the GSH conjugate (M15) indicates that catechol intermediate (M5) can be further oxidized to a reactive ortho-quinone intermediate, which is subsequently trapped by GSH, suggesting the potential for a bioactivation mechanism. Reaction phenotyping demonstrated that the formation of M5 is catalyzed almost exclusively by the CYP3A subfamily. However, its direct translation to in vivo oxidative stress or covalent protein binding requires further studies. Conclusions: These findings demonstrate that feature-based molecular networking is a valuable strategy for metabolite characterization, underscoring the urgent need for further in vivo metabolism studies to definitively assess hepatotoxic risks associated with these reactive metabolites. Full article

Background: Multiple sclerosis (MS), an autoimmune disease, involves peripheral immune activation followed by CNS inflammation in a compartmentalized manner. Although high-efficacy disease-modifying therapies (HE-DMTs) have been effective in suppressing relapses in MS patients, they fail to effectively target chronic microglial activation and smoldering lesions in MS patients. Bruton’s tyrosine kinase inhibitors (BTKis), which are orally active and capable of crossing the blood–brain barrier, have been found to be effective in modulating B cells and CNS-resident myeloid cells. Objective: The objective was to assess the efficacy and safety of Bruton’s tyrosine kinase inhibitors in patients with relapsing, secondary, and primary progressive MS. Methods: We performed a systematic review and meta-analysis according to the Cochrane and PRISMA guidelines (PROSPERO registration number: 1323474). We included randomized controlled trials (RCTs) that assessed fenebrutinib, evobrutinib, or tolebrutinib in adult MS patient populations. The main outcome measures were annualized relapse rate, MRI lesion activity, disability progression (EDSS), and hepatotoxicity. The quality of the included trials was assessed for bias by the RoB2 tool. Results: Six RCTs with 3616 participants were included. BTK inhibitors significantly reduced ARR compared with control therapy (pooled RR 0.24; 95% CI 0.15–0.39). MRI activity was reduced (mean difference −1.45 new/enlarging T2 lesions; 95% CI −2.08 to −0.82). Disability progression was unchanged in short-term relapsing MS trials. Serious hepatotoxicity was reported in 11.0% of BTKi-treated patients compared with 13.7% of control patients (pooled RR 0.80; 95% CI 0.66–0.96). However, increased transaminase elevations were reported in placebo-controlled trials, which indicates that hepatotoxicity remains a clinically relevant safety concern for the class. Conclusions: BTK inhibitors reduce inflammatory disease activity in relapsing MS and have emerging efficacy in progressive MS phenotypes; however, continued monitoring for hepatotoxicity is warranted. Optimization of CNS penetrance and pharmacologic selectivity may influence long-term clinical positioning. Full article

Hepatocellular carcinoma (HCC) is among the most prevalent and lethal malignancies worldwide, with limited therapeutic outcomes due to systemic toxicity and suboptimal efficacy of conventional chemotherapeutics such as doxorubicin (DOX). In this study, we formulated and standardized DOX-loaded chitosan/poly (lactic-co-glycolic acid) nanoparticles (DLCNs) via a nanoprecipitation method and evaluated their therapeutic potential in a diethylnitrosamine (DEN)-induced Wistar rat model of HCC. Physicochemical analyses confirmed nanoscale size, favorable zeta potential, and high encapsulation efficiency, while Fourier-transform infrared spectroscopy (FTIR) verified polymer–drug interactions. Biochemical analysis revealed that DLCNs significantly normalized elevated liver function markers (Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), restored serum α-fetoprotein (AFP) to near-control levels, and reduced lipid peroxidation compared with free DOX and DEN controls. Antioxidant profiling demonstrated marked recovery of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), indicating restoration of hepatic redox balance. Histopathological evaluation further corroborated these findings, showing recovery of hepatic lobular architecture and reduction in necrosis and inflammatory infiltrates in DLCN-treated Wistar Albino rats, while free DOX groups exhibited hepatocellular damage. Overall, the results demonstrate that encapsulating DOX in a chitosan/PLGA nanocarrier improves therapeutic efficacy, mitigates hepatotoxicity, and enhances antioxidant defense, establishing DLCNs as a favorable candidate for HCC. Full article

Background/Objectives: Poly (ADP-ribose) polymerase (PARP1) has emerged as a promising therapeutic target in human breast cancer particularly in BRCA1/2 mutation carriers where a synthetic lethal interaction leads to massive tumor cell death upon specific inhibitors’ administration. Current clinically approved PARP inhibitors (Talazoparib and Olaparib) show outstanding therapeutic capabilities but suffer from severe side effects. Most importantly, some of them can cause life-threatening cardiotoxicity through hERG off-target effects. Here, we performed an extensive study to identify lead compounds with improved binding modes and favorable predicted pharmacokinetics using an integrated computational strategy. Methods: An artificial intelligence-driven drug design (AIDDISON™ v2023) workflow was employed to search ultra-large chemical space libraries for active compounds, which were then optimized via computer-aided methods to form a PARP-Tailored Database (PTD). This database was then analyzed through a virtual screening workflow, molecular docking studies, molecular dynamics (MD) simulations, MM/GBSA binding free energy calculations, DFT analysis and ADME/Tox predictions using the Schrödinger suite (v2023-2), MobaXterm v25.2, Gaussian 16.0, ProTox-3 and Pred-hERG v5.0 respectively. Results: Three compounds (1a–1c) were identified as promising candidates. Among them 1a appeared to be the most active compound with a favorable docking score (−9.488 kcal/mol) that is not only higher than 1b and 1c but also higher than that of Talazoparib (−6.778 kcal/mol). MD simulations of 1a–1c in the active site revealed an average RMSD of ~2.5–3.6 Å which is better compared to the parent Talazoparib (5.6 Å). Interestingly, on the 250 ns extended MD study, 1a exhibited a slightly reduced RMSD between 2.4 and 3.2 Å, whereas Talazoparib retained higher fluctuations of ~5 Å to 6 Å. MM/GBSA binding energy analysis indicated 1a to have better predicted binding affinity (−67.820 kcal/mol), which is also better than Talazoparib (−63.734 kcal/mol). DFT calculations showed good electronic properties and in silico ADMET studies also indicated 1a to have good drug-likeness and lower predicted hepatotoxicity and cardiotoxicity risk. Conclusions: These findings identify compound 1a as a promising lead, while compounds 1b and 1c remain viable candidates for further optimization. However, experimental validation is critical to confirm the predicted biological activity and safety profiles. Full article

Micro- and nanoplastics (MNPs) are emerging environmental contaminants of increasing relevance to human health. Growing evidence suggests that, following ingestion, inhalation, or, less convincingly, dermal exposure, MNPs may cross biological barriers, enter lymphatic and vascular compartments, and reach the liver. Owing to portal blood flow, sinusoidal architecture and Kupffer cell activity, the liver appears to be one of the principal sites of early particle sequestration. Human biomonitoring, ex vivo and postmortem studies have detected MNPs in blood and multiple organs, including the liver, although the currently available evidence remains limited and methodologically heterogeneous. Their identification relies on multistep analytical procedures that integrate sample pretreatment with FTIR, Raman spectroscopy, LD-IR, Py-GC-MS and supplementary imaging methods. However, each of these techniques presents significant limitations, particularly in the analysis of nanoplastics. Experimental studies indicate that MNPs may induce hepatic injury through oxidative stress, mitochondrial impairment, endoplasmic reticulum stress, inflammation, DNA damage, dysregulated lipid metabolism and disruption of the gut–liver axis, consequently contributing to steatosis, cholestatic anomalies and fibrosis. Consequently, MNPs should be considered potential contributors to liver pathology, although more comprehensive human data are still required. Full article

Polycystic ovary syndrome (PCOS) is frequently accompanied by visceral obesity, insulin resistance, low-grade chronic inflammation, and metabolic syndrome (MetS). These alterations promote significant dysfunction in adipose tissue and liver metabolism through cytokine production. Growing evidence indicates that the interaction between hepatokines and adipokines plays a central role in the development of metabolic and hepatic abnormalities in women with PCOS. This narrative review was conducted to analyze the relationship between adipose tissue dysfunction and liver metabolic impairment in women with PCOS, emphasizing the involvement of hepatokines and adipokines in insulin resistance, inflammation, hepatic steatosis, hepatic fibrosis and MetS. From this perspective, contemporary clinical, biochemical, and molecular studies were reviewed to evaluate how adipocyte-derived factors and hepatocyte-derived cytokines influence metabolic homeostasis in the liver and adipose tissue in women with PCOS. Increased visceral adiposity in PCOS enhances the release of free fatty acids (FFAs) to the liver, resulting in hepatotoxicity, oxidative stress, and hepatic inflammation. Several hepatokines, including fetuin-A, angiopoietin-like protein 3 (ANGPTL3), selenoprotein P(Sep-P), and hepassocin (HPS), show abnormal circulating levels in PCOS and are strongly associated with insulin resistance, dyslipidemia, and progression to hepatic steatosis. In contrast, fibroblast growth factor 21 (FGF-21), follistatin, and interleukin (IL-6) may exert dual effects. Adipokines, such as resistin, visfatin, apelin, and retinol-binding protein 4 (RBP-4), contribute to chronic inflammation, impaired glucose metabolism, androgen excess, and hepatic steatosis and fibrosis. Some of these adipokines, such as leptin and vaspin, may exert both beneficial and detrimental effects, while others, including chemerin and omentin, appear to play predominantly beneficial roles in metabolism. Reduced adiponectin-to-leptin levels further aggravate metabolic dysfunction. These changes indicate that adipose tissue–liver crosstalk is a key mechanism linking PCOS and MetS. Overall, metabolic disturbances in PCOS are strongly mediated by dysregulated communication between adipose tissue and the liver. Altered hepatokine and adipokine profiles contribute to insulin resistance, liver dysfunction, hypertension and the development of MetS in women with PCOS. Understanding these intricate interactions may support the early identification of high-risk patients and the development of targeted therapeutic strategies. Full article

Objective: Linezolid (LZD), an oxazolidinone antibiotic widely used against Gram-positive infections, has been associated with mitochondrial dysfunction and hepatotoxicity, particularly during prolonged use. This study aimed to investigate the protective effects of adenosine triphosphate (ATP) and Liv-52 against LZD-induced liver injury, with a focus on oxidative stress, inflammation, and necroptosis pathways. Methods: Twenty-four male Wistar rats were randomly assigned to four groups: healthy control (HG), LZD-treated (LZDG), Liv-52 + LZD (LVLZ), and ATP + LZD (ATLZ). Liv-52 (50 mg/kg, orally) and ATP (5 mg/kg, intraperitoneally) were administered prior to LZD (125 mg/kg, orally) for 14 days. Results: Following LZD administration, malondialdehyde (MDA) levels markedly increased, indicating oxidative stress, while total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT) activities significantly decreased. Histopathological examination revealed pronounced hepatocellular damage accompanied by increased NF-κB, NLRP3, RIPK3, and MLKL expression, indicating activation of inflammatory and necroptotic pathways. Treatment with ATP and Liv-52 significantly ameliorated these biochemical, histopathological, and molecular alterations. Conclusions: Treatment with ATP and Liv-52 significantly attenuated oxidative stress, improved histopathological alterations, and suppressed the expression of inflammatory and necroptotic markers. Notably, ATP exhibited a more pronounced protective effect compared to Liv-52. In conclusion, LZD induces hepatotoxicity through oxidative stress-mediated inflammatory and necroptotic mechanisms, while ATP and Liv-52 confer hepatoprotection, with ATP showing superior efficacy. Full article

Honokiol (HON) and magnolol (MAG), hepatoprotective neolignans from Magnolia spp., are promising candidates for mitigating liver damage associated with long-term parenteral nutrition (PN). However, their clinical use is limited by poor aqueous solubility. This study aimed to develop a multifunctional nanoemulsion platform based on clinically used lipid nanoemulsions (Lipofundin^®/Lipidem^®), enriched with omega-3 fatty acids and loaded with HON, MAG, or a combination of both. Nanoemulsions were prepared using a two-step homogenization process. Pre-emulsions containing HON, MAG, or both neolignans were first obtained using high-shear homogenization, then mixed in a 1:1 volume ratio with Lipofundin or Lipidem and subsequently subjected to high-pressure homogenization. All nanoemulsions met pharmacopeial standards and literature-recommended quality criteria. The formulations showed mean droplet diameters below 500 nm, PFAT5 values below the 0.05% limit, and PDI values < 0.2. Strongly negative zeta potentials (≤−30 mV) confirmed stability. The formulations were non-hemolytic, fully compatible with PN admixtures for 24 h, and non-cytotoxic in THLE-2 cells. Furthermore, all developed nanoemulsions demonstrated lower in vitro hepatotoxicity than clinically used reference formulations, indicating their promising clinical potential. However, further in vivo studies are required to confirm their therapeutic benefits and hepatoprotective effect during parenteral nutrition (PN). Full article

Cadmium is a widespread environmental xenobiotic that poses serious risks to hepatic, renal, and male reproductive functions. Natural compounds such as silymarin, a bioactive extract from Silybum marianum, have gained attention for their protective potential against xenobiotic-induced toxicity. This study investigated whether subchronic oral administration of silymarin (30 mg/kg) mitigates cadmium-induced toxicity (5 mg/kg) in adult rats over six weeks. Twenty-four rats were assigned to four groups: control, cadmium-exposed, silymarin-treated, and co-treated. Biochemical, hematological, oxidative stress, and reproductive parameters were assessed. Sperm quality was evaluated using CASA, and testicular tissues were examined histologically. Cadmium exposure significantly reduced body weight (−30.8%), elevated transaminases (AST, ALT; p < 0.01), increased serum creatinine and total cholesterol, and induced multi-organ oxidative stress, as reflected by elevated malondialdehyde and markedly reduced SOD, CAT, and thiol group levels in testicular, hepatic, and renal tissues (p < 0.01). Sperm concentration dropped from 75.2 to 21.8 × 10⁶/mL, with total motility falling to 35% and progressive motility to 18%, accompanied by severe seminiferous tubule degeneration (Score III in 5 rats). Co-administration of silymarin partially restored these parameters, sperm concentration recovered to 38.5 × 10⁶/mL, total motility improved to 50.2%, and antioxidant enzyme activities and liver/kidney biomarkers showed significant but incomplete recovery (p < 0.05). Molecular docking revealed favorable binding affinities of silybin toward GPx (−8.4 kcal/mol), CAT (−8.3 kcal/mol), and SOD (−6.4 kcal/mol), offering a preliminary computational hypothesis suggesting possible interactions between silybin and antioxidant enzymes, pending experimental validation. Silymarin alone exerted no adverse effects. These findings establish silymarin as a partial but promising multi-organ cytoprotectant against cadmium toxicity, and highlight the need for future studies optimizing dosing strategies, exploring longer treatment durations, and investigating combination approaches with metal chelators or Nrf2-activating agents to achieve complete tissue recovery. Full article

Aflatoxin B1 (AFB1), a common contaminant in broiler feed, impairs hepatic function and poses a significant threat to the poultry industry by disrupting cellular autophagy. Ferulic acid (FA) is a naturally occurring phenolic compound with antioxidant, anti-inflammatory, and autophagy-modulating properties. However, whether FA alleviates AFB1-induced autophagy impairment in broiler liver remains unclear. In this study, an AFB1-induced liver injury model was established. A series of experiments were conducted to evaluate the effects of AFB1 and FA on autophagy-related processes. The results showed that AFB1 exposure was associated with reduced expression of autophagy-related markers, including ULK1, ATG14, ATG5, and LC3-II/LC3-I ratio, suggesting alterations in autophagy-related processes associated with autophagosome formation and maturation. FA supplementation partially reversed these changes and alleviated ultrastructural liver damage induced by AFB1. Transcriptomic and western blot analyses further demonstrated that AFB1 exposure increased p53 expression, dysregulated the BRAF/ERK1/ERK2/mTOR signaling pathway, increased p70S6K expression, and decreased 4E-BP1 expression. FA supplementation alleviated these changes. These results showed that FA may alleviate AFB1-induced alterations in autophagy-related biomarkers in broiler liver, accompanied by changes in the BRAF/ERK1/ERK2/mTOR signaling pathway, suppression of p70S6K expression, and restoration of 4E-BP1 expression, which may contribute to its protective effects against AFB1-induced liver toxicity in broilers. Full article

Background: Methotrexate-induced oxidative stress is mechanistically linked not only to hepatocellular injury but also to DNA damage, indicating that oxidative stress, hepatotoxicity, and genotoxicity represent interconnected manifestations of the same antifolate-driven toxic cascade. Methotrexate (MTX)-induced hepatotoxicity is characterized not only by oxidative stress, but also by progressive fibrotic remodeling driven by activation of the TGF-β/SMAD signaling pathway. Objective: We aimed to examine the hepatoprotective effects of Loureirin B, with a particular focus on its anti-fibrotic potential and underlying molecular mechanisms in MTX-induced liver injury. Methods: Thirty female Wistar rats were assigned to normal control, MTX, and MTX + Loureirin B groups. Liver injury was induced with a single intraperitoneal MTX dose (20 mg/kg), followed by oral administration of Loureirin B (50 mg/kg/day) for 10 days. Biochemical, molecular, and histopathological analyses were performed, including ALT, AST, ALP, MDA, SIRT1, TGF-β, SMAD3, hydroxyproline, and VEGF levels, alongside the evaluation of necrosis, fibrosis, and inflammatory infiltration. Results: MTX induced significant hepatic injury characterized by elevated serum ALT, AST, and ALP levels, increased oxidative stress, suppression of SIRT1, and increased TGF-β and SMAD3 levels, accompanied by elevated collagen-associated markers. Loureirin B treatment significantly reduced the serum liver enzyme levels and oxidative stress, partially restored SIRT1 levels, and decreased fibrosis-associated markers, including hydroxyproline and VEGF. Although the TGF-β levels were significantly reduced following Loureirin B treatment, the reduction in SMAD3 levels did not remain statistically significant after correction for multiple comparisons. Histopathological findings further demonstrated attenuation of fibrosis-associated changes and partial improvement in hepatic architecture. Conclusions: Loureirin B may exert protective effects against methotrexate-associated liver injury through the modulation of oxidative stress, partial restoration of SIRT1 levels, attenuation of profibrotic alterations associated with the TGF-β/SMAD pathway, and modulation of VEGF-related responses. Full article