Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most prevalent chronic liver disease worldwide, affecting approximately 32%-38% of the adult population and posing a growing public health burden. MASLD represents a continuous disease spectrum ranging from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH), progressive hepatic fibrosis, cirrhosis, and ultimately hepatocellular carcinoma (HCC). The pathological core of MASLD lies in disruption of hepatic lipid metabolic homeostasis, characterized by an imbalance among de novo lipogenesis, fatty acid β-oxidation, and very-low-density lipoprotein (VLDL)-mediated lipid export. This metabolic disequilibrium subsequently drives inflammatory injury and fibrotic progression. Among the multiple regulatory pathways involved, thyroid hormone (TH) signaling has emerged as a central regulator of hepatic metabolic homeostasis. The liver is a major peripheral target organ of TH action, where TH predominantly exerts its metabolic effects through thyroid hormone receptor β (TRβ). Large-scale epidemiological studies and meta-analyses have demonstrated that hypothyroidism is significantly associated with increased MASLD prevalence, more severe histological injury, and advanced hepatic fibrosis, suggesting that dysregulation of TH signaling may participate throughout the entire MASLD disease spectrum. At the molecular level, TH regulates hepatic lipid metabolism by coordinating suppression of lipogenesis, enhancement of mitochondrial fatty acid oxidation, and promotion of VLDL assembly and secretion through integrated genomic actions of the T3-TRβ axis and non-genomic signaling pathways. Across different stages of MASLD, TH signaling exerts stage-dependent protective effects. In the steatosis stage, TH improves metabolic flexibility by modulating insulin sensitivity, glucose metabolism, and lipid droplet clearance, thereby alleviating early lipotoxic stress. During progression to MASH, TH attenuates inflammatory amplification by improving mitochondrial homeostasis, suppressing activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, and modulating the gut-liver axis microenvironment. In advanced stages, TH signaling influences hepatic stellate cell activation and extracellular matrix deposition, partly through interaction with the transforming growth factor-β (TGF-β)/SMAD pathway, while alterations in intrahepatic TH availability, mediated by dynamic changes in iodothyronine deiodinase 1 (DIO1), contribute to fibrosis progression and hepatocellular dedifferentiation. In hepatocellular carcinoma, coordinated downregulation of TRβ and DIO1 establishes a tumor-associated hypothyroid state that promotes metabolic reprogramming and tumor progression. The clinical relevance of TH signaling in MASLD has been underscored by the recent approval of Resmetirom, a liver-targeted TRβ‑selective agonist, for the treatment of non-cirrhotic MASH with moderate-to-severe fibrosis (F2-F3). This approval represents a landmark transition from mechanistic understanding to metabolism-centered precision therapy in MASLD. Clinical trials have demonstrated that Resmetirom not only improves key histological endpoints, including MASH resolution and fibrosis regression, but also favorably modulates atherogenic lipid profiles, highlighting the therapeutic potential of selectively targeting hepatic TH pathways. This review systematically summarizes the multidimensional regulatory roles of TH across the MASLD disease spectrum and discusses emerging diagnostic and therapeutic implications of TH-based interventions, aiming to inform future mechanistic research and optimize clinical management strategies.

ObjectiveTo evaluate the antitumor activity of Periplaneta americana extract（PAE） against human-derived lung adenocarcinoma organoids（LUAD-PDOs） and to elucidate its potential mechanism based on transcriptomics. MethodsFresh tumor and adjacent normal tissues from patients with LUAD were collected to construct LUAD-PDOs and normal lung organoid（Nor-PDOs） models using 3D organoid culture technology. The effective intervention concentration of PAE was determined using the cell counting kit-8（CCK-8） assay. Experimental groups included the model group（LUAD-PDOs）， normal group， model administration group（LUAD-PDOs+PAE）， and normal administration group（Nor-PDOs+PAE）. Hematoxylin-eosin（HE） staining was used to observe the pathological structures of PDOs， immunohistochemistry（IHC） was performed to detect the expressions of the proliferation marker Ki-67 and lung adenocarcinoma differentiation markers cytokeratin-7（CK-7） and Napsin A， TUNEL staining was applied to detect cell apoptosis. RNA sequencing（RNA-Seq） was conducted to identify differentially expressed genes（DEGs）， followed by Gene Ontology（GO）， Kyoto Encyclopedia of Genes and Genomes（KEGG）， and Gene Set Enrichment Analysis（GSEA）， alongside protein-protein interaction（PPI） network analysis to screen core mechanisms. Finally， key targets were validated by integrating external database analysis with immunofluorescence（IF）. ResultsNor-PDOs and LUAD-PDOs that highly recapitulated the pathological characteristics of the primary tissues were successfully established. The CCK-8 assay determined that the effective intervention concentration of PAE was 16 g·L^-1. Morphological observation showed that Nor-PDOs exhibited lumen-forming structures， whereas LUAD-PDOs displayed dense， solid structures. CCK-8 and TUNEL assays revealed that， compared with the model group， PAE intervention inhibited the proliferation of LUAD-PDOs and promoted apoptosis in LUAD cells， while showing no significant effect on the viability of Nor-PDOs. Transcriptomic analysis identified 719 DEGs that were significantly reversed after PAE intervention（347 up-regulated and 372 down-regulated）（P<0.05）. GO enrichment analysis indicated that DEGs in the model administration group were significantly enriched in biological processes related to cell cycle regulation compared to the model group. KEGG pathway analysis revealed that PAE affected pathways related to proliferation and metabolism， including pathways in cancer and the p53 signaling pathway. GSEA further confirmed that PAE significantly enhanced the activity of the p53 signaling pathway（P<0.05）. PPI network analysis indicated that breast cancer type 1 susceptibility protein（BRCA1） and checkpoint kinase 1（CHEK1） were the core down-regulated targets in the p53 pathway. IF verified the high expression of BRCA1 and CHEK1 in LUAD-PDOs and their significant downregulation after PAE intervention（P<0.05）. Furthermore， survival analysis based on The Cancer Genome Atlas（TCGA） database indicated that low expression of BRCA1 and CHEK1 was significantly associated with prolonged overall survival in patients with LUAD（P<0.05）. ConclusionPAE effectively inhibits proliferation of LUAD-PDOs and promotes their apoptosis， its anti-tumor mechanism is potentially associated with the activation of the p53 signaling pathway， with BRCA1 and CHEK1 genes likely serving as key downstream targets for the effects of PAE.

ObjectiveTo establish the mouse models of psoriasis-like lesions induced by continuous cold exposure or intermittent cold exposure combined with imiquimod （IMQ）， and to evaluate the interventional effects of Kaixuan Jiedu core prescription （KXJD） on the two models. MethodsMale C57BL/6J mice were selected and classified into two experimental batches. The first batch of 36 mice was randomized into a room temperature group， a continuous cold exposure （10 ℃/24 h） group， and an intermittent cold exposure （10 ℃/6 h） group. Each group was further divided into a normal subgroup and a model subgroup （topical application of IMQ to induce skin lesions）， with 6 mice in each subgroup， for modeling and evaluation. The second batch of 54 mice， with 6 in each group， were subjected to the same temperature grouping with an additional KXJD （30.42 g·kg^-1， continuous gavage for 5 days） group. Comprehensive evaluation of model characteristics and KXJD efficacy was conducted through Psoriasis Area and Severity Index （PASI） scoring， skin temperature measurement by infrared thermography， histopathological observation by hematoxylin-eosin （HE） staining， detection of vascular endothelial growth factor （VEGF） and platelet endothelial cell adhesion molecule 1 （CD31） by immunohistochemistry， detection of Claudin-1 and Occludin by immunofluorescence assay， determination of serum levels of tumor necrosis factor-α （TNF-α） and interleukin （IL）-10 by enzyme-linked immunosorbent assay （ELISA）， and quantification of mRNA levels of IL-17A， IL-23， IL-6， and chemokine ligand 20 （CCL20） in skin lesions by quantitative Real-time polymerase chain reaction （Real-time PCR）. ResultsModel mice in all temperature groups exhibited typical psoriasis-like skin lesions. Compared with the normal groups， the model groups showed increased PASI scores， decreased skin temperatures （P<0.05）， obvious epidermal thickening， parakeratosis， and dermal inflammatory cell infiltration， as well as elevated mRNA levels of IL-17A， IL-23， IL-6， and CCL20 （P<0.05）. Cold exposure further aggravated psoriasis. The total PASI score of the intermittent cold exposure model group was higher than that of the room temperature model group （P<0.05）. The serum IL-10 did not show a compensatory elevation， and the blood vessels presented a characteristic of elevated CD31 expression （P<0.05） without a synchronous increase in VEGF. The continuous cold exposure model group exhibited more significant dermal capillary tortuosity and dilation， with the highest mRNA levels of IL-17A， IL-23， IL-6， and CCL20 among all groups. Compared with the respective model groups， KXJD intervention alleviated skin lesions， reduced epidermal thickness and inflammatory cell infiltration， and increased skin temperature， with the temperature increase being particularly significant in the intermittent cold exposure+KXJD group （P<0.05）. Furthermore， KXJD down-regulated the expression of VEGF and CD31， restored the expression of Claudin-1 and Occludin， decreased the mRNA levels of IL-17A and IL-23 （P<0.05）， and reduced the serum TNF-α level. ConclusionThis study successfully established compound psoriasis-like mouse models induced by cold exposure combined with IMQ. It confirms that cold aggravates the severity of psoriasis by exacerbating the closure of Xuanfu （sweat pores）， microcirculation disorders， and immune imbalance. Moreover， different cold exposure patterns have distinct mechanism differences. Continuous cold exposure focuses on enhancing the inflammatory response via the IL-23/IL-17 axis and angiogenesis， simulating chronic aggravation under a long-term cold environment. Intermittent cold exposure tends to impair immune regulation and induce microvascular endothelial stress， corresponding to acute exacerbations caused by sudden temperature drops. KXJD can effectively alleviate psoriasis-like skin lesions under cold conditions by unblocking Xuanfu， regulating vasomotor function， and correcting abnormal immune-inflammatory responses.

ObjectiveTo investigate the ameliorative effects of Kaixuan Jiedu core prescription （KXJD） on skin lesions in psoriasis-like mouse models under cold environment exposure， and to analyze its influences on transient receptor potential （TRP） channels and related neuroimmune regulatory factors. MethodsThirty-six C57BL/6J mice were randomized into 6 groups， with 6 mice in each group. Two feeding conditions were set： Normal temperature and cold ［simulating a cold environment at （10±0.5） ℃， for 6 h daily］. Mice were induced to develop psoriasis-like lesions by applying imiquimod externally. The model mice were allocated into model groups and KXJD （30.42 g·kg^-1， continuous gavage for 5 days） groups. Normal mice were used as the control group. Specifically， mice were allocated into normal temperature， normal temperature model， normal temperature+KXJD， cold exposure control， cold exposure model， and cold exposure+KXJD groups. The pathological changes in skin lesions were observed by hematoxylin-eosin （HE） staining. The expression of cluster of differentiation （CD） 3⁺ T lymphocytes， CD11c⁺ dendritic cells （DCs）， phosphorylated extracellular signal-regulated kinase （p-ERK）， and substance P （SP） were detected by immunofluorescence assay. The protein level of transient receptor potential cation channel subfamily M member 8 （TRPM8） in the skin tissue was determined by Western blot. The expression of TRPM8， transient receptor potential cation channel subfamily V member 1 （TRPV1）， transient receptor potential cation channel subfamily A member 1 （TRPA1）， and transient receptor potential cation channel subfamily V member 2 （TRPV2） at the protein and mRNA levels was determined by immunohistochemistry and Real-time PCR， respectively. The levels of calcitonin gene-related peptide （CGRP） and neuropeptide Y （NPY） in the serum were analyzed by enzyme-linked immunosorbent assay （ELISA）. The enrichment analysis of differentially expressed genes （DEGs） and TRP pathway network construction were conducted based on the GEO database. The co-expression of TRPM8 and CGRP in the skin lesions was verified by immunofluorescence double labeling. ResultsBoth the normal temperature and cold exposure model groups showed typical psoriasis-like skin lesions. Compared with the normal temperature and cold exposure control groups， the model groups had excessive epidermal keratinization， thickened spinous layer， and inflammatory infiltration in the dermis， with increased pathological scores （P<0.05）， increased infiltration of CD3⁺ and CD11c⁺ cells and expression of p-ERK and SP， upregulated mRNA levels of TRPM8， TRPA1， and TRPV2， downregulated mRNA level of TRPV1 （P<0.05）， and reduced content of CGRP and increased content of NPY in the serum. Compared with the normal temperature and cold exposure model groups， KXJD reduced the pathological manifestations and pathological scores of psoriasis-like skin lesions （P<0.05）， and inhibited the infiltration of CD3⁺ and CD11c⁺ cells and the expression of p-ERK and SP. Gene enrichment analysis suggested that the DEGs of psoriasis were significantly enriched in the interleukin （IL）-17 signaling pathway and TRP channel inflammatory regulation. Compared with the normal temperature and cold exposure model groups， KXJD reversed the abnormal mRNA levels of genes related to the TRP channel subfamilies （P<0.05）， increased the CGRP level， and decreased the NPY level. Immunofluorescence double labeling further confirmed that compared with the model groups， KXJD down-regulated the co-expression of TRPM8 and CGRP in the skin lesions. ConclusionKXJD may ameliorate psoriasis-like skin lesions by downregulating the overexpressed cold-sensitive receptor TRPM8 in skin lesions and correcting the disorder of neuropeptide （such as SP and CGRP） release mediated by it， thereby inhibiting the IL-23/helper T cell 17 （Th17） core inflammatory pathway， suppressing the infiltration of inflammatory cells and the activation of the ERK signaling pathway， and regulating the Xuanfu （sweat pore）-TRPM8-neuroimmune response axis.

ObjectiveTo investigate the ameliorative effects and mechanisms of Kaixuan Jiedu core prescription （KXJD） on neuroimmunological inflammation in imiquimod （IMQ）-induced psoriasis-like mice. MethodsA total of 24 C57BL/6J mice were randomly divided into four groups （n=6）： Normal， model， KXJD， and tropomyosin receptor kinase A （TrkA） inhibitor GW441756 groups. The mice in the model， KXJD， and GW441756 groups were topically treated with 5% IMQ cream （62.5 mg·d^-1） on the back to induce psoriasis-like inflammation. The KXJD group received KXJD by gavage （30.42 g·kg^-1）， the GW441756 group received intraperitoneal injection of GW441756 （10 mg·kg^-1）， and the normal and model groups received an equal volume of normal saline by gavage， with continuous intervention for 5 days. The severity of skin lesions was evaluated using the psoriasis area and severity index （PASI）. Hematoxylin-eosin （HE） staining was used to measure epidermal thickness and observe pathological changes in the lesioned skin. Immunohistochemistry was employed to detect the expression of proliferating cell nuclear antigen （Ki67） and interleukin-17A （IL-17A） in the lesioned skin. Enzyme-linked immunosorbent assay （ELISA） was used to quantify the levels of interleukin-23 （IL-23） and calcitonin gene-related peptide （CGRP） in the lesioned tissues. Western blot was used to detect the expression of TrkA and phosphorylated TrkA （p-TrkA）. Immunofluorescence assay was performed to detect the expression of TrkA receptor， protein gene product 9.5 （PGP9.5）， cluster of differentiation 11c （CD11c）， and CGRP in the lesions. Flow cytometry was used to detect the activation of splenic dendritic cells （DCs）. ResultsCompared with the normal group， the model group exhibited typical psoriasis-like inflammation， characterized by erythema， infiltration and scaling， with histopathological findings of epidermal hyperkeratosis and acanthosis. The model group showed significantly increased expression of Ki67， IL-17A， IL-23 and p-TrkA （P<0.05， P<0.01）， increased fluorescence intensity of CD11c， and significantly decreased CGRP expression （P<0.05）. The splenic DC activation was significantly enhanced， as indicated by the increased mean fluorescence intensity （MFI） of CD86 （P<0.05）. Compared with the model group， both the KXJD and GW441756 groups showed amelioration of the psoriasis-like skin inflammation， with significantly down-regulated expression of IL-17A， IL-23 and p-TrkA （P<0.05， P<0.01）， significantly up-regulated expression of CGRP （P<0.01）， reduced CD11c⁺ DC infiltration， and restored splenic DC activation balance （down-regulated CD86 MFI and up-regulated CD80 and CD40 MFI）. Furthermore， the inhibitory effect of KXJD on Ki67 was significantly superior to that of the GW441756 group （P<0.01）. ConclusionKXJD may alleviate IMQ-induced psoriasis-like inflammation in mice by targeting and inhibiting TrkA receptor phosphorylation， regulating CGRP expression in the lesions， and ameliorating aberrant activation of dendritic cells， while also significantly inhibiting keratinocyte proliferation.

ObjectiveTo investigate the effects and molecular mechanisms of Kaixuan Jiedu core prescription （KXJD） on neuroinflammation and immuno-inflammation in the mouse model of imiquimod （IMQ）-induced psoriasis-like skin lesions by regulating the nerve growth factor （NGF）-tropomyosin receptor kinase A （TrkA）/transient receptor potential vanilloid 1 （TRPV1）-protease-activated receptor-2 （PAR-2） signaling pathway. MethodsA psoriasis-like skin lesion model was established in male C57BL/6J mice with IMQ. A total of 24 mice were randomized into four groups （n=6 per group）： Blank control， model， methotrexate （MTX， 1 mg·kg^-1）， and KXJD （30.42 g·kg^-1）. Immunohistochemistry was employed to detect the expression of cluster of differentiation 3 （CD3）， EGF-like module-containing mucin-like hormone receptor-like 1 （F4/80）， lymphocyte antigen 6 complex locus G （Ly-6G）， substance P （SP）， calcitonin gene-related peptide （CGRP）， NGF， phosphorylated TrkA （p-TrkA）， phosphorylated TRPV1 （p-TRPV1）， and PAR-2 in skin lesions. Serum levels of interleukin-17A （IL-17A） and interleukin-23 （IL-23） were measured by enzyme-linked immunosorbent assay （ELISA）. Immunofluorescence assay and Western blot were employed to determine the expression of phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK） and phosphorylated nuclear factor-κB p65 （p-NF-κB p65）. Reverse transcription quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA levels of interleukin-1β （IL-1β）， tumor necrosis factor （TNF）， interleukin-6 （IL-6）， and C-X-C motif chemokine ligand 1 （CXCL1） in skin lesions. Correlation analysis was performed. ResultsCompared with the blank control group， the model group showed increased positive areas of CD3⁺， F4/80⁺， and Ly-6G⁺ in skin lesions （P<0.05）， elevated serum levels of IL-17A and IL-23 （P<0.05）， increased positive areas of SP and CGRP in skin lesions （P<0.05）， increased positive areas of NGF， p-TrkA， p-TRPV1， and PAR-2 （P<0.05）， elevated ratios of p-p38 MAPK/p38 MAPK and p-NF-κB p65/NF-κB p65 （P<0.05）， and upregulated mRNA levels of IL-1β， TNF， IL-6， and CXCL1 （P<0.05）. Compared with those in the model group， all the above indicators were reversed in the KXJD group （P<0.05）. MTX only downregulated the expression of p-TRPV1 and PAR-2 （P<0.05）， with no significant effects on the expression of NGF， p-TrkA， or CGRP. ConclusionKXJD inhibits the NGF-TrkA/TRPV1-PAR-2 signaling pathway to reduce neuropeptide release and simultaneously downregulates the p38 MAPK/NF-κB signaling pathway and the expression of downstream pro-inflammatory factors to ameliorate psoriasis-like neuroinflammation and immuno-inflammation. The therapeutic effect of KXJD on psoriasis-like inflammation is closely associated with the inhibition of the NGF-TrkA/TRPV1-PAR-2 signaling pathway. This study provides experimental evidence for the modern interpretation of the Xuanfu theory.

Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.

Readiness for Hospital Discharge(RHD)refers to a multidimensional assessment of a patient's ability to transition safely from hospital to home,encompassing physiological stability,psychological preparedness,and social support adequacy.For patients requiring Home Nutrition Support(HNS),discharge readiness is particularly critical due to their heightened need for post-discharge specialized care,which significantly influences long-term recovery and quality of life.This paper reviews the concept,influencing factors,and unmet needs of RHD in patients with HNS and proposes targeted strategies to enhance discharge preparedness.By addressing gaps in current practices,we aim to optimize RHD in this vulnerable population and provide clinicians with evidence-based guidance for developing effective discharge plans.

Objective:This study aimed to investigate the association between anemia and hypothyroidism during early pregnancy.Methods:We conducted a retrospective analysis of 3,165 pregnant women who registered at Qingdao Women and Children's Hospital from April 2021 to March 2022.Participants were categorized into a hypothyroidism group(n=177)and a euthyroid control group(n=2 988).Maternal demographic data,anemia-related markers(hemoglobin,Hb),and thyroid function parameters(FT3,FT4,TSH)were collected.Statistical analyses included independent t-tests,chi-square tests,Spearman correlation,and multivariate logistic regression.Results:The hypothyroidism group exhibited a significantly higher anemia incidence(10.17%vs 5.02%,P<0.05)and lower mean Hb levels(122.70±10.19 g/L vs 124.60±9.19 g/L,P<0.05)compared to controls.Spearman analysis revealed positive correlations between Hb and FT3(r=0.176)and FT4(r=0.051)(both P<0.05).Multivariate logistic regression identified anemia as an independent risk factor for hypothyroidism(OR=2.038,95%CI:1.202～3.455,P=0.008).Conclusion:Anemia in early pregnancy is associated with the risk of hypothyroidism.We recommend enhanced thyroid function screening and early intervention for anemic pregnant women to mitigate potential complications.

Aim To investigate the therapeutic effects of a newly developed Tadalafil tablet on pulmonary fi-brosis induced by paraquat(PQ)in rats,as well as its impact on histone acetylation levels in epithelial cells.Methods SD rats were randomly divided into four groups:the control group(control),the model group(PQ),the Tadalafil new tablet treatment group(N-Tad,1 mg·kg-1),and the positive control drug treatment group(Cialis,5 mg·kg-1).The model group and treatment group rats were intraperitoneally injected with PQ(30 mg·kg-1).Two hours after the initial treatment,the rats in the treatment group re-ceived N-Tad or Cialis via gavage,while the control and model groups were administered an equal volume of physiological saline by gavage once daily for 28 days.The weight gain rate and lung tissue index for each group of rats were calculated.Additionally,the effects of N-Tad treatment on lung tissue structural damage and collagen deposition in rats with PQ-in-duced pulmonary fibrosis were observed using HE stai-ning,Masson trichrome staining,and immunohisto-chemical techniques.By employing the Western blot technique,the effects of Tadalafil intervention on the expression of the epithelial marker E-cadherin(E-Cad),the stromal marker fibronectin(Fn),and the histone acetylation marker acetylated histones(Ac-his-tones)in A549 cells were observed.Results Com-pared to the control group,rats with PQ-induced pul-monary fibrosis exhibited a significant decrease in the rate of body weight growth,an increase in lung tissue index(P＜0.05),and a notable increase in the expression and distribution of the fibrosis marker alpha-smooth muscle actin(α-SMA)in lung tissue.The structure of the lung tissue was disrupted,accompanied by the deposition of interstitial collagen fibers.Both N-Tad and Cialis treatments could significantly enhance the rate of weight gain,decrease the lung tissue index,inhibit the expression of α-SMA,and reduce the depo-sition of interstitial collagen in the lung tissue of rats with pulmonary fibrosis.Notably,low-dose N-Tad treatment was comparable to high-dose Cialis treat-ment.At the cellular level,Tadalafil significantly in-hibited the high expression of Fn induced by transfor-ming growth factor beta 1(TGF-β1)in A549 cells.It also upregulated the expression of E-cadherin and sig-nificantly increased the levels of acetylated histones(P＜0.05).Conclusions N-Tad promotes histone acetylation in alveolar epithelial cells,significantly in-hibits epithelial-mesenchymal transition,increases E-cadherin expression,and improves lung tissue structur-al damage and collagen deposition caused by PQ.Ad-ditionally,it offers the advantage of a lower effective dose compared to Cialis,providing a new option for the treatment of pulmonary fibrosis.