Mefunidone alleviates silica-induced inflammation and fibrosis by inhibiting the TLR4-NF-κB/MAPK pathway and attenuating pyroptosis in murine macrophages.

AIMS: Silicosis is the most common and severe type of pneumoconiosis, imposing a substantial disease burden and economic loss on patients and society. The pathogenesis and key targets of silicosis are not yet clear, and there are currently no effective treatments available. Therefore, we conducted research on mefunidone (MFD), a novel antifibrotic drug, to explore its efficacy and mechanism of action in murine silicosis. METHODS: Acute 7-day and chronic 28-day silicosis models were constructed in C57BL/6J mice by the intratracheal instillation of silica and subsequently treated with MFD to assess its therapeutic potential. The effects of MFD on silica-induced inflammation, pyroptosis, and fibrosis were further investigated using immortalized mouse bone marrow-derived macrophages (iBMDMs). RESULTS: In the 7-day silica-exposed mouse models, MFD treatment significantly alleviated pulmonary inflammation and notably reduced macrophage infiltration into the lung tissue. RNA-sequencing analysis of silica-induced iBMDMs followed by gene set enrichment analysis revealed that MFD profoundly influenced cytokine-cytokine receptor interactions, chemokine signaling, and the toll-like receptor signaling pathways. MFD treatment also markedly reduced the secretion of inflammatory cytokines and chemokines from silica-exposed iBMDMs. Moreover, MFD effectively downregulated the activation of the TLR4-NF-κB/MAPK signaling pathway induced by silica and mitigated the upregulation of pyroptosis markers. Additionally, MFD treatment significantly suppressed the activation of fibroblasts and alveolar epithelial cells co-cultured with silica-exposed mouse macrophages. Ultimately, in the 28-day silica-exposed mouse models, MFD administration led to a substantial reduction in the severity of pulmonary fibrosis. CONCLUSION: MFD mitigates silica-induced pulmonary inflammation and fibrosis in mice by suppressing the TLR4-NF-κB/MAPK signaling pathway and reducing pyroptotic responses in macrophages. MFD could potentially emerge as a novel therapeutic agent for the treatment of silicosis.

Design, Synthesis, and Biological Evaluation of Quinoline (Quinolinone) Derivatives as NADPH Oxidase (NOX) Inhibitors.

NADPH oxidases (NOXs) are the sole enzyme in the human body that can directly produce reactive oxygen species. Recent studies have shown that NOXs is a very promising target for the treatment of diabetic nephropathy (DN). Here, a series of quinoline(quinolinone) derivatives have been designed based on pharmacophore strategy, synthesized and evaluated. Among them, 19d exhibits potent antiproliferative and NOXs inhibitory activities, and is worthy for further investigation.

A phase I, randomized study to evaluate the safety, tolerability, and pharmacokinetics of mefunidone in healthy subjects.

Background: Mefunidone is a novel synthetic compound and is better when compared to pirfenidone for the anti-fibrotic treatment of renal fibrosis in end-stage renal disease. We conducted this first-in-human, phase I clinical trial to determine the safety, tolerability, and pharmacokinetic (PK) (including food effect) profiles of mefunidone administered orally as single and multiple ascending doses in healthy subjects. Methods: Part A assessed single ascending doses of mefunidone from 25 mg to 800 mg or placebo once daily in the fasting state. Part A also assessed the effect of food on tolerability and PK in the 100 mg cohort. Part B consisted of three treatment groups who received 100 mg, 200 mg, or 400 mg of mefunidone or placebo twice daily (BID, bis in die) on days 1-6 and once in the morning on day 7. Results: Single oral doses of mefunidone up to 800 mg and multiple doses of mefunidone up to 400 mg BID were all well-tolerated. Mefunidone behaved with ideal dose proportionality within the single-dose range of 50 mg-600 mg and the multiple-dose range of 100 mg BID to 400 mg BID by day 7. High-fat fed conditions led to a delay in Tmax by approximately 1 h and a slight reduction of approximately 20% in Cmax compared to that in fasting conditions, but it did not significantly affect systemic exposure. Conclusion: Mefunidone exhibited favorable pharmacokinetics and safety profiles. The present study informed and supported further developmental clinical studies of mefunidone. Clinical Trial Registration: clinicaltrials.gov, identifier CXHL1900206.

Inhibition of Hsp110-STAT3 interaction in endothelial cells alleviates vascular remodeling in hypoxic pulmonary arterial Hypertension model.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive and devastating disease characterized by pulmonary vascular remodeling which is associated with the malignant phenotypes of pulmonary vascular cells. Recently, the effects of heat shock protein 110 (Hsp110) in human arterial smooth muscle cells were reported. However, the underlying roles and mechanisms of Hsp110 in human pulmonary arterial endothelial cells (HPAECs) that was disordered firstly at the early stage of PAH remain unknown. METHODS: In this research, the expression of Hsp110 in PAH human patients and rat models was investigated, and the Hsp110 localization was determined both in vivo and in vitro. The roles and mechanism of elevated Hsp110 in excessive cell proliferation and migration of HPAECs were assessed respectively exposed to hypoxia. Small molecule inhibitors targeting Hsp110-STAT3 interaction were screened via fluorescence polarization, anti-aggregation and western blot assays. Moreover, the effects of compound 6 on HPAECs abnormal phenotypes in vitro and pulmonary vascular remodeling of hypoxia-indued PAH rats in vivo by interrupting Hsp110-STAT3 interaction were evaluated. RESULTS: Our studies demonstrated that Hsp110 expression was increased in the serum of patients with PAH, as well as in the lungs and pulmonary arteries of PAH rats, when compared to their respective healthy subjects. Moreover, Hsp110 levels were significantly elevated in HPAECs under hypoxia and mediated its aberrant phenotypes. Furthermore, boosted Hsp110-STAT3 interaction resulted in abnormal proliferation and migration via elevating p-STAT3 and c-Myc in HPAECs. Notably, we successfully identified compound 6 as potent Hsp110-STAT3 interaction inhibitor, which effectively inhibited HPAECs proliferation and migration, and significantly ameliorated right heart hypertrophy and vascular remodeling of rats with PAH. CONCLUSIONS: Our studies suggest that elevated Hsp110 plays a vital role in HPAECs and inhibition of the Hsp110-STAT3 interaction is a novel strategy for improving vascular remodeling. In addition, compound 6 could serve as a promising lead compound for developing first-in-class drugs against PAH.

A Novel PDK1/MEK Dual Inhibitor Induces Cytoprotective Autophagy via the PDK1/Akt Signaling Pathway in Non-Small Cell Lung Cancer.

In a preliminary study, we synthesized a series of new PDK1/MEK dual inhibitors. Antitumor activity screening showed that Compound YZT exerts a strong inhibitory action in A549 cells. However, the specific mechanism of YZT against non-small cell lung cancer (NSCLC) is largely unknown. This work confirmed the anti-proliferation and pro-apoptosis effects of YZT in NSCLC cells. Furthermore, YZT promotes autophagy and provokes complete autophagic flux in NSCLC cells. Notably, compared with YZT alone, the combination of YZT with the autophagy inhibitor chloroquine (CQ) or 3-methyladenine (3-MA) markedly strengthened the anti-proliferative and pro-apoptotic actions, suggesting that YZT-induced autophagy is cytoprotective. We further found that YZT-induced autophagy may exert a cytoprotective function by preserving the integrity of mitochondria and decreasing mitochondrial apoptosis. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis suggested that PDK1 is an upstream protein of the Akt/mTOR axis and western blotting verified that YZT induces autophagy by the PDK1/Akt/mTOR signaling axis. Finally, YZT plus CQ significantly enhanced the anticancer activities compared to YZT alone in an animal study and immunohistochemistry showed that the level of LC3 was increased by YZT, which is in line with the in vitro results. In short, our study provides reliable experimental basis for developing Compound YZT as a new chemotherapeutic drug candidate and suggests that combined administration of YZT with CQ is a potential therapy against NSCLC.

Discovery of Ureido-Based Apcin Analogues as Cdc20-specific Inhibitors against Cancer.

Cdc20 is a promising drug target that plays an important role in the mid-anaphase process of cellular mitosis, and Apcin is the only reported core structure of the Cdc20-specific inhibitor. Some potent Apcin derivatives were obtained in our previous research, and a structure-activity relationship was determined. In this study, we designed and synthesized a series of ureido-based Apcin derivatives. The proliferation-inhibition experiments on four cancer-cell lines showed that ureido skeleton could promote the anti-proliferation activity of purine-substituted compounds, whereas the ureido analogues with pyrimidine substitutes showed no significant improvement in the inhibitory effect compared with the original ones. Further tests confirmed that ureido-based compounds can enhance the binding affinity to Cdc20 by increasing the levels of Cdc20 downstream proteins. Compound 27 revealed a remarkably antitumor activity pattern against Hela (IC50 = 0.06 ± 0.02 µM) and potent binding affinity to Cdc20. Moreover, compound 20 induced caspase-dependent apoptosis and cell-cycle arrest at the G2/M phase, and compound 27 induced caspase-dependent apoptosis and promoted microtubule polymerization. Finally, a molecular-docking simulation was performed for compounds 20 and 27 to predict the potential ligand-protein interactions with the active sites of the Cdc20 proteins.

Fluorofenidone protects against acute liver failure in mice by regulating MKK4/JNK pathway.

AIMS: Acute liver failure (ALF) is a life-threatening disease characterized by abrupt and extensive hepatic necrosis and apoptosis, resulting in high mortality. The approved drug, N-acetylcysteine (NAC), is only effective for acetaminophen (APAP)-associated ALF at the early stage. Thus, we investigate whether fluorofenidone (AKF-PD), a novel antifibrosis pyridone agent, protects against ALF in mice and explore its underlying mechanisms. METHODS: ALF mouse models were established using APAP or lipopolysaccharide/D-galactosamine (LPS/D-Gal). Anisomycin and SP600125 were used as JNK activator and inhibitor, respectively, and NAC served as a positive control. Mouse hepatic cell line AML12 and primary mouse hepatocytes were used for in vitro studies. RESULTS: AKF-PD pretreatment alleviated APAP-induced ALF with decreased necrosis, apoptosis, reactive oxygen species (ROS) markers, and mitochondrial permeability transition in liver. Additionally, AKF-PD alleviated mitochondrial ROS stimulated by APAP in AML12 cells. RNA-sequencing in the liver and subsequent gene set enrichment analysis showed that AKF-PD significantly impacted MAPK and IL-17 pathway. In vitro and in vivo studies demonstrated that AKF-PD inhibited APAP-induced phosphorylation of MKK4/JNK, while SP600125 only inhibited JNK phosphorylation. The protective effect of AKF-PD was abolished by anisomycin. Similarly, AKF-PD pretreatment abolished hepatotoxicity caused by LPS/D-Gal, decreased ROS levels, and diminished inflammation. Furthermore, unlike NAC, AKF-PD, inhibited the phosphorylation of MKK4 and JNK upon pretreatment, and improved survival in cases of LPS/D-Gal-induced mortality with delayed dosing. CONCLUSIONS: In summary, AKF-PD can protect against ALF caused by APAP or LPS/D-Gal, in part, via regulating MKK4/JNK pathway. AKF-PD might be a novel candidate drug for ALF.

Corrigendum: Protective effects of Mefunidone on ischemia-reperfusion injury/folic acid-induced acute kidney injury.

[This corrects the article DOI: 10.3389/fphar.2022.1043945.].

Recent advances in the development of HIPK2 inhibitors as anti-renal fibrosis agents.

HIPK2 is a serine/threonine kinase, located in the nucleus, that was initially found to be able to phosphorylate p53 at Ser46 to promote apoptosis; it has been widely studied. It has been reported that HIPK2 can simultaneously regulate TGF-ß/Smad3, Wnt/ß-catenin, Notch and NF-κB pathways in the kidney to initiate inflammation and fibrosis, resulting in the development of chronic kidney disease (CKD). Therefore, inhibition of HIPK2 is strongly considered an effective method for the treatment of CKD. In brief, this review summarizes the progress of HIPK2 in CKD as well as the reported HIPK2 inhibitors and their role in different CKD models.

Pulmonary artery smooth muscle cell phenotypic switching: A key event in the early stage of pulmonary artery hypertension.

Pulmonary arterial hypertension (PAH) is a currently incurable pulmonary vascular disease. Since current research on PAH is mainly aimed at the middle and late stages of disease progression, no satisfactory results have been achieved. This has led researchers to focus on the early stages of PAH. This review highlights for the first time a key event in the early stages of PAH progression, namely, the occurrence of pulmonary arterial smooth muscle cell (PASMC) phenotypic switching. Summarizing the related reports of phenotypic switching provides new perspectives and directions for the early pathological progression and treatment strategies for PAH.

Imidazo[1,2-a]pyridine Derivatives as AMPK Activators: Synthesis, Structure-Activity Relationships, and Regulation of Reactive Oxygen Species in Renal Fibroblasts.

Adenosine 5'-monophosphate activated protein kinase (AMPK) has emerged as a promising target for the discovery of drugs to treat diabetic nephropathy (DN). Herein, a series of imidazo[1,2-a]pyridines were designed and synthesized. Among them, the active compound (EC50 =11.0 nM) showed good enzyme activation and molecular docking results showed hydrogen bonding interactions with the key amino acids Asn111 and Lys29 in the active site. Meanwhile, further cellular level experiments revealed that it could reduce reactive oxygen species (ROS) levels in NRK-49F cells induced by high glucose, and Western Blot experiments also demonstrate that it can increase the levels of p-AMPK and p-ACC and decrease the levels of TGF-ß1. The results of this study extend the structural types of AMPK activators and provide novel lead compounds for the subsequent development.

Dual inhibitors of ASK1 and PDK1 kinases: Design, synthesis, molecular docking and mechanism studies of N-benzyl pyridine-2-one containing derivatives as anti-fibrotic agents.

Utilizing fragment-based hybrid designing strategies, 24 N-benzyl pyridine-2-one containing derivatives were synthesized by successfully incorporating 6-(4H-1,2,4-triazol-3-yl) pyridin-2-amine of scaffold of ASK1 inhibitor (GS-444217). These newly synthesized compounds were screened in cell-free ASK1 and PDK1 kinase and cellular vitality assays. Among all compounds tested, both 21c and 21d displayed single digit potency of 9.13, 1.73 nM in inhibiting ASK1, and exhibited excellent enzyme inhibitory activity against PDK1 (the inhibition rates at 10 µM were 13.63% and 23.80%, respectively). Specifically, both compounds inhibited the TGF-ß1 induced fibrotic response and blocked the up-regulated protein expression levels of ASK1-p38/JNK signaling pathways and possessed the potency in reducing PDK1/Akt phosphorylation. The results herein showed the potential lead characteristics of 21c or 21d as dual inhibitors ASK1/PDK1 kinases.

Protective effects of mefunidone on ischemia-reperfusion injury/Folic acid-induced acute kidney injury.

Renal ischemia-reperfusion injury (IRI) is one of the most common causes of acute kidney injury (AKI). It poses a significant threat to public health, and effective therapeutic drugs are lacking. Mefunidone (MFD) is a new pyridinone drug that exerts a significant protective effect on diabetic nephropathy and the unilateral ureteral obstruction (UUO) model in our previous study. However, the effects of mefunidone on ischemia-reperfusion injury-induced acute kidney injury remain unknown. In this study, we investigated the protective effect of mefunidone against ischemia-reperfusion injury-induced acute kidney injury and explored the underlying mechanism. These results revealed that mefunidone exerted a protective effect against ischemia-reperfusion injury-induced acute kidney injury. In an ischemia-reperfusion injury-induced acute kidney injury model, treatment with mefunidone significantly protected the kidney by relieving kidney tubular injury, suppressing oxidative stress, and inhibiting kidney tubular epithelial cell apoptosis. Furthermore, we found that mefunidone reduced mitochondrial damage, regulated mitochondrial-related Bax/bcl2/cleaved-caspase3 apoptotic protein expression, and protected mitochondrial electron transport chain complexes III and V levels both in vivo and in vitro, along with a protective effect on mitochondrial membrane potential in vitro. Given that folic acid (FA)-induced acute kidney injury is a classic model, we used this model to further validate the efficacy of mefunidone in acute kidney injury and obtained the same conclusion. Based on the above results, we conclude that mefunidone has potential protective and therapeutic effects in both ischemia-reperfusion injury- and folic acid-induced acute kidney injury.

Mefunidone ameliorates lipopolysaccharide-induced acute lung injury through inhibiting MAPK signaling pathway and enhancing Nrf2 pathway.

BACKGROUND AND OBJECTIVE: Acute lung injury (ALI) is a life-threatening disease which has high mortality and lacks effective pharmacological treatments. Excessive inflammation and oxidative stress are the key pathogenesis of ALI. Mefunidone (MFD), a novel small molecule compound, displayed anti-inflammation and anti-oxidative stress effects on streptozocin (STZ) and db/db mice in our previous studies. In this study, we aimed to investigate the effects of MFD on lipopolysaccharide (LPS)-induced ALI and explore the potential molecular mechanisms. METHODS: We investigated the effects of MFD on LPS-induced ALI mouse model and LPS-stimulated immortalized mouse bone marrow-derived macrophages (iBMDMs). RESULTS: MFD could alleviate pulmonary structure disorder and attenuate pulmonary neutrophils infiltration induced by LPS. MFD could also decreased proinflammatory cytokines release and reduce reactive oxygen species (ROS) generation stimulated by LPS. Further, MFD could significantly reduce LPS-induced phosphorylation levels of mitogen-activated protein kinase (MAPK), increase expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) and restore the expressions of antioxidant enzymes. CONCLUSION: Our results firstly supported that MFD effectively protected LPS-induced ALI against inflammation and oxidative stress through inhibiting MAPK signaling pathway and activating Nrf2 pathway.

Identification of selective homeodomain interacting protein kinase 2 inhibitors, a potential treatment for renal fibrosis.

Homeodomain interacting protein kinase 2 (HIPK2) has emerged as a promising target for the discovery of anti-renal fibrosis drugs. Herein, to develop specific pharmacologic inhibitors of HIPK2, we designed and synthesized a series of compounds containing benzimidazole and pyrimidine scaffolds via fragment-based drug design strategy. Kinase assay was applied to evaluate the inhibitory activity of target compounds against HIPKs enzyme. The molecular docking study suggest the contribution of tyrosine residues beside the active sites of HIPK1-3 to the selectivity of active compounds. Compound 15q displayed good selectivity and potent inhibitory activity against HIPK2 compared to other two subtype enzymes. 15q could downregulate phosphorylated p53, the direct substrate of HIPK2, and decrease the fibrosis-related downstream of HIPK2, such as p-Smad3 and α-SMA in NRK-49F cells. 15q showed no effect on the cell apoptosis in fibrotic or cancer cell lines, suggesting little cancer risk of 15q. Notably, 15q displayed encouraging in vivo anti-fibrotic effects in the unilateral ureteral obstruction mouse model, which could be used as a potential lead for structural optimization and candidate for the development of selective HIPK2 inhibitors.

Novel pyrazolo[3,4-b]pyridine derivatives: Synthesis, structure-activity relationship studies, and regulation of the AMPK/70S6K pathway.

A series of novel pyrazolo[3,4-b]pyridine derivatives were designed, synthesized, and biologically evaluated for anti-lung cancer activity. Structure-activity relationship and AutoGPA models were constructed based on the in vitro antiproliferative potency of the compounds against a human lung adenocarcinoma cell line (A549). Compound 9d exhibits improved potency for A549 cell growth inhibition (3.06 ± 0.05 µM) compared with A-769662 (45.29 ± 2.14 µM). Compound 9d can elevate the phosphorylation levels of adenosine monophosphate-activated protein kinase (AMPK) and its substrate acetyl-CoA carboxylase and reduce the level of phosphorylated ribosomal S6 kinase (p-70S6K) at 1 µM, which is comparable to the activity of A-769662 at 20 µM. 9d induced G2/M cell cycle arrest, which was rescued when co-incubated with "Compound C," a potent AMPK inhibitor. Taken together, compound 9d showed potential anti-lung cancer activity via inducing cell cycle arrest by regulation of the AMPK/70S6K pathway in A549 cells, which could provide a new lead for the discovery of anti-lung cancer agents.

An emerging strategy for targeted therapy of pulmonary arterial hypertension: Vasodilation plus vascular remodeling inhibition.

Pulmonary arterial hypertension (PAH) is a rapidly progressing disease with limited therapeutic options. Studies have elucidated the multifactorial pathological characteristics of PAH, indicating the complexity and difficulty of PAH treatment. Currently available treatments focus primarily on vasodilation rather than on vascular remodeling, although several drugs have been developed for the latter. This paradigm for management leads to PAH remaining an incurable disease; thus, there is an urgent need to explore new strategies for coping with this devastating disease. In this review, we discuss current strategies and options for PAH therapy and emerging novel therapeutic approaches in PAH treatment. This viewpoint suggests a shift in PAH treatment strategy from mono-activity to dual effects on vasoconstriction and vascular remodeling.

Mefunidone Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Mice.

Idiopathic pulmonary fibrosis (IPF) is one of the most common and devastating interstitial lung diseases with poor prognosis. Currently, few effective drugs are available for IPF. Hence, we sought to explore the role of mefunidone (MFD), a newly synthesized drug developed by our team, in lung fibrosis. In this study, MFD was found to attenuate bleomycin (BLM) -induced lung fibrosis and inflammation in mice according to Ashcroft and alveolitis scoring. The protein contents and total cell counts in bronchoalveolar lavage fluids of BLM-treated mice were also lowered by MFD. Moreover, the elevation of TGF-ß/Smad2 and phosphorylation of MAPK pathways was repressed by MFD. Additionally, MFD attenuated the swelling and vacuolization of mitochondria, lowered the ratio of apoptotic cells, restored the mitochondrial membrane potential, and reversed the expression of cleaved-caspase 3, Bcl-2 and Bax. Meanwhile, the level of epithelial marker, E-cadherin, was restored by MFD, while the levels of mesenchymal markers such as Snail and vimentin were down-regulated by MFD. Besides, MFD inhibited the expression of fibronectin and α-smooth muscle actin in TGF-ß treated normal human lung fibroblasts. Thus, our findings suggested that MFD could ameliorate lung fibrosis, cell apoptosis and EMT potentially via suppression of TGF-ß/Smad2 and MAPK pathways.

Design, synthesis, and biological evaluation of 1,2,4-oxadiazole-containing pyrazolo[3,4-b]pyridinones as a new series of AMPKɑ1ß1γ1 activators.

Adenosine monophosphate-activated protein kinase (AMPK) plays a key role in maintaining whole-body homeostasis and has been regarded as a therapeutic target for the treatment of diabetic nephropathy (DN). Herein, a series of 1,2,4-oxadiazole-containing pyrazolo[3,4-b]pyridinone derivatives is reported as AMPKɑ1ß1γ1 activators. The in vitro biological assay demonstrated that compounds 12k (EC50 [AMPKα1γ1ß1] = 180 nM) and 13q (EC50 [AMPKα1γ1ß1] = 2 nM) displayed significant enzyme activation. Mechanism studies indicated that both compounds reduced the levels of reactive oxygen species in a rat kidney fibroblast cell line (NRK-49F) stimulated by transforming growth factor-ß and induced early apoptosis of NRK-49F cells at 10 µM. Molecular docking studies suggested that 13q exhibited critical hydrogen-bond interactions with the critical amino acid residues Lys29, Lys31, Asn111, and Asp88 at the binding site of the AMPK protein. These results enrich the structure pool of AMPK activators and provide novel lead compounds for the subsequent development of compounds with a promising therapeutic potential against DN.

Protective Effect of Fluorofenidone Against Acute Lung Injury Through Suppressing the MAPK/NF-κB Pathway.

Acute lung injury (ALI) is a severe disease that presents serious damage and excessive inflammation in lungs with high mortality without effective pharmacological therapy. Fluorofenidone (AKFPD) is a novel pyridone agent that has anti-fibrosis, anti-inflammation, and other pharmacological activities, while the effect of fluorofenidone on ALI is unclarified. Here, we elucidated the protective effects and underlying mechanism of fluorofenidone on lipopolysaccharide (LPS)-induced ALI. In this study, fluorofenidone alleviated lung tissue structure injury and reduced mortality, decreased the pulmonary inflammatory cell accumulation and level of inflammatory cytokines IL-1ß, IL-6, and TNF-α in the bronchoalveolar lavage fluid, and attenuated pulmonary apoptosis in LPS-induced ALI mice. Moreover, fluorofenidone could block LPS-activated phosphorylation of ERK, JNK, and P38 and further inhibited the phosphorylation of IκB and P65. These results suggested that fluorofenidone can significantly contrast LPS-induced ALI through suppressing the activation of the MAPK/NF-κB signaling pathway, which indicates that fluorofenidone could be considered as a novel therapeutic candidate for ALI.