Polydatin alleviates traumatic spinal cord injury by reducing microglial inflammation via regulation of iNOS and NLRP3 inflammasome pathway

Polydatin is a glucoside of resveratrol with lots of functional properties in the central nervous system, such as anti-edema, anti-oxidation and anti-inflammation. The purpose of this study was to evaluate the effects of polydatin on traumatic spinal cord injury (SCI) and explore the relative mechanisms. SCI models were established using the weight-drop method in rats, additionally, single polydatin administration (20, 40 mg/kg body weight) remarkably improved motor function of SCI rat, along with decreased nitric oxide (NO) generation and inflammatory factor (IL-1β, IL-6 and TNF-α) production in spinal cord tissues. Similar to the results of in vivo experiments, the inflammatory response was aggravated with the intervention of lipopolysaccharide (LPS) in BV2 microglia. However, polydatin treatment (1, 2 and 4 μM) inhibited iNOS expression, decreased NLRP3 inflammasome activation, which subsequently relieved microglial inflammation. Above all, our data indicated that polydatin possessed neuroprotective effects in SCI rats, possibly by suppressing iNOS expression and NLRP3 inflammasome activation in microglia.     

6-Gingerol ameliorates sepsis-induced liver injury through the Nrf2 pathway

Sepsis-induced liver injury is very common in intensive care units. Here, we investigated the effects of 6-gingerol on sepsis-induced liver injury and the role of the Nrf2 pathway in this process. 6-Gingerol is the principal ingredient of ginger that exerts anti-inflammatory and antioxidant effects. Using cecal ligation and puncture (CLP) to induce polymicrobial sepsis and related liver injury, we found that mice pre-treated with 6-Gingerol showed less incidences of severe liver inflammation and death than untreated CLP groups. 6-Gingerol administration also inhibited the expression of pyroptosis-related proteins, including NOD-like receptor protein 3 (NLRP3), IL-1β, and caspase-1. Consistent with these findings, 6-gingerol reduced the effects of pyroptosis induced by lipopolysaccharide (LPS) and adenosine 5′-triphosphate (ATP) in RAW 264.7 cells, as evidenced by IL-1β and caspase-1 protein levels in the supernatant and propidium iodide (PI) staining. 6-Gingerol was shown to activate the Nrf2 pathway in vivo and in vitro. Notably, Nrf2 siRNA transfection nullified the inhibitory effects of 6-gingerol on pyroptosis in vitro. In summary, these findings suggested that 6-gingerol alleviated sepsis-induced liver injury by inhibiting pyroptosis through the Nrf2 pathway.     

Treatment with 5-methoxytryptophan attenuates microglia-induced neuroinflammation in spinal cord trauma

Neuroinflammation following spinal cord injury (SCI) leads to extensive secondary damage in neural tissue adjacent to the primary lesion foci. 5-Methoxytryptophan (5MTP) is a metabolite of tryptophan and proven to play a protective role in several inflammation-related diseases. However, the specific efficacy and molecular mechanism of 5MTP in SCI remains unknown. Here, we aimed to investigate the anti-inflammatory role of 5MTP in microglia-induced neuroinflammation and its therapeutic effect in SCI. To assess the effect of 5MTP in neuroinflammation, we used lipopolysaccharide (LPS) to stimulate microglia in vitro and detected the microglial phenotype using immunofluorescence staining, the inflammatory-related pathway using western blotting, and pro-inflammatory cytokines using ELISA and immunofluorescence. To explore the therapeutic effect of 5MTP in SCI, we performed contusion of the spinal cord in mice and measured the levels of neuroinflammation, glial accumulation, histological and functional recovery using ELISA, immunofluorescence staining, immunohistochemical staining, hematoxylin-eosin staining, Nissl staining and the Basso Mouse Scale, respectively. We found that treatment with 5MTP contributed to decreased activation of pro-inflammatory microglia and reduced the generation of inflammatory cytokines, including TNF-α, IL-1β, IL-6 and IL-18, by negative regulation of the p38-MAPK signaling pathway and NLRP3/caspase-1 expression. In vivo, administration of 5MTP showed mitigatory neuroinflammation levels associated with alleviated glial scar in SCI mice; hence, the neurological integrity and the neuronal survival, as well as locomotor function, were improved following 5MTP administration.5MTP, as a novel anti-neuroinflammatory reagent, can attenuate activated microglia-induced secondary injury following SCI, and therefore, shows promise as a potential compound for application in a clinical trial for SCI therapy.     

Melatonin prevents endothelial cell pyroptosis via regulation of long noncoding RNA MEG3/miR-223/NLRP3 axis

OBJECTIVE Atherosclerosis(AS) is an inflammatory disease linked to endothelial dysfunction.Melatonin is reported to possess substantial anti-inflammatory properties, which has proven to be effective in AS. Emerging literature suggests that pyroptosis plays a critical role during AS progression. However, whether pyroptosis contributes to endothelial dysfunction and the underlying molecular mechanisms remained unexploited.This study was designed to investigate the antipyroptotic effects of melatonin in atherosclerotic endothelium and to elucidate the potential mechanisms. METHODS ApoE-/-mice were fed a high-fat diet to establish an atherosclerotic model, then divided into normal diet(ND) group, normal diet+melatonin(ND+melatonin) group, high fat diet(HFD)group and high fat diet+melatonin(HFD+melatonin) group.After 12 weeks, HE and oil Red O staining were used to detect the formation of atherosclerosis; qRT-RCR and Western blotting were used to detect the expression of NLRP3, ASC, IL-1β, IL-18, GSDMD, NF-κB, miR-223 and MEG3 in aortic endothelium; The luciferase assay was used to detect the binding of mi R-223 to MEG3. Human aortic endothelial cells(HAECs) were pretreated with ox-LDL. After melatonin treatment, qRT-RCR was used to detect the expression of mi R-223 and MEG3. Western blotting was used to detect NLRP3, ASC, c-caspase1,p-caspase1, GSDMD expression. In addition, after overexpressing MEG3 and knocking out mi R-223, the pyroptosis of HAECs was also detected. RESULTS We found intragastric administration of melatonin for 12 weeks markedly reduced the atherosclerotic plaque in aorta.Meanwhile, melatonin also attenuated the expression of pyroptosis-related genes, including NLRP3, ASC,cleaved caspase1, NF-κB/GSDMD, GSDMD N-termini,IL-1β, and IL-18 in aortic endothelium of melatonin-treated animals. Consistent antipyroptotic effects were also observed in ox-LDL-treated human aortic endothelial cells(HAECs). We found that lnc RNA MEG3 enhanced pyroptosis in HAECs. Moreover, MEG3 acted as an endogenous sponge by sequence complementarity to suppress the function of mi R-223 and to increase NLRP3 expression and enhance endothelial cel pyroptosis. Furthermore, knockdown of mi R-223 blocked the antipyroptotic actions of melatonin in ox-LDL-treated HAECs. CONCLUSION Our results suggest that melatonin prevents endothelial cell pyroptosis via MEG3/mi R-223/NLRP3 axis in atherosclerosis, and therefore, melatonin replacement might be considered a new strategy for protecting endothelium against pyroptosis, thereby for the treatment of atherosclerosis associated with pyroptosis.     

Glycyrrhizin attenuates hepatic ischemia-reperfusion injury by suppressing HMGB1-dependent GSDMD-mediated kupffer cells pyroptosis

Gasdermin D (GSDMD), a genetic substrate for inflammatory caspases, plays a central role in pyroptosis of macrophages and release of interleukin‑1β (IL-1β), but was mainly referred to microbial infection. High mobility group box-1 (HMGB1), served as an alarm molecule during various pathological process, has been widely recognized to be involved in liver ischemia-reperfusion (I/R). Glycyrrhizin, a natural anti-inflammatory and antiviral triterpene in clinical use, was recently referred to have ability to prevent I/R induced liver injury by inhibiting HMGB1 expression and activity. However, the mechanisms responsible for damage amelioration subsequently to HMGB1 inhibition during liver I/R remain enigmatic. This study was designed to explore the functional role and molecular mechanism of glycyrrhizin in the regulation of I/R induced liver injury. We found that liver I/R promotes GSDMD-mediated pyroptotic cell death of Kupffer cells, which was inhibited by glycyrrhizin. Interestingly, endogenous HMGB1, not exogenous one, was involved in hypoxia-reoxygenation (H/R) induced pyroptosis. Moreover, GSDMD knockdown protects kupffer cells against H/R induced pyroptosis in vitro. Here, we report, for the first time, that glycyrrhizin attenuated tissue damage and kupffer cells pyroptosis during liver ischemia-reperfusion injury (LIRI) and identify a previously unrecognized HMGB1- dependent GSDMD- mediated signaling pathway in the mechanism of kupffer cells pyroptosis induced by H/R. Our findings provide the first demonstration of GSDMD-determined pyroptotic cell death responsible for I/R induced release of IL-1β and this would provide a mandate to better understand the unconventional mechanisms of cytokine release in the sterile innate immune system.     

白藜芦醇对脂多糖诱导的人肺上皮细胞焦亡的保护机制研究

目的:探究白藜芦醇对脂多糖(LPS)诱导的人肺上皮细胞(又称BEAS-2B)增殖、炎症因子释放和焦亡的影响。方法:用CCK-8法检测LPS和LPS与白藜芦醇联用对BEAS-2B细胞增殖的影响;采用ELISA法检测细胞上清炎症因子肿瘤坏死因子(TNF-α)、白介素-6(IL-6)、白介素-1β(IL-1β)和白介素-18(IL-18)表达以及qPCR和Western blot检测焦亡基因NLRP3、Gasdermin D、Caspase-1、ELAVL1的表达;分析其对细胞活力、BEAS-2B细胞中细胞因子的含量及其焦亡相关基因、相关蛋白表达的影响。结果:LPS可以抑制BEAS-2B细胞的增殖,同时可以促进炎症因子的表达,经qPCR和Western blot检测结果表明LPS可以促进NLRP3、Gasdermin D、Caspase-1、ELAVL1基因的表达;其经用白藜芦醇处理48 h后,可以有效逆转LPS所引起的细胞增殖受抑制和炎症因子高表达的现象;此外,NLRP3、Gasdermin D、Caspase-1、ELAVL1的表达也部分受抑制。结论:白藜芦醇通过减少炎症因子的释放和NLRP3、Gasdermin D、Caspase-1、ELAVL1表达对LPS诱导的BEAS-2B焦亡起到一定的保护作用。     

基于NLRP3/GSDMD信号通路研究人参皂苷Rb1对高糖诱导的胰岛β细胞焦亡的影响

目的: 研究人参皂苷Rb1(GRb1)抑制高糖诱导的胰岛β细胞焦亡及对NLRP3/GSDMD信号通路的调节机制。方法: 高糖(50 mmol·L^-1)诱导大鼠胰岛细胞瘤细胞(rat insulinoma cells, INS-1)焦亡模型,并构建NLRP3过表达质粒转染INS-1细胞,采用倒置显微镜观察GRb1对细胞形态变化的影响;采用ELISA法检测GRb1对细胞上清液中乳酸脱氢酶(LDH)、白细胞介素-1β(IL-1β)、胰岛素水平的影响;采用Western blot法和qRT-PCR法检测GRb1对INS-1细胞中核苷酸结合域样受体蛋白3(nucleotide binding domain like receptor protein 3, NLRP3)和切割蛋白D(gasdermin D, GSDMD)表达的影响。结果: 在高糖环境下,GRb1可减轻INS-1细胞形态学改变,显著增加INS-1细胞胰岛素分泌,降低细胞上清液中IL-1β、LDH水平(P＜0.05),且呈剂量依赖性;GRb1呈剂量依赖性抑制高糖诱导的INS-1细胞中GSDMD及上游调节因子NLRP3的表达(P＜0.05);过表达NLRP3后可显著逆转高糖环境下GRb1对INS-1细胞的部分保护性作用(P＜0.05)。结论: GRb1能够改善高糖诱导的INS-1细胞焦亡,减轻炎症反应,其机制可能与抑制NLRP3/GSDMD信号通路有关,从而防治糖尿病及其并发症的发生。     

The mechanisms of NLRP3 inflammasome/pyroptosis activation and their role in Parkinson's disease

Parkinson's disease (PD) is a typical neurodegenerative disease and the pathological feature of which is the death of dopamine neurons in the substantia nigra region. At present, neuronal death caused by inflammatory cytokine-mediated neuroinflammation is being extensively studied. The nucleotide-binding oligomerization domain-, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome is an inflammatory complex existing in microglia. Its activation promotes the secretion of the inflammatory cytokine interleukin-1β/18 (IL-1β/18) and induces pyroptosis, a type of cell death that possesses the potential for inflammation, to rupture microglia to further release IL-1β. In this review we focus on the mechanisms of activation of the NLRP3 inflammasome and pyroptosis and their inflammatory effects on the development of PD. In addition, we focus on some inhibitors of NLRP3 inflammatory pathways to alleviate the progression of PD by inhibiting central inflammation and provide new therapeutic strategies for the treatment of PD.     

Kanglexin,a novel anthraquinone compound,protects against myocardial ischemic injury in mice by suppressing NLRP3 and pyroptosis

OBJECTIVE To investigate the myocardial protection effect of a novel anthraquinone compound(4,5-dihydroxy-7-methyl-9,10-anthraquinone-2-ethyl succinate) named Kanglexin(KLX) in vivo and in vitro. METHODS Male C57 BL/6 mice were pre-treated either with KLX(20, 40 mg·kg~(-1)·d~(-1), ig) or vehicle for 7 consecutive days prior to ligation of coronary artery to induce permanent MI. Neonatal mouse cardiomyocytes(NMCMs) were exposed to hypoxia or LPS to detect the myocardial protection effect of KLX. Echocardiographic and myocardial infarct size were used to evaluate the effect of KLX on MI treated mice. Electron microscopic examination and H&E staining were preformed to determine morphological changes of each group. Western blotting and q PCR were used to detect the expressions of pyroptosis relative proteins. The numbers of TUNEL and PI-positive cells were measured to assess pyroptotic cell death.RESULTS KLX reduced myocardial infarct size and LDH release and improved cardiac function as compared to vehicle-treated mice 24 h after MI. We found that MI triggered NLRP3 inflammasome activation leading to conversion of IL-1β and IL-18 into their active mature forms in the heart. We also showed that MI induced pyroptosis, as evidenced by increased DNA fragmentation, mitochondrial swelling and cell membrane rupture as well as increased levels of several pyroptosis-related proteins, including GSDMD, N-GSDMD and cleaved caspase-1. All these detrimental alterations were prevented by KLX administration. In hypoxia-or LPS-treated NMCMs,we showed that 10 μmol·L~(-1) KLX decreased the elevated levels of TUNEL-and PI-positive cel s as wel as pyroptosisrelated proteins. CONCLUSION KLX prevents MI-induced cardiac damages and cardiac dysfunction at least partly through attenuating NLRP3 and subsequent cardiomyocyte pyroptosis, and it is worthy of more rigorous investigations for its potential for alleviating ischemic heart disease.     

Scutellarin inhibits caspase-11 activation and pyroptosis in macrophages via regulating PKA signaling

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.KEY WORDS: Caspase-11, Macrophages, Gasdermin D, Pyroptosis, Scutellarin, PKA signaling     

Ghrelin alleviates traumatic brain injury-induced acute lung injury through pyroptosis/NF-κB pathway

Acute lung injury (ALI) is one of the severe complications in patients with traumatic brain injury (TBI), contributing to the high mortality. Ghrelin has protective effects against various inflammatory diseases, but the effects of Ghrelin on TBI-induced ALI and its mechanisms remain unknown. In this study, Ghrelin administration was performed on the mice with TBI, then histological change in cortex and lung tissues, lung vascular permeability and macrophage number in bronchoalveolar lavage fluid (BALF) were examined, respectively. Simultaneously, the alterations of proinflammatory factors and pyroptosis-related proteins in lung tissues were detected. As a result, TBI-induced ALI was ameliorated after Ghrelin treatment, which was demonstrated by improved histology, reduced lung vascular permeability, and peripheral macrophage number. Furthermore, Ghrelin decreased the mRNA levels of proinflammatory factors (IL-1β, IL-6, TNF-α and IL-18), the protein levels of pyroptosis-related proteins (NLRP3, Caspase1-P20, HMGB1 and Gasdermin D), and the phosphorylation levels of NF-κB in lung tissues. These results showed that Ghrelin attenuating TBI-induced ALI might be via ameliorating inflammasome-induced pyroptosis by blocking NF-κB signal, which are important for the prevention and treatment of TBI-induced ALI.     

Gasdermin D in pyroptosis

Pyroptosis is the process of inflammatory cell death. The primary function of pyroptosis is to induce strong inflammatory responses that defend the host against microbe infection. Excessive pyroptosis, however, leads to several inflammatory diseases, including sepsis and autoimmune disorders. Pyroptosis can be canonical or noncanonical. Upon microbe infection, the canonical pathway responds to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), while the noncanonical pathway responds to intracellular lipopolysaccharides (LPS) of Gram-negative bacteria. The last step of pyroptosis requires the cleavage of gasdermin D (GsdmD) at D275 (numbering after human GSDMD) into N- and C-termini by caspase 1 in the canonical pathway and caspase 4/5/11 (caspase 4/5 in humans, caspase 11 in mice) in the noncanonical pathway. Upon cleavage, the N-terminus of GsdmD (GsdmD-N) forms a transmembrane pore that releases cytokines such as IL-1β and IL-18 and disturbs the regulation of ions and water, eventually resulting in strong inflammation and cell death. Since GsdmD is the effector of pyroptosis, promising inhibitors of GsdmD have been developed for inflammatory diseases. This review will focus on the roles of GsdmD during pyroptosis and in diseases.     

Biochanin A protects lipopolysaccharide/D-galactosamine-induced acute liver injury in mice by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation

Biochanin A, an isoflavone existed in red clover and peanuts, has been reported to possess a wide spectrum of pharmacological activities, such as anti-inflammatory and antioxidant effects. However, the protective effects and mechanism of biochanin A on liver injury have not been reported. In this study, acute liver injury was induced by intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (D-GalN). Biochanin A was administrated 1 h prior to LPS/D-GalN challenge. Serum ALT, AST, IL-1β, and TNF-α levels, hepatic malondialdehyde (MDA), GPx, SOD, and Catalase contents, tissue histology, IL-1β, TNF-α, NLRP3, and Nrf2 expression were detected. The results showed that serum ALT, AST, IL-1β, and TNF-α levels and hepatic MDA content increased after LPS/GalN treatment. These changes were attenuated by biochanin A. Meanwhile, biochanin A dose-dependently up-regulated the expression of Nrf2 and HO-1. Biochanin A also inhibited hepatic IL-1β and TNF-α expression in a dose-dependent manner. Biochanin A did not inhibit LPS/D-GalN-induced hepatic NLRP3, ASC, and caspase-1 expression. However, the interaction of NLRP3 with ASC and caspase-1 were inhibited by biochanin A. In addition, LPS/D-GalN-induced up-regulation of thioredoxin-interacting protein (TXNIP) and interaction between TXNIP and NLRP3 were also inhibited by biochanin A. In conclusion, biochanin A protected against LPS/GalN-induced liver injury by activating the Nrf2 pathway and inhibiting NLRP3 inflammasome activation.     

Neuroprotective Effect of Ginsenoside Rd in Spinal Cord Injury Rats

In this study, the neuroprotective effects of ginsenoside Rd (GS Rd) were evaluated in a rat model of spinal cord injury (SCI). Rats in SCI groups received a T8 laminectomy and a spinal contusion injury. GS Rd 12.5, 25 and 50 mg/kg were administered intraperitoneally 1 hr before the surgery and once daily for 14 days. Dexamethasone 1 mg/kg was administered as a positive control. Locomotor function was evaluated using the BBB score system. H&E staining and Nissl staining were performed to observe the histological changes in the spinal cord. The levels of MDA and GSH and the activity of SOD were assessed to reflect the oxidative stress state. The production of TNF‐α, IL‐1β and IL‐1 was assessed using ELISA kits to examine the inflammatory responses in the spinal cord. TUNEL staining was used to detect the cell apoptosis in the spinal cord. Western blot analysis was used to examine the expression of apoptosis‐associated proteins and MAPK proteins. The results demonstrated that GS Rd 25 and 50 mg/kg significantly improved the locomotor function of rats after SCI, reduced tissue injury and increased neuron survival in the spinal cord. Mechanically, GS Rd decreased MDA level, increased GSH level and SOD activity, reduced the production of pro‐inflammatory cytokines and prevented cell apoptosis. The effects were equivalent to those of dexamethasone. In addition, GS Rd effectively inhibited the activation of MAPK signalling pathway induced by SCI, which might be involved in the protective effects of GS Rd against SCI. In conclusion, GS Rd attenuates SCI‐induced secondary injury through reversing the redox‐state imbalance, inhibiting the inflammatory response and apoptosis in the spinal cord tissue.     

PFOS facilitates liver inflammation and steatosis: An involvement of NLRP3 inflammasome-mediated hepatocyte pyroptosis

Perfluorooctane sulfonate (PFOS) is a fluorinated organic pollutant with substantial accumulation in mammalian liver tissues. However, the impact of chronic PFOS exposure on liver disease progression and the underlying molecular mechanisms remain elusive. Herein, we for the first time revealed that micromolar range of PFOS exposure initiates the activation of NLR pyrin domain containing 3 (NLRP3) inflammasome to drive hepatocyte pyroptosis. We showed that 5 mg/kg/day PFOS exposure may exacerbated liver inflammation and steatosis in high-fat diet (HFD)-fed mice with concurrently elevated expression of NLRP3 and caspase-1. PFOS exposure resulted in viability impairment and LDH release in BRL-3A rat liver cells. 25–100 μM concentrations of PFOS exposure activated the NLRP3 inflammasome, leading to consequent GSDMD cleavage, IL-1β release and the initiation of pyroptosis in a dose-dependent manner, whereas treatment with 10 μM NLRP3 inhibitor MCC950 abrogated this effect. Moreover, pretreatment of 5 mM ROS scavenger N-acetyl-L-cysteine (NAC) ameliorated PFOS-induced NLRP3 inflammasome activation and pyroptosis. Collectively, our data highlight a pivotal role of pyroptotic death in PFOS-mediated liver inflammation and metabolic disorder.     

Therapeutic effect of methyl salicylate 2-O-β-d-lactoside on LPS-induced acute lung injury by inhibiting TAK1/NF-kappaB phosphorylation and NLRP3 expression

Acute lung injury (ALI), characterized by pulmonary edema and inflammatory cell infiltration, is a common syndrome of acute hypoxemic respiratory failure. Methyl salicylate 2-O-β-d-lactoside (MSL), a natural derivative of salicylate extracted from Gaultheria yunnanensis (Franch.) Rehder, was reported to have potent anti-inflammatory effects on the progression of collagen or adjuvant-induced arthritis in vivo and in vitro. The aim of this study is to investigate the therapeutic effect of MSL on lipopolysaccharide (LPS)-induced acute lung injury and reveal underlying molecular mechanisms. Our results showed that MSL significantly ameliorated pulmonary edema and histological severities, and inhibited IL-6 and IL-1β production in LPS-induced ALI mice. MSL also reduced MPO activity in lung tissues and the number of inflammatory cells in BALF. Moreover, we found that MSL significantly inhibited LPS-induced TAK1 and NF-κB p65 phosphorylation, as well as the expression of NLRP3 protein in lung tissues. Furthermore, MSL significantly inhibited LPS-induced TAK1 and NF-κB p65 phosphorylation in Raw264.7 cells. In addition, MSL significantly inhibited nuclear translocation of NF-κB p65 in cells treated with LPS in vitro. Taken together, our results suggested that MSL exhibited a therapeutic effect on LPS-induced ALI by inhibiting TAK1/NF-κB phosphorylation and NLRP3 expression.