Metabolic dysfunction-associated fatty liver disease (MAFLD), characterized by fatty acid overload, secondary chronic inflammation, and fibrosis, has become the most prevalent chronic liver disease globally. While no effective pharmacotherapy exists for MAFLD, mitigating inflammatory responses represents a promising approach to preventing the progression from steatosis to severe steatohepatitis. The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, which detects endogenous danger and stress signals, has emerged as a significant target for inflammatory disease treatment, as transcriptional inactivation of its components demonstrates the therapeutic potential for MAFLD. Natural products targeting NLRP3 inflammasome activation have shown promising efficacy in MAFLD therapy. This review synthesizes the current understanding of NLRP3 inflammasome activation and therapeutic targets for NLRP3 homeostasis. Additionally, natural products reported to inhibit NLRP3 inflammasome for MAFLD improvement are categorized according to their mechanisms of action. The review also addresses limitations and future directions regarding natural products targeting NLRP3 inflammasome in MAFLD treatment. Enhanced understanding of NLRP3 inflammasome activation mechanisms in MAFLD and the identification of novel natural products supported by mechanistic research will significantly advance MAFLD treatment.
Humans ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology* ; Inflammasomes/metabolism* ; Biological Products/therapeutic use* ; Animals ; Fatty Liver/immunology*

OBJECTIVE: To investigate the inhibitory effect of Tanreqing Injection (TRQ) on the activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome in macrophages infected with influenza A virus and the underlying mechanism based on mitophagy pathway. METHODS: The inflammatory model of murine macrophage J774A.1 induced by influenza A virus [strain A/Puerto Rico/8/1934 (H1N1), PR8] was constructed and treated by TRQ, while the mitochondria-targeted antioxidant Mito-TEMPO and autophagy specific inhibitor 3-methyladenine (3-MA) were used as controls to intensively study the anti-inflammatory mechanism of TRQ based on mitophagy-mitochondrial reactive oxygen species (mtROS)-NLRP3 inflammasome pathway. The levels of NLRP3, Caspase-1 p20, microtubule-associated protein 1 light chain 3 II (LC3II) and P62 proteins were measured by Western blot. The release of interleukin-1β (IL-1β) was tested by enzyme linked immunosorbent assay, the mtROS level was detected by flow cytometry, and the immunofluorescence and co-localization of LC3 and mitochondria were observed under confocal laser scanning microscopy. RESULTS: Similar to the effect of Mito-TEMPO and contrary to the results of 3-MA treatment, TRQ could significantly reduce the expressions of NLRP3, Caspase-1 p20, and autophagy adaptor P62, promote the expression of autophagy marker LC3II, enhance the mitochondrial fluorescence intensity, and inhibit the release of mtROS and IL-1β (all P<0.01). Moreover, LC3 was co-localized with mitochondria, confirming the type of mitophagy. CONCLUSION TRQ could reduce the level of mtROS by promoting mitophagy in macrophages infected with influenza A virus, thus inhibiting the activation of NLRP3 inflammasome and the release of IL-1β, and attenuating the inflammatory response.
Mitophagy/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Animals ; Macrophages/virology* ; Inflammasomes/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Mitochondria/metabolism* ; Reactive Oxygen Species/metabolism* ; Influenza A virus/physiology* ; Interleukin-1beta/metabolism* ; Cell Line ; Injections

OBJECTIVE: To evaluate the protective effects of gentiopicroside (GPS) against reactive oxygen species (ROS)-induced NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in endothelial cells, aiming to reduce atherosclerosis. METHODS: Eight-week-old male ApoE-deficient mice were randomly divided into 2 groups (n=10 per group): the vehicle group and the GPS treatment group. Both groups were fed a high-fat diet for 16 weeks. GPS (40 mg/kg per day) was administered by oral gavage to the GPS group, while the vehicle group received an equivalent volume of the vehicle solution. At the end of the treatment, blood and aortic tissues were collected for assessments of atherosclerosis, lipid profiles, oxidative stress, and molecular expressions related to NLRP3 inflammasome activation, ROS production, and apoptosis. Additionally, in vitro experiments on human aortic endothelial cells treated with oxidized low-density lipoprotein (ox-LDL) were conducted to evaluate the effects of GPS on NLRP3 inflammasome activation, pyroptosis, apoptosis, and ROS production, specifically examining the role of the sirtuin 1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. SIRT1 and Nrf2 inhibitors were used to confirm the pathway's role. RESULTS: GPS treatment significantly reduced atherosclerotic lesions in the en face aorta (P<0.01), as well as in the thoracic and abdominal aortic regions, and markedly decreased sinus lesions within the aortic root (P<0.05 or P<0.01). Additionally, GPS reduced oxidative stress markers and proinflammatory cytokines, including interleukin (IL)-1 β and IL-18, in lesion areas (P<0.05, P<0.01). In vitro, GPS inhibited ox-LDL-induced NLRP3 activation, as evidenced by reduced NLRP3 (P<0.01), apoptosis-associated speck-like protein containing a CARD, cleaved-caspase-1, and cleaved-gasdermin D expressions (all P<0.01). GPS also decreased ROS production, apoptosis, and pyroptosis, with the beneficial effects being significantly reversed by SIRT1 or Nrf2 inhibitors. CONCLUSION GPS exerts an antiatherogenic effect by inhibiting ROS-dependent NLRP3 inflammasome activation via the SIRT1/Nrf2 pathway.
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Reactive Oxygen Species/metabolism* ; Iridoid Glucosides/therapeutic use* ; NF-E2-Related Factor 2/metabolism* ; Animals ; Atherosclerosis/metabolism* ; Inflammasomes/drug effects* ; Male ; Sirtuin 1/metabolism* ; Signal Transduction/drug effects* ; Humans ; Endothelial Cells/pathology* ; Mice ; Oxidative Stress/drug effects* ; Apoptosis/drug effects* ; Lipoproteins, LDL ; Mice, Inbred C57BL

OBJECTIVE: To investigate the anti-inflammatory effect of rutaecarpine (RUT) on monosodium urate crystal (MSU)-induced murine peritonitis in mice and further explored the underlying mechanism of RUT in lipopolysaccharide (LPS)/MSU-induced gout model in vitro. METHODS: In MSU-induced mice, 36 male C57BL/6 mice were randomly divided into 6 groups of 8 mice each group, including the control group, model group, RUT low-, medium-, and high-doses groups, and prednisone acetate group. The mice in each group were orally administered the corresponding drugs or vehicle once a day for 7 consecutive days. The gout inflammation model was established by intraperitoneal injection of MSU to evaluate the anti-gout inflammatory effects of RUT. Then the proinflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA) and the proportions of infiltrating neutrophils cytokines were detected by flow cytometry. In LPS/MSU-treated or untreated THP-1 macrophages, cell viability was observed by cell counting kit 8 and proinflammatory cytokines were measured by ELISA. The percentage of pyroptotic cells were detected by flow cytometry. Respectively, the mRNA and protein levels were measured by real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot, the nuclear translocation of nuclear factor κB (NF-κB) p65 was observed by laser confocal imaging. Additionally, surface plasmon resonance (SPR) and molecular docking were applied to validate the binding ability of RUT components to tumor necrosis factor α (TNF-α) targets. RESULTS: RUT reduced the levels of infiltrating neutrophils and monocytes and decreased the levels of the proinflammatory cytokines interleukin 1β (IL-1β) and interleukin 6 (IL-6, all P<0.01). In vitro, RUT reduced the production of IL-1β, IL-6 and TNF-α. In addition, RT-PCR revealed the inhibitory effects of RUT on the mRNA levels of IL-1β, IL-6, cyclooxygenase-2 and TNF-α (P<0.05 or P<0.01). Mechanistically, RUT markedly reduced protein expressions of tumor necrosis factor receptor (TNFR), phospho-mitogen-activated protein kinase (p-MAPK), phospho-extracellular signal-regulated kinase, phospho-c-Jun N-terminal kinase, phospho-NF-κB, phospho-kinase α/β, NOD-like receptor thermal protein domain associated protein 3 (NLRPS), cleaved-cysteinyl aspartate specific proteinase-1 and cleaved-gasdermin D in macrophages (P<0.05 or P<0.01). Molecularly, SPR revealed that RUT bound to TNF-α with a calculated equilibrium dissociation constant of 31.7 µmol/L. Molecular docking further confirmed that RUT could interact directly with the TNF-α protein via hydrogen bonding, van der Waals interactions, and carbon-hydrogen bonding. CONCLUSION RUT alleviated MSU-induced peritonitis and inhibited the TNFR1-MAPK/NF-κB and NLRP3 inflammasome signaling pathway to attenuate gouty inflammation induced by LPS/MSU in THP-1 macrophages, suggesting that RUT could be a potential therapeutic candidate for gout.
Animals ; NF-kappa B/metabolism* ; Male ; Indole Alkaloids/therapeutic use* ; Signal Transduction/drug effects* ; Mice, Inbred C57BL ; Inflammation/complications* ; Uric Acid ; Quinazolines/therapeutic use* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Humans ; Gout/chemically induced* ; Inflammasomes/metabolism* ; Cytokines/metabolism* ; THP-1 Cells ; Mitogen-Activated Protein Kinases/metabolism* ; Mice ; Molecular Docking Simulation ; Lipopolysaccharides ; Quinazolinones

In recent years, pyroptosis, an inflammatory form of programmed cell death, has gained increasing attention in the field of metabolic disease research. Pyroptosis is closely associated with inflammatory responses. A growing body of evidence suggests that pyroptosis not only plays a critical role in regulating inflammation but can also influence metabolic status, cellular function, and tissue damage through multiple pathways, thereby either exacerbating or alleviating the progression of metabolic diseases. However, the precise molecular mechanisms of pyroptosis and its roles across different metabolic diseases remain unclear, and investigations into related therapeutic targets are still in early stages. Systematically elucidating the mechanisms by which pyroptosis contributes to metabolic diseases and exploring its potential roles in inflammation and pathophysiology may provide new insights and strategies for the prevention and treatment of metabolic disorders, and further promote advances in this research field.
Pyroptosis/physiology* ; Humans ; Metabolic Diseases/metabolism* ; Inflammation/physiopathology* ; Animals ; Inflammasomes

OBJECTIVES: To study the therapeutic mechanism of Tuihuang Mixture against cholestasis. METHODS: Forty-eight Wistar rats were randomized equally into blank group, model group, ursodeoxycholic acid group and Tuihuang Mixture group. Except for those in the blank group, all the rats were given α‑naphthylisothiocyanate (ANIT) to establish rat models of cholestasis, followed by treatments with indicated drugs or distilled water. Serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL of the rats were determined, and hepatic expressions IL-1β, IL-18, FXR, NLRP3, ASC, Caspase-1 and GSDMD were detected using q-PCR, ELISA or Western blotting. Histopathological changes of the liver tissues were observed using HE staining. RESULTS: The rat models of cholestasis had significantly increased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL with increased mRNA and protein expressions of IL-1β and IL-18, decreased protein and mRNA expressions of FXR, and increased protein expressions of NLRP3 and Caspase-1 and mRNA expressions of NLRP3, ASC, Caspase-1 and GSDMD in the liver tissue, showing also irregular arrangement of liver cells, proliferation of bile duct epithelial cells and inflammatory cells infiltration. Treatment of the rat models with Tuihuang Mixture significantly decreased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL, lowered IL-1β and IL-18 and increased FXR protein and mRNA expressions, and reduced NLRP3, ASC, Caspase-1 and GSDMD proteins and NLRP3, ASC and Caspase-1 mRNA expressions in the liver tissue. Tuihuang Mixture also significantly alleviated hepatocyte injury, bile duct epithelial cell proliferation and inflammatory cell infiltration in the liver of the rat models. CONCLUSIONS Tuihuang Mixture can effectively improve cholestasis in rats possibly by inhibiting NLRP3 inflammatosome-mediated pyroptosis via regulating FXR.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein ; Rats ; Receptors, Cytoplasmic and Nuclear/metabolism* ; Cholestasis/drug therapy* ; Rats, Wistar ; Inflammasomes/metabolism* ; 1-Naphthylisothiocyanate ; Drugs, Chinese Herbal/therapeutic use* ; Male ; Interleukin-18/metabolism* ; Caspase 1/metabolism* ; Interleukin-1beta/metabolism* ; Liver/metabolism*

OBJECTIVES: To observe the therapeutic effect of spermine in neonatal mouse models of severe hand, foot and mouth disease (HFMD) caused by enterovirus 71 (EV71) infection and explore its therapeutic mechanism in light of regulation of macrophage GBP5/NLRP3 inflammasome pathway. METHODS: Neonatal BALB/c mice (3-5 days old) were divided into control group, EV71 infection group and Spermine treatment group. The mice in the latter two groups received an intraperitoneal injection of 50 μL EV71 suspension (1×10⁶ TCID50 of EV71), followed 3 days later by intraperitoneal injection of 50 μL PBS or 100 μmol/L spermine. GBP5, NLRP3, CXCL10, and TNFSF10 expressions in heart, liver, lung and kidney tissues of the mice were detected using Western blotting and qPCR, and tissue pathologies and macrophage infiltration were assessed with HE staining and immunohistochemistry. In cultured THP-1 and RAW264.7 cells, the effects of EV71 infection, GBP5 siRNA transfection and treatment with spermine or eflornithine on GBP5, NLRP3, CXCL10, and TNFSF10 mRNA expressions were investigated using qPCR. RESULTS: In the neonatal mice, EV71 infection resulted in multiple organ damage, macrophage infiltration and activation of the GBP5/NLRP3 pathway, and spermine treatment significantly improved tissue injuries, reduced macrophage infiltration, and down-regulated the expressions of GBP5, NLRP3 and the inflammatory factors in the infected mice. In THP-1 and RAW264.7 cells, EV71 infection caused significant upregulation of GBP5, NLRP3, CXCL10, and TNFSF10 expressions, which were obviously lowered by spermine treatment. In THP-1 cells, treatment with eflornithine significantly suppressed the reduction of GBP5, NLRP3, CXCL10, and TNFSF10 expressions induced by GBP5 siRNA transfection. CONCLUSIONS Spermine suppressed EV71 infection-induced inflammatory responses by inhibiting GBP5-mediated NLRP3 inflammasome activation, suggesting a new strategy for treatment of severe HFMD.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein ; Mice ; Macrophages/metabolism* ; Enterovirus A, Human ; Mice, Inbred BALB C ; Inflammasomes/metabolism* ; Spermine/therapeutic use* ; Animals, Newborn ; Humans ; Enterovirus Infections ; Hand, Foot and Mouth Disease/drug therapy* ; RAW 264.7 Cells ; Chemokine CXCL10/metabolism*

OBJECTIVES: To study the mechanism mediating the protective effect of asiaticoside (AS) against myocardial ischemia-reperfusion injury (MIRI) in rats. METHODS: Fifty SD rats were randomized into sham-operated group, MIRI model group and AS treatment group. AS treatment was administered at low, moderate and high doses by daily gavage for 2 weeks before MIRI modeling (n=10). Serum levels of lactate dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB), interleukin-18 (IL-18) and IL-1β, the volume of myocardial infarction and ischemia, and myocardial pathologies of the rats were determined or observed. The protein expression levels of NLRP3, ASC, caspase-1, GSDMD, GSDMD-N, IL-1β and IL-18 in the myocardial tissues were detected using Western blotting. The changes in the expression levels of these proteins were also detected in H9C2 cells with AS pretreatment prior to hypoxia-reoxygenation (H/R) injury. RESULTS: The rats models of MIRI exhibited significant myocardial infarction and ischemia with increased serum levels of LDH and CK-MB and myocardial expressions of NLRP3, ASC, caspase-1, GSDMD, GSDMD-N, IL-1β and IL-18. AS pretreatment effectively reduced myocardial infarction volume in the rat models and significantly reduced serum LDH and CK-MB levels and the protein levels in the myocardial tissue in a dose-dependent manner. In the H9C2 cell model of H/R injury, AS pretreatment significantly suppressed the elevation of the protein expressions of NLRP3, ASC, caspase-1, GSDMD, GSDMD-N, IL-1β and IL-18. Molecular docking studies showed that AS had a strong binding affinity with NLRP3. CONCLUSIONS Asiaticoside can alleviate MIRI in rats possibly by inhibiting NLRP3 inflammasome-mediated pyroptosis.
Animals ; Myocardial Reperfusion Injury/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Pyroptosis/drug effects* ; Rats, Sprague-Dawley ; Rats ; Inflammasomes/metabolism* ; Triterpenes/pharmacology* ; Interleukin-18/metabolism* ; Male ; Interleukin-1beta/metabolism* ; Caspase 1/metabolism*

OBJECTIVES: To investigate the therapeutic mechanism of 2,6-dimethoxy-1,4-benzoquinone (DMQ) for alleviating dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. METHODS: Eighteen male C57BL/6J mice were equally randomized into control group, DSS group and DMQ treatment group. In DSS and DMQ groups, the mice were treated with DSS in drinking water to induce UC, and received intraperitoneal injections of sterile PBS or DMQ (20 mg/kg) during modeling. The changes in body weight, disease activity index (DAI), colon length, spleen weight, and colon histological scores of the mice were examined, and the percentages of Th17 and IFN-γ⁺ CD8⁺ T cells in the mesenteric lymph nodes and spleen were analyzed using flow cytometry. The expressions of tight junction proteins (Occludin and ZO-1), proteins associated with inflammasome activation (caspase-1 and p20), IL-1β and TNF-α in the colon tissues were detected using Western blotting or ELISA. In the cell experiment, mouse bone marrow-derived macrophages (BMDMs) primed with lipopolysaccharide (LPS) were treated with DMQ, followed by stmulation with nigericin to activate the classical NLRP3 inflammasome pathway. In cultured human peripheral blood mononuclear cells (PBMCs) treated with either LPS alone or LPS plus nigericin, the effects of DMQ on inflammasome activation, pyroptosis, and cytokine release were evaluated via Western blotting, ELISA, and flow cytometry. RESULTS: In DSS-treated mice, DMQ treatment significantly alleviated DSS-induced body weight loss, colon shortening, spleen enlargement, and colon inflammation. The DMQ-treated mice showed significantly reduced percentages of Th17 cells and IFN-γ⁺ CD8⁺ T cells in the mesenteric lymph nodes and spleen, with increased occludin and ZO-1 expressions and decreased caspase-1 expression in the colon tissue. DMQ obviously inhibited classical NLRP3 inflammasome activation in mouse BMDMs and both the classical and alternative pathways of NLRP3 activation in human PBMCs, causing also suppression of caspase-1-dependent pyroptosis. CONCLUSIONS DMQ ameliorates DSS-induced UC in mice by inhibiting NLRP3 inflammasome activation.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Mice, Inbred C57BL ; Colitis, Ulcerative/metabolism* ; Dextran Sulfate/adverse effects* ; Male ; Inflammasomes/metabolism* ; Mice ; Benzoquinones/therapeutic use* ; Th17 Cells ; Caspase 1/metabolism*

OBJECTIVES: To investigate the effect of avitinib for suppressing NLRP3 inflammasome activation and alleviating septic shock and explore the underlying mechanism. METHODS: Mouse bone marrow-derived macrophages (BMDM), human monocytic leukemia cell line THP-1, and peripheral blood mononuclear cells (PBMC) isolated from healthy volunteers were pre-treated with avitinib, followed by activation of the canonical NLRP3 inflammasome using agonists including nigericin, monosodium urate (MSU) crystals, or adenosine triphosphate (ATP). Non-canonical NLRP3 inflammasome activation was induced via intracellular transfection of lipopolysaccharide (LPS). Western blotting was used to detect the secretory protein markers of NLRP3 inflammasome activation and assess pyroptosis, and the levels of inflammatory cytokines in cell culture supernatant were determined with ELISA. In a mouse model of LPS-induced septic shock, the effect of avitinib treatment on the levels of inflammatory cytokines in serum and peritoneal lavage fluid were examined with ELISA, and survival curves of the mice were plotted using the Kaplan-Meier method. RESULTS: Avitinib significantly inhibited NLRP3 inflammasome activation in multiple cell types, and dose-dependently reduced IL-1β secretion and caspase-1 cleavage while suppressing GSDMD-mediated pyroptosis without obviously affecting IL-6 or TNF-α levels. In the mouse models of LPS-induced septic shock, avitinib significantly lowered IL-1β levels in serum and peritoneal fluid and extended survival time of the mice. CONCLUSIONS Avitinib suppresses NLRP3 inflammasome activation and alleviates septic shock in mice.
Animals ; Shock, Septic/metabolism* ; Mice ; NLR Family, Pyrin Domain-Containing 3 Protein ; Inflammasomes/drug effects* ; Humans ; Macrophages/metabolism* ; Interleukin-1beta/metabolism* ; Lipopolysaccharides