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Background: Idiosyncratic drug-induced liver injury (IDILI) is common in hepatology practices and, in some cases, lethal. Increasing evidence show that tricyclic antidepressants (TCAs) can induce IDILI in clinical applications but the underlying mechanisms are still poorly understood. Methods: We assessed the specificity of several TCAs for NLRP3 inflammasome via MCC950 (a selective NLRP3 inhibitor) pretreatment and Nlrp3 knockout (Nlrp3−/−) BMDMs. Meanwhile, the role of NLRP3 inflammasome in the TCA nortriptyline-induced hepatotoxicity was demonstrated in Nlrp3−/− mice. Results: We reported here that nortriptyline, a common TCA, induced idiosyncratic hepatotoxicity in a NLRP3 inflammasome-dependent manner in mildly inflammatory states. In parallel in vitro studies, nortriptyline triggered the inflammasome activation, which was completely blocked by Nlrp3 deficiency or MCC950 pretreatment. Furthermore, nortriptyline treatment led to mitochondrial damage and subsequent mitochondrial reactive oxygen species (mtROS) production resulting in aberrant activation of the NLRP3 inflammasome; a selective mitochondrial ROS inhibitor pretreatment dramatically abrogated nortriptyline-triggered the NLRP3 inflammasome activation. Notably, exposure to other TCAs also induced aberrant activation of the NLRP3 inflammasome by triggering upstream signaling events. Conclusion: Collectively, our findings revealed that the NLRP3 inflammasome may act as a crucial target for TCA agents and suggested that the core structures of TCAs may contribute to the aberrant activation of NLRP3 inflammasome induced by them, an important factor involved in the pathogenesis of TCA-induced liver injury. DBhggTBWtuReWsEtfqqAGm Video Abstract [ABSTRACT FROM AUTHOR]

The abnormal activation of the NLRP3 inflammasome is closely related to the occurrence and development of many inflammatory diseases. Targeting the NLRP3 inflammasome has been considered an efficient therapy to treat infections. We found that dihydrotanshinone I (DHT) specifically blocked the canonical and non-canonical activation of the NLRP3 inflammasome. Nevertheless, DHT had no relation with the activation of AIM2 or the NLRC4 inflammasome. Further study demonstrated that DHT had no influences on potassium efflux, calcium flux, or the production of mitochondrial ROS. We also discovered that DHT suppressed ASC oligomerization induced by NLRP3 agonists, suggesting that DHT inhibited the assembly of the NLRP3 inflammasome. Importantly, DHT possessed a significant therapeutic effect on NLRP3 inflammasome–mediated sepsis in mice. Therefore, our results aimed to clarify DHT as a specific small-molecule inhibitor for the NLRP3 inflammasome and suggested that DHT can be used as a potential drug against NLRP3-mediated diseases. [ABSTRACT FROM AUTHOR]

Idiosyncratic drug-induced liver injury (IDILI) is an infrequent but potentially serious disease that develops the main reason for post-marketing safety warnings and withdrawals of drugs. Epimedii Folium (EF), the widely used herbal medicine, has shown to cause idiosyncratic liver injury, but the underlying mechanisms are poorly understood. Increasing evidence has indicated that most cases of IDILI are immune mediated. Here, we report that icariside Ⅱ (ICS Ⅱ), the major active and metabolic constituent of EF, causes idiosyncratic liver injury by promoting NLRP3 inflammasome activation. ICS Ⅱ exacerbates NLRP3 inflammasome activation triggered by adenosine triphosphate (ATP) and nigericin, but not silicon dioxide (SiO 2), monosodium urate (MSU) crystal or cytosolic lipopolysaccharide (LPS). Additionally, the activation of NLRC4 and AIM2 inflammasomes is not affected by ICS Ⅱ. Mechanistically, synergistic induction of mitochondrial reactive oxygen species (mtROS) is a crucial contributor to the enhancing effect of ICS Ⅱ on ATP- or nigericin-induced NLRP3 inflammasome activation. Importantly, in vivo data show that a combination of non-hepatotoxic doses of LPS and ICS Ⅱ causes the increase of aminotransferase activity, hepatic inflammation and pyroptosis, which is attenuated by Nlrp3 deficiency or pretreatment with MCC950 (a specific NLRP3 inflammasome inhibitor). In conclusion, these findings demonstrate that ICS Ⅱ causes idiosyncratic liver injury through enhancing NLRP3 inflammasome activation and suggest that ICS Ⅱ may be a risk factor and responsible for EF-induced liver injury. The activated NLRP3 inflammasome-mediated IL-1 β secretion and subsequently the production of TNF- α , pyroptosis and oxidative stress synergistically induced liver injury after the combination of non-hepatotoxic doses of LPS and ICS Ⅱ. ICS Ⅱ may be a risk factor and responsible for Epimedii Folium-induced idiosyncratic hepatotoxicity. Image 1 [ABSTRACT FROM AUTHOR]

Aberrant activation of NLRP3 inflammasome has been implicated in the pathogenesis of diverse inflammation-related diseases, and pharmacological molecules targeting NLRP3 inflammasome are of considerable value to identifying potential therapeutic interventions. Cardamonin (CDN), the major active ingredient of the traditional Chinese medicinal herb Alpinia katsumadai , has exerted an excellent anti-inflammatory activity, but the mechanism underlying this role is not fully understood. Here, we show that CDN blocks canonical and noncanonical NLRP3 inflammasome activation triggered by multiple stimuli. Moreover, the suppression of CDN on inflammasome activation is specific to NLRP3, not to NLRC4 or AIM2 inflammasome. Besides, the inhibitory effect is not dependent on the expression of NF- κ B-mediated inflammasome precursor proteins. We also demonstrate that CDN suppresses the NLRP3 inflammasome through blocking ASC oligomerization and speckle formation in a dose-dependent manner. Importantly, CDN improves the survival of mice suffering from lethal septic shock and attenuates IL-1 β production induced by LPS in vivo , which is shown to be NLRP3 dependent. In conclusion, our results identify CDN as a broad-spectrum and specific inhibitor of NLRP3 inflammasome and a candidate therapeutic drug for treating NLRP3 inflammasome-driven diseases. Cardamonin is a broad-spectrum inhibitor of NLRP3 inflammasome triggered by multiple stimuli. Moreover, the suppression of cardamonin on inflammasome activation is specific to NLRP3, not to NLRC4 or AIM2 inflammasome. Importantly, cardamonin improves the survival of mice suffering from LPS-induced lethal endotoxic shock, which is shown to be NLRP3 dependent. fx1 [ABSTRACT FROM AUTHOR]

• BA selectively inhibits NLRP3 inflammasome activation by acting on the upstream of ASC oligomerization. • BA attenuates NLRP3 inflammasome activation in LPS-mediated inflammation and MSU-induced peritonitis mouse model. • BA can serve as a drug candidate for NLRP3 inflammasome-driven diseases. Brevilin A (BA), is a natural biologically active ingredient derived from Centipeda minima with several reports of anti-cancer, while its anti-inflammatory activity is rarely reported. Current studies have found the dysregulated activation of NLRP3 inflammasome cause a variety of inflammatory diseases. Targeting the NLRP3 inflammasome contributes to the treatment of NLRP3-induced diseases. Here, we found that BA significantly attenuates the activation of caspase-1 and the subsequent secretion of the interleukin-1β (IL-1β) in mouse macrophages and human THP-1 cells, showing the inhibitory effect of BA on the NLRP3 inflammasome activation. Moreover, BA specifically inhibits NLRs inflammasomes activation triggered by multi-stimuli, but it has no effect on the AIM2 inflammasome activation, indicating that BA is a specific inhibitor of the NLRs inflammasomes. Research on the mechanism found BA inhibits NLRP3 inflammasome activation by blocking the upstream of ASC oligomerization. Importantly, in vivo experiments showed that BA markedly reduces the secretion of IL-1β to suppress NLRP3 inflammasome in the LPS-induced inflammation and MSU-challenged peritonitis model. In conclusion, our experiments show that BA is an effective NLRP3 inflammasome inhibitor and can be regarded as a drug candidate for NLRP3 inflammasome-driven diseases. [ABSTRACT FROM AUTHOR]

Background: Abnormal activation of NLRP3 inflammasome is related to a series of inflammatory diseases, including type 2 diabetes, gouty arthritis, non-alcoholic steatohepatitis (NASH), and neurodegenerative disorders. Therefore, targeting NLRP3 inflammasome is regarded as a potential therapeutic strategy for many inflammatory diseases. A growing number of studies have identified tanshinone I (Tan I) as a potential anti-inflammatory agent because of its good anti-inflammatory activity. However, its specific anti-inflammatory mechanism and direct target are unclear and need further study. Methods: IL-1β and caspase-1 were detected by immunoblotting and ELISA, and mtROS levels were measured by flow cytometry. Immunoprecipitation was used to explore the interaction between NLRP3, NEK7 and ASC. In a mouse model of LPS-induced septic shock, IL-1β levels in peritoneal lavage fluid and serum were measured by ELISA. Liver inflammation and fibrosis in the NASH model were analyzed by HE staining and immunohistochemistry. Results: Tan I inhibited the activation of NLRP3 inflammasome in macrophages, but had no effect on the activation of AIM2 or NLRC4 inflammasome. Mechanistically, Tan I inhibited NLRP3 inflammasome assembly and activation by targeting NLRP3-ASC interaction. Furthermore, Tan I exhibited protective effects in mouse models of NLRP3 inflammasome-mediated diseases, including septic shock and NASH. Conclusions: Tan I specifically suppresses NLRP3 inflammasome activation by disrupting the association of NLRP3 and ASC, and exhibits protective effects in mouse models of LPS-induced septic shock and NASH. These findings suggest that Tan I is a specific NLRP3 inhibitor and may be a promising candidate for treating NLRP3 inflammasome-related diseases. [ABSTRACT FROM AUTHOR]

• Psoralidin is an inflammasome agonist found in Chinese herbal medicine. • Psoralidin could induce the hepatotoxicity via activating inflammasomes. Idiosyncratic drug-induced liver injury (IDILI) is a rare but potentially fatal disease that is unpredictable and independent of the dose of the drug. Increasing evidence suggests that the majority of IDILI cases are immune-mediated, and the aberrant activation of inflammasome plays a vital role in progression. Psoraleae Fructus (PF), a tonic Chinese medicine, has been able to cause IDILI, but the precise mechanism of hepatotoxicity remains unclear. In this study, eight bioactive compounds involved in PF-induced inflammasome activation were investigated. The results demonstrated that psoralidin activated the inflammasomes followed by secreting caspase-1 and interleukin 1β (IL-1β) in a dose-dependent manner. Interestingly, MCC950, a potent inhibitor of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, could not entirely suppress the psoralidin-induced inflammasome activation. Moreover, psoralidin significantly induced IL-1β maturation and caspase-1 activation in NLRP3-knockout bone marrow-derived macrophages (BMDMs), suggesting that psoralidin not only activates the NLRP3 inflammasome but also activates other types of inflammasomes. The results also demonstrated that psoralidin activated the inflammasomes by promoting the C-terminal caspase recruitment domain (ASC) oligomerization, and the production of mitochondrial reactive oxygen species (mtROS) is a decisive factor in psoralidin-induced inflammasome activation. Importantly, in vivo data revealed that psoralidin induced hepatic inflammation, increased aminotransferase activity and increased the production of IL-1β and tumor necrosis factor (TNF-α) in a susceptible mouse model of lipopolysaccharide (LPS)-mediated IDILI. In summary, these results confirmed that psoralidin causes IDILI by inducing inflammasome activation. The study suggests that psoralidin is a possible risk factor and is responsible for PF-induced IDILI. [ABSTRACT FROM AUTHOR]

• Glaucocalyxin A alleviates septic shock via inhibiting NLRP3 inflammasome activation. Glaucocalyxin A (GLA) is a bioactive ent-kauranoid diterpenoid derived from the herbal medicine, Rabdosia japonica var. glaucocalyx, and it has been reported to possess marked anti-inflammatory properties. However, the underlying mechanisms are not fully understood. Here, we reported that GLA dramatically inhibited canonical and non-canonical NLRP3 inflammasome activation induced by multiple agonists. In addition, GLA also blocked NLRC4 inflammasome activation but had no effect on AIM2 inflammasome. Furthermore, we found that GLA inhibited NLRP3 or NLRC4 agonists-induced ASC oligomerization, which is an upstream event of the inflammasomes assembly. Most importantly, administration of GLA significantly reduced lipopolysaccharide (LPS)-induced mortality in septic-shock mouse model. Additionally, GLA dose-dependently inhibited the production of interleukin (IL)-1β, but had no effect on NLRP3-independent TNF-α production induced by LPS in vivo. In conclusion, our study suggests that GLA alleviates LPS-induced septic shock and inflammation via inhibiting NLRP3 inflammasome activation and provides a promising candidate drug for the treatment of NLRP3-driven diseases. [ABSTRACT FROM AUTHOR]

• DCL inhibits NLRP3 inflammasome activation in primary BMDMs and hPBMCs. • DCL reduces the NLRP3-dependent inflammation in LPS-induced sepsis model. • DCL is a novel and potent drug for treating NLRP3-associated diseases. Uncontrolled activation of NLRP3 inflammasome initiates a series of human inflammatory diseases. Targeting NLRP3 inflammasome has attracted considerable attention in developing potential therapeutic interventions. Here, we reported that dehydrocostus lactone (DCL), a main component of Saussurea lappa from the traditional Chinese medicine, inhibited NLRP3 inflammasome-mediated caspase-1 activation and subsequent interleukin (IL)-1β production in primary mouse macrophages and human peripheral blood mononuclear cells and exerted an inhibitory effect on NLRP3-driven inflammation. Mechanistically, DCL significantly blocked the ASC oligomerization, which is essential for the assembly of activated inflammasome. Importantly, in vivo experiments showed that DCL reduced IL-1β secretion and peritoneal neutrophils recruitment in LPS-mediated inflammation mouse model, which is demonstrated to be NLRP3 dependent. These results suggest that DCL is a potent pharmacological inhibitor of NLRP3 inflammasome and may be developed as a therapeutic drug for treating NLRP3-associated diseases. [ABSTRACT FROM AUTHOR]