Dehydrocostus lactone inhibits NLRP3 inflammasome activation by blocking ASC oligomerization and prevents LPS-mediated inflammation in vivo

•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.