**5. Conclusions**

Increased ROS, NO, and NLRP3 ATPase activity by LPS and/or ATP treatment causes activation of the NLRP3 inflammasome in macrophages. Juglone treatment reduced the production of ROS and NO, and inhibited the ATPase activity of NLRP3 in J774.1 macrophages. Moreover, juglone treatment suppressed NLRP3 expression and inhibited NLRP3 inflammasome activation, thereby inhibiting the cleavage of caspase-1. Secretion of the pro-inflammatory cytokines IL-1β and IL-18 was also decreased by juglone in a concentration-dependent manner. Thus, juglone should be considered as a therapeutic strategy for inflammation-related diseases.

**Supplementary Materials:** The following are available online. Figure S1: Original images for Western blots of IL-1β, IL-18 and β-actin., Figure S2: Original images for Western blots of NLRP3, pro-caspase and cleaved caspase-1.

**Author Contributions:** Conceptualization, N.-H.K. and M.-D.H.; methodology, H.-K.K. and S.-I.J.; formal analysis, H.-K.K., J.-H.L., S.-I.J. and H.-M.W.; investigation, N.-H.K.; resources, N.-H.K.; data curation, G.-S.L., H.-S.L., K.-W.N. and W.-J.K.; writing—original draft preparation, N.-H.K. and M.-D.H.; writing—review and editing, G.-S.L., H.-S.L., K.-W.N. and W.-J.K.; visualization, N.-H.K.; supervision, K.-W.N. and M.-D.H.; project administration, M.-D.H.; funding acquisition, M.-D.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This study was supported by the Soonchunhyang University Research Fund.

**Conflicts of Interest:** The authors declare no conflict of interest.
