CY-09 exhibits a dose-dependent inhibitory effect on monosodium urate (MSU), nigericin, ATP-induced caspase-1 activation and IL-1β secretion at the doses of 1 to10 μM in LPS-primed bone marrow-derived macrophages (BMDMs). Cytosolic LPS-induced noncanonical NLRP3 activation in BMDMs can also be blocked by CY-09 treatment. CY-09 specifically inhibits NLRP3 inflammasome activation and has no effect on LPS-induced priming effects. CY-09 treatment remarkably suppresses nigericin-induced ASC oligomerization. It is found that CY-09 treatment inhibits the interaction of Flag-NLRP3 and mCherry-NLRP3 in HEK-293T cells, suggesting that CY-09 blocks NLRP3 oligomerization.

CY-09 treatment in vivo efficiently suppresses monosodium urate (MSU) injection-induced IL-1β production and neutrophil influx, suggesting that CY-09 can block MSU-induced NLRP3 inflammasome activation in vivo . CY-09 treatment also increases the survival of NLRP3 mutant mice up to days 30 to 48 even after treatment is stopped at day 25. The caspase-1 cleavage observed in adipose tissue of high-fat diet (HFD)-treated mice is also suppressed by CY-09.