Premna odorata extract exhibits anti-inflammatory activity via suppression of NLRP3 inflammasome

Premna odorata (family Verbenaceae), known as "Alagaw" in the Philippines, has traditionally been used to treat inflammatory respiratory conditions; however, molecular evidence supporting its pharmacological effects remains limited. Given that NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome-driven IL-1β secretion plays a central role in inflammatory respiratory conditions, we investigated whether P. odorata extract (POE) modulates NLRP3 inflammasome activation. In LPS-primed J774A.1 and THP-1 macrophages, POE reduced IL-1β secretion induced by ATP or nigericin without affecting NLRC4 or AIM2 inflammasome activation, indicating NLRP3 selectivity. POE treatment inhibited adaptor apoptosis-associated speck-like protein containing CARD (ASC) oligomerization and speck formation without affecting cell viability or intracellular ROS levels, indicating suppression of inflammasome assembly. In vivo, POE attenuated inflammatory cell infiltration in an LPS-induced zebrafish model. Together, these findings indicate that POE suppresses NLRP3 inflammasome-mediated inflammatory responses, providing a molecular basis for its traditional use in managing inflammatory conditions and offering a promising natural scaffold for the development of NLRP3-targeted therapeutics.