Isorhamnetin and hyperoside derived from water dropwort inhibits inflammasome activation

Background: Water dropwort (Oenanthe javanica), an umbelliferous plant, has been reported as hypolipidemic, antiplatelet, antitumor, or immune-stimulating agents and it has been suggested to cure cardiovascular disease and cancer.

Purpose: Present study aimed to evaluate the effect of the extracts of water dropwort (EWD) and its pharmacological molecules, hyperoside and isorhamnetin, on inflammatory response, especially inflammasome activation.

Study design/methods: The anti-inflammasome properties of EWD, isorhamnetin, and hyperoside were elucidated by human and mouse macrophages.

Results: EWD attenuated secretion of interleukin (IL)-1β and formation of Asc pyroptosome resulting from NLRP3, NLRC4, and AIM2 inflammasome activation without interruption of cytokine transcription. Isorhamnetin selectively inhibited NLRP3 and AIM2 inflammasome activation and down-regulated expression of pro-inflammatory cytokines. Hyperoside selectively interrupted NLRC4 and AIM2 inflammasome activation but did not alter cytokine expression. In addition, EWD, isorhamnetin, and hyperoside inhibited caspase-1.

Conclusion: Isorhamnetin and hyperoside, a key molecule of water dropwort, have been suggested as candidates to attenuate inflammasome inhibition.