Chemical Constituents from the Aerial Parts of Artemisia iwayomogi and Their Anti-Neuroinflammatory Activities.

Neuroinflammation, predominantly mediated by microglial activation, is a key immunological response in the pathogenesis of neurodegenerative disorders. In our preliminary study, the aerial part of Artemisia iwayomogi inhibits LPS-induced microglial activation. The present study aims to identify chemical constituents with anti-neuroinflammatory properties in the aerial parts of A . iwayomogi . Two new guaianolide sesquiterpenes, iwayomogins A and B ( 1 and 2 ), along with thirteen known sesquiterpene lactones ( 3 - 15 ), one diterpene glycoside ( 16 ), and nine phenolic compounds ( 17 - 25 ) were isolated from the aerial parts of A . iwayomogi by repeated chromatography. The structures of the isolates were elucidated by their spectroscopic data. All isolates were evaluated for their inhibitory activities on nitric oxide (NO) production in LPS-induced BV-2 microglial cells. 2,3-Dehydro-1- epi -asperilin ( 11 ) exhibited the strongest inhibitory effect on NO production (IC 50 value of 1.78 μM). In the molecular docking study, three compounds ( 1 , 2 , and 11 ) showed good binding affinities with iNOS. Additionally, compounds 1 , 2 , and 11 inhibit pro-inflammatory cytokines (TNF-α and IL-6) in dose-dependent manners. The present study demonstrates that the chemical constituents from A . iwayomogi inhibit NO production and pro-inflammatory cytokine release in BV-2 cells. However, further evaluation with biological experiments utilizing in vivo models is necessary.