Inhibitory Effect of a Sesquiterpene from Artemisia iwayomogi on Expression of Inducible Nitric Oxide Synthase by Suppression of I-κBα Degradation in LPS-stimulated RAW 264.7 Cells

ABSTRACT

A sesquiterpene was purified from Artemisia iwayomogi methanolic extract during the course of searching anti-inflammatory principle from medicinal plants. A sesquiterpene identified as armefolin inhibited the production of nitric oxide (NO) and attenuated inducible nitric oxide synthase (iNOS) protein level in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Armefolin also down-regulated mRNA expressions of iNOS and pro-inflammatory cytokines, interleukin-1β and interleukin-6 in LPS-activated macrophages. Moreover, armefolin suppressed the degradation of inhibitory-κBα (I-κBα) in LPS-activated macrophages. These data suggest that armefolin from A. iwayomogi can suppress the LPS-induced production of NO and the expression of iNOS gene through inhibiting the degradation of I-κBα. Taken together, armefolin from A. iwayomogi might be a candidate as promising anti-inflammatory agent.