Sesquiterpene lactone fraction from Artemisia khorassanica inhibits inducible nitric oxide synthase and cyclooxygenase-2 expression through the inactivation of NF-κB.

OBJECTIVE: Members of the Artemisia genus (Astraceae) are important medicinal plants throughout the world. Here, we prepared a sesquiterpene lactone fraction from Artemisia khorassanica (SLAK) and evaluated its effect on inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) expression, and nuclear factor-κB (NF-κB) activity.
METHODS: The effects of SLAK on lipopolysaccharide (LPS)-induced NO, prostaglandin E(2) (PGE(2)), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) production was evaluated in mouse macrophage J774A.1 cells. Moreover, we evaluated SLAK modulation of iNOS and COX-2 enzyme expression by western blot analysis.
RESULTS: Our data revealed that SLAK (10-100 μg/mL), in a dose-dependent manner, inhibits NO, PGE(2), TNF-α, and IL-1β production induced by LPS in the J774A.1 cells. These data were consistent with the modulation of iNOS and COX-2 expressions. It was also showed that SLAK suppresses the iNOS and COX-2 enzyme expression through the inhibition of NF-κB activity.
CONCLUSION: In this study, we demonstrated that SLAK inhibits the production of NO, PGE2, TNF-α, and IL-1β in LPS-stimulated macrophages. This anti-inflammatory effect possibly occurs by inhibiting iNOS and COX-2 expression via the inactivation of NF-κB pathway.