Atractylenoide ii isolated from atractylodes macrocephala inhibited inflammatory responses in lipopolysaccharide-induced raw264.7 macrophages and bv2 microglial cells

Atractylodes macrocephala is a perennial herb and is a member of the Compositae family. This plant is known to contain various bioactive constituents indicating anti-inflammatory, neuroprotective, anti-oxidant, immunological enhancement, and gastroprotective effects. In this investigation, we isolated four compounds with similar chemical structures from A. mac-rocephala, and evaluated their anti-inflammatory effects. Among the four compounds, compound 2(atractylenolide II) showed the second-best inhibitory effect on the lipopolysaccharide(LPS)-induced production of nitric oxide in RAW264.7 macrophages and BV2 microglial cells. Compound 2 also inhibited the LPS-induced the production of prostaglandin E2(PGE₂), and the expression of inducible nitric oxide synthase(iNOS) and cyclooxygenase(COX)-2 proteins in both cells. In addition, compound 2 suppressed the production of pro-inflammatory cytokines including interleukin(IL)-1β, IL-6, and tumor necrosis factor(TNF)-α. These inhibitory effects were contributed by inactivation of nuclear factor kappa B(NF-κB) and mitogen-activated protein kinases(MAPKs) pathways by treatment with compound 2. This compound did not induce the expression of heme oxy-genase(HO)-1 protein indicating that the anti-inflammatory effect of compound 2 was independent with HO-1 protein. Taken together, these results suggested that atractylenolide II can be a candidate material to treat inflammatory diseases.