Anti-inflammatory activity of Angelica dahurica ethanolic extract on RAW264.7 cells via upregulation of heme oxygenase-1

In this study, we analyzed the anti-inflammatory effects of Angelica dahurica Bentham et Hooker ethanolic extract (ADEE) on RAW264.7 cells, to understand the mechanism underlying its observed effects. ADEE inhibited cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, leading to the suppression of COX-2-derived prostaglandin E2 and iNOS-derived production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. These inhibitory effects of ADEE were accompanied by the reduced production of tumor necrosis factor α and interleukin (IL)-6. ADEE also inhibited nuclear factor κB (NFκB) translocation to the nucleus by interrupting inhibitor kappa Bα (IκBα) degradation. ADEE upregulated heme oxygenase 1 expression, and treatment with tin protoporphyrin IX (SnPP), a selective inhibitor of HO-1, reversed the LPS-induced generation of proinflammatory cytokines. ADEE also induced IL-4 and IL-5 expression in concanavalin-A-stimulated splenocytes. These results suggest that ADEE has anti-inflammatory activity, which acts via the suppression of the NF-κB pathway.