(7R,8S)-Dehydrodiconiferyl Alcohol Suppresses Lipopolysaccharide-Induced Inflammatory Responses in BV2 Microglia by Inhibiting MAPK Signaling

(7R,8S)-Dehydrodiconiferyl alcohol (DDA), a lignan isolated from the dried stems of Clematis armandii, has been found to exert potential anti-inflammatory activity in vitro. In the present study, we investigated the effects and possible mechanisms of DDA on lipopolysaccharide (LPS)-mediated inflammatory response in murine BV2 microglia. Our results revealed that non-toxic concentrations (6.25-25 mu M) of DDA markedly suppressed LPS-induced production of nitric oxide, expression of inducible nitric oxide synthase and cyclooxygenase-2, and release of inflammatory factors, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and IL-6 in a concentration dependent manner. In addition, DDA time- and concentration-dependently attenuated LPS-induced phosphorylation of c-Jun N-terminal kinase 1/2 (JNK), but not protein kinase B, p38, or extracellular signal-regulated kinase 1/2. Moreover, DDA significantly suppress LPS-mediated nuclear factor-kappa B (NF-kappa B) activation by inhibiting phosphorylation and nuclear translocation of NF-kappa B p65. Collectively, our results demonstrated that DDA inhibited LPS-stimulated inflammatory response in BV2 cell, at least in part, through inhibition of NF-kappa B activation and modulation of JNK signaling.