Anti-inflammatory Effects of Magnolia sieboldii Extract in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

Purpose: To investigate the effect of Magnolia sieboldii extract (MSE) on the production of proinflammatory cytokines by macrophage.Methods: The whole plant of M. sieboldii was extracted with methanol at room temperature. The in vitro anti-inflammatory activity of MSE was investigated on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. LPS-induced nitric oxide(NO) production was determined by Griess method. Production of pro-inflammatory cytokines including Interleukin-1 beta (IL-1 β), Interleukin-6 (IL-6), tumor necrosis factor- alpha (TNF-α) and cyclooxygenase-2 (COX-2) was examined using reverse trancriptase - polymerase chain reaction (RT-PCR) and Western blot analysis.Results: Under in vitro conditions, MSE in doses ranging from 25 - 100 μg/mL significantly inhibited lipopolysaccharide (0.5 μg/mL)-induced nitric oxide production (p < 0.001), and the production of proinflammatory mediators (p < 0.05).Conclusions: The anti-inflammatory effect of MSE on pro-inflammatory cytokines seems to ameliorate inflammatory symptoms via immune regulation.Keywords: Anti-inflammatory, Nitric oxide, Cytokines, Immune regulation, Macrophage, Lipopolysaccharide, Polymyxin B, Magnolia sieboldii