Arctiin inhibits the production of pro-inflammatory cytokines in LPS-stimulated macrophages. RAW 264.7 cells (A:Western blot, B, D, and F:ELISA) and primary macrophages (C, E, and G:ELISA) were treated with different concentrations of arctiin (12.5~100 μg/ml) in the presence of LPS (100 ng/ml) and was monitored as described in 'Materials and Methods'. Each bar represents the means ± S.D. from three separate experiments. †P< 0.05, ††P< 0.01 compares to the control. *P< 0.05, **P< 0.01 compared to the LPS.