Effects of ginsenoside Rh1 combined with DEX on TNF-induced cytokine production. RAW264.7 cells were pretreated with solvent, DEX (1 μM) or DEX combined with Rh1 (10 μM, 1 μM, 0.1 μM ) or Rh1 alone for 2 h (short-term treatment protocol) or 24 h (prolonged treatment protocol), as indicated in the figures. Afterwards, TNF (20 ng /ml) was added for 8 h. (A) Expression of the pro-inflammatory mediators IL-6, IL-17, MMP-1 and TNF-α was monitored by means of quantitative PCR. Gene expression of the housekeeping gene β-actin was used for normalization. (B) Protein expression of IL-6 and IL-17 were also determined by ELISA. Statistical significance was determined by one-way analysis of variance (*P <0.05, **P <0.01 versus TNF group; #P <0.05, ##P <0.01 versus the DEX group). The experiments were replicated three times, and results are representative of at least three independent induction experiments. DEX, dexamethasone; IL, interleukin; MMP-1, matrix matalloproteinase-1; TNF, tumor necrosis factor.