Anti-inflammatory activity ofRubus idaeus L. and possible mechanisms involved were explored in lipopolysaccharide (LPS)-treated RAW 264.7 cells. The effects of ethanol extract of R. idaeus on the levels of pro-inflammatory cytokines, including tumor necrosis factor-alfa (TNF-α), interleukin-6 (IL-6) and interleukin-1 beta (IL-1β), as well as pro-inflammatory mediators, such as nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were studied by Sandwich ELISA, real-time PCR, and Western blot analysis. Moreover, the effects of ethanol extract of R. idaeus on anti-inflammatory cytokine interleukin-10 (IL-10) and anti-inflammatory mediator heme oxygenase-1 (HO-1) were also investigated using the same methods. Furthermore, nuclear factor-gB (NF-κB) level was assayed by immunocytochemistry. The results showed that the production of IL-1β, IL-6, NO, TNF-α and COX-2 in LPS-treated cells could be significantly inhibited (P〈0.01 or P〈0.05) by ethanol extract ofR. idaeus compared with that in the cells treated with LPS only. Meanwhile, the production of NF-r,B was also inhibited by the extract. Based on these results, the anti-inflammatory activity ofR. idaeus was attributed to the down-regulation of IL-6, IL-1β and TNF-α levels as well as gene expression of iNOS and COX-2 through the suppression of NF-κB activation, and induction of anti-inflammatory cytokine IL- 10 and anti-inflammatory mediator HO- 1.