Objective: To study the anti-inflammatory effect and mechanism of Ginseng Radix et Rhizoma polysaccharide on inflammation factors caused by lipopolysaccharide(LPS)-induced macrophage in mice. Method: RAW264.7 cells were cultured in 6-well plates with the concentration of 2×104 cells/mL. The cells was divided into blank group

model group

LPS plus dexamethasone group

LPS plus Ginseng Radix et Rhizoma polysaccharide groups (31.25

62.6

125

250

500 mg·L-1).RAW264.7 cells were polarized to inflammatory macrophage by treating with 1 mg·L-1 LPS for 24 h.The content of nitricoxide (NO) was assayed by Griess reagent. Enzyme linked immunosorbent assay (ELISA) was used to detect the content of inflammatory mediators

such as tumor necrosis factor-α (TNF-α) and interleukin-6(IL-6) in cell supernatant.The expressions of iNOS

IL-6

TNF-α mRNA were detected by real-time quantitative PCR (Real-time PCR). And the expression of mitogen-activated protein kinase nuclear transcription factor(NF)-κB p65 protein was determined by Western blot. Result: Compared with blank group

the expressions of NO

IL-6

TNF-α of model group were significantly higher (P<0.01).It meant that the inflammation model was successfully established.Compared with model group

31.25-500 mg·L-1 of Ginseng Radix et Rhizoma polysaccharide in LPS-induced RAW 264.7 cells greatly inhibited the release of inflammatory mediators

such as NO

TNF-α and IL-6 levels(P<0.05

P<0.01). Compared with the model group

31.25-500 mg·L-1 of Ginseng Radix et Rhizoma polysaccharide reduced the concentrations of iNOS

IL-6

TNF-α mRNA (P<0.05

P<0.01). And the expression of p65 protein was decreased (P<0.05

P<0.01). Conclusion: Ginseng Radix et Rhizoma polysaccharide can significantly inhibit the over expression of macrophage inflammatory factors NO

TNF-α and IL-6.Its mechanism may be related to the inhibition of the expressions of related inflammatory factors mRNA and the inhibition of NF-κB signaling pathway.