Objective: To observe the protective effect of Panax japonicus ethanol extract on the inflammation of mice mononuclear macrophage RAW264.7 cells induced by lipopolysaccharide(LPS). Method: The RAW264.7 cells were treated with different concentration of P. japonicus ethanol extract

cell viability was determined with MTT method; the nitric oxide(NO) release of RAW264.7 cells stimulated by LPS and treated with LPS and P. japonicus ethanol extract was detected with Griess. ELISA were used to detect the expression of Tumor necrosis factor-α(TNF-α)

interleukin 1β(IL-1β); nitric oxide synthase mRNA (iNOS mRNA) and neclear factor-κB(NF-κB) was tested by PCR and Western bolt respectively. Result: The safe range of ethanol extract of P. japonicus is less than 100 mg·L-1; Concentration of LPS was 1 mg·L-1;Compared with the LPS model group

P. japonicus ethanol extract 0.1

1

10

40 mg·L-1 could inhibit the of NO effectively

the inhibition rates were 31.2%

41%

46.1%

55.2%

and inhibit the release of TNF-α

IL-1β

with significant difference(P<0.05 or P<0.01);P. japonicus ethanol extract 10

40 mg·L-1 could down-regulate the expression of iNOS mRNA and inhibit NF-κB nuclear translocation. Conclusion: P. japonicus ethanol extract has protective effects on RAW264.7 cells stimulated by LPS

the mechanism of P. japonicus ethanol extract may be related to it's regulation on NF-κB signal pathway

thereby inhibiting the release of NO and reducing the expression of TNF-α

IL-1β and iNOS.