Abstract: Objective To investigate the effect of N-acetyl-seryl-aspartyl-lysyl-proline（AcSDKP） on mouse RAW264.7 macrophage cell line.Methods RAW264.7 mouse macrophage cells were cultured in vitro. Cells were divided into five groups，namely the control group （vehicle only），lipopolysaccharides （LPS） group （LPS only），and AcSDKP intervention groups （LPS plus AcSDKP at 1 nmol/L，10 nmol/L and 100 nmol/L）. The mRNA levels of tumor necrosis factor-α （TNF-α），interleukin （IL）-1β，IL-6 and inducible nitric oxide synthase（iNOS） were measured by real-time RT-PCR. The chemotactic motility of RAW264.7 cells was detected by using Transwell assay. Western blot was performed to determine the iNOS，phosphorylated inhibitor of κB protein kinase complex （p-IKK），phosphorylated inhibitor of κB （p-IκB） and phosphorylated P65（p-P65） expression.Results The mRNA levels of TNF-α，IL-1β and IL-6 in LPS group were increased by（41±2.1），（1073±80.8） and（1726±110.2） folds compared with in control group， respectively（P<0.01）；the TNF-α mRNA levels in AcSDKP （1 nmol/L，10 nmol/L and 100 nmol/L） treatment groups were decreased by 8.1% （P>0.05），19.0% （P<0.01） and 39.3% （P<0.01），respectively as compared with in LPS group，IL-1β were decreased by 22.0%，35.8% and 38.2%，respectively，（P<0.01），and IL-6 were decreased by 15.8%，35.7% and 43.3%， respectively （P<0.01）；The migrated cell counts across the chamber membrane in LPS group （136±5.3）/HP were significantly higher than those in control group [（64±5.3），P<0.01]，however，the cell counts in AcSDKP treatment groups [（105±4.8） /HP，（85.3±5.0）/HP and （73.7±5.6）/HP，P<0.05] were significantly lesser than those in LPS group （P<0.05）；The mRNA and protein levels of iNOS were increased by （21±2.5） and （5.9±0.4） folds compared with those in the control group，However，the mRNA levels of iNOS in AcSDKP treatment groups were decreased by 37.8%，23.3% and 33.1%，respectively，and their protein levels were decreased by 27.0% and 40.2%（P<0.01）at the concentration of 10 nmol/L and 100 nmol/L of AcSDKP intervention；Relative levels of p-IKK，p-IκB and p-P65 protein in LPS group were increased by （25.9±4.8），（9.5±0.6） and （2.1±0.2） folds，respectively，as compared with those in control group；After AcSDKP （10 nmol/L） treatment，these protein levels were decreased by 42.5%（P<0.01），17.8%（P<0.05） and 29.7%（P<0.05），respectively，than those in cells treated with LPS alone.Conclusions AcSDKP exhibits a significant inhibitory effect on the proinflammatory profiles induced by LPS in mouse Raw264.7 macrophages in vitro，and this effect may be related to the blockage of the IKK/IκB/NF-κB signaling pathway.

Key words: RAW264.7 macrophages, N-acetyl-seryl-aspartyl-lysyl-proline, Inflammatory cytokines, Nuclear factor-κB, In vitro