中文摘要：

应用免疫细胞化学染色及Western印迹检测血管平滑肌细胞（vascular smooth muscle cells，VSMC）环加氧酶-2（cyclo—oxygenase-2，COX-2）表达、NF-kB抑制蛋白α（IkB-α）水平和NF—kB p65核转位的变化：电泳迁移率改变分析（electrophoretic mobility shift assay，EMSA）确定旋覆花内酯（1—o-acetylbritannilactone，ABL）对核内NF-kB p65与DNA调控元件的结合活性的影响。结果表明，脂多糖（lipopolysaccharide，LPS）处理的VSMC，p65核转位加快，细胞核内的NF-kB p65水平快速升高，同时伴有IkB3—α的减少；用ABL预处理VSMC后，LPS诱导的p65核转位增加及IkB3—α减少受到明显抑制，抑制作用呈剂量依赖性。EMSA结果显示，LPS处理VSMC，其核蛋白与含有NF—kB结合位点的探针的结合活性升高；而用ABL预处理的VSMC，LPS诱导的核蛋白与探针结合活性的升高受到明显抑制。进而，ABL对NF—kB活化启动的下游炎性基因COX-2表达也具有较强的抑制效果。因此，ABL是一种抗炎物质，通过抑制NF—kB活化和炎性基因COX-2的表达而减弱或消除LPS诱导的VSMC炎症应答反应。

英文摘要：

Immunocytochemistry and Western blot analysis were adopted to measure the nuclear translocation of NF-kB p65 and the expression of IkB-α, cyclo-oxygenase-2 （COX-2）. Electrophoretic mobility shift assay （EMSA） was performed to detect DNA-binding activity of NF-kB in vascular smooth muscle cells （VSMC） pretreated with ABL. Western blot and immunocytochemistry analysis showed that lipopolysaccharide （LPS） treatment resulted in increasing nuclear translocation of NF-kB p65, and declining levels of IkB-α in VSMC. However, 1-o- acetylbritannilactone （ABL） pretreatment inhibited the nuclear translocation of p65 and degradation of IkB-α induced by LPS, and the inhibitory effect of ABL was concentration-dependent. LPS increased the binding of nuclear extracts from VSMC induced by LPS to double strands oligonucleotide probe containing NF-kB binding site using EMSA. The shift bands were abolished when a 100-fold excess of unlabeled NF-kB oligonucleotide probe was included. Pretreatment with ABL significantly reduced the nuclear level of NF-kB and declined the binding activity of nuclear extracts with DNA probe induced by LPS. Furthermore, ABL consequentially inhibited the expression of NF-kB-dependent COX-2 gene induced by LPS. These results suggest that ABL may be one anti-inflammatory drug which inhibits the expression of COX-2 gene by blocking NF-kB activation and thus suppresses the inflammatory response to LPS in VSMC