邻甲氧基桂皮醛对IL-1刺激脑微血管内皮细胞COX活性及PGE2释放的影响

目的：观察桂枝汤有效部位A分离的邻甲氧基桂皮醛对发热相关的环氧酶（COX）和前列腺素E₂（PGE₂）的影响。方法：建立大鼠脑微血管内皮细胞（rCMEC）培养,进行Ⅷ因子相关抗原鉴定。待细胞生长至融合状态后加入不同含量的邻甲氧基桂皮醛（12.5,25,50,100,200 μg·mL^-1）孵育3 h,之后以30 ng·mL^-1的IL-1刺激12 h。ELISA方法检测细胞培养液中PGE2的含量及细胞内COX-1和COX-2的活性。结果：Ⅷ因子抗体免疫组化染色可见90％以上的培养细胞呈阳性,确认为rCMEC。暴露于30 ng·mL^-1 IL-1后,rCMEC内COX-2活性及释放的PGE₂量显著增加,COX-1活性变化无统计学差异。加入不同含量的邻甲氧基桂皮醛后,随含量增加可下调COX-1,COX-2活性及PGE₂量,且呈剂量依赖关系；至含量为200 μg·mL^-1时,COX-2活性及释放的PGE₂与IL-1单独作用组相比均有显著性差异,COX-1活性虽有所降低,但无统计学上的显著差异。结论：邻甲氧基桂皮醛能下调IL-1刺激rCMEC释放升高的PGE₂,作用机制可能与抑制COX-2活性有关。

Effect of 2-methoxycinnamaldehyde on activity of COX and PGE2release in cerebral microvascular endothelial cells stimulated by IL-1

OBJECTIVE: To observe the effect of 2-methoxycinnamaldehyde (isolated from fraction A of Guizhi Tang) on activity of COX and PGE2 release in rat cerebral microvascular endothelial cells (rCMEC) stimulated by IL-1. METHOD: rCMEC were cultured, and identified by immunohistochemistry for von Willebrand factor (VIII factor, a marker for all endothelial cells) in cytoplasm of the cells. Different concentrations of 2-methoxycinnamaldehyde were added respectively and incubated for 3 hours, then stimulated for another 12 hours by IL-1. Activities of COX-1 and COX-2 in rCMEC, and production of PGE2 in the conditioned media were measured by ELISA. RESULT: Positive immunostaining for VIII factor was present diffusely in the cytoplasm of > 90% rCMEC. After being exposed to 30 ng x mL(-1) IL, the activity of COX-2 in rCMEC and the production of PGE2 in conditioned media were higher than those of control group, while there was no difference on activity of COX-1 in the two groups. 2-methoxycinnamaldehyde could down-regulate them in concentration-dependently, and significant differences on the activity of COX-2 and amount of PGE2 were showed in 200 microg x mL(-1) concentration. CONCLUSION: 2-methoxycinnamaldehyde can affect the PGE2 release in rCMEC induced by IL-1, which might be related with its inhibition on the activity of COX-2.