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.