Objective: To compare the effects of 6 phenylallyl compounds on cyclooxygenase-2(COX-2) and prostaglandin synthase(PGES) mRNA expression

and provide some evidence for their structure-activity relationship. Method : Macrophages stimulated by lipopolysaccharide(LPS) model was used to test the effects of cinnamic alchohol

O-methoxy cinnamic alchohol

cinnamaldehyde

O-methoxy cinnamaldehyde

cinnamic acid and O-methoxy cinnamic acid on COX-2 and PGES at mRNA level. The RAW264.7 cells was treated with 1 mg·L-1 LPS and phenylallyl compounds (0

12

19

32

54

90

150 mg·L-1) for 4 h

and the mRNA was detected by TaqMan real time PCR. Result : The cinnamaldehyde had the strongest effect

showed significant effect on COX-2 (P<0.05) and membrane-associated PGES-1(mPGES-1) (P<0.01) at 32 mg·L-1. The O-methoxy cinnamaldehyde took second place

showed significant effect on COX-2(P<0.05) and mPGES-1 (P<0.05) at 54 mg·L-1. The other 4 phenylallyl compounds had effects in different degree

but was much weaker than cinnamaldehyde and O-methoxy cinnamaldehyde. Conclusion : It is key mechanism of anti-inflammatory and antipyretic for the phenylallyl compounds to down-regulate PGE2 production by inhibiting COX-2 and mPGES-1. The efficacy of the phenylallyl compounds was aldehyde>alcohol>acidum

and it is degraded by the methoxyl. The action intensity may be closely related to the different oxidation state of propenyl and impacted by methoxyl.