桂枝汤苯丙烯类化合物对环氧合酶-2 及前列腺素抑制的作用

目的:对比桂枝汤中6种苯丙烯类化合物对环氧合酶-2( COX-2)及前列腺素合酶(PGES)的影响,为其抗炎、解热、镇痛作用“构效关系”提供相关实验依据.方法:将小鼠巨噬细胞RAW264.7以5×105个/mL,1.90 mL/孔接种于6孔培养板,用1 mg·L-1脂多糖(LPS)分别刺激0,1,2,4,8,12,24 h,提取其总RNA并用TaqMan real time PCR法检测COX-2及PGESmRNA表达情况,选择1 mg·L-1 LPS剂激4h作为实验条件,建立体外炎症模型.并用桂皮醇、邻甲氧基桂皮醇、桂皮醛、邻甲氧基桂皮醛、桂皮酸、邻甲氧基桂皮酸6种苯丙烯类化合物以0,12,19,32,54,90,150 mg·L-1进行干预,检测其对COX-2及mPGES-1 mRNA表达情况的影响.结果:COX-2与mPGES-1 mRNA表达随LPS刺激时间变化,COX-2于4h时达峰值后下降,而mPGES-1则一直呈上升趋势.mPGES-2与cPGES mRNA则并不随LPS刺激而变化.桂皮醛作用最强,在32 mg·L-1时显著抑制COX-2(P ＜0.05)和mPGES-1(P＜0.01)；邻甲氧基桂皮醛次之,在54 mg·L-1时显著抑制COX-2(P ＜0.05)和mPGES-1(p＜0.05).其余4种化合物对COX-2和mPGES-1也均有一定的抑制作用,但其强度远弱于桂皮醛和邻甲氧基桂皮醛,在实验所设浓度范围内均无统计学意义.结论:抑制COX-2和mPGES-1,是桂枝汤苯丙烯类化合物抑制前列腺素E2( PGE2)分泌,进而发挥抗炎解热作用的重要机制.其作用强弱顺序为醛＞醇＞酸,结构中有邻甲氧基则作用减弱,其作用强弱似与丙烯基末端的氧化态关系密切,同时也受到甲氧基的影响.

Comparative Study on the Effects of Phenylallyl Compounds from Guizhi Decoction on COX-2 and PGES

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.