Strong activation of cyclooxygenase I and II catalytic activity by dietary bioflavonoids
Strong activation of cyclooxygenase I and II catalytic activity by dietary bioflavonoids
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DOI：
10.1194/jlr.m800358-jlr200
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发表时间：
2008-12-01
影响因子：
6.5
通讯作者：
Zhu, Bao Ting
中科院分区：
文献类型：
--
作者：
Bai, Hyoung -Woo;Zhu, Bao Ting
环加氧酶（COX）催化花生四烯酸转化为前列腺素（PG）、血栓烷和羟基二十碳四烯酸。在本研究中，我们研究了几种膳食生物素在体外和培养细胞中调节考克斯I和II催化活性的能力。我们发现，其中一些是迄今已知的考克斯I和II的催化活性的最强大的直接刺激剂，在体外增加前列腺素产物的形成高达11倍以上的控制。双歧杆菌的这种刺激作用是酶特异性的，因为它们都不刺激许多测试的脂氧合酶的催化活性。与苯酚（一种通常在体外使用的原型考克斯刺激剂）相比，天然存在的双酚A在刺激考克斯活性方面的有效性高达29倍。使用培养的完整细胞进行的其他研究表明，当某些在生化试验中具有活性的膳食化合物以0.01至1 μ M的浓度存在时，它们也会激活PGE（2）（一种代表性的PG）的形成。饮食化合物对COX介导的PG形成的刺激作用在完整细胞中比在体外测定中更有效。从机制上讲，双氢叶酸主要起到减缓考克斯酶自杀性失活的作用，但它们似乎没有重新激活失活的酶。这项研究的发现表明，一些生物素可能会作为人类考克斯酶的天然辅助因子。- Bai，H-W.，和B。T.竹饮食中的维生素B2对环氧合酶I和II催化活性的强烈激活作用。J. Lipid Res. 2008. 49：2557-2570。
Cyclooxygenases ( COXs) catalyze the conversion of arachidonic acid to prostaglandins ( PGs), thromboxanes, and hydroxyeicosatetraenoic acids. In the present study, we investigated several dietary bioflavonoids for their ability to modulate the catalytic activity of COX I and II in vitro and also in cultured cells. We found that some of them are the most powerful direct stimulators of the catalytic activity of COX I and II known to date, increasing the formation of prostaglandin products in vitro by up to 11-fold over the controls. This stimulatory effect of bioflavonoids is enzyme specific because none of them stimulates the catalytic activity of a number of lipooxygenases tested. Compared with phenol, a prototypical COX stimulator commonly used in vitro, the naturally occurring bioflavonoids are up to 29 times more efficacious in stimulating the COX activity. Additional studies using intact cells in culture showed that some of the dietary compounds that were active in the biochemical assays also activated the formation of PGE(2) ( a representative PG) when they were present at 0.01 to 1 mu M concentrations. The stimulatory effect of dietary compounds on COX-mediated PG formation is far more potent in intact cells than in the in vitro assays. Mechanistically, bioflavonoids mainly acted to slow down the suicidal inactivation of the COX enzymes, but they did not appear to reactivate the inactivated enzymes. The finding of this study suggests that some of the bioflavonoids likely will serve as the naturally occurring cofactors for the COX enzymes in humans. - Bai, H-W., and B. T. Zhu. Strong activation of cyclooxygenase I and II catalytic activity by dietary bioflavonoids. J. Lipid Res. 2008. 49: 2557-2570.