Gómez-Ruiz José Angel, Leake David S, Ames Jennifer M
School of Food Biosciences, University of Reading, Whiteknights, Reading, Berkshire RG6 6AP, United Kingdom.
J Agric Food Chem. 2007 Aug 22;55(17):6962-9. doi: 10.1021/jf0710985. Epub 2007 Jul 27.
In this paper we report the antioxidant activity of different compounds which are present in coffee or are produced as a result of the metabolism of this beverage. In vitro methods such as the ABTS*+ [ABTS = 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] decolorization assay and the oxygen radical absorbance capacity assay (ORAC) were used to assess the capacity of coffee compounds to scavenge free radicals. The importance of caffeine metabolites and colonic metabolites in the overall antioxidant activity associated with coffee consumption is shown. Colonic metabolites such as m-coumaric acid and dihydroferulic acid showed high antioxidant activity. The ability of these compounds to protect human low-density lipoprotein (LDL) oxidation by copper and 2,2'-azobis(2-amidinopropane) dihydrochloride was also explored. 1-Methyluric acid was particularly effective at inhibiting LDL oxidative modification. Different experiments showed that this caffeine metabolite is not incorporated into LDL particles. However, at physiologically relevant concentrations, it was able to delay for more than 13 h LDL oxidation by copper.
在本文中，我们报告了咖啡中存在的或因该饮品代谢而产生的不同化合物的抗氧化活性。采用体外方法，如ABTS*+[ABTS = 2,2'-偶氮二(3-乙基苯并噻唑啉-6-磺酸)]脱色测定法和氧自由基吸收能力测定法(ORAC)，来评估咖啡化合物清除自由基的能力。结果表明了咖啡因代谢物和结肠代谢物在与咖啡消费相关的总体抗氧化活性中的重要性。结肠代谢物如间香豆酸和二氢阿魏酸具有较高的抗氧化活性。还探究了这些化合物通过铜和2,2'-偶氮二(2-脒基丙烷)二盐酸盐保护人低密度脂蛋白(LDL)氧化的能力。1-甲基尿酸在抑制LDL氧化修饰方面特别有效。不同实验表明，这种咖啡因代谢物不会掺入LDL颗粒中。然而，在生理相关浓度下，它能够将铜介导的LDL氧化延迟超过13小时。
