Department of Chemistry and Biomedical Sciences, Karlstad University, Karlstad, Sweden.
Br J Nutr. 2010 Apr;103(8):1102-9. doi: 10.1017/S0007114509992935. Epub 2009 Dec 1.
Ellagic acid, a natural polyphenol found in certain fruits, nuts and vegetables, has in recent years been the subject of intense research within the fields of cancer and inflammation. Pain, fever and swelling, all typical symptoms of inflammation, are ascribed to elevated levels of PGE2. In the present study, we have investigated the effects of ellagic acid on PGE2 release and on prostaglandin-synthesising enzymes in human monocytes. Ellagic acid was found to inhibit Ca ionophore A23187-, phorbol myristate acetate- and opsonised zymosan-induced release of PGE2 from monocytes pre-treated with the inflammatory agent lipopolysaccharide. Ellagic acid suppressed the lipopolysaccharide-induced increase in protein expression of cyclo-oxygenase-2 (COX-2), microsomal PGE synthase-1 (mPGEs-1) and cytosolic phospholipase A2alpha (cPLA2alpha), while it had no effect on the constitutively expressed COX-1 protein. Ellagic acid had no apparent inhibitory effect on these enzymes when the activities were determined in cell-free assays. We conclude that the inhibitory effect of ellagic acid on PGE2 release from monocytes is due to a suppressed expression of COX-2, mPGEs-1 and cPLA2alpha, rather than a direct effect on the activities of these enzymes.
鞣花酸是一种天然多酚，存在于某些水果、坚果和蔬菜中，近年来一直是癌症和炎症领域研究的热点。疼痛、发烧和肿胀是炎症的典型症状，这些症状都归因于 PGE2 水平的升高。在本研究中，我们研究了鞣花酸对 PGE2 释放和人单核细胞中前列腺素合成酶的影响。研究发现，鞣花酸可抑制脂多糖预处理的单核细胞中钙离子载体 A23187、佛波醇肉豆蔻酸酯和调理酵母聚糖诱导的 PGE2 释放。鞣花酸抑制了脂多糖诱导的环氧化酶-2（COX-2）、微粒体 PGE 合酶-1（mPGEs-1）和细胞质型 PLA2alpha（cPLA2alpha）蛋白表达的增加，而对组成型表达的 COX-1 蛋白没有影响。当在无细胞测定中测定这些酶的活性时，鞣花酸对它们没有明显的抑制作用。我们得出结论，鞣花酸抑制单核细胞中 PGE2 的释放是由于 COX-2、mPGEs-1 和 cPLA2alpha 的表达受到抑制，而不是对这些酶的活性的直接影响。
