Rafi Mohamed M, Shafaie Yassaman
Department of Food Science, Cook College, Rutgers, The State University of New Jersey, 65 Dudley Road, New Brunswick, NJ, USA.
Mol Nutr Food Res. 2007 Mar;51(3):333-40. doi: 10.1002/mnfr.200600170.
Lutein is an oxycarotenoid primarily found in dark-green leafy vegetables such as spinach and kale. Other dietary sources which contain moderate amounts of lutein include corn, egg yolks, and fruits like oranges and kiwi. Although a number of in vivo studies have demonstrated the anti-inflammatory effect of lutein, its in vitro anti-inflammatory molecular mechanism of action is unknown. In this study, we have investigated the in vitro anti-inflammatory effect of lutein using LPS-stimulated mouse macrophage cell line (RAW 264.7). The inhibition of LPS-stimulated nitric oxide (NO) was measured and the expression of inducible NO synthase (iNOS) was assessed at the mRNA and protein levels in mouse macrophage cells after treatment with lutein. Lutein decreased the LPS-induced NO production by 50% compared to LPS alone. Real-time PCR analysis showed a 1.9-fold reduction in iNOS expression at the mRNA level. Western blotting revealed that lutein decreased LPS-induced iNOS expression at the protein level by 72.5%. The results of this study suggest the anti-inflammatory properties of lutein demonstrated by the decrease in the expression of iNOS at the mRNA and protein levels in RAW 264.7 mouse macrophage cells.
叶黄素是一种含氧类胡萝卜素，主要存在于菠菜和羽衣甘蓝等深绿色叶菜中。其他含有适量叶黄素的膳食来源包括玉米、蛋黄以及橙子和猕猴桃等水果。尽管许多体内研究已经证明了叶黄素的抗炎作用，但其体外抗炎分子作用机制尚不清楚。在本研究中，我们使用脂多糖（LPS）刺激的小鼠巨噬细胞系（RAW 264.7）研究了叶黄素的体外抗炎作用。在用叶黄素处理小鼠巨噬细胞后，测量了对LPS刺激的一氧化氮（NO）的抑制作用，并在mRNA和蛋白质水平评估了诱导型NO合酶（iNOS）的表达。与单独使用LPS相比，叶黄素使LPS诱导的NO产生减少了50%。实时PCR分析显示，iNOS在mRNA水平的表达降低了1.9倍。蛋白质印迹法显示，叶黄素使LPS诱导的iNOS在蛋白质水平的表达降低了72.5%。本研究结果表明，叶黄素在RAW 264.7小鼠巨噬细胞中通过降低iNOS在mRNA和蛋白质水平的表达而表现出抗炎特性。
