BETA-CAROTENE INHIBITS THE OXIDATIVE MODIFICATION OF LOW-DENSITY-LIPOPROTEIN
BETA-CAROTENE INHIBITS THE OXIDATIVE MODIFICATION OF LOW-DENSITY-LIPOPROTEIN
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DOI：
10.1016/0005-2760(91)90164-d
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发表时间：
1991-10-15
期刊：
影响因子：
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通讯作者：
GRUNDY, SM
中科院分区：
文献类型：
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作者：
JIALAL, I;NORKUS, EP;GRUNDY, SM
多项证据表明，氧化型低密度脂蛋白(Ox-LDL)可促进动脉粥样硬化的形成。因此，需要确定抗氧化剂在防止低密度脂蛋白氧化中的作用。β-胡萝卜素除了是单线态氧的有效猝灭剂外，还可以作为一种捕捉自由基的抗氧化剂。由于之前的研究未能表明β-胡萝卜素抑制低密度脂蛋白的氧化，我们重新检查了它对低密度脂蛋白氧化修饰的影响。在这些研究中，低密度脂蛋白在无细胞(PBS中为2.5mU-MCu2+)和细胞系统(Ham‘s F-10培养基中的人单核巨噬细胞)中被氧化。在这两个体系中，β-胡萝卜素抑制低密度脂蛋白的氧化修饰，表现为脂质过氧化含量(硫代巴比妥酸反应物质的活性)的减少，低密度脂蛋白(电泳迁移率)的负电荷和共轭双烯的形成。通过抑制低密度脂蛋白氧化，β-胡萝卜素大大减少了巨噬细胞对低密度脂蛋白的降解。β-胡萝卜素(2-mU-M)比α-生育酚(40-mU-M)对低密度脂蛋白氧化的抑制作用更强。因此，β-胡萝卜素，如抗坏血酸和α-生育酚，可以抑制低密度脂蛋白的氧化，并可能在预防动脉粥样硬化方面发挥重要作用。
Several lines of evidence indicate that oxidized LDL (Ox-LDL) may promote atherogenesis. Hence, the role of antioxidants in the prevention of LDL oxidation needs to be determined. Beta-Carotene, in addition to being an efficient quencher of singlet oxygen, can also function as a radical-trapping antioxidant. Since previous studies have failed to show that beta-carotene inhibits LDL oxidation, we re-examined its effect on the oxidative modification of LDL. For these studies, LDL was oxidized in both a cell-free (2.5-mu-M Cu2+ in PBS) and a cellular system (human monocyte macrophages in Ham's F-10 medium). Beta-Carotene inhibited the oxidative modification of LDL in both systems as evidenced by a decrease in the lipid peroxide content (thiobarbituric-acid-reacting substances activity), the negative charge of LDL (electrophoretic mobility) and the formation of conjugated dienes. By inhibiting LDL oxidation, beta-carotene substantially decreased its degradation by macrophages. Beta-Carotene (2-mu-M) was more potent than alpha-tocopherol (40-mu-M) in inhibiting LDL oxidation. Thus, beta-carotene, like ascorbate and alpha-tocopherol, inhibits LDL oxidation and might have an important role in the prevention of atherosclerosis.