Participation of singlet oxygen in ultraviolet-a-induced lipid peroxidation in mouse skin and its inhibition by dietary β-carotene:: An ex vivo study
Participation of singlet oxygen in ultraviolet-a-induced lipid peroxidation in mouse skin and its inhibition by dietary β-carotene:: An ex vivo study
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DOI：
10.1016/j.freeradbiomed.2004.09.004
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发表时间：
2004-12-01
影响因子：
7.4
通讯作者：
Terao, J
中科院分区：
文献类型：
--
作者：
Bando, N;Hayashi, H;Terao, J
饮食中的β-胡萝卜素在皮肤中起到光保护剂的作用，但确切的保护机制尚不清楚。本实验通过对过氧化磷脂酰胆碱(PC)和β-胡萝卜素氧化产物的表征，探讨了β-胡萝卜素对U-V-A皮肤损伤的作用机制。BALB/c小鼠饲喂基础饲料或添加β-胡萝卜素的饲料，3周后从背部皮肤制备匀浆，进行UV-A照射。分析表明，β-胡萝卜素组的脂质过氧化程度明显低于对照组。采用薄层层析-印迹、气相色谱/质谱(MS)/选择离子监测等方法对过氧化PC中的羟基过氧化脂肪酸的异构体组成进行了测定。暴露于UV-A的对照组与油酸反应生成的过氧化PC的9-和10-异构体较实验组增加。亚甲基蓝敏化的小鼠皮肤脂肪体外光氧化也得到了类似的结果。对匀浆进行的液相色谱/MS分析证实了β-胡萝卜素5，8-内源性过氧化产物的形成，这是O-1(2)反应的特异性标志。这些结果表明，饮食中的β-胡萝卜素通过猝灭O-1(2)在皮肤中积累，并作为保护剂对抗U-V-A诱导的氧化损伤。(C)2004 Elsevier Inc.保留所有权利。
Dietary beta-carotene acts as a photoprotective agent in the skin, but the exact mechanism of protection is unknown. This ex vivo study is focused on determining the mechanism of action of beta-carotene against U-V-A-induced skin damage by characterizing peroxidized phosphatidylcholine (PC) and beta-carotene oxidation products. BALB/c mice were fed with basal or a beta-carotene-supplemented diet, and homogenates from their dorsal skin were prepared after 3 weeks for UV-A irradiation. Analyses revealed that the degree of lipid peroxidation in the beta-carotene group was significantly lower than that in the controls. The isomeric composition of hydroperoxy fatty acids, constituting peroxidized PC, was determined by thin-layer chromatography-blotting followed by gas chromatography/mass spectrometry (MS)/selected ion monitoring analysis. The 9- and 10-isomers of peroxidized PC, resulting from the reaction of singlet molecular oxygen (O-1(2)) With oleic acid, were elevated in the UV-A-exposed control group compared to the experimental group. Similar results were obtained from methylene-blue-sensitized photooxidation of mouse skin lipids in vitro. Liquid chromatography/MS analysis of the homogenates confirmed the formation of beta-carotene 5,8-endoperoxide, a specific marker for the O-1(2) reaction. These results indicate that dietary beta-carotene accumulates in the skin and acts as a protective agent against U-V-A-induced oxidative damage, by quenching the O-1(2). (C) 2004 Elsevier Inc. All rights reserved.