Yoshida Yasukazu, Hayakawa Mieko, Habuchi Yoko, Itoh Nanako, Niki Etsuo
Human Stress Signal Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka Ikeda, Osaka 563-8577, Japan.
Lipids. 2007 May;42(5):463-72. doi: 10.1007/s11745-007-3043-7. Epub 2007 Mar 27.
The evaluation of antioxidant activity in vivo is difficult. In this study, the effects of dietary natural and synthetic antioxidants on the lipid peroxidation in mice were assessed using a biomarker, total hydroxyoctadecadienoic acid (tHODE). Biological samples such as plasma, erythrocytes, and tissues were first reduced and then saponified to convert various oxidation products of linoleates to tHODE. Subsequently, the absolute concentration of tHODE and its stereoisomer ratio, [9- and 13-(Z,E)-HODE)/[9- and 13-(E,E)-HODE], which is a measure of the hydrogen donor capacity of antioxidants, were determined by gas chromatography-mass spectrometry (GC-MS) analyses. These were then compared with total 8-iso-prostaglandin F(2alpha) (t8-iso-PGF(2alpha)) which was also assessed after reduction and saponification. Remarkable increases in tHODE and t8-iso-PGF(2alpha) levels were observed in the plasma, erythrocytes, liver, and brain of mice that were fed an alpha-tocopherol (alphaT)-stripped (E-free) diet for 1 month when compared with those of mice that were fed a standard diet (alphaT = 0.002 wt%). When mice were fed for 1 month on an E-free diet supplemented with a lipophilic antioxidant (0.04 wt%), namely, alphaT, alpha-tocotrienol (alphaT3), gamma-tocopherol (gammaT), or 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran (BO-653), a potent synthetic antioxidant, the increases of tHODE and t8-iso-PGF(2alpha) in the plasma, erythrocytes, liver, and brain were suppressed to the levels lower than those of mice fed a standard diet. The (Z,E/E,E) HODE ratio was decreased in the plasma and erythrocytes of mice fed the E-free diet when compared with that in mice fed the standard diet. This stereo-isomeric ratio was significantly recovered by the addition of alphaT and BO-653. These results show that the tHODE level and the (Z,E/E,E) HODE ratio are useful biomarkers for the assessment of antioxidant capacity in vivo and that the antioxidant capacity decreased in the order: BO-653 > alphaT3 >or= alphaT, gammaT, as assessed by tHODE levels from blood, liver, and brain.
体内抗氧化活性的评估具有一定难度。在本研究中，使用生物标志物总羟基十八碳二烯酸（tHODE）评估了膳食中天然和合成抗氧化剂对小鼠脂质过氧化的影响。首先对血浆、红细胞和组织等生物样本进行还原，然后皂化，将亚油酸酯的各种氧化产物转化为tHODE。随后，通过气相色谱 - 质谱（GC-MS）分析测定tHODE的绝对浓度及其立体异构体比例，即[9-和13-(Z,E)-HODE]/[9-和13-(E,E)-HODE]，该比例可衡量抗氧化剂的氢供体能力。然后将这些结果与同样经过还原和皂化后评估的总8-异前列腺素F(2α)（t8-iso-PGF(2α)）进行比较。与喂食标准饮食（α-生育酚（αT）含量 = 0.002 wt%）的小鼠相比，喂食α-生育酚（αT）缺乏（无E）饮食1个月的小鼠血浆、红细胞、肝脏和大脑中的tHODE和t8-iso-PGF(2α)水平显著升高。当小鼠喂食添加了亲脂性抗氧化剂（0.04 wt%）的无E饮食1个月，所述亲脂性抗氧化剂即αT、α-生育三烯酚（αT3）、γ-生育酚（γT）或强效合成抗氧化剂2,3-二氢-5-羟基-4,6-二叔丁基-2,2-二戊基苯并呋喃（BO-653）时，血浆、红细胞、肝脏和大脑中tHODE和t8-iso-PGF(2α)的升高被抑制至低于喂食标准饮食小鼠的水平。与喂食标准饮食的小鼠相比，喂食无E饮食的小鼠血浆和红细胞中的(Z,E/E,E) HODE比例降低。添加αT和BO-653后，这种立体异构体比例得到显著恢复。这些结果表明，tHODE水平和(Z,E/E,E) HODE比例是评估体内抗氧化能力的有用生物标志物，并且根据血液、肝脏和大脑中的tHODE水平评估，抗氧化能力按以下顺序降低：BO-653 > αT3 ≥ αT, γT。
