Chida M, Suzuki K, Nakanishi-Ueda T, Ueda T, Yasuhara H, Koide R, Armstrong D
Department of Ophthalmology, Showa University School of Medicine, Tokyo, Japan.
Ophthalmic Res. 1999;31(6):407-15. doi: 10.1159/000055565.
Lipid peroxidation in aliquots of bovine retina (without rod outer segments, ROS), purified ROS and retinal pigment epithelium (RPE) was initiated with 5 mM ferric iron and 80 mM ADP. After 30 min of oxidation at 37 degrees C, the concentration of thiobarbituric-acid-reacting substances (TBARS) which approximates lipid hydroperoxide (LHP), increased in the ROS from 2.0 +/- 3.6 to 90.2 +/- 34.5 nmol malondialdehyde (MDA)/mg protein and in the RPE from 0.54 +/- 0.2 to 51.5 +/- 15.8 nmol MDA/mg protein. Sixteen lipid and aqueous antioxidants (AOX) from natural or synthetic sources, including five flavonoids, were evaluated for their ability to inhibit the oxidative reaction. Palm-oil-derived vitamin E showed significant protection in retina, ROS and RPE (64, 68 and 74%), respectively. Of the flavonoids tested, good protection in the retina was found at 10(-5) M for epigallocatechin gallate (50%) and at 50 ng/ml for pycnogenol (61%) and catechin (52%). When catechin and palm oil vitamin E, catechin and coenzyme Q(10) or coenzyme Q(10) and pycnogenol were combined, the individual effect was enhanced. TBARS as an indirect measure of LHP level and hemoglobin-methylene blue determination for direct LHP were used as alternative end-point determinations of lipid peroxidation. These measure different aspects of AOX reactions. The results demonstrate the usefulness of an in vitro model system that can rapidly and accurately determine the capacity of a single AOX against lipid peroxidation or be used to show synergistic efficacy.
用5 mM三价铁和80 mM ADP引发牛视网膜（不含视杆外段，即ROS）、纯化的ROS和视网膜色素上皮（RPE）等分试样中的脂质过氧化反应。在37℃氧化30分钟后，近似脂质氢过氧化物（LHP）的硫代巴比妥酸反应物质（TBARS）浓度在ROS中从2.0±3.6增加到90.2±34.5 nmol丙二醛（MDA）/mg蛋白质，在RPE中从0.54±0.2增加到51.5±15.8 nmol MDA/mg蛋白质。评估了16种天然或合成来源的脂质和水性抗氧化剂（AOX）抑制氧化反应的能力，其中包括5种黄酮类化合物。棕榈油衍生的维生素E在视网膜、ROS和RPE中分别显示出显著的保护作用（64%、68%和74%）。在所测试的黄酮类化合物中，表没食子儿茶素没食子酸酯在10⁻⁵ M时对视网膜有良好的保护作用（50%），碧萝芷在50 ng/ml时（61%）和儿茶素在50 ng/ml时（52%）对视网膜有良好的保护作用。当儿茶素与棕榈油维生素E、儿茶素与辅酶Q₁₀或辅酶Q₁₀与碧萝芷联合使用时，各自的效果会增强。用TBARS作为LHP水平的间接测量指标，用血红蛋白-亚甲蓝测定法直接测定LHP，作为脂质过氧化的替代终点测定方法。这些方法测量AOX反应的不同方面。结果证明了一种体外模型系统的实用性，该系统可以快速准确地测定单一AOX对脂质过氧化的能力，或用于显示协同功效。
