Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Kowloon, Hong Kong.
J Agric Food Chem. 2010 Feb 10;58(3):1523-34. doi: 10.1021/jf9032602.
Catechins, active constituents of green tea, are well-known antioxidative natural products. It was proposed that green tea extract (GTE) consumption could benefit the eye, and the pharmacokinetics of catechins and oxidation status in rat eye were investigated after oral administration. Sprague-Dawley rats were fed GTE and sacrificed at different time intervals. Their eyes were dissected into cornea, lens, retina, choroid-sclera, vitreous humor, and aqueous humor for analysis of catechins and 8-epi-isoprostane by HPLC-ECD and GC-NCI-MS, respectively. Catechins were differentially distributed in eye tissues. Gallocatechin was present at the highest concentration in the retina, 22729.4 +/- 4229.4 pmol/g, and epigallocatechin in aqueous humor at 602.9 +/- 116.7 nM. The corresponding area-under-curves were 207,000 pmol x h/g and 2035.0 +/- 531.7 nM x h, respectively. The time of maximum concentration of the catechins varied from 0.5 to 12.2 h. Significant reductions in 8-epi-isoprostane levels were found in the compartments except the choroid-sclera or plasma, indicating antioxidative activities of catechins in these tissues.
儿茶素是绿茶中的有效成分，是众所周知的抗氧化天然产物。有研究提出，绿茶提取物（GTE）的摄入对眼睛有益，因此研究了口服 GTE 后大鼠眼内儿茶素的药代动力学和氧化状态。将 Sprague-Dawley 大鼠喂食 GTE 并在不同时间间隔处死，将其眼睛解剖为角膜、晶状体、视网膜、脉络膜-巩膜、玻璃体和房水，分别通过 HPLC-ECD 和 GC-NCI-MS 分析儿茶素和 8-epi-前列腺素。儿茶素在眼部组织中分布不均。表没食子儿茶素没食子酸酯在视网膜中的浓度最高，为 22729.4 +/- 4229.4 pmol/g，表儿茶素没食子酸酯在房水中的浓度最高，为 602.9 +/- 116.7 nM。相应的曲线下面积分别为 207000 pmol x h/g 和 2035.0 +/- 531.7 nM x h。儿茶素的最大浓度时间从 0.5 到 12.2 小时不等。除脉络膜-巩膜或血浆外，其他部位的 8-epi-前列腺素水平均显著降低，表明儿茶素在这些组织中具有抗氧化活性。
