Anthocyanins protect against A2E photooxidation and membrane permeabilization in retinal pigment epithelial cells
Anthocyanins protect against A2E photooxidation and membrane permeabilization in retinal pigment epithelial cells
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DOI：
10.1562/2004-12-14-ra-402.1
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发表时间：
2005-05-01
影响因子：
3.3
通讯作者：
Sparrow, JR
中科院分区：
文献类型：
--
作者：
Jang, YP;Zhou, JL;Sparrow, JR
双视黄吡啶A2E是一种自发荧光色素，随着年龄的增长积累在视网膜色素上皮细胞中，在一些视网膜疾病中，可以介导细胞膜的洗涤剂样扰动和光诱导的细胞损伤。A2E敏化引发的光动力学事件包括单线态氧的生成和A2E在碳-碳双键上的氧化。为了评估植物来源的花色苷调节A2E积累对视网膜色素上皮(RPE)细胞的不利影响的能力，从越橘提取物中分离出这些黄素盐。分离得到了9个花色苷组分，它们都反映了飞雀素、花青素、花青素和花青素的单糖苷，它们都至少部分地通过猝灭单线态氧来抑制A2E的光氧化。所测试的花色苷具有不同效率的抗氧化活性。与这种变化相关的结构特征可能包括在中性pH下形成稳定的喹酮类无氢碱的能力，C(吡喃)环上的共轭二烯结构，B(苯)环上存在羟基，以及B环上取代基的排列赋予的相对疏水性。吸收了花青素的细胞也表现出对A2E类似洗涤剂作用所产生的膜通透性的抵抗。
The pyridinium bisretinoid A2E, an autofluorescent pigment that accumulates in retinal pigment epithelial cells with age and in some retinal disorders, can mediate a detergent-like perturbation of cell membranes and light-induced damage to the cell. The photodynamic events initiated by the sensitization of A2E include the generation of singlet oxygen and the oxidation of A2E at carbon-carbon double bonds. To assess the ability of plant-derived anthocyanins to modulate adverse effects of A2E accumulation on retinal pigment epithelium (RPE) cells, these flavylium salts were isolated from extracts of bilberry. Nine anthocyanin fractions reflecting monoglycosides of delphinidin, cyanidin, petunidin and malvidin were obtained and all were shown to suppress the photooxidation of A2E at least in part by quenching singlet oxygen. The anthocyanins tested exhibited antioxidant activity of variable efficiency. The structural characteristics relevant to this variability likely included the ability to form a stable quinonoidal anhydro base at neutral pH, a conjugated diene structure in the C (pyrane) ring, the presence of hydroxyl groups on the B (benzene) ring and the relative hydrophobicity conferred by the arrangement of substituents on the B ring. Cells that had taken up anthocyanins also exhibited a resistance to the membrane permeabilization that occurs as a result of the detergent-like action of A2E.