Research Division of Food Functionality, Korea Food Research Institute, Wanju 55365, Korea.
Department of Food Science and Human Nutrition, Jeonbuk National University, Jeonju-si 54896, Korea.
Molecules. 2020 Apr 9;25(7):1737. doi: 10.3390/molecules25071737.
Age-related macular degeneration (AMD) is a major cause of irreversible loss of vision with 80-90% of patients demonstrating dry type AMD. Dry AMD could possibly be prevented by polyphenol-rich medicinal foods by the inhibition of N-retinylidene-N-retinylethanolamine (A2E)-induced oxidative stress and cell damage. (AL) leaves are medicinal and have antioxidant activity. The purpose of this study was to elucidate the protective effects of the extract of AL leaves (ALE) on dry AMD models, including in vitro A2E-induced damage in ARPE-19 cells, a human retinal pigment epithelial cell line, and in vivo light-induced retinal damage in BALB/c mice. According to the total phenolic contents (TPCs), total flavonoid contents (TFCs) and antioxidant activities, ALE was rich in polyphenols and had antioxidant efficacies on 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2',7'-dichlorofluorescin diacetate (DCFDA) assays. The effects of ALE on A2E accumulation and A2E-induced cell death were also monitored. Despite continued exposure to A2E (10 μM), ALE attenuated A2E accumulation in APRE-19 cells with levels similar to lutein. A2E-induced cell death at high concentration (25 μM) was also suppressed by ALE by inhibiting the apoptotic signaling pathway. Furthermore, ALE could protect the outer nuclear layer (ONL) in the retina from light-induced AMD in BALB/c mice. In conclusion, ALE could be considered a potentially valuable medicinal food for dry AMD.
年龄相关性黄斑变性（AMD）是导致不可逆视力丧失的主要原因，80-90%的患者表现为干性 AMD。通过富含多酚的药用食物抑制 N-视黄基-N-视黄基乙醇胺（A2E）诱导的氧化应激和细胞损伤，可能预防干性 AMD。（AL）叶是药用的，具有抗氧化活性。本研究旨在阐明 AL 叶提取物（ALE）对干性 AMD 模型的保护作用，包括体外 ARPE-19 细胞（人视网膜色素上皮细胞系）中 A2E 诱导的损伤和 BALB/c 小鼠光诱导的视网膜损伤。根据总酚含量（TPCs）、总黄酮含量（TFCs）和抗氧化活性，ALE 富含多酚，对 2,2-二苯基-1-苦基肼（DPPH）、2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）、铁还原抗氧化能力（FRAP）和 2'，7'-二氯荧光素二乙酸酯（DCFDA）测定具有抗氧化功效。还监测了 ALE 对 A2E 积累和 A2E 诱导的细胞死亡的影响。尽管持续暴露于 A2E（10 μM），但 ALE 减轻了 APRE-19 细胞中 A2E 的积累，其水平与叶黄素相似。ALE 通过抑制凋亡信号通路，还抑制了高浓度（25 μM）A2E 诱导的细胞死亡。此外，ALE 可保护 BALB/c 小鼠视网膜外核层（ONL）免受光诱导的 AMD 损伤。总之，ALE 可以被认为是一种有价值的干性 AMD 药用食品。
