Flavonoids protect human retinal pigment epithelial cells from oxidative-stress-induced death
Flavonoids protect human retinal pigment epithelial cells from oxidative-stress-induced death
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DOI：
10.1167/iovs.04-1369
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发表时间：
2006-07-01
影响因子：
4.4
通讯作者：
Maher, Pamela
中科院分区：
文献类型：
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作者：
Hanneken, Anne;Lin, Fen-Fen;Maher, Pamela
目的。目的：探讨膳食黄酮类化合物和合成黄酮类化合物对氧化应激诱导的视网膜色素上皮（RPE）细胞凋亡的保护作用。采用过氧化氢（H-2 - O-2）或过氧化氢t-丁基（t- BOOH）对人ARPE- 19细胞和人RPE原代细胞的存活率进行了研究。采用MTT法测定24 h后黄酮类化合物的有效浓度（EC (50)s）和毒性（LD (50)s）。在相同条件下比较维生素E和C对RPE细胞存活的影响。在细胞暴露于氧化应激后的不同时间间隔内，测定了特定类黄酮保护RPE细胞免于细胞死亡的能力。用二氯荧光素（DCF）荧光检测了黄酮类化合物阻断细胞内活性氧积累的能力。最后，通过免疫印迹法检测转录因子Nrf2和2期基因产物血红素加氧酶对黄酮类化合物2期解毒酶的诱导作用。特异性黄酮类化合物保护人RPE细胞免受氧化应激诱导的死亡，其效力在80%至100%之间，效力在高纳摩尔和低微摩尔范围内。多数有效黄酮类化合物毒性较低。有效黄酮类化合物包括膳食黄酮类化合物非西汀、木犀草素、槲皮素、戊二醇、黄芩素、高良姜素和EGCG，以及合成的3,6-二羟基黄酮醇和3,7 -二羟基黄酮醇。几种类黄酮可以保护RPE细胞，即使它们是在细胞暴露于氧化应激后添加的。黄酮类化合物通过细胞内途径阻止活性氧的积累。这些黄酮类化合物在人RPE细胞中诱导Nrf2和2期基因产物血红素加氧酶1的表达。结果确定了一组黄酮类化合物，保护RPE细胞免受氧化应激诱导的死亡，具有高度的效力和低毒性。许多黄酮类化合物还可诱导2期解毒蛋白的表达，该蛋白可提供额外的氧化应激保护。这组黄酮类化合物和含有高水平这些化合物的食物可能对患有与氧化应激相关的视网膜疾病的患者有一些临床益处。
PURPOSE. To determine whether specific dietary and synthetic flavonoids can protect human retinal pigment epithelial ( RPE) cells from oxidative- stress - induced death.METHODS. The efficacy and potency were determined of a variety of dietary and synthetic flavonoids on the survival of human ARPE- 19 cells and primary human RPE cells treated with either hydrogen peroxide ( H-2 O-2) or t- butyl hydroperoxide ( t- BOOH). We determined the effective concentrations ( EC (50)s) and the toxicities ( LD (50)s) of the flavonoids after 24 hours, by using the MTT assay. The efficacy of vitamins E and C on RPE cell survival were compared under identical conditions. The ability of specific flavonoids to protect RPE cells from cell death was determined at various time intervals after the cells were exposed to oxidative stress. The ability of flavonoids to block the accumulation of intracellular reactive oxygen species was examined with dichlorofluorescein ( DCF) fluorescence. Finally, the ability of flavonoids to induce phase- 2 detoxifying enzymes was tested by immunoblot analysis for the transcription factor Nrf2 and the phase- 2 gene product hemeoxygenase 1.RESULTS. Specific flavonoids protected human RPE cells from oxidative- stress - induced death with efficacies between 80% and 100% and potencies in the high- nanomolar and low- micromolar range. The toxicities of most of the effective flavonoids were low. The effective flavonoids included the dietary flavonoids fisetin, luteolin, quercetin, eriodictyol, baicalein, galangin and EGCG, and the synthetic flavonoids, 3,6- dihydroxy flavonol and 3,7 dihydroxy flavonol. Several flavonoids can protect RPE cells even when they are added after the cells have been exposed to oxidative stress. The flavonoids acted through an intracellular route to block the accumulation of reactive oxygen species. Many of these flavonoids induced the expression of Nrf2 and the phase- 2 gene product heme- oxygenase 1 in human RPE cells.CONCLUSIONS. The results identify a select group of flavonoids that protect RPE cells from oxidative- stress - induced death with a high degree of potency and low toxicity. Many of these flavonoids also induce the expression of phase- 2 detoxification proteins which could function to provide additional protection against oxidative stress. This select group of flavonoids and the foods that contain high levels of these compounds may have some clinical benefit for patients with retinal diseases associated with oxidative stress.