Arumugam Bavani, Palanisamy Uma Devi, Chua Kek Heng, Kuppusamy Umah Rani
Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway, Selangor, Malaysia.
Mol Vis. 2019 Feb 7;25:47-59. eCollection 2019.
Oxidative stress is implicated in the etiology of diabetes and its debilitating complications, such as diabetic retinopathy (DR). Various flavonoids have been reported to be useful in reducing DR progression. Myricetin derivatives (F2) isolated from leaf extract of have the potential to serve as functional food as reported previously. The present study was performed with the aim of determining the antioxidant potential and protective effect of myricetin derivatives (F2) isolated from leaf extract of against glucose oxidase (GO)-induced hydrogen peroxide (HO) production that causes oxidative stress in ARPE-19 (RPE) cells.
Antioxidant properties were assessed through various radical (DPPH, ABTS, and nitric oxide) scavenging assays and determination of total phenolic content and ferric reducing antioxidant power level. ARPE-19 cells were preincubated with samples before the addition of GO (to generate HO). Cell viability, change in intracellular reactive oxygen species (ROS), HO levels in cell culture supernatant, and gene expression were assessed.
F2 showed higher antioxidant levels than the extract when assessed for radical scavenging activities and ferric reducing antioxidant power. F2 protected the ARPE-19 cells against GO-HO-induced oxidative stress by reducing the production of HO and intracellular reactive oxygen species. This was achieved by the activation of nuclear factor erythroid 2-related factor 2 (Nrf2/) and superoxide dismutase (), as well as downregulation of nitric oxide producer () at the transcriptional level.
The results showed that myricetin derivatives from have the capacity to exert considerable exogenous antioxidant activities and stimulate endogenous antioxidant activities. Therefore, these derivatives have excellent potential to be developed as therapeutic agents for managing DR.
氧化应激与糖尿病及其使人衰弱的并发症（如糖尿病视网膜病变，DR）的病因有关。据报道，多种类黄酮有助于减缓DR的进展。如先前报道，从[植物名称]叶提取物中分离出的杨梅素衍生物（F2）有潜力作为功能性食品。本研究旨在确定从[植物名称]叶提取物中分离出的杨梅素衍生物（F2）对葡萄糖氧化酶（GO）诱导的过氧化氢（HO）生成的抗氧化潜力和保护作用，GO诱导的HO生成会在ARPE - 19（视网膜色素上皮，RPE）细胞中引起氧化应激。
通过各种自由基（DPPH、ABTS和一氧化氮）清除试验以及总酚含量和铁还原抗氧化能力水平的测定来评估抗氧化性能。在添加GO（以生成HO）之前，将ARPE - 19细胞与样品预孵育。评估细胞活力、细胞内活性氧（ROS）的变化、细胞培养上清液中的HO水平以及基因表达。
在评估自由基清除活性和铁还原抗氧化能力时，F2显示出比提取物更高的抗氧化水平。F2通过减少HO和细胞内活性氧的产生，保护ARPE - 19细胞免受GO - HO诱导的氧化应激。这是通过在转录水平激活核因子红细胞2相关因子2（Nrf2/）和超氧化物歧化酶（），以及下调一氧化氮产生酶（）来实现的。
结果表明，来自[植物名称]的杨梅素衍生物具有发挥相当大的外源性抗氧化活性和刺激内源性抗氧化活性的能力。因此，这些衍生物具有作为治疗DR的治疗剂开发的巨大潜力。
