Coumarins comprise a group of natural phenolic compounds found in a variety of plant sources. In view of the established low toxicity, relative cheapness, presence in the diet and occurrence in various herbal remedies of coumarins, it appears prudent to evaluate their properties and applications further. The purpose of this study is to investigate cellular protective activity of coumarin compound, fraxin extracted from Weigela florida var. glabbra, under oxidative stress, to identify genes expressed differentially by fraxin and to compare antioxidative effect of fraxin with its structurally related chemicals. Of the coumarins, protective effects of fraxin against cytotoxicity induced by H2O2 were examined in human umbilical vein endothelial cells (HUVECs). Fraxin showed free radical scavenging effect at high concentration (0.5 mM) and cell protective effect against H2O2-mediated oxidative stress. Fraxin recovered viability of HUVECs damaged by H2O2-treatment and reduced the lipid peroxidation and the internal reactive oxygen species level elevated by H2O2 treatment. Differential display reverse transcription-PCR revealed that fraxin upregulated antiapoptotic genes (clusterin and apoptosis inhibitor 5) and tumor suppressor gene (ST13). Based on structural similarity comparing with fraxin, seven chemicals, fraxidin methyl ether (29.4% enhancement of viability), prenyletin (26.4%), methoxsalen (20.8%), diffratic acid (19.9%), rutoside (19.1%), xanthyletin (18.4%), and kuhlmannin (18.2%), enhanced more potent cell viability in the order in comparison with fraxin, which showed only 9.3% enhancement of cell viability. These results suggest that fraxin and fraxin-related chemicals protect HUVECs from oxidative stress.

中文翻译：

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天然化合物，fraxin和与fraxin结构相关的化学物质可保护细胞免受氧化应激。

香豆素包含在多种植物来源中发现的一组天然酚类化合物。鉴于已确定的低毒性，相对便宜，在饮食中存在和存在于香豆素的各种草药中，谨慎地评估其性质和应用似乎是谨慎的。这项研究的目的是研究香豆素类化合物（从魏氏佛罗里达州变种中提取的六恶英）的细胞保护活性。在氧化应激条件下，文盲鉴定出fraxin差异表达的基因，并比较fraxin及其结构相关化学物质的抗氧化作用。在香豆素中，在人的脐静脉内皮细胞（HUVEC）中检测到了六恶英对过氧化氢诱导的细胞毒性的保护作用。Fraxin在高浓度下显示出清除自由基的作用（0。5 mM）和对H2O2介导的氧化应激的细胞保护作用。Fraxin恢复了被H2O2处理损坏的HUVEC的活力，并减少了脂质过氧化作用和H2O2处理所提高的内部活性氧水平。差异显示逆转录-PCR显示，fraxin上调抗凋亡基因（簇蛋白和凋亡抑制剂5）和肿瘤抑制基因（ST13）。根据与fraxin的结构相似性，使用7种化学物质，fraxidin甲醚（提高29.4％的活力），prenyletin（26.4％），methoxsalen（20.8％），diffratic acid（19.9％），rutoside（19.1％），xanthyletin（18.4） ％）和kuhlmannin（18.2％）与fraxin相比，顺序增强了更有效的细胞活力，而fraxin仅显示9.3％的细胞活力增强。