Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress. The aim of this study was to provide evidence of the protective effect of this extract on endothelial function by reducing oxidative stress induced by high d-glucose and H2O2, as well as by stimulating nitric oxide (NO) levels in human umbilical vein endothelial cells (HUVECs). A methanolic extract with a high content of polyphenols (520 ± 30 mg gallic acid equivalents/g dry extract) was obtained from G. tinctoria leaves. Its main constituent was ellagic acid. The results of Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays of the extract confirmed its antioxidant activity by inhibition pathway of radical species. The incubation of HUVECs with the extract decreased the apoptosis and reactive oxygen species (ROS) synthesis induced by high extracellular concentration of d-glucose or hydrogen peroxide. The extract increased endothelial NO levels and reduced vasoconstriction in human placental vessels. This study provides evidence about the antioxidant and endothelial protective properties of methanolic G. tinctoria leaf extract. The extract improves the availability of NO in HUVECs, inhibiting the production of ROS and vasoconstriction.

中文翻译：

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具有抗氧化性能的枪花提取物改善内皮功能

Mapuche-Pewenche人收集了Gunnera tinctoria，用作食品和药物。带有化学成分例如鞣花酸和槲皮素衍生物的丁香叶甲醇提取物的多酚含量高，表明其可用于预防内皮功能障碍和氧化应激。这项研究的目的是通过降低高d-葡萄糖和H2O2诱导的氧化应激以及刺激人脐静脉内皮细胞中的一氧化氮（NO）水平来提供这种提取物对内皮功能的保护作用的证据（ HUVEC）。从丁香叶中获得了多酚含量较高的甲醇提取物（520±30 mg没食子酸当量/ g干提取物）。其主要成分是鞣花酸。铁还原抗氧化能力和2的结果 提取物的2-二苯基-1-picylhydrazyl自由基清除试验证实了自由基种类的抑制途径具有抗氧化活性。HUVEC与提取物的孵育降低了细胞外高浓度的d-葡萄糖或过氧化氢诱导的细胞凋亡和活性氧（ROS）合成。提取物可增加人胎盘血管中的内皮一氧化氮水平并减少血管收缩。该研究提供了关于甲醇丁香叶提取物的抗氧化剂和内皮保护特性的证据。该提取物可提高HUVEC中NO的利用率，从而抑制ROS的产生和血管收缩。HUVEC与提取物的孵育降低了细胞外高浓度的d-葡萄糖或过氧化氢诱导的细胞凋亡和活性氧（ROS）合成。提取物可增加人胎盘血管中的内皮一氧化氮水平并减少血管收缩。该研究提供了关于甲醇丁香叶提取物的抗氧化剂和内皮保护特性的证据。该提取物可提高HUVEC中NO的利用率，从而抑制ROS的产生和血管收缩。HUVEC与提取物的孵育降低了细胞外高浓度的d-葡萄糖或过氧化氢诱导的细胞凋亡和活性氧（ROS）合成。提取物可增加人胎盘血管中的内皮一氧化氮水平并减少血管收缩。该研究提供了关于甲醇丁香叶提取物的抗氧化剂和内皮保护特性的证据。该提取物可提高HUVEC中NO的利用率，从而抑制ROS的产生和血管收缩。该研究提供了关于甲醇丁香叶提取物的抗氧化剂和内皮保护特性的证据。该提取物可提高HUVEC中NO的利用率，从而抑制ROS的产生和血管收缩。该研究提供了关于甲醇丁香叶提取物的抗氧化剂和内皮保护特性的证据。该提取物可提高HUVEC中NO的利用率，从而抑制ROS的产生和血管收缩。