Devienne Karina F, Cálgaro-Helena Anaísa F, Dorta Daniel J, Prado Ieda M R, Raddi Maria Stella G, Vilegas Wagner, Uyemura Sérgio A, Santos Antonio C, Curti Carlos
Instituto de Química de Araraquara, Universidade Estadual Paulista, Araraquara, SP, Brazil.
Phytochemistry. 2007 Apr;68(7):1075-80. doi: 10.1016/j.phytochem.2007.01.014. Epub 2007 Mar 6.
The isocoumarins (1-50 microM) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8'-paepalantine dimer, and vioxanthin isolated from Paepalanthus bromelioides, were assessed for antioxidant activity using isolated rat liver mitochondria and non-mitochondrial systems, and compared with the flavonoid quercetin. The paepalantine and paepalantine dimers, but not vioxanthin, were effective at scavenging both 1,1-diphenyl-2-picrylhydrazyl (DPPH(*)) and superoxide (O(2)(-)) radicals in non-mitochondrial systems, and protected mitochondria from tert-butylhydroperoxide-induced H(2)O(2) accumulation and Fe(2+)-citrate-mediated mitochondrial membrane lipid peroxidation, with almost the same potency as quercetin. These results point towards paepalantine, followed by paepalantine dimer, as being a powerful agent affording protection, apparently via O(2)(-) scavenging, from oxidative stress conditions imposed on mitochondria, the main intracellular source and target of those reactive oxygen species. This strong antioxidant action of paepalantine was reproduced in HepG2 cells exposed to oxidative stress condition induced by H(2)O(2).
从凤梨叶花烛（Paepalanthus bromelioides）中分离出的异香豆素（1 - 50微摩尔）：巴西花烛碱（9,10 - 二羟基 - 5,7 - 二甲氧基 - 1H - 萘并(2,3 - c)吡喃 - 1 - 酮）、8,8'-巴西花烛碱二聚体和紫黄质，使用分离的大鼠肝线粒体和非线粒体系统评估其抗氧化活性，并与类黄酮槲皮素进行比较。在非线粒体系统中，巴西花烛碱和巴西花烛碱二聚体（而非紫黄质）能够有效清除1,1 - 二苯基 - 2 - 苦基肼自由基（DPPH(*)）和超氧阴离子自由基（O(2)(-)），并保护线粒体免受叔丁基过氧化氢诱导的H(2)O(2)积累以及柠檬酸亚铁介导的线粒体膜脂质过氧化作用的影响，其效力与槲皮素几乎相同。这些结果表明，巴西花烛碱及其二聚体是一种强大的保护剂，显然是通过清除O(2)(-)，保护线粒体免受氧化应激条件的影响，而线粒体是细胞内活性氧的主要来源和靶点。巴西花烛碱的这种强大抗氧化作用在暴露于H(2)O(2)诱导的氧化应激条件下的HepG2细胞中得到了重现。
