Reactive oxygen species flavonoids

CANADA A T, GiANNiLLA E, NGUYEN J D and MASON R p (1990) The production of reactive oxygen species by dietary flavonoids, Free Rad Biol Med, 9, 441-9. 

Colquhoun and Schumacher [98] have shown that y-linolcnic acid and eicosapentaenoic acid, which inhibit Walker tumor growth in vivo, decreased proliferation and apoptotic index in these cells. Development of apoptosis was characterized by the enhancement of the formation of reactive oxygen species and products of lipid peroxidation and was accompanied by a decrease in the activities of mitochondrial complexes I, III, and IV, and the release of cytochrome c and caspase 3-like activation of DNA fragmentation. Earlier, a similar apoptotic mechanism of antitumor activity has been shown for the flavonoid quercetin [99], Kamp et al. [100] suggested that the asbestos-induced apoptosis in alveolar epithelial cells was mediated by iron-derived oxygen species, although authors did not hypothesize about the nature of these species (hydroxyl radicals, hydrogen peroxide, or iron complexes ). 

Galati, G. et al., Glutathione-dependent generation of reactive oxygen species by the peroxidase-catalysed redox cycling of flavonoids, Chem. Res. Toxicol., 12, 521, 1999. 

In addition to measuring the antioxidant effects of prenylated flavonoids from Sophora flavescens by using in vitro l,l-diphenyl-2-picrylhydrazyl (DPPH), 2,2/-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), per-oxynitrite (ONOCT), and total reactive oxygen species (ROS) assays, the examination of the inhibition of tert-butylhydroperoxide (f-BIIP)-induced intracellular ROS generation and f-BHP-induced activation of nuclear factor-kB (NF-/cB) was also added as a further examination of kuraridinol (9),... 

Oxidative cellular damage by reactive oxygen species such as superoxide anion, hydroperoxy and hyassociated with various human chronic diseases, e.g. cancers, inflammation, arthritis, atherosclerosis and also with the process of ageing. Claims that diet and increased intake of nutrients exhibiting antioxidative activity have a preventative effect on chronic diseases have increased in recent years. In this context, polyphenolic compounds such as tannins, flavonoids, coumarins, lignans and caffeic acid derivatives, which are abundantly contained in a large number of medicinal plants, foods and beverages, are of particular interest for human health care because of the antioxidative properties widely found in plant phenolics. The antioxidative activity of tannins has been extensively studied in various in vitro and in vivo experimental systems and summarized in reviews [96, 97]. Such activity includes the inhibition of lipid peroxidation induced by NADPH-ADP and ascorbic acid-ADP in rat liver microsomes and mitochondria, respectively... 

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