Kostyuk V A, Potapovich A I
Laboratory of Bioenergetics, Byelorussian State University, Scorina St. 4, Minsk, 220050, Belarus.
Arch Biochem Biophys. 1998 Jul 1;355(1):43-8. doi: 10.1006/abbi.1998.0708.
Quercetin, dihydroquercetin, and rutin are capable of scavenging superoxide anion (rate constants of the reaction with superoxide at pH 10 were 1.7 x 10(5), 1.5 x 10(5), and 0.5 x 10(5) M-1 s-1, respectively). At the same time rutin and quercetin but not dihydroquercetin are iron ion chelators. These substances were used to elucidate the role of radical scavenging and iron chelating in flavonoid protection against asbestos-induced oxidative cellular injury. Exposure of rat peritoneal macrophages to chrysotile asbestos fibers resulted in "frustrated" phagocytosis, cell injury, and a LDH release. Quercetin, dihydroquercetin, and rutin were effective in protecting the phagocytic cells against injury caused by asbestos. Moreover, these flavonoids exhibited cellular protection in the same order of effectiveness as that observed for the quenching of superoxide: quercetin > dihydroquercetin > rutin. Exposure of human red blood cells to asbestos fibers also caused progressive cell injury and lysis. Quercetin and rutin protected the red cells (quercetin > rutin), whereas dihydroquercetin was ineffective in preventing asbestos-induced hemolysis. The protective ability of quercetin and rutin may be related to their iron-chelating activity. Due to this these flavonoids can be located on asbestos surface in sites of initiation of free radical reactions and their antiradical moieties can scavenge reactive oxygen species immediately after the appearance. Thus, both antiradical and chelating effects appear to be involved in the flavonoid protection against silica-induced cell injury.
槲皮素、二氢槲皮素和芦丁能够清除超氧阴离子（在pH 10时与超氧反应的速率常数分别为1.7×10⁵、1.5×10⁵和0.5×10⁵ M⁻¹ s⁻¹）。同时，芦丁和槲皮素是铁离子螯合剂，而二氢槲皮素不是。这些物质被用于阐明自由基清除和铁螯合在黄酮类化合物保护细胞免受石棉诱导的氧化损伤中的作用。将大鼠腹膜巨噬细胞暴露于温石棉纤维会导致“受挫”吞噬作用、细胞损伤和乳酸脱氢酶释放。槲皮素、二氢槲皮素和芦丁能有效保护吞噬细胞免受石棉引起的损伤。此外，这些黄酮类化合物表现出的细胞保护作用的有效性顺序与超氧淬灭的顺序相同：槲皮素＞二氢槲皮素＞芦丁。将人类红细胞暴露于石棉纤维也会导致细胞逐渐损伤和裂解。槲皮素和芦丁能保护红细胞（槲皮素＞芦丁），而二氢槲皮素在预防石棉诱导的溶血方面无效。槲皮素和芦丁的保护能力可能与其铁螯合活性有关。因此，这些黄酮类化合物可以位于自由基反应起始部位的石棉表面，其抗自由基部分在活性氧出现后能立即清除它们。因此，抗自由基和螯合作用似乎都参与了黄酮类化合物对二氧化硅诱导的细胞损伤的保护作用。
