Zbikowska Halina Malgorzata, Antosik Adam, Szejk Magdalena, Bijak Michal, Olejnik Alicja Klaudia, Saluk Joanna, Nowak Paweł
Redox Rep. 2014 Mar;19(2):65-71. doi: 10.1179/1351000213Y.0000000074. Epub 2013 Nov 20.
Radioprotective potential of quercetin, a powerful free radical scavenger, was investigated in human red blood cells (RBCs) and in isolated RBC membranes exposed to γ-irradiation-induced oxidative stress.
RBCs and RBC membrane suspensions were irradiated (50 Gy) in the presence of quercetin (2-50 µM). Oxidative damage of the membranes was analysed by protein carbonyl measurement (enzyme-linked immunosorbent assay). In RBCs, the concentration of glutathione (GSH) was determined. Lipid peroxidation in RBCs, and for comparison in plasma and peripheral lymphocytes, was quantified by the amount of thiobarbituric acid-reactive substances (TBARS). Radiation-induced damage of the RBC membrane integrity was evaluated by the degree of haemolysis.
Quercetin (50 µM) brought back the level of carbonyls to normal in γ-irradiated RBC membrane proteins and inhibited radiation-induced lipid peroxidation in plasma and lymphocytes, by 75 and 96%, respectively. However, it moderately decreased reduced/oxidized glutathione (GSH/GSSG) ratio and significantly increased TBARS concentrations, by 60 and 28% in irradiated and non-irradiated RBCs, respectively. Haemolysis rate was much higher in RBCs irradiated in the presence of quercetin vs. non antioxidant.
In non-cellular systems (RBC membranes or plasma) and in lymphocytes, quercetin shows antioxidative/radioprotective activity but in whole RBCs it acts as a pro-oxidant and a cytotoxic substance. The possible mechanisms of such action are discussed.
研究强大的自由基清除剂槲皮素对人红细胞（RBC）以及暴露于γ射线诱导的氧化应激下的离体红细胞膜的辐射防护潜力。
在槲皮素（2 - 50 μM）存在的情况下，对红细胞和红细胞膜悬液进行照射（50 Gy）。通过蛋白质羰基测量（酶联免疫吸附测定）分析膜的氧化损伤。在红细胞中，测定谷胱甘肽（GSH）的浓度。通过硫代巴比妥酸反应性物质（TBARS）的量对红细胞中的脂质过氧化进行定量，并与血浆和外周淋巴细胞中的脂质过氧化进行比较。通过溶血程度评估辐射诱导的红细胞膜完整性损伤。
槲皮素（50 μM）使γ射线照射的红细胞膜蛋白中的羰基水平恢复正常，并分别抑制血浆和淋巴细胞中辐射诱导的脂质过氧化75%和96%。然而，它适度降低了还原型/氧化型谷胱甘肽（GSH/GSSG）比值，并分别使照射和未照射的红细胞中的TBARS浓度显著增加60%和28%。与未添加抗氧化剂相比，在槲皮素存在下照射的红细胞的溶血率要高得多。
在非细胞系统（红细胞膜或血浆）和淋巴细胞中，槲皮素表现出抗氧化/辐射防护活性，但在完整的红细胞中，它作为促氧化剂和细胞毒性物质起作用。讨论了这种作用的可能机制。
