Università degli Studi di Roma "Foro Italico", Department of Movement, Human and Health Sciences, Unit of Biology, Genetics and Biochemistry, Rome, Italy.
Università degli Studi di Roma "Foro Italico", Department of Movement, Human and Health Sciences, Unit of Biology, Genetics and Biochemistry, Rome, Italy.
Nutr Res. 2018 Feb;50:73-81. doi: 10.1016/j.nutres.2017.12.002. Epub 2017 Dec 14.
The polyphenolic flavonoid quercetin has been shown to be a powerful antioxidant, in vitro and in murine models. However, its effect on redox status has been poorly examined in humans, particularly in combination with strenuous exercise. We hypothesized that quercetin supplementation would beneficially affect redox homeostasis in healthy individuals undergoing eccentric exercise. To test this hypothesis, the effects of chronic consumption of quercetin on glutathione system (reduced, oxidized, and reduced to oxidized glutathione ratio), oxidative damage [thiobarbituric acid reactive substances (TBARs)], antioxidant enzymatic network (catalase, glutathione peroxidase, superoxide dismutase) and resistance to lysis, were investigated in erythrocytes, a traditional model widely used to study the effects of oxidative stress as well as the protective effects of antioxidants. In a two weeks controlled, randomized, crossover, intervention trial, 14 individuals ingested 2 caps (1 g/d) of quercetin or placebo. Blood samples were collected before, after 2 weeks of supplementation and after a bout of eccentric exercise. Quercetin, reduced significantly erythrocytes lipid peroxidation levels and the susceptibility to hemolysis induced by the free radical generator AAPH, while no differences in antioxidant enzyme activities and glutathione homeostasis were found between the two groups. After a single bout of eccentric exercise, quercetin supplementation improved redox status as assessed by reduced/oxidized glutathione ratio analysis and reduced TBARs levels both in erythrocytes and plasma. In conclusion, our study provides evidences that chronic quercetin supplementation has antioxidant potential prior to and after a strenuous eccentric exercise thus making the erythrocytes capable to better cope with an oxidative insult.
类黄酮多酚槲皮素已被证明具有强大的抗氧化作用，无论是在体外实验还是在鼠类模型中。然而，其对人类氧化还原状态的影响在很大程度上仍未得到研究，特别是在与剧烈运动相结合的情况下。我们假设，槲皮素补充剂将有益于接受离心运动的健康个体的氧化还原稳态。为了验证这一假设，我们研究了慢性摄入槲皮素对谷胱甘肽系统（还原型、氧化型和还原型对氧化型谷胱甘肽的比例）、氧化损伤[硫代巴比妥酸反应物质（TBARS）]、抗氧化酶网络（过氧化氢酶、谷胱甘肽过氧化物酶、超氧化物歧化酶）和红细胞溶血抗性的影响，红细胞是一种广泛用于研究氧化应激以及抗氧化剂保护作用的传统模型。在一项为期两周的对照、随机、交叉、干预试验中，14 名个体摄入 2 粒（1 克/天）槲皮素或安慰剂。在补充前、补充 2 周后和一次离心运动后采集血样。槲皮素可显著降低红细胞脂质过氧化水平和自由基生成剂 AAPH 诱导的溶血敏感性，而两组间抗氧化酶活性和谷胱甘肽稳态无差异。单次离心运动后，槲皮素补充可改善氧化还原状态，这可通过还原/氧化型谷胱甘肽比分析和降低红细胞和血浆中的 TBARS 水平来评估。总之，我们的研究提供了证据表明，慢性槲皮素补充在剧烈离心运动前后具有抗氧化潜力，从而使红细胞能够更好地应对氧化应激。
