Duthie S J, Johnson W, Dobson V L
Rowett Research Institute, Bucksburn, Aberdeen, UK.
Mutat Res. 1997 Apr 24;390(1-2):141-51. doi: 10.1016/s0165-1218(97)00010-4.
The effects of the flavonoids quercetin, myricetin and silymarin on DNA damage and cytotoxicity in human cells were investigated. DNA strand breaks and oxidised pyrimidines were determined using alkaline single cell gel electrophoresis (the comet assay). Inhibition of cell growth was also measured. Caco-2 (colon), HepG2 (liver), HeLa (epithelial) cells and normal human lymphocytes showed different, dose-dependent susceptibilities (in terms of strand breakage) to the various flavonoids, quercetin being the most damaging. This agreed well with the ability of the flavonoids to inhibit cell growth. None of the flavonoids induced DNA base oxidation above background levels. All of the flavonoids under investigation caused depletion of reduced glutathione, which, in the case of quercetin, occurred prior to cell death. Neither cytotoxicity nor genotoxicity was associated with the antioxidant enzyme capacity (glutathione, glutathione reductase, glutathione peroxidase and catalase) of the cells.
研究了黄酮类化合物槲皮素、杨梅素和水飞蓟宾对人细胞DNA损伤和细胞毒性的影响。使用碱性单细胞凝胶电泳（彗星试验）测定DNA链断裂和氧化嘧啶。还测量了细胞生长抑制情况。Caco-2（结肠）、HepG2（肝脏）、HeLa（上皮）细胞和正常人淋巴细胞对各种黄酮类化合物表现出不同的剂量依赖性敏感性（就链断裂而言），槲皮素的损伤最大。这与黄酮类化合物抑制细胞生长的能力非常吻合。没有一种黄酮类化合物诱导的DNA碱基氧化超过背景水平。所有研究的黄酮类化合物都会导致还原型谷胱甘肽耗竭，就槲皮素而言，这发生在细胞死亡之前。细胞毒性和遗传毒性均与细胞的抗氧化酶能力（谷胱甘肽（GSH）、谷胱甘肽还原酶、谷胱甘肽过氧化物酶和过氧化氢酶）无关。
