Møller Peter, Loft Steffen, Alfthan Georg, Freese Riitta
Institute of Public Health, c/o Department of Pharmacology, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
Mutat Res. 2004 Jul 13;551(1-2):119-26. doi: 10.1016/j.mrfmmm.2004.02.020.
Berry extracts possess antioxidant activity in cell free systems, whereas cell culture and animal experimental systems have produced mixed outcomes. Our aim was to investigate the effects of blackcurrant juice and specifically blackcurrant anthocyanins on the steady state level of oxidative DNA damage in mononuclear blood cells (MNBC) of humans, determined as strand breaks (SB) as well as endonuclease III (Endo III) and formamidopyrimidine DNA glycosylase (Fpg) sensitive sites by the comet assay. Fifty-seven healthy humans completed a 3-week controlled parallel intervention study with three groups randomized to supplementation with blackcurrant juice, anthocyanin drink, or a control drink. The daily doses ranged from 475 to 1000ml/d according to body weight (mean anthocyanin intakes in blackcurrant juice and anthocyanin drink groups were 397 and 365g/d, respectively) and they were ingested during three daily meals while all volunteers were on the same strictly controlled low-flavonoid diet. Fasting venous blood samples were obtained at baseline and after 3-week of supplementation. The baseline level of oxidative DNA damage was low (e.g. less than 200 Fpg lesions per diploid cell). Fpg sensitive sites increased during the intervention within the blackcurrant juice group, whereas there were no differences between treatments in any of the DNA damage markers. In conclusion, this study shows that even large amounts of dietary antioxidants did not decrease the already low steady state levels of oxidative DNA damage in healthy adequately nourished humans.
浆果提取物在无细胞体系中具有抗氧化活性，而细胞培养和动物实验体系的结果则喜忧参半。我们的目的是研究黑加仑汁，特别是黑加仑花青素对人类单核血细胞（MNBC）中氧化性DNA损伤稳态水平的影响，通过彗星试验将其确定为链断裂（SB）以及对核酸内切酶III（Endo III）和甲酰胺嘧啶DNA糖基化酶（Fpg）敏感的位点。57名健康人完成了一项为期3周的对照平行干预研究，三组被随机分配补充黑加仑汁、花青素饮料或对照饮料。根据体重，每日剂量范围为475至1000毫升/天（黑加仑汁组和花青素饮料组的平均花青素摄入量分别为397和365微克/天），并且在一日三餐时饮用，同时所有志愿者都采用相同的严格控制的低黄酮类饮食。在基线时和补充3周后采集空腹静脉血样本。氧化性DNA损伤的基线水平较低（例如，每个二倍体细胞中少于200个Fpg损伤）。在干预期间，黑加仑汁组中的Fpg敏感位点增加，而在任何DNA损伤标志物方面，各治疗组之间没有差异。总之，本研究表明，即使大量摄入膳食抗氧化剂，也不会降低健康且营养充足的人体内已经很低的氧化性DNA损伤稳态水平。
