Yoshioka Yasukiyo, Li Xiu, Zhang Tianshun, Mitani Takakazu, Yasuda Michiko, Nanba Fumio, Toda Toshiya, Yamashita Yoko, Ashida Hitoshi
Organization of Advanced Science and Technology, Kobe University, Kobe, Hyogo 657-8501, Japan.
Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan.
J Clin Biochem Nutr. 2017 Mar;60(2):108-114. doi: 10.3164/jcbn.16-48. Epub 2016 Dec 6.
Black soybean seed coat extract (BE), which contains abundant polyphenols such as procyanidins, cyanidin 3-glucoside, (+)-catechin, and (-)-epicatechin, has been reported on health beneficial functions such as antioxidant activity, anti-inflammatory, anti-obesity, and anti-diabetic activities. In this study, we investigated that prevention of BE and its polyphenols on 2,2'-azobis(2-methylpropionamide) dihydrochloride (AAPH)-induced oxidative DNA damage, and found that these polyphenols inhibited AAPH-induced formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for oxidative DNA damage in HepG2 cells. Under the same conditions, these polyphenols also inhibited AAPH-induced accumulation of reactive oxygen species (ROS) in the cells. Inhibition of ROS accumulation was observed in both cytosol and nucleus. It was confirmed that these polyphenols inhibited formation of AAPH radical using oxygen radical absorbance capacity assay under the cell-free conditions. These results indicate that polyphenols in BE inhibit free radical-induced oxidative DNA damages by their potent antioxidant activity. Thus, BE is an effective food material for prevention of oxidative stress and oxidative DNA damages.
黑豆种皮提取物（BE）含有丰富的多酚类物质，如原花青素、花青素3 - 葡萄糖苷、（+）-儿茶素和（-）-表儿茶素，据报道具有抗氧化、抗炎、抗肥胖和抗糖尿病等有益健康的功能。在本研究中，我们研究了BE及其多酚类物质对2,2'-偶氮二异丁脒二盐酸盐（AAPH）诱导的氧化性DNA损伤的预防作用，发现这些多酚类物质抑制了AAPH诱导的8 - 羟基-2'-脱氧鸟苷（8-OHdG）的形成，8-OHdG是HepG2细胞中氧化性DNA损伤的生物标志物。在相同条件下，这些多酚类物质还抑制了AAPH诱导的细胞内活性氧（ROS）的积累。在细胞质和细胞核中均观察到ROS积累的抑制。通过无细胞条件下的氧自由基吸收能力测定证实，这些多酚类物质抑制了AAPH自由基的形成。这些结果表明，BE中的多酚类物质通过其强大的抗氧化活性抑制自由基诱导的氧化性DNA损伤。因此，BE是预防氧化应激和氧化性DNA损伤的有效食品原料。
