Kurata Rie, Adachi Masaru, Yamakawa Osamu, Yoshimoto Makoto
Department of Upland Farming Research, National Agricultural Research Center for Kyushu Okinawa Region, Yokoichi 6651-2, Miyakonojo, Miyazaki 885-0091, Japan.
J Agric Food Chem. 2007 Jan 10;55(1):185-90. doi: 10.1021/jf0620259.
Sweetpotato leaves (Ipomoea batatas L.) contain a high content of polyphenolics that consist of caffeic acid, chlorogenic acid, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, and 3,4,5-tri-O-caffeoylquinic acid. We investigated the suppression of the proliferation of selected human cancer cells by phenolic compounds isolated from sweetpotato leaf. The human cancer cells used in this research included a stomach cancer (Kato III), a colon cancer (DLD-1), and a promyelocytic leukemia cell (HL-60). Caffeic acid and di- and tricaffeoylquinic acids dose-dependently depressed cancer cell proliferation, and the difference in sensitivity between caffeoylquinic acid derivatives and each kind of cancer cell was observed. Specifically, 3,4,5-tri-O-caffeoylquinic acid effectively depressed the growth of three kinds of cancer cells, and caffeic acid had an exceptionally higher effect against HL-60 cells than other di- and tricaffeoylquinic acids. In attempting to clarify the mechanism of growth suppression with the addition of the apoptotic inhibitor N-ethylmaleimide, we observed that the nuclear granulation in 3,4,5-tri-O-caffeoylquinic acid-treated HL-60 cells suggested apoptosis induction. This effect was confirmed by DNA fragmentation, an increase of caspase-3 activity, and expression of c-Jun. Growth suppression of HL-60 cells by 3,4,5-tri-O-caffeoylquinic acid was determined to be the result of apoptotic death of the cells. These results indicate that 3,4,5-tri-O-caffeoylquinic acid may have potential for cancer prevention.
甘薯叶（Ipomoea batatas L.）含有高含量的多酚类物质，包括咖啡酸、绿原酸、3,4 - 二 - O - 咖啡酰奎尼酸、3,5 - 二 - O - 咖啡酰奎尼酸、4,5 - 二 - O - 咖啡酰奎尼酸和3,4,5 - 三 - O - 咖啡酰奎尼酸。我们研究了从甘薯叶中分离出的酚类化合物对所选人类癌细胞增殖的抑制作用。本研究中使用的人类癌细胞包括胃癌细胞（Kato III）、结肠癌细胞（DLD - 1）和早幼粒细胞白血病细胞（HL - 60）。咖啡酸以及二咖啡酰奎尼酸和三咖啡酰奎尼酸均呈剂量依赖性地抑制癌细胞增殖，并且观察到咖啡酰奎尼酸衍生物与每种癌细胞之间的敏感性差异。具体而言，3,4,5 - 三 - O - 咖啡酰奎尼酸有效地抑制了三种癌细胞的生长，并且咖啡酸对HL - 60细胞的作用比对其他二咖啡酰奎尼酸和三咖啡酰奎尼酸的作用格外高。在尝试通过添加凋亡抑制剂N - 乙基马来酰亚胺来阐明生长抑制机制时，我们观察到经3,4,5 - 三 - O - 咖啡酰奎尼酸处理的HL - 60细胞中的核颗粒化表明诱导了凋亡。通过DNA片段化、caspase - 3活性增加和c - Jun表达证实了这种作用。确定3,4,5 - 三 - O - 咖啡酰奎尼酸对HL - 60细胞的生长抑制是细胞凋亡死亡的结果。这些结果表明3,4,5 - 三 - O - 咖啡酰奎尼酸可能具有癌症预防潜力。
