Growth suppression of human cancer cells by polyphenolics from sweetpotato (Ipomoea batatas L.) leaves.
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.
Kurata
Rie
R
Department of Upland Farming Research, National Agricultural Research Center for Kyushu Okinawa Region, Yokoichi 6651-2, Miyakonojo, Miyazaki 885-0091, Japan. rkurata@affrc.go.jp
Adachi
Masaru
M
Yamakawa
Osamu
O
Yoshimoto
Makoto
M
D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms; D005419:Flavonoids / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D027723:Ipomoea batatas / Q000737:chemistry*; D009369:Neoplasms / Q000473:pathology*; D010636:Phenols / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms
D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols