Isolation and Identification of Phlorotannins from Ecklonia stolonifera with Antioxidant and Hepatoprotective Properties in Tacrine-Treated HepG2 Cells
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- 作者：Min-Sup Lee ; Taisun Shin ; Tadanobu Utsuki ; Jae-Sue Choi ; Dae-Seok Byun ; Hyeung-Rak Kim
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：May 30, 2012
- 年：2012
- 卷：60
- 期：21
- 页码：5340-5349
- 全文大小：482K
- 年卷期：v.60,no.21(May 30, 2012)
- ISSN：1520-5118
文摘
Four kinds of phlorotannins having antioxidant activity were isolated from the ethyl acetate fraction of Ecklonia stolonifera ethanolic extract. The structures of the phlorotannins were determined on the basis of spectroscopic evidence, including 1D and 2D nuclear magnetic resonance. The isolated phlorotannins showed potential radical-scavenging activities against 2,2-diphenyl-1-picrylhydrazyl and suppressed the intracellular reactive oxygen species in tacrine-treated HepG2 cells. Among them, eckol and 2-phloroeckol showed hepatoprotective activity in tacrine-treated HepG2 cells; however, phlorofucofuroeckol B and 6,6鈥?bieckol did not show the activity, even though having high antioxidant activity. Both eckol and 2-phloroeckol inhibited the expression of Fas-mediated cell-death proteins, including tBid, caspase-3, and poly(ADP-ribose) polymerase, and suppressed the release of cytochrome c from mitochondria to cytosol in a dose-dependent manner in tacrine-treated HepG2 cells. These results suggest that eckol and 2-phloroeckol are the principal hepatoprotective constituents of the ethyl acetate fraction of E. stolonifera ethanolic extract.