title: Antioxidant effects of phlorotannins isolated from Ishige okamurae in free radical mediated oxidative systems.
abstract: Three phlorotannins, including phloroglucinol, diphlorethohydroxycarmalol, and 6,6'-bieckol, were isolated from Ishige okamurae by column chromatography. The structures of the phlorotannins were determined on the basis of spectroscopic analysis, including NMR and mass spectrometry (MS) techniques. Antioxidant effects of phlorotannins were measured by direct free radical scavenging activities using the electron spin resonance spectrometry (ESR) technique and cellular systems in vitro. The results indicated that diphlorethohydroxycarmalol and 6,6'-bieckol showed potential radical scavenging activities against the 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, alkyl, and superoxide radicals. Moreover, no cytotoxicities of the phlorotannins on human fetal lung fibroblasts cell line (MRC-5), mouse macrophages cell line (RAW264.7), and human leukemic cell line (HL-60) were observed. In addition, diphlorethohydroxycarmalol and 6,6'-bieckol significantly reduced the intracellular reactive oxygen species level assessed by 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay in RAW264.7 cells, and myeloperoxide (MPO) activity in HL-60 cells and radical-mediated oxidation of cell membrane proteins in RAW264.7 cells were dose-dependently inhibited in the presence of diphlorethohydroxycarmalol and 6,6'-bieckol. In conclusion, these results suggested that phlorotannins could be used as novel functional foodstuffs or antioxidants in the cosmetic and drug industries.
authors.affiliation: Marine Bioprocess Research Center, Pukyong National University, Busan 608-737, South Korea.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zou
authors.forename: Zhong-Ji
authors.initials: ZJ
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Moon-Moo
authors.initials: MM
authors.lastname: Kim
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Se-Kwon
authors.initials: SK
authors.lastname: Kim
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D004147:Dioxins / Q000302:isolation & purification / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D005347:Fibroblasts / Q000187:drug effects; D018922:HL-60 Cells; D006575:Heterocyclic Compounds, 3-Ring / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008264:Macrophages / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D000459:Phaeophyceae / Q000737:chemistry*; D010696:Phloroglucinol / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D004147:Dioxins; D006575:Heterocyclic Compounds, 3-Ring; C513811:diphlorethohydroxycarmalol; C062360:6,6'-bieckol; D010696:Phloroglucinol