title: The coantioxidative effects of carboxyethyl-6-hydroxychromans and alpha-Tocopherol.
abstract: alpha-Tocopherol (alpha-Toc) is abundant in LDL and thought to prevent the oxidation of LDL together with various water-soluble antioxidants. Recently, it was reported that alpha-Toc and gamma-Toc metabolites, alpha-carboxyethyl-6-hydroxychromans (CEHC) and gamma-CEHC, are water-soluble antioxidants. In this study, we investigated the interaction between alpha-Toc and CEHC against 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and LDL oxidation. We administered 600 mg of alpha-Toc to healthy male volunteers to obtain LDL including high levels of alpha-Toc before antioxidant administration. The alpha-Toc content of their LDL was increased after consumption at 24 h (18.3 microg/mL) above the level before consumption (6.6 microg/mL). The lag time of LDL at 24 h after alpha-Toc consumption (alpha-Toc rich LDL) with alpha-CEHC (98.5+/-8.2 min) or gamma-CEHC (101.3+/-9.0 min) was longer than that of only alpha-Toc-rich LDL (78.1+/-9.0 min). Furthermore, we examined the interaction of LDL with CEHC and alpha-Toc in vitro (5-20 microg/mL). The lag times of 5 and 10 microg/mL alpha-Toc were 65.5+/-18.9 min and 69.5+/-15.5 min, and that of 20 microg/mL alpha-Toc (83.5+/-20.2 min) was longer than the control value (55.7+/-14.1 min). The lag time of 20 microg/mL alpha-Toc with alpha-CEHC (98.7+/-25.7 min) or gamma-CEHC (100.6+/-25.3 min) was longer than that of only alpha-Toc (83.5+/-20.2 min). These results suggest that CEHC has the potential to delay the oxidation of LDL, while enhancing the antioxidative activity of alpha-Toc both in vitro and ex vivo.
authors.affiliation: Institute of Environmental Science for Human Life, Ochanomizu University, Tokyo 112-8610, Japan.
authors.forename: Harumi
authors.initials: H
authors.lastname: Uto-Kondo
authors.forename: Chikako
authors.initials: C
authors.lastname: Kiyose
authors.forename: Reiko
authors.initials: R
authors.lastname: Ohmori
authors.forename: Hisako
authors.initials: H
authors.lastname: Saito
authors.forename: Chie
authors.initials: C
authors.lastname: Taguchi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kishimoto
authors.forename: Naoko
authors.initials: N
authors.lastname: Machida
authors.forename: Maiko
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Eri
authors.initials: E
authors.lastname: Yoshioka
authors.forename: Emi
authors.initials: E
authors.lastname: Saita
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Hirata
authors.forename: Osamu
authors.initials: O
authors.lastname: Igarashi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kondo
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D002839:Chromans / Q000737:chemistry / Q000494:pharmacology*; D004347:Drug Interactions; D004587:Electrophoresis, Agar Gel; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D006834:Hydrazines / Q000737:chemistry; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D010851:Picrates; D024502:alpha-Tocopherol / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002839:Chromans; D016166:Free Radical Scavengers; D006834:Hydrazines; D008077:Lipoproteins, LDL; D010851:Picrates; C483420:carboxyethyl-hydroxychroman; C004931:1,1-diphenyl-2-picrylhydrazyl; D024502:alpha-Tocopherol