title: Green tea catechins prevent low-density lipoprotein oxidation via their accumulation in low-density lipoprotein particles in humans.
abstract: Green tea is rich in polyphenols, including catechins which have antioxidant activities and are considered to have beneficial effects on cardiovascular health. In the present study, we investigated the effects of green tea catechins on low-density lipoprotein (LDL) oxidation in vitro and in human studies to test the hypothesis that catechins are incorporated into LDL particles and exert antioxidant properties. In a randomized, placebo-controlled, double-blind, crossover trial, 19 healthy men ingested green tea extract (GTE) in the form of capsules at a dose of 1 g total catechin, of which most (>99%) was the gallated type. At 1 hour after ingestion, marked increases of the plasma concentrations of (-)-epigallocatechin gallate and (-)-epicatechin gallate were observed. Accordingly, the plasma total antioxidant capacity was increased, and the LDL oxidizability was significantly reduced by the ingestion of GTE. We found that gallated catechins were incorporated into LDL particles in nonconjugated forms after the incubation of GTE with plasma in vitro. Moreover, the catechin-incorporated LDL was highly resistant to radical-induced oxidation in vitro. An additional human study with 5 healthy women confirmed that GTE intake sufficiently increased the concentration of gallated catechins, mainly in nonconjugated forms in LDL particles, and reduced the oxidizability of LDL. In conclusion, green tea catechins are rapidly incorporated into LDL particles and play a role in reducing LDL oxidation in humans, which suggests that taking green tea catechins is effective in reducing atherosclerosis risk associated with oxidative stress.
authors.affiliation: Department of Nutrition and Food Science, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Suzuki-Sugihara
authors.affiliation: Endowed Research Department "Food for Health," Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan. Electronic address: kishimoto.yoshimi@ocha.ac.jp.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kishimoto
authors.affiliation: Endowed Research Department "Food for Health," Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Saita
authors.affiliation: Endowed Research Department "Food for Health," Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Taguchi
authors.affiliation: Central Reseach Institute, ITO EN, LTD., 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Central Reseach Institute, ITO EN, LTD., 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ichitani
authors.affiliation: Central Reseach Institute, ITO EN, LTD., 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
authors.forename: Yuuichi
authors.initials: Y
authors.lastname: Ukawa
authors.affiliation: Central Reseach Institute, ITO EN, LTD., 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
authors.forename: Yuko M
authors.initials: YM
authors.lastname: Sagesaka
authors.affiliation: Department of Nutrition and Food Science, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Suzuki
authors.affiliation: Endowed Research Department "Food for Health," Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan; Institute of Life Innovation Studies, Toyo University, 1-1-1 Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kondo
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use*; D050197:Atherosclerosis / Q000097:blood / Q000453:epidemiology / Q000378:metabolism / Q000517:prevention & control; D015415:Biomarkers / Q000097:blood; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008077:Lipoproteins, LDL / Q000037:antagonists & inhibitors* / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*; D018515:Plant Leaves / Q000737:chemistry*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D008077:Lipoproteins, LDL; D010936:Plant Extracts; C099252:oxidized low density lipoprotein; D002392:Catechin
keywords: Epigallocatechin gallate; Humans; Lipid peroxidation; Lipoproteins; Low-density lipoprotein; Tea