title: Epigallocatechin gallate, a constituent of green tea, regulates high glucose-induced apoptosis.
abstract: A high concentration of glucose has been implicated as a causal factor in initiation and progression of diabetic complications, and there is evidence to suggest that hyperglycemia increases the production of free radicals and oxidative stress. Therefore, compounds that scavenge reactive oxygen species may confer regulatory effects on high glucose-induced apoptosis. Epigallocatechin gallate (EGCG), the major polyphenolic of green tea, is reported to have an antioxidant activity. We investigated the effect of EGCG on high glucose-induced apoptosis in U937 cells. Upon exposure to 35 mM glucose for 2 days, there was a distinct difference between untreated cells and cells pre-treated with 1 microM EGCG for 2 h in regard to cellular redox status and oxidative DNA damage to cells. EGCG pre-treated cells showed significant suppression of apoptotic features such as DNA fragmentation, damage to mitochondrial function, and modulation of apoptotic marker proteins upon exposure to high glucose. This study indicates that EGCG may play an important role in regulating the apoptosis induced by high glucose presumably through scavenging of reactive oxygen species.
authors.affiliation: School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Taegu 702-701, Korea.
authors.forename: Chang Joo
authors.initials: CJ
authors.lastname: Oh
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Yang
authors.forename: Seoung Woo
authors.initials: SW
authors.lastname: Shin
authors.forename: Seong Hun
authors.initials: SH
authors.lastname: Choi
authors.forename: Chan Ik
authors.initials: CI
authors.lastname: Park
authors.forename: Chae Ha
authors.initials: CH
authors.lastname: Yang
authors.forename: Jeen-Woo
authors.initials: JW
authors.lastname: Park
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D005947:Glucose / Q000633:toxicity*; D017127:Glycation End Products, Advanced / Q000378:metabolism; D006801:Humans; D007211:Indoles; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects; D010084:Oxidation-Reduction; D013662:Tea / Q000737:chemistry*; D020298:U937 Cells
chemical_list: D000975:Antioxidants; D005456:Fluorescent Dyes; D017127:Glycation End Products, Advanced; D007211:Indoles; D013662:Tea; C007293:DAPI; D002392:Catechin; C045651:epigallocatechin gallate; D005947:Glucose