title: Radical-scavenging abilities and antioxidant properties of theaflavins and their gallate esters in H2O2-mediated oxidative damage system in the HPF-1 cells.
abstract: The antioxidant properties of theaflavins and their gallate esters, namely theaflavin (TF1), theaflavin-3(3')-gallate (TF2) and theaflavin-3,3'-digallate (TF3) were investigated by comparing with epigallocatechin gallate (EGCG). The order of hydroxyl radicals-scavenging ability was TF3>TF2>TF1>EGCG. The order of 2,2-diphenyl-1-picrylhydrazyl scavenging ability was TF3>TF2>EGCG>TF1. TF1, TF2, and TF3 showed more effective effects than EGCG in protection against H2O2-mediated damage in HPF-1 cells. TF2 was the most potent accelerant of HPF-1 cell proliferation. TF1, TF2 and TF3 suppressed the accumulation of intracellular reactive species in H2O2-mediated damage HPF-1 cells. Pre-treated for 2h and eliminated from the cells, TF1 and TF3 still showed protective effects against H2O2-mediated damage in HPF-1 cells. This suggests that the protective effects of TF1 and TF3 on oxidative damage HPF-1 cells may be responsible for other mechanisms, rather than only scavenging the already formed reactive species. It remains to be determined whether TF1 and TF3 improved the normal HPF-1 cell resistive abilities toward radical-damage in pre-treatment. Further studies of the effects of theaflavins on some enzymes or signal transduction in the normal HPF-1 cells are underway.
authors.affiliation: Department of Tea Science, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, China.
authors.forename: Ziyin
authors.initials: Z
authors.lastname: Yang
authors.forename: Guoliang
authors.initials: G
authors.lastname: Jie
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.forename: Naoharu
authors.initials: N
authors.lastname: Watanabe
authors.forename: Youying
authors.initials: Y
authors.lastname: Tu
mesh_terms: D044946:Biflavonoids / Q000737:chemistry / Q000494:pharmacology*; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D008168:Lung / Q000166:cytology / Q000196:embryology; D016877:Oxidants / Q000633:toxicity*; D021281:Quantitative Structure-Activity Relationship
chemical_list: D044946:Biflavonoids; D016166:Free Radical Scavengers; D016877:Oxidants; C491764:epigallocatecol gallate; C056068:theaflavin; C088983:theaflavine gallate; C077197:theaflavin digallate; D005707:Gallic Acid; D002392:Catechin; D006861:Hydrogen Peroxide