Grape seed proanthocyanidin extract attenuates oxidant injury in cardiomyocytes.
This study sought to test whether grape seed proanthocyanidin extract (GSPE) attenuates exogenous and endogenous oxidant stress induced in chick cardiomyocytes and whether this cytoprotection is mediated by PKC activation, mito K(ATP) channel opening, NO production, oxidant scavenging, or iron chelating effects. Cells were exposed to hydrogen peroxide (H(2)O(2)) (exogenous oxidant stress, 0.5mM) or antimycin A (endogenous oxidant stress, 100 micro M) for 2h following pretreatment with GSPE at various concentrations for 2h. Cells were also pretreated with GSPE or with inhibitors of PKC (chelerytherine), mito K(ATP) channel (5-hydroxydecanoate), nitric oxide synthase (nitro-L-arginine methyl ester) for 2h. Oxidant stress was measured by 2',7'-dichlorofluorescin diacetate and cell viability was assessed using propidium iodide. Free radical scavenging and iron chelating ability was tested in vitro. GSPE dose-dependently attenuated oxidant formation and significantly improved cell survival and contractile function. However, inhibitors of PKC, mito K(ATP) channel or NO synthase failed to abolish the protective action of GSPE during H(2)O(2) or antimycin A exposure. In vitro studies suggested that GSPE scavenges H(2)O(2), hydroxyl radical and superoxide, and may chelate iron. These results indicate that GSPE confers cardioprotection against exogenous H(2)O(2)- or antimycin A-induced oxidant injury. Its effect does not require PKC, mito K(ATP) channel, or NO synthase, presumably because it acts by reactive oxygen species scavenging and iron chelating directly.
Department of Medicine, Section of Emergency Medicine, University of Chicago, 5841 S. Maryland Avenue, MC 5068, Chicago, IL 60637, USA.
Zuo-Hui
ZH
Shao
Lance B
LB
Becker
Terry L
TL
Vanden Hoek
Paul T
PT
Schumacker
Chang-Qing
CQ
Li
Danhong
D
Zhao
Kim
K
Wojcik
Travis
T
Anderson
Yimin
Y
Qin
Lucy
L
Dey
Chun-Su
CS
Yuan
D000818:Animals; D000968:Antimycin A / Q000009:adverse effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D005419:Flavonoids; D006861:Hydrogen Peroxide / Q000009:adverse effects*; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology; D032383:Myocytes, Cardiac / Q000187:drug effects*; D009569:Nitric Oxide / Q000502:physiology; D016877:Oxidants / Q000009:adverse effects*; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D015221:Potassium Channels; D044945:Proanthocyanidins / Q000494:pharmacology*; D011493:Protein Kinase C / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds; D013481:Superoxides / Q000378:metabolism; D027843:Vitis
D005419:Flavonoids; D008565:Membrane Proteins; D016877:Oxidants; D010936:Plant Extracts; D015221:Potassium Channels; D044945:Proanthocyanidins; D017382:Reactive Oxygen Species; C117780:mitochondrial K(ATP) channel; D013481:Superoxides; D009569:Nitric Oxide; D000968:Antimycin A; D006861:Hydrogen Peroxide; D011493:Protein Kinase C