Antioxidant effects of ginsenoside Re in cardiomyocytes.
We have previously demonstrated that American ginseng berry extract exhibited significant protection against oxidant-mediated injury in cardiomyocytes. To extend this work, we sought to investigate the antioxidant effects of Re, a protopanaxatriols-type and single chemical integrant present in American ginseng berry extract, using the same chick cardiomyocyte model of oxidant injury as well as ESR spectroscopy in a cell-free chemical system. In cells exposed to 2 h of H2O2 (0.5 mM), pretreatment with Re (0.05, 0.1, or 0.5 mg/ml for 2 h) significantly attenuated 2',7'-dichlorofluorescein (DCF) fluorescence by 51% (from 1345+/-67 to 658+/-46 a.u., P<0.001), and remarkably reduced cell death (from 51.5+/-3.0% to 11.8+/-1.5%, P<0.001, compared to the control). Similar results were also observed in cells exposed to antimycin A (100 microM), a mitochondrial electron transport chain site III inhibitor which increases endogenous oxidative stress. In the ESR study, however, Re failed to reduce the formation of the superoxide/DMPO adduct and DPPH radicals. These results suggest that ginsenoside Re functions as an antioxidant, protecting cardiomyocytes from oxidant injury induced by both exogenous and endogenous oxidants, and that its protective effects may be mostly attributed to scavenging H2O2 and hydroxyl radicals.
Tang Center for Herbal Medicine Research, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA.
Jing-Tian
JT
Xie
Zuo-Hui
ZH
Shao
Terry L
TL
Vanden Hoek
Wei-Tien
WT
Chang
Jing
J
Li
Sangeeta
S
Mehendale
Chong-Zhi
CZ
Wang
Chin-Wang
CW
Hsu
Lance B
LB
Becker
Jun-Jie
JJ
Yin
Chun-Su
CS
Yuan
D000818:Animals; D000968:Antimycin A / Q000633:toxicity; D000975:Antioxidants / Q000494:pharmacology*; D002470:Cell Survival; D002642:Chick Embryo; D004578:Electron Spin Resonance Spectroscopy; D036145:Ginsenosides / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000633:toxicity; D023421:Models, Animal; D032383:Myocytes, Cardiac / Q000187:drug effects*; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress; D014475:Uncoupling Agents / Q000633:toxicity
D000975:Antioxidants; D036145:Ginsenosides; D016877:Oxidants; D014475:Uncoupling Agents; C049864:ginsenoside Re; D000968:Antimycin A; D006861:Hydrogen Peroxide