Baicalein attenuates oxidant stress in cardiomyocytes.
Flavonoids within Scutellaria baicalensis may be potent antioxidants on the basis of our studies of S. baicalensis extract. To further this work, we studied the antioxidative effects of baicalein, a flavonoid component of S. baicalensis, in a chick cardiomyocyte model of reactive oxygen species (ROS) generation during hypoxia, simulated ischemia-reperfusion, or mitochondrial complex III inhibition with antimycin A. Oxidant stress was measured by oxidation of the intracellular probes 2',7'-dichlorofluorescin diacetate and dihydroethidium. Viability was assessed by propidium iodide uptake. Baicalein attenuated oxidant stress during all conditions studied and acted within minutes of treatment. For example, baicalein given only at reperfusion dose dependently attenuated the ROS burst at 5 min after 1 h of simulated ischemia. It also decreased subsequent cell death at 3 h of reperfusion from 52.3 +/- 2.5% in untreated cells to 29.4 +/- 3.0% (with return of contractions; P < 0.001). In vitro studies using electron paramagnetic resonance spectroscopy with the spin trap 5-methoxycarbonyl-5-methyl-1-pyrroline-N-oxide revealed that baicalein scavenges superoxide but does not mimic the effects of superoxide dismutase. We conclude that baicalein can scavenge ROS generation in cardiomyocytes and that it protects against cell death in an ischemia-reperfusion model when given only at reperfusion.
Shao
Zuo-Hui
ZH
Section of Emergency Medicine, Department of Medicine, University of Chicago, Illinois 60637, USA.
Vanden Hoek
Terry L
TL
Qin
Yimin
Y
Becker
Lance B
LB
Schumacker
Paul T
PT
Li
Chang-Qing
CQ
Dey
Lucy
L
Barth
Eugene
E
Halpern
Howard
H
Rosen
Gerald M
GM
Yuan
Chun-Su
CS
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D019659:Asteraceae; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000196:embryology / Q000502:physiology*; D018715:Microscopy, Video; D008929:Mitochondria, Heart / Q000187:drug effects / Q000502:physiology; D017202:Myocardial Ischemia / Q000503:physiopathology; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000166:cytology; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D010477:Perfusion; D010936:Plant Extracts / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism
D000975:Antioxidants; D044950:Flavanones; D005419:Flavonoids; D016877:Oxidants; D010936:Plant Extracts; D017382:Reactive Oxygen Species; C006680:baicalein