Carvedilol-mediated antioxidant protection against doxorubicin-induced cardiac mitochondrial toxicity.
The cardiotoxicity associated with doxorubicin (DOX) therapy limits the total cumulative dose and therapeutic success of active anticancer chemotherapy. Cardiac mitochondria are implicated as primary targets for DOX toxicity, which is believed to be mediated by the generation of highly reactive free radical species of oxygen from complex I of the mitochondrial electron transport chain. The objective of this study was to determine if the protection demonstrated by carvedilol (CV), a beta-adrenergic receptor antagonist with strong antioxidant properties, against DOX-induced mitochondrial-mediated cardiomyopathy [Toxicol. Appl. Pharmacol. 185 (2002) 218] is attributable to its antioxidant properties or its beta-adrenergic receptor antagonism. Our results confirm that DOX induces oxidative stress, mitochondrial dysfunction, and histopathological lesions in the cardiac tissue, all of which are inhibited by carvedilol. In contrast, atenolol (AT), a beta-adrenergic receptor antagonist lacking antioxidant properties, preserved phosphate energy charge but failed to protect against any of the indexes of DOX-induced oxidative mitochondrial toxicity. We therefore conclude that the cardioprotective effects of carvedilol against DOX-induced mitochondrial cardiotoxicity are due to its inherent antioxidant activity and not to its beta-adrenergic receptor antagonism.
Centre of Neurosciences and Cellular Biology of Coimbra, Department of Zoology, University of Coimbra, Portugal.
Paulo J
PJ
Oliveira
James A
JA
Bjork
Maria S
MS
Santos
Richard L
RL
Leino
M Kent
MK
Froberg
António J
AJ
Moreno
Kendall B
KB
Wallace
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000633:toxicity*; D000975:Antioxidants / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology; D002227:Carbazoles / Q000494:pharmacology*; D009202:Cardiomyopathies / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D000077261:Carvedilol; D022081:Cell Surface Extensions / Q000187:drug effects; D004317:Doxorubicin / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology; D008297:Male; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000473:pathology; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D010101:Oxygen Consumption / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism
D000319:Adrenergic beta-Antagonists; D000903:Antibiotics, Antineoplastic; D000975:Antioxidants; D002227:Carbazoles; D007473:Ion Channels; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011412:Propanolamines; D000077261:Carvedilol; D004317:Doxorubicin; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D002118:Calcium; C013289:tetraphenylphosphonium