Interrelations between oxidative stress and calcineurin in the attenuation of cardiac apoptosis by eugenol.
In view of the known involvement of oxidative stress and calcineurin (Ca(2+)-calmodulin dependent protein phosphatase) in beta-Adrenergic stimulated events, we examined the influence of eugenol (an antioxidant generally regarded as safe by the Food and Agricultural Organization of the United Nations) on isoproterenol-induced apoptosis in neonatal cardiomyocytes. In comparison to unstimulated controls, cardiomyocytes stimulated with 50 microM isoproterenol for 48 h demonstrated (a) increased intracellular Ca(2+) levels (b) oxidative stress involving enhanced reactive oxygen species, decreased GSH/GSSG ratio, enhanced lipid peroxidation, increased activities of superoxide dismutase and glutathione peroxidase (c) apoptosis, evidenced by increased number of annexin V/TUNEL positive cells, enhanced membrane fluidity, decreased mitochondrial membrane potential, increased activities of caspase 3 and 9 along with (d) increased calcineurin activity. Pre-incubation of cardiomyocytes with 100 microM eugenol for 1 h, followed by isoproterenol treatment for 48 h, led to reversal of enhanced intracellular Ca(2+) levels, oxidative stress, calcineurin activation and apoptosis caused by isoproterenol. In addition, similar treatment of cardiomyocytes with 10 nM FK506, a calcineurin inhibitor, could also attenuate isoproterenol-induced apoptosis. These results indicate the beneficial effects of eugenol in preventing cardiomyocyte apoptosis.
Choudhary
Rashmi
R
Department of Biochemistry, Osmania University, Hyderabad, India.
Mishra
Kaushala Prasad
KP
Subramanyam
Chivukula
C
D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D019703:Calcineurin / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D005054:Eugenol / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology*; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D002316:Cardiotonic Agents; D005054:Eugenol; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D019703:Calcineurin; D020169:Caspases; D007545:Isoproterenol; D002118:Calcium