Interrelations between oxidative stress and calcineurin in the attenuation of cardiac apoptosis by eugenol

• DOI: 10.1007/s11010-006-2386-3
• Publication Date: 2006-01-27T11:09:08Z
• Authors: Rashmi Choudhary; Kaushala Prasad M...; Chivukula Subrama...
• Keywords: Glutathione Peroxidase; 0303 health sciences; Cardiotonic Agents; Superoxide Dismutase; Calcineurin; Isoproterenol; Apoptosis; Antioxidants; Membrane Potentials; Mitochondria; Rats; Oxidative Stress; 03 medical and health sciences; Animals, Newborn; Caspases; Eugenol; Animals; Calcium; Myocytes, Cardiac; Lipid Peroxidation; Rats, Wistar; Cells, Cultured

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.