Abstract:
Oxidative stress has been implicated with cardiovascular aging. Most antioxidant intervention studies have involved long-term treatments as a potential means to eliminate age-related oxidative damage in many systems. In the present study, not only light and electron microscopic pictures of the heart and thoracic aorta of young and aged and, caffeic acid phenethyl ester (CAPE) and melatonin and administered aged Sprague Dawley rats, but also antioxidant system status was evaluated. Significantly elevated levels of malondialdehyde (MDA) were observed in the heart and thoracic aorta of aged rats (P < 0.05 and P < 0.001, respectively). Chronic melatonin and CAPE administration significantly reduced the levels of MDA in the heart (P = 0.005 and P = 0.05, respectively) and thoracic aorta (P < 0.001 and P < 0.05, respectively) of aged animals. Additionally, melatonin and CAPE were efficient in stimulating the activities and increasing the levels of the antioxidant enzymes in the heart and aorta. Prominent electron microscopic alterations in cardiac myocytes such as nuclear irregularity, mitochondrial degeneration, myofilament disorganization and disruption, and lipofuscin accumulation were observed in aged rats. The main age-related histologic modifications observed in aorta were irregularity in endothelial cells and their nuclei, divergence of endothelial cells from basement membrane and neighboring cells, and elastic fibril fragmentation and reduction. Melatonin and CAPE obviously reduced these alterations in both heart and aorta of aged rats. Taking the results together, we suggest that supplemental administration of CAPE and melatonin is beneficial in delaying age-related cellular damage in cardiovascular system.