Effect of Long-Term Dietary Restriction on Myocardial Apoptosis

Caloric or dietary restriction (DR) is a practical intervention for weight loss and increasing lifespan. However, the effects of long-term dietary restriction and signaling process of it on cell aging and apoptosis remain unclear, especially in sensitive somatic tissues such as myocardial. Therefore, the purpose of this study was investigating the effect of long-term dietary restriction on some indices of myocardial apoptosis in rats. This study was conducted with a two-group experimental design (animal model) for three months. Sixteen 3-month-old male Wistar14848 rats were selected and randomly divided into two groups of dietary restriction (n = 8; weight: 385.25 ± 29.6 g) and control (n = 8; weight: 231.25 ± 27.63 g). All animals in control group were fed ad libitum (0% of dietary restriction; 23.0 ± 2.16 g/day) and animals of dietary-restriction group had daily access to 50% of the intake of the ad libitum-fed control animals (-50% of dietary restriction; 11.5 ± 1.8 g/day). After 3 months, the hearts of rats were extracted and Bax, Bcl2 and caspase-3 mRNA, as important proteins in mitochondrial apoptosis pathway, were evaluated using real-time polymerase chain reaction (real-time PCR) method. Independent t-test was applied for statistical analysis of the data at the significant level of P < 0.05. The expressions of Bax and Bcl-2 genes in dietary-restriction group were unsignificantly higher than the control group (27.7% and 27.9%, respectively). In addition, caspase-3 expression and Bax/Bcl2 ratio in control group were unsignificantly higher than the dietary-restriction group (39.4% and 6.9%, respectively). In general, 3-month dietary restriction (-50%) did not affect myocardial apoptosis. However, it likely seems that dietary restriction alleviates myocardial apoptosis via increasing Bcl-2 and decreasing caspase-3.