Betaine, a multifunction molecule, has a cardio protective feature but the mechanism is not well-understood. Hence, we evaluated the effect of betaine on cardiac tissue and serum biomarkers. Betaine administered to Albino rats at 50, 150 and 250 mg/kg, and sham group received deionized water. Myocardial infarction was induced by isoproterenol (100 mg/kg). The tunnel test and immunohistochemistry were performed on heart tissue to detect apoptosis and nitric oxide levels respectively. Serum levels of lipid peroxidation (LPO) and superoxide dismutase (SOD) were measured with colorimetric methods. The apoE and Bcl-2 gene expression were measured by RT-PCR in heart tissues and peripheral blood mononuclear cells (PBMCs). The results showed that betaine pretreatment at 250mg/kg for 60 days which reduces the apoptotic cells in the heart tissue after isoproterenol-induced myocardial infraction (P= 0.038). Cardiac Bcl-2 levels were upregulated by betaine, in which the maximum levels were observed in 150 mg/kg dosage. Similar finding was observed in the apoE expression in PBMCs. The tissue NOS levels were not change by betaine pretreatment significantly. Both superoxide dismutase and lipid peroxidation levels were reduced by betaine pretreatment dose dependently. Our results confirm the protective effect of betaine pretreatment that is mediated by Bcl-2 and anti-oxidative properties. Manuscript profile