Cardioprotective effects of (E)-4-hydroxy-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide: a newly synthesized coumarin hydrazone against isoproterenol-induced myocardial infarction in a rat model

The current study was carried out to evaluate the effect of pretreatment and co-treatment with a newly synthesized coumarin hydrazone, (E)-4-hydroxy-N'-(1-(3-oxo-3H-benzo[f]chromen-2-yl)ethylidene)benzohydrazide (hereinafter EK6), against isoproterenol-induced myocardial infarction in rats. Changes in biochemistry, cardiac biomarkers, electrocardiography, and histopathology after treatment with EK6 or acenocoumarol (Sintrom) were studied. Animals were randomly divided into 4 groups: vehicle control (C), isoproterenol + Sintrom (ISO + Sin), isoproterenol + EK6 (ISO + EK6), and isoproterenol (ISO). Myocardial infarction was induced by subcutaneous ISO administration at a dose of 85 mg·kg^-1·day^-1 with a drug-free interval of 24 h on days 6 and 7. Treatment with ISO led to significant elevation (p < 0.05) in serum levels of cardiac injury biomarkers, namely cardiac troponin-T, lactate dehydrogenase, creatine kinase-MB, alanine aminotransferase, and aspartate aminotransferase compared with levels in the vehicle control. A change in the lipid profile was also observed as a significant increase in total cholesterol and triglycerides. Furthermore, ISO caused significant alterations in the electrocardiogram pattern, including significant ST-segment elevation, significant decreased R wave amplitude, and significant increase in heart rate (16%) as well as marked changes in the histopathology of the heart tissue. Pretreatment and co-treatment with newly synthesized coumarin hydrazone restored all ISO-induced biochemical, lipid, cardiac, and histopathological changes in rats with myocardial infarction.