Possible protective mechanisms exerted by metformin or metformin and vitamin E in isoproterenol-induced cardiac injury.

Several studies have reported that metformin is cardioprotective for diabetic and non-diabetic ischemic hearts through mechanisms that cannot be entirely attributed to its anti-hyperglycemic effect. This study was designed to investigate the cardioprotective effects of metformin with and without vitamin E after induction myocardial infarction (MI) in rats, using isoproterenol. Administration of metformin or vitamin E significantly reduced the cardiac mass index (P < 0.01), ameliorated the changes to cardiac biomarkers, and attenuated oxidative stress levels compared to the isoproterenol group. Interestingly, combination therapy showed a slight synergistic effect. Histopathological analysis suggested that metformin treatment reduced NF-κB expression and protected against isoproterenol-induced MI. Our results indicate that metformin mediates a cardioprotective effect against isoproterenol-induced MI via antioxidant activity and modulation of the NF-κB signaling pathway. This suggests that metformin would be beneficial in MI treatment.