RESUMO
Despite considerable advances in interventions and treatment, there is a high mortality rate in patients with myocardial infarction (MI). This is the first study to investigate the protective effects of 3, 4-dihydroxybenzoic acid against isoproterenol induced MI in rats. MI was induced by isoproterenol (100-mg/kg body weight) in rats. Then, rats were treated with 3, 4-dihydroxybenzoic acid (16-mg/kg body weight) for 2 weeks. Serum creatine kinase-MB, cardiac troponin-T, cardiac troponin-I, and heart thiobarbituric acid reactive substances were significantly (p < 0.05) increased and heart superoxide dismutase and catalase activities were significantly (p < 0.05) reduced in isoproterenol-induced myocardial infarcted rats. Isoproterenol induction significantly (p < 0.05) elevated the plasma homocysteine and serum high sensitivity-C-reactive protein levels. Furthermore, an enzyme-linked immunosorbent assay, reverse transcription polymerase chain study, and immunohistochemical (IHC) staining revealed significantly (p < 0.05) elevated levels and expression of serum/myocardial nuclear factor-κB, tumor necrosis factor-alpha, interleukin-1 beta, and Interleukin-6 and significantly (p < 0.05) reduced levels/expression of serum/myocardial interleukin-10 in myocardial infarcted rats. Nevertheless, isoproterenol-induced rats treated with 3, 4-dihydroxybenzoic acid considerably (p < 0.05) attenuated all the biochemical, molecular, and IHC parameters investigated and inhibited oxidative stress and inflammation and protected the heart, through its antioxidant and anti-inflammatory mechanisms.