Cardioprotection with forsythoside B in rat myocardial ischemia-reperfusion injury: relation to inflammation response

The present study was undertaken to examine the effect of forsythoside B (FB) on rat myocardial ischemia-reperfusion (I/R) model and elucidate the potential mechanism. Left ventricular systolic pressure (LVSP) and +/-dp/dt(max) were detected. Blood samples were collected to determine serum levels of troponin T (Tn-T), TNF-alpha and IL-6. Hearts were harvested to assess histopathological change and infarct size, determine content of MDA, myeloperoxidase (MPO), SOD and GPx activities, analyze expression of high-mobility group box 1 (HMGB1), phosphor-I kappaB-alpha and phosphor-nuclear factor kappaB (NF-kappaB) in ischemic myocardial tissue by Western blot. Compared with control group, rats treatment with FB showed a significant recovery in myocardial function with improvement of LVSP and +/-dp/dt(max). The myocardial infarct volume, serum levels of Tn-T, TNF-alpha and IL-6, content of MDA and MPO activity in myocardial tissue were all reduced, protein expression of HMGB1, phosphor-I kappaB-alpha and phosphor-NF-kappaB were down-regulated, while attenuated the decrease of SOD and GPx activities. Besides, the infiltration of polymorph nuclear leukocytes (PMNs) and histopathological damages in myocardium were decreased in FB treated groups. These findings suggested that FB rescued cardiac function from I/R injury by limiting inflammation response and its antioxidant properties.