Cardioprotective effects of Amentoflavone by suppression of apoptosis and inflammation on an in vitro and vivo model of myocardial ischemia-reperfusion injury

Inflammation modulation is currently considered a promising therapeutic strategy to counteract the burden of cardiovascular disease. Amentoflavone (AME) is a natural biflavone with two apigenin molecules that, possess promising anti-inflammatory, anti-oxidative, and anti-cancer properties. In the present study, we aimed to investigate the effects of AME on myocardial ischemia-reperfusion injury in vivo and in vitro, and to elucidate the underlying mechanism. Our results showed that AME significantly reduced the levels of LDH, CK-MB, IL-6, IL-1β, and TNF-α after hypoxia (H) 12 h/reoxygenation (R) 4 h treatment, and significantly increased the cell survival rate of H9c2 cardiomyocytes induced by H/R and inhibited their apoptosis rate. AME (25, 50, 100 mg·kg-1·d-1, i.g.) or a positive control drug diltiazem (DIZ) (16 mg·kg-1·d-1, i.g.) was used as pretreatment for 7 days; the myocardial ischemia-reperfusion(I/R) model was established. TTC staining results showed that the infarct volume was significantly reduced after AME and DIZ treatment. Oral administration of AME dose-dependently ameliorated I/R injury-induced increase in pro-inflammatory factors (IL-6, IL-1β, and TNF-α) and levels of LDH and CK-MB. Results of TUNEL and HE staining showed that the I/R model had more induced apoptosis, but could be effectively reduced by pretreatment with AME. After surgery, the heart of the rat was examined via western blotting to detect inflammation-related proteins. Compared with the sham group, the p-AKT in the I/R group was significantly reduced and the content of p-NF-κBp65 was significantly increased. However, these changes could be reversed by AME treatment. DIZ treatment exerted similar beneficial effects in I/R rats as the high dose of AME did. This study highlights the excellent therapeutic potential of AME for managing myocardial ischemia-reperfusion injury.