OBJECTIVETo investigate the effect of edaravone on oxidative stress and myocardial fibrosis induced by isoproterenol in rats.

METHODSFifty male SD rats were randomly divided into 5 groups, including a control group, a myocardial fibrosis model (established by injections of isopropyl adrenaline for 10 days) group, and 3 edaravone groups with edaravone treatment at low, medium, or high doses for 14 days. After the treatments, the rats were examined for the degree of myocardial fibrosis, left ventricular mass index (LVMI), collagen volume fraction (CVF), and myocardial contents of collagen I (Col I), collage III (Col III), hydroxyproline (Hyp), superoxide dismutase (SOD), malondialdehyde (MDA), and nitric oxide (NO); The expression of transforming growth factor-β1 (TGF-β1) in the myocardial tissues was examined by immunofluorescence assay and Western blotting.

RESULTSCompared with the control rats, the rat models of myocardial fibrosis showed significantly increased CVF and LVMI (P=0.000), which were lowered by edaravone treatments in a dose-dependent manner (P<0.05). The myocardial contents of Col I, Col III and Hyp also increased in the model group (P=0.000) and were lowered dose-dependently by edaravone; the contents of MDA was higher (P=0.000) and SOD and NO were lower in the model group (P=0.000), and edaravone treatments obviously increased SOD and NO contents (P<0.05). The model rats showed significantly increased myocardial expression of TGF-β1 (P=0.000), which was markedly lowered by edaravone treatments (P=0.000). The myocardial content of MDA was positively correlated while SOD and NO were negatively with LVMI, CVF, Col I, Col III and Hyp; TGF-β1 was positively correlated with LVMI, CVF, Col I, Col III, Hyp and MDA but negatively with SOD and NO.

CONCLUSIONEdaravone can relieve oxidative stress and inhibit TGF-β1 activation to ameliorate myocardial fibrosis in rats.