Protective Effects of Myrtus communis Linn Fruit and Leaf Extracts on Isoproterenol-Induced Heart Failure in Rat

Abstract

Myrtus communis Linn. (MC) is a cardiotonic plant in traditional Persian medicine. This study was conducted to evaluate the protective effect of MC on isoproterenol-induced heart failure (HF) in rats. Isoproterenol was injected subcutaneously in all groups except the control group for 4 consecutive days to induce myocardial injury in male Wistar rats. In the case of treatment groups, the animals were treated with different doses of the hydro-alcoholic extract of MC fruit or leaves (150, 300, and 700 mg/kg), and were compared with healthy and HF rats. In order to evaluate cardiac function, echocardiography was performed on day 28 after treatment. MC fruit and leaf extracts were administered to all groups except the healthy control group for 28 days by gavage. At the end of the experimental period, the animals were sacrificed and the left ventricle regions of tissue hearts were collected to measure the levels of oxidative stress factors (MDA, SOD, GSH) using ELISA methods. Cardiac fibrosis was evaluated by Mason’s trichrome staining. Hematoxylin-eosin staining was used to assess histopathological changes in cardiac structure.  Our results showed that administration of MC fruit and leaf extracts significantly reduced the MDA level and increased SOD and GSH levels in treated HF rats compared to the HF group (P<0.05). In addition, MC mitigated fibrosis and improved cardiac histological changes compared to the HF group. Collectively, our findings show that MC can be considered as a good candidate to provide cardioprotective effects in HF rats through reduction of oxidative stress and myocardial fibrosis.