Cardioprotective Effect of Epiisopiloturine, an Imidazole Alkaloid from Pilocarpus microphyllus, in Rats Submitted to Cardiac Ischemia and Reperfusion

Acute myocardial infarction (AMI), which is characterized by severe and fatal arrhythmias resultant from cardiac ischemia/reperfusion (CIR), is the leading cause of morbidity and mortality in the world. Considering that epiisopiloturin (EPI), an imidazole alkaloid found in the leaves of Pilocarpus microphyllus produded anti-inflammatory and antioxidant effects in an animal model of peritonitis, paw edema and peritonitis in mice, we decided to investigate the potential cardioprotective activity of EPI in animal model of CIR. Then, adult rats submitted to CIR pretreated with EPI 10 mg/kg (EPI10+CIR group) or 15 mg/kg (EPI15+CIR group) were compared to control animals submitted to CIR treated with saline solution 0.9% (CIR group). To evaluate the incidence of ventricular arrhythmias (VA), atrioventricular block (AVB) and lethality (LET) induced by CIR in these rats, the ECG analysis was performed. Serum levels of cardiac damage markers, total creatine kinase (CK) and CK-MB, were measured. The results showed that the AVB incidence was reduced from 80% to 30%, and LET incidence was reduced from 70% to 20%, compared to CIR group. Serum levels of LDH, total CK and, CK-MB was similar in all groups studied. These results indicate that the treatment with EPI (15 mg/kg, IV) before CIR was effective to produce cardioprotective effects. Thus, the use of EPI could be a promisse strategy to reduce the incidence of severe and fatal arrhythmias associated with AMI.