Abstract
Arrhythmia is an important cause of death after myocardial infarction (MI). Different substances have been evaluated for their anti-arrhythmic effect in MI. This study was performed to evaluate the anti-arrhythmic impacts of crocin in an MI animal model (rat) by estimation of the expression of connexin 43 (Cx43). Fifty male Sprague-Dawley rats were grouped into 5 groups, each composed of 10 rats. The first group was regarded as the normal control group and the second one was considered as the MI group, which was caused by ligation of the left anterior descending artery. The other three groups received crocin 50 or 10 mg/kg/ day or metoprolol 100 mg/kg/day for 1 week, following ligation of the left anterior descending artery. Evaluated outcomes were cardiac Cx43 expression, arrhythmia incidence, histological findings, and myocyte resting potential. Crocin-treated MI groups showed a significantly lower arrhythmia score than the non-treated MI group, 10 mg/kg/day (1.85 +/- 0.55, p < 0.01) and 50 mg/kg/ day (1.70 +/- 0.33, p < 0.01). Groups that received crocin 10 mg/kg/day (66.30 +/- 2.59, p < 0.01), crocin 50 mg/kg/day (68.10 +/- 2.43, p < 0.01), and metoprolol 100 mg/kg/day (-63.54 +/- 0.63 mV, p < 0.01) significantly prevented depolarization in comparison with the non-treated MI group. Expression of Cx43 mRNA in crocin 10 mg/kg/day (1.54 +/- 0.24, p < 0.01), crocin 50 mg/kg/day (1.73 +/- 0.09, p < 0.01), and metoprolol 100 mg/kg/day (1.75 +/- 0.14, p < 0.01) treatment groups was significantly higher in comparison with the non-treated MI group. Crocin showed a preventive effect on the arrhythmogenic impact of MI in an experimental model of ischemic injury through an increase in expression of Cx43.