Berberine alleviates ischemic arrhythmias via recovering depressed Ito and ICa currents in diabetic rats

The present study was designed to elucidate the potential mechanism underlying that berberine suppressed ischemic arrhythmias in a rat model of diabetes mellitus (DM). Streptozotocin (STZ)-induced diabetic rats were subjected to ischemia by the occlusion of left anterior descending (LAD) coronary artery. Berberine was orally administered for 7 days before ischemic injury in diabetic rats. Whole-cell patch-clamp was performed to measure the transient outward K+ current (Ito) and L-type Ca2+ current (ICa). Results showed that oral administration of berberine (100 mg/kg) attenuated ischemia-induced arrhythmias in diabetic rats. Berberine significantly shortened the prolonged QTc interval from 214 ± 6 ms to 189 ± 5 ms in ischemic diabetic rats, and also restored the diminished Ito and ICa current densities in the same animal model rats. In conclusion, the ability of berberine to protect diabetic rats against cardiac arrhythmias makes it possible to be a prospective therapeutic agent in clinical management of cardiac disease secondary to diabetes.