Oxymatrine, the main alkaloid component of Sophora roots, protects heart against arrhythmias in rats.

Oxymatrine is one of the main alkaloid components extracted from SOPHORA roots and has been shown to play various protective roles in the cardiovascular system. The present study was designed to study the protective effect of oxymatrine on arrhythmias and their ionic channel mechanism. Rat arrhythmic models were established by aconitine injection and coronary artery ligation. Rat cardiomyocytes were acutely isolated, and the whole-cell patch clamp technique was employed to investigate the effects of oxymatrine on sodium channels. Pretreatment with oxymatrine markedly increased the dose of aconitine required to induce arrhythmias in rats. Additionally, oxymatrine significantly delayed the initial time and shortened the duration time of rat arrhythmias induced by coronary artery ligation. Cardiac mortality rate in coronary artery ligation-induced arrhythmias was also effectively decreased by oxymatrine in rats. The electrophysiological study showed that oxymatrine could significantly inhibit sodium and calcium currents in isolated rat cardiomyocytes in a concentration-dependent manner. In summary, oxymatrine plays a remarkably preventive role in rat arrhythmias through the inhibition of sodium and calcium currents. © Georg Thieme Verlag KG Stuttgart · New York.