Antagonistic Effect of Neferine on Hyperthyroid Arrhythmia

Background Hyperthyroidism can cause heart damage, which manifests as myocardial hypertrophy and changes in electrophysiological characteristics, and is prone to arrhythmia. Purpose This study aimed to verify whether the natural product neferine (Nef), a non-specific cation channel blocker derived from lotus seeds, has an antagonistic effect on hyperthyroid-induced arrhythmias. Materials and Methods Male Sprague–Dawley (SD) rats were used to establish a hyperthyroidism-induced myocardial injury model by intraperitoneal injection of l -thyroxine for 4 weeks. The antagonistic effect of Nef on arrhythmia was studied via in vivo epicardial monophasic action potential (MAP) recording and isolated heart perfusion, and the effect of Nef on the intracellular Ca 2+ concentration in myocardial cells was also investigated. Results Administration of Nef slowed heart rate, reduced left ventricular pressure, significantly antagonized the shortening of MAP duration during arrhythmias, decreased the incidence of triggered activity, shortened the duration of arrhythmia, and reduced the intracellular Ca 2+ concentration during diastole and the peak concentration during systole, demonstrating an anti-arrhythmic effect. The antagonistic effect of Nef on arrhythmia was more significant in the hyperthyroid model group. Conclusion Hyperthyroidism can cause pathological structural changes in the myocardium and easily induce arrhythmia. Nef has an antagonistic effect on hyperthyroid arrhythmia by blocking cation channels.