Antiarrhythmic Mechanisms of Chinese Herbal Medicine Dingji Fumai Decoction

Background. Dingji Fumai decoction (DFD) is used to treat ventricular arrhythmia, and it has provided a very good curative effect. However, its cellular electrophysiological mechanism is unknown. Methods. Electrocardiogram was recorded, and oxidative stress response and ion-channel-related molecules were detected in rats with barium chloride- and aconitine-induced ventricular arrhythmia. Moreover, whole-cell patch-clamp assay was used to investigate the inhibitory effect of DFD on Nav(1.5) in Chinese hamster ovary cells. Results. DFD prolonged the occurrence time and shortened the duration of ventricular arrhythmia, decreased the malondialdehyde and increased the superoxide dismutase, and alleviated the activation of Na+-K+-ATPase and connexin-43. DFD suppressed Nav(1.5)dose-dependently with an IC50 of 24.0 +/- 2.4 mg/mL. Conclusions. The clinical antiarrhythmic mechanisms of DFD are based on its antioxidant potential, alleviation of Na+-K+-ATPase and connexin-43, and class I antiarrhythmic properties by suppressing Nav(1.5)dose-dependently with an IC50 of 24.0 +/- 2.4 mg/mL.