Anti-arrhythmic effects and electrophysiological properties of Ophiopogon total saponins

The arrhythmias induced by chloroform-epinephine, BaCl2, and aconitine were prevented and antagonized by Ophiopogon total saponins (OTS) which were extracted from the root of Ophiopogon japonicus (Thunb) Ker-Gawl. The incidence of ventricular arrhythmia produced by ligation of the left anterior descending coronary artery was effectively decreased without any changes in the hemodynamic indices of dogs. The electrophysiological effects of OTS in vivo and in vitro were studied by means of contact electrode and intracellular microelectrode techniques. The results showed that OTS shortened APD10, APD50, APD90; decreased APA and Vmax of both monophasic and transmembrane action potentials. OTS also increased the ERP/APD ratio and prevented or abolished the arrhythmikinesis provoked by ouabain and aconitine. The anti-arrhythmic properties of OTS lead us to draw an inference that the anti-arrhythmic mechanism may be related to the blocking of sodium and calcium channels.