Influences of ginsenosides Rb1, Rb2, and Rb3 on electric and contractile activities of normal and damaged cultured myocardiocytes

Free radical damage to the cultured myocardiocytes of Wistar rat was induced by adding xanthine 0.42 mmol.L-1 and xanthine oxidase 5.3 nmol.L-1 to the culture medium. 30 micrograms.ml-1 of Rb1, Rb2 or Rb3 extracted from the leaf and stem of Panax ginseng C A Meyer restored the action potentials (AP) of free radical damaged cells to normal, indicating their antioxidative action. On normal myocardial cells, Rb1, Rb2, Rb3 20 micrograms.ml-1 inhibited the AP and spontaneous contractility, (suggesting the Ca channel blockade action of panaxadiol saponins). The degrees of their inhibitory effects were found to be Rb1 > Rb2 > Rb3. Their effects against X-XO were basically the same.