ABSTRACT
Herbal remedies are suitable alternatives for synthetic drugs due to their availability, minimal side effects and lower price. Biologically active substances of plant origin represent an essential branch of modern cardiovascular pharmacotherapy. The aim of the present study is to investigate rate-dependent electrophysiological effects of Crocus sativus on extra-cellular field potential of isolated rabbit heart in-vitro. Male Newsland rabbits [1.5-2 kg] were used in all of experiments; various experimental stimulating protocols [WBCL, recovery, rate-dependent protocols] were applied to study electrophysiological properties of Node [N=25]. All of the stimulated protocols repeated in the presence and absence different concentration of saffron [54,108 mg]. Results were shown as mean +/- SE. Saffron inhibited basic and rate-dependent electrophysiological properties of AV-Node. Significant prolongation of WBCL from 141 +/- 4.7 to 165.9 +/- 6.7 msec [in control and saffron group] was recorded [p<0.05]. Rate-dependent protective role of plant to increases difference between atrial and nodal effective refractory period and was observed [from 10 +/- 5.5 to 23.6 +/- 7.4 msec in control and saffron] [p<0.05]. Rate-dependent minor inhibitory role of Crocus sativus in AV-Node can modify protective role of AV-Node during arrhythmia