RESUMO
The cardiac activity of Saussurea lappa roots was evaluated in isolated perfused rabbit heart by the Langendorff's technique. Heart rate, contractility and coronary flow were determined in the presence of different concentrations of methanolic extract of Saussurea lappa, digoxin and diltiazem. The extract exhibited significant [p<0.01] positive inotropic effect at the first three doses [0.5/ Micro g, 2.5/ Micro g and 5.0/ Micro g] while a significant negative chronotropic effect and coronary flow rates were observed at all the doses tested. These effects were comparable to the effects of digoxin and diltiazem. The increase in force of contraction with decrease in heart rate and coronary flow rates were also observed to be dose dependent as increase in the dose of test extract further enhanced the effects except contractility that started decreasing at higher doses. It is conceivable therefore, that Saussurea lappa roots contain certain pharmacologically active compounds that could be involved in the cardiotonic activity of the extract