Cardiac activity of isolated constituents of Inula racemosa.

Roots of the plant Inula racemosa are used as folk medicine in east Asia and Europe. Inula racemosa in combination with Commiphora mukul was reported to cure myocardial ischemia. However, systematic investigation of the plant for its specific role in heart diseases has not been conducted so far. In the present study, we have reported the isolation of four major constituents A, B, C and D along with some minor constituents from the plant Inula racemosa. Among the major constituent, constituent Dhas been selected first from spectral data and studied for its cardiac activity on isolated frog heart. The experimental data show that constituent D decreases heart rate and force of contraction at 40 mcg/ml. Actions of Adrenaline are blocked by constituent D and it also acts as an agonist for Propranolol. The studies indicate that constituent D produces a negative ionotropic and negative chronotropic effect on frog's heart. These studies can be utilized as a cardiac marker for exploring the cardiac activity of the plant Inula racemosa.