Evaluation of cardiotonic activity of leaves of Vitex negundo Linn

Abstract

The present study was undertaken to evaluate the cardiotonic activity of the aqueous extract of leaves of Vitex negundo Linn. The leaves are believed to contain some antioxidants and hence pose it to be used in the prevention of cardiovascular diseases. The cardiotonic effect of aqueous extract of leaves of V. negundo Linn. was studied by using isolated frog heart perfusion technique (IFHP). Ringer solution without calcium was used as a vehicle for administration of aqueous extract as test and digoxin as standard. A significant increase in the height of force of contraction (positive ionotropic effect) and decrease in heart rate (negative chronotropic effect) was observed at smaller doses (0.4 mg). The effect increased as dose was increased. The test extract had not produced cardiac arrest even at a dose of 2 mg, a higher concentration as compared to standard, digoxin that showed cardiac arrest at dose of 0.2 mg. Hence,
as compared to standard, test drug showed wide therapeutic index.
Key words: Digoxin, isolated frog heart perfusion technique, therapeutic index, Vitex negundo Linn