Cardiovascular Actions and Active Constituents of Nerium Oleander L.: A Comparative Study with Digitalis

Abstract

The chloroform extract of the leaf and the bark of Nerium oleander L. was tested for cardiac glycosides using Liebermann Burchard test, Kedde's reagent and Keller-Killiani's test which gave positive result indicating the existence of cardiac glycosides in the extract. Further identification of cardiac glycosides in the chloroform and alcohol extracts by thin layer chromatography using silica gel ·G and silica gel GF 254 (50: 50) as adsorbent, ethyl acetate/methanol/ (75/10/7) as solvent systems and 50% as sprayer showed many coloured spots, one of them had Rf value near reference cardiac glycoside, oleandrin.

The biological assay of cardiac glycosides in the leaf and the bark of Nerium oleander L. by guinea-pig method according to BP 1980 showed that total cardiac glycosides in term of oleandrin was 0.37 and 0.44 per cent, respectively. The potency of cardiac glycosides in the leaf as compared to digitalis was 0.95, and in the bark was 1.14 which suggested that cardiac glycosides in the bark of Nerium oleander L. were more potent than those in the leaf and in digitalis.

The action of cardiac glycosides in the leaf and in the bark of Nerium oleander: L. on the right ventricular strip of guinea-pig in vitro was similar to the action of digitalis, that is, they possessed cardiotonic action at low doses, and toxic action was produced at high doses, as shown by contracture. The infusion of diluted alcoholic extract into the vein of guinea-pig in vivo produced similar changes in the electrocardiogram recorded in the animal.