Abstract

Aim. The effects of the water extract of the leaves of Euphorbia Poissonii (Euphorbiacea) on frog heart contraction and its possible mechanism action were investigated. Method. By using the Langerdhorff model of the isolated frog heart preparation, the strength and frequency of heart contractions as well as cardiac output were measured under perfusion with test drugs. Results and conclusion. When assessed with digoxin and adrenaline as positive controls, the water extract (3 mg/mL) exhibited significant positive inotropic (70.00% improvement compared to baseline) and chronotropic (17.79% improvement) effects. Additionally, heart contractility was inhibited in the presence of propranolol and amlodipine, suggesting that the testing extract is having adrenergic properties. Reversible heart arrest was noticed at the dose of 6 mg/mL.

Key words: adrenergic agonism; Euphorbia poissonii; frog heart; inotropic and chronotropic effects