Mechanism and inotropic actions of the water extracts of the leaves and seeds of Datura metel (Solanaceae) on isolated frog???s heart


David Emery Tsala, Mbida Hacheked, Nnanga Nga, Ngo Lemba Tom Esther, Habtemariam Solomon, Ze Minkande Jacqueline

Datura metel leaves are used by athletes to enhance their performances. The water extract of the leaves and seeds was tested for their cardiotonic effect. Langherdoff’s model for the measurement of the mechanical activity of the isolated amphibian heart in ventricular perfusion was used to evaluate some parameters of cardiac contractility. The effect of the extracts was also compared to sympathetic agonist and antagonist. The leaf and seed extracts induced a significant (p < 0.05) positive inotropic effect (68.65% and 70.42%) when used at 1.5 and 2.5 mg/mL, respectively. No significant change in the heart rate was observed. In addition, reversible heart arrest for the leaf and seed extracts was noticed at the dose of 6 and 5 mg/ml, respectively. The stimulatory activity of the tested extracts was inhibited by acetylcholine and amlodipine, suggesting that the extracts have cardiotonic properties, likely through muscarinic receptors and calcium channels