Study of the mechanism of action of ethanol extract of Chamomilla recutita (L) Rauschert on the myocardium of guinea pig

Abstract

The Chamomilla recutita (L) Rauchester is a plant known since ancient times due to the medicinal,cosmetic, aromatic and ornamental properties. Its effects include astringent, hypoallergenic, soothing,sedative, anti-inflammatory, analgesic and others. Despite its widespread use could be found shortly onthe effects of this plant in mammalian heart, so this study aims to evaluate the inotropic effects of ethanolextract of chamomile in the myocardium of guinea pig (Cavia porcellus). The experiments wereperformed in isolated guinea pig left atrium mounted in Cuba (4-5 ml Tyrode, 29 ± 0.1 ° C, 95% O2, 5%CO2), stretched (1gf) and stimulated (400 V, 0.5 ms) , and force of contraction was recorded, digitizedand recorded on a computer. Isometric force of atrial contraction in the presence of the extract wasreduced by 60% indicating a negative inotropic effect of concentration-dependent manner and reversibleafter washing, with an EC50 of 1.98 mg / mL. Some possible mechanisms of action were theninvestigated, resulting in a relative effectiveness as a result of 30% of the inotropic effects produced byCaCl2, and no significant result produced by the TEA and the adrenergic and cholinergic receptors.Conclusions: Chamomile depressed the force of contraction in guinea pig left atrium, partially inhibitingthe calcium channel currents. Potassium currents and cholinergic and adrenergic receptors do not interferein the mechanism of negative inotropism produced by chamomile because their effects were notstatistically significant.