Eugenol delays the onset of ouabain-induced ventricular cardiac arrhythmias in guinea pigs.

Eugenol is an aromatic compound used in the manufacture of medicines, perfumes, cosmetics and as an anaesthetic due to the ability of the drug to block the neuronal isoform of voltage-gated Na channels (Na ). Some arrhythmias are associated with gain of function in the sodium current (I ) found in cardiomyocytes, and antiarrhythmic sodium channel blockers are commonly used in the clinical practice. This study sought to elucidate the potential mechanisms of eugenol's protection in the arrhythmic model of ouabain-induced arrhythmias in guinea pig heart.

Eugenol interacts with cardiac sodium channel and reduces heart excitability and arrhythmias.

Aims: Eugenol is a natural compound found in the essential oils of many aromatic plants. The compound is used as a local anesthetic because of its inhibitory effect on the voltage-gated Na channels (Na), which are expressed in the nociceptive neurons. Eugenol has shown wide range of activities in the cardiovascular system; most of these activities are attributed to the modulation of voltage-sensitive Ca channels.

Dengue virus infection induces inflammation and oxidative stress on the heart.

Objective: Dengue fever is one of the most important arboviral diseases in the world, and its severe forms are characterised by a broad spectrum of systemic and cardiovascular hallmarks. However, much remains to be elucidated regarding the pathogenesis triggered by (DENV) in the heart. Herein, we evaluated the cardiac outcomes unleashed by DENV infection and the possible mechanisms associated with these effects.

(-)-Terpinen-4-ol changes intracellular Ca handling and induces pacing disturbance in rat hearts.

(-)-Terpinen-4-ol is a naturally occurring plant monoterpene and has been shown to have a plethora of biological activities. The objective of this study was to investigate the effects of (-)-terpinen-4-ol on the rat heart, a key player in the control and maintenance of arterial blood pressure. The effects of (-)-terpinen-4-ol on the rat heart were investigated using isolated left atrium isometric force measurements, in vivo electrocardiogram (ECG) recordings, patch clamp technique, and confocal microscopy.

Dissection of the Effects of Quercetin on Mouse Myocardium.

Quercetin is a plant flavonoid with several biological activities. This study aimed to describe quercetin effects on contractile and electrophysiological properties of the cardiac muscle as well as on calcium handling. Quercetin elicited positive inotropism that was significantly reduced by propranolol indicating an involvement of the sympathetic nervous system.

Geraniol blocks calcium and potassium channels in the mammalian myocardium: useful effects to treat arrhythmias.

Geraniol is a monoterpene present in several essential oils, and it is known to have a plethora of pharmacological activities. In this study, we explored the contractile and electrophysiological properties of geraniol and its antiarrhythmic effects in the heart. The geraniol effects on atrial contractility, L-type Ca(2+) current, K(+) currents, action potential (AP) parameters, ECG profile and on the arrhythmia induced by ouabain were evaluated.

The positive inotropic effect of the ethyl acetate fraction from Erythrina velutina leaves on the mammalian myocardium: the role of adrenergic receptors.

Objectives: We studied the effects of ethyl acetate fraction (EAcF) obtained from Erythrina velutina leaves on mammalian myocardium.

Methods: The effect of EAcF on the contractility was studied using guinea-pig left atria mounted in a tissue bath (Tyrode's solution, 29°C, 95% CO2 , 5% O2 ) and electrically stimulated (1 Hz). Concentration-response curves of EAcF were obtained in the presence of propranolol (1 μm), nifedipine (1 μm) and in reserpinized animals (5 mg/kg).

R(+)-pulegone impairs Ca²+ homeostasis and causes negative inotropism in mammalian myocardium.

The present study aimed to investigate the inotropic effects of R(+)-pulegone, a monoterpene found in plant species belonging to the genus Mentha, on the mammalian heart. In electrically stimulated guinea pig atria, R(+)-pulegone reduced the contractile force (~83%) and decreased the contraction time measured at 50% of the maximum force amplitude (CT(50)) from 45.8 ± 6.

Aqueous fraction from Costus spiralis (Jacq.) Roscoe leaf reduces contractility by impairing the calcium inward current in the mammalian myocardium.

Ethnopharmacological Relevance: Brazilian folk medicine uses infusion of Costus spiralis leaf to help people to treat arterial hypertension and syndromes of cardiac hyperexcitability.

Aim Of The Study: Evaluate the aqueous fraction (AqF) effect on atrial contractility and investigate its mechanism of action.

Materials And Methods: The AqF effect on the cardiac contractility was studied on isolated electrically driven guinea pig left atria.