Antiarrhythmic Properties of Elsholtzia ciliata Essential Oil on Electrical Activity of the Isolated Rabbit Heart and Preferential Inhibition of Sodium Conductance

Abstract

Elsholtzia ciliata essential oil (E. ciliata) has been developed in Lithuania and internationally patented as exerting antiarrhythmic properties. Here we demonstrate the pharmacological effects of this herbal preparation on cardiac electrical activity. We used cardiac surface ECG and a combination of microelectrode and optical mapping techniques to track the action potentials (APs) in the Langendorff-perfused rabbit heart model during atrial/endo-/epi-cardial pacing. Activation time, conduction velocity and AP duration (APD) maps were constructed. E. ciliata increased the QRS duration and shortened QT interval of ECG at concentrations of 0.01–0.1 μL/mL, whereas 0.3 μL/mL (0.03%) concentration resulted in marked strengthening of changes. In addition, the E. ciliata in a concentration dependent manner reduced the AP upstroke dV/dtmax and AP amplitude as well as APD. A marked attenuation of the AP dV/dtmax and a slowing spread of electrical signals suggest the impaired functioning of Na+-channels, and the effect was use-dependent. Importantly, all these changes were at least partially reversible. Our results indicate that E. ciliata modulates cardiac electrical activity preferentially inhibiting Na+ conductance, which may contribute to its effects as a natural antiarrhythmic medicine.

Elsholtzia ciliata Essential Oil Exhibits a Smooth Muscle Relaxant Effect

“…Our study demonstrates that EO has a potent relaxing influence on smooth muscles in the prostate and aorta which may be related to the inhibition of α 1 -adrenoreceptors. This physiologically relevant effect, together with the previously identified antiarrhythmic and hypotensive effects [1,2], sketches a promising picture of EO's potential therapeutic applications across a diverse spectrum of medical conditions.…”

“…Previous electrophysiological studies with Langendorff-perfused rabbit hearts revealed that EO at a higher concentration (0.3 µL/mL) shortened action potentials and slowed the impulse propagation down via the atrioventricular node, inducing an conduction block. These results suggested that EO can have an inhibitory effect not only on Na + -current but also the Ca 2+ -current [2]. Another study found that the furan derivative, 5-hydroxymethylfurfural, relaxed coronary arteries in a concentration-dependent manner and exerted negative inotropic, lusitropic, and chronotropic effects in isolated rat hearts.…”

“…[8,9]. Earlier studies demonstrated that EO possesses features of class 1B antiarrhythmic drugs [2]. However, there are no data about the physiological effects of 2AF and 5MFF.…”

“…Primarily, the antiproliferative activity of EO on three cancer cell lines (human glioblastoma (U87), pancreatic cancer (Panc-1), and triple-negative breast cancer (MDA-MB231)) was determined [1]. Later, studies with isolated rabbit hearts revealed the antiarrhythmic properties typical for first-class antiarrhythmic drugs [2]. Recently, an in vivo study conducted on pigs showed that EO possesses a hypotensive effect, leading to a notable reduction in arterial blood pressure.…”

Elsholtzia ciliata (Thunb.) Hyland: A Review of Phytochemistry and Pharmacology

“…The reduction of action potential duration can reduce the occurrence of early depolarization. This experiment provides theoretical basis for E. ciliata in the treatment of arrhythmia [ 48 ].…”