Channelopathy Activity Of A-41(Propyl Ester of Gallic Acid): Experimental and Computational Study of Antihypertensive Activity

Abstract

This study aimed to evaluate the antihypertensive potential of the natural compound A41, a bioactive molecule, using integrated in vitro, in vivo, and in silico approaches. The rationale for selecting A41 is based on preliminary screening that suggested its strong calcium-modulating activity, a key factor in vascular tone regulation. In vitro experiments were performed on isolated rat aortic rings to investigate A41’s effect on vascular smooth muscle ion channels, particularly voltage-operated L-type Ca²⁺ channels and receptor-operated Ca²⁺ channels. The study also explored endothelium-dependent pathways. Selective ion channel blockers were applied to confirm the involvement of specific mechanisms. A41 significantly inhibited Ca²⁺ entry through L-type Ca²⁺ channels under hypertensive conditions, achieving 82.2 ± 2.0 % relaxation at 35 μM, with an IC₅₀ of 22.10 μM. Additionally, receptor-operated Ca²⁺-induced contractions were reduced by 87.0 ± 2.7 % at 50 μM. Molecular docking simulations demonstrated high binding affinity of A41 to calcium-regulating proteins, including the sodium-calcium exchanger (NCX) and plasma membrane Ca²⁺ ATPase, with binding free energies of −6.6 kcal/mol and estimated inhibitory constants (Kᵢ) of 14.558 μM. In vivo studies were conducted using male Wistar rats (n = 6) in an adrenaline-induced hypertension model. Intravenous administration of A41 (dose: 50 mg/kg) produced a marked antihypertensive effect, lowering systolic blood pressure to 82.8 ± 8.3 mmHg and diastolic pressure to 61.3 ± 5.9 mmHg within 3 h. Together, these findings demonstrate that A41 exerts antihypertensive effects by modulating calcium transport mechanisms in vascular smooth muscle, involving both ion channels and calcium-handling proteins, supporting its potential as a candidate for hypertension therapy.

HIGHLIGHTS

• A41 was investigated for antihypertensive activity using integrated in vitro, in vivo, and in silico approaches.
• In vitro studies assessed A41’s effects on L-type and receptor-operated Ca²⁺ channels in isolated rat aortic rings.
• In vivo evaluation was conducted in an adrenaline-induced hypertension model in male Wistar rats.
• In silico molecular docking targeted key aortic ion channels involved in calcium regulation.
• The study aimed to elucidate the calcium-modulating mechanisms underlying A41’s vascular effects.

GRAPHICAL ABSTRACT