Examination of the Role of Potassium Channels in the Relaxant Effects of Quercetin on Intestinal Smooth Muscle Contractions; [بررسی نقش کانا لهای پتاسیمی در اثرات رفع انقباضی کوئرستین بر انقباضات عضلات صاف روده] Publisher



Sadraei H ; Bahrami F ; Ghasemi M
Source: Koomesh Published:2025

Abstract

Background: Quercetin is a natural compound and a plant polyphenol with multiple pharmacological effects on the gastrointestinal system. Studies have shown that quercetin exhibits relaxant effects on the smooth muscles of the gastrointestinal tract, including the ileum. Objectives: This study aims to evaluate the extent to which potassium channels contribute to the relaxant effects of quercetin on intestinal smooth muscle contractions. Methods: This study used isolated ileum tissue from male Wistar rats (200 - 220g) in various experimental groups (n = 6). Ileum contractions were recorded using an oscillography device. The antispasmodic effects of diazoxide and quercetin on the ileum muscles in response to spasmogens acetylcholine and KCl were examined in the presence of ATP-sensitive potassium channel inhibitor (glibenclamide) and a non-selective potassium channel inhibitor (tetraethylammonium). The amplitude of ileum smooth muscle contractions was measured and expressed as a percentage of the contractions recorded before drug administration. Results: Diazoxide had relaxant effects on contractions induced by KCl (20mM) and acetylcholine. In the presence of glibenclamide, the inhibitory effect of diazoxide on spasmogens was significantly reduced. Tetraethylammonium caused a concentration-dependent increase in KCl and acetylcholine-induced spasmogen contractions. Quercetin inhibited ileum contractions induced by KCl and acetylcholine in a concentration-dependent manner. Tetraethylammonium (10 mM) and glibenclamide (50 µM) blocked the inhibitory effects of quercetin on contractions induced by KCl and acetylcholine. Conclusion: This study indicates that quercetin possesses relaxant effects and that part of the relaxant mechanism of quercetin on ileum smooth muscle is through the activation of ATP-sensitive potassium channels. Copyright © 2025, Sadraei et al.