Relaxant Effect of Urginea maritima on Tracheal Smooth Muscle Mediated by the Effect on Beta-2 Adrenergic, Muscarinic Receptors and Calcium and Potassium Channels.

Hamideh Kazemi Rad,Fatemeh Amin,Arghavan Memarzia,Mohammad Hossein Boskabady,Gabriel A Agbor

doi:10.1155/2021/6637990

Abstract

Urginea maritima (U. maritima) showed anti-inflammatory, antioxidant, antibacterial, diuretic, vasodilatation, and wound-healing effects on fungal infections, cardiac disorders, digestive disorders, rheumatoid disease, and respiratory disorders such as bronchitis, bronchial nosocomial infections, and severe cough. To examine the bronchodilatory effect of U. maritima, the relaxant effect of its extract on rat tracheal smooth muscle (TSM) and its possible mechanism was examined in this study. Male Wistar rats' TSM were divided into eight groups (n = 8 in each group). Four of these groups were TSM tissues, contracted with KCl (60 mM) incubated with atropine, glibenclamide, and indomethacin and nonincubated TSM, while the other four groups were TSM tissues contracted with methacholine (10 μM) for 5 min, incubated with propranolol, chlorpheniramine, and diltiazem and nonincubated TSM. Cumulative concentrations of U. maritima extract (12.5, 25, 50, 100, 20, and 400 μg/ml) were then added to organ bath every 5 min. Theophylline (0.2, 0.4, 0.6, and 0.8 mM) as positive control and saline (1 ml) as negative control were also examined in nonincubated tissues. A concentration-dependent relaxant effect of U. maritima on nonincubated TSM contracted with KCl (60 mM) or methacholine (10 μM) (p < 0.01 and p < 0.001) was observed. The relaxant effects of U. maritima extract in the incubated tissues with glibenclamide, propranolol, diltiazem, atropine, and chlorpheniramine were significantly lower than those in the nonincubated tissues (p < 0.05 to p < 0.001). EC50 values of U. maritima extract in the incubated TSM with glibenclamide, propranolol, diltiazem, and atropine were significantly higher than those in the nonincubated tissues (p < 0.05 for diltiazem-incubated tissues and p < 0.001 for other cases). U. maritima extract displayed considerable relaxant effect on TSM comparable to the effect of theophylline. Beta-2 adrenoceptor stimulation and muscarinic receptor inhibition as well as potassium opening and calcium channels blocking effects are the possible mechanisms for the relaxant effects of the plant.

Highlights

One of the most important chronic inflammatory diseases in the world is asthma with considerable morbidity
Over the past 30 years, there has been an increase in the number of patients with asthma, and 250,000 people die from this disease each year. e treatment of this disease is very costly and the direct and indirect costs of the asthma are globally on the rise [2]. e precise mechanism of asthma pathophysiology and the role of biochemical intermediates involved in asthma are not yet known, but, Evidence-Based Complementary and Alternative Medicine based on available information, leukotrienes, prostaglandins, histamine, nitric oxide, and type II immune response cytokines are among the most important mechanisms involved in the pathophysiology of asthma. ese mechanisms cause airway inflammation as well as bronchospasm in asthmatic patients [3]. e adrenoceptor and cholinergic pathways affected the airway smooth muscle tone
3.1. e Relaxant Effect of U. maritima Extract on tracheal smooth muscle (TSM) Contraction Induced by Methacholine in Nonincubated and Incubated Tissues

Summary

Introduction

One of the most important chronic inflammatory diseases in the world is asthma with considerable morbidity. Androgen intermediates like histamine and prostaglandins may cause bronchial smooth muscle contraction directly or reflexively through stimulation of receptors [4]. E potent digitalis-like cardiac effect of the plant was described for centuries [16], and it showed heart stimulatory and diuretic effects [17]. Fresh bulbs of this species are used to accelerate wound-healing, as well as in digestive disorders and rheumatoid disease [18]. U. maritima extract caused peripheral vasodilatation in anesthetized rabbits [21] and it showed similar effect to that of digitalis on the heart. Erefore, to examine the bronchodilatory effect of U. maritima, this study sought to investigate the relaxant effect mechanisms of action of its extract on tracheal smooth muscle (TSM) in Wistar rats

Materials and Methods

Results

Findings

Conclusions