Asthma is one of the main intractable diseases recognized by the international medical community. The current widely used bronchodilators for asthma—β2-adrenal receptor agonists—have limited therapeutic effects, necessitating the development of novel antiasthma drugs with increased efficacy and fewer adverse effects. In this study, we investigated the relaxant effects and underlying mechanism of an ethyl acetate extract from dandelion (EAED) on mouse airway smooth muscle. The effects of EAED on agonist-induced precontraction in mouse airway smooth muscle were evaluated with force measurement. Mouse lung slices were used to study the effects of EAED on bronchial smooth muscle. The intracellular Ca2+ concentration was measured using a calcium imaging system. L-type voltage-dependent calcium channel (VDLCC) and non-selective cationic channel (NSCC) currents were measured by patch-clamp. The lung functions of healthy and asthmatic mouse groups were assessed via the forced oscillation technique. EAED inhibits acetylcholine-induced sustained contractions of whole airway smooth muscle by inhibiting VDLCCs, NSCCs, and some unknown channels, reduces the agonist-induced increase in the cytosolic free Ca2+ concentration in airway smooth muscle cells, blocks VDLCC and NSCC currents, and relieves the respiratory resistance of healthy and asthmatic mice. EAED may have potential beneficial effects on mitigating asthma attacks.

中文翻译：

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蒲公英提取物通过阻断 VDLCC 和 NSCC 通道放松小鼠气道平滑肌

哮喘是国际医学界公认的主要疑难杂症之一。目前广泛使用的治疗哮喘的支气管扩张剂——β2-肾上腺受体激动剂——治疗效果有限，需要开发疗效更高、副作用更少的新型抗哮喘药物。在这项研究中，我们研究了蒲公英乙酸乙酯提取物 (EAED) 对小鼠气道平滑肌的松弛作用及其潜在机制。通过力测量评估 EAED 对激动剂诱导的小鼠气道平滑肌预收缩的影响。使用小鼠肺切片研究 EAED 对支气管平滑肌的影响。使用钙成像系统测量细胞内Ca2+浓度。通过膜片钳测量 L 型电压依赖性钙通道 (VDLCC) 和非选择性阳离子通道 (NSCC) 电流。通过强制振荡技术评估健康小鼠组和哮喘小鼠组的肺功能。EAED通过抑制VDLCC、NSCC和一些未知通道，抑制乙酰胆碱诱导的全气道平滑肌持续收缩，减少激动剂诱导的气道平滑肌细胞胞质游离Ca2+浓度的升高，阻断VDLCC和NSCC电流，缓解健康小鼠和哮喘小鼠的呼吸阻力。EAED 可能对减轻哮喘发作具有潜在的有益作用。