Xie Weiwei, Gao Jiaming, Liang Yingran, Huang Chenxing, Zhang Boyong, Chen Xiaonan, Yao Xi, Nan Guo, Wu Honghua, Wang Yuefei, Wu Lin, Wang Taiyi, Zhu Yan
State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, People's Republic of China.
Institute of Basic Medical Sciences of Xiyuan Hospital, Beijing Key Laboratory of Pharmacology of Chinese Materia, Beijing, 100091, People's Republic of China.
Drug Des Devel Ther. 2025 Jan 9;19:141-157. doi: 10.2147/DDDT.S485723. eCollection 2025.
The major cardiac voltage-gated sodium channel Na1.5 (I) is essential for cardiac action potential initiation and subsequent propagation. Compound Chinese medicine Wenxin Keli (WXKL) has been shown to suppress arrhythmias and heart failure. However, its active components have not been fully elucidated. This study focused on identifying the active inhibitor of I in WXKL and exploring their mode of action in electrophysiological conduction.
A chemical fraction library was constructed from an aqueous extract of WXKL and screened using an automated patch-clamping system in cells stably expressing the Na1.5 gene SCN5A. Candidate fractions with I-inhibition activity were analyzed by HPLC-ESI-IT-TOF-MS and GC-MS to identify the ingredients. Na1.5 blocker molecules identified by single-cell electrocardiogram were tested in hiPSC-derived cardiomyocytes. We evaluated the SCN5A inhibitory potential of Wenxin Keli effective monomer employing molecular docking and molecular dynamics simulation approaches.
A primary screen of the WXKL chemical library identified five fractions that significantly inhibited the Na1.5 channel, with one of them rich in poly-saturated fatty acids. Molecular structural characterization revealed the presence of lauric acid, myristic acid, palmitic acid, and stearic acid in the active subfraction. Electrophysiological characterization demonstrated lauric acid (LA) as the most effective monomer for I-inhibition with an IC at 27.40 ± 12.78 μM. LA shifted the steady-state inactivation of I to more negative potentials and decreased the amplitude of extracellular field potential in hiPSC-derived cardiomyocytes. We demonstrate for the first time that naturally poly-saturated fatty acid, lauric acid, as a potential novel I blocker. Molecular docking and molecular dynamics simulation suggested that LA binds to the Na1.5 protein, with a significant binding affinity forming interactions with functionally essential residues and blocks the inward flow of Na. Mechanistically, lauric acid acts on the fast inactivation of Na1.5 alter electrophysiology conduction of hiPSC-derived cardiomyocytes and contribute to the antiarrhythmic effect of WXKL.
Lauric acid is a potent blocker for sodium channel Na1.5 and alleviates arrhythmia via inhibiting I.
主要的心脏电压门控钠通道Na1.5（I）对于心脏动作电位的起始和随后的传导至关重要。复方中药稳心颗粒（WXKL）已被证明可抑制心律失常和心力衰竭。然而，其活性成分尚未完全阐明。本研究聚焦于鉴定稳心颗粒中I的活性抑制剂，并探索其在电生理传导中的作用模式。
从稳心颗粒的水提取物构建化学组分库，并使用自动膜片钳系统在稳定表达Na1.5基因SCN5A的细胞中进行筛选。对具有I抑制活性的候选组分通过HPLC-ESI-IT-TOF-MS和GC-MS进行分析以鉴定成分。通过单细胞心电图鉴定的Na1.5阻断剂分子在人诱导多能干细胞衍生的心肌细胞中进行测试。我们采用分子对接和分子动力学模拟方法评估稳心颗粒有效单体对SCN5A的抑制潜力。
对稳心颗粒化学库的初步筛选鉴定出五个显著抑制Na1.5通道的组分，其中一个富含多不饱和脂肪酸。分子结构表征显示活性亚组分中存在月桂酸、肉豆蔻酸、棕榈酸和硬脂酸。电生理表征表明月桂酸（LA）是最有效的I抑制单体，IC为27.40±12.78μM。月桂酸将I的稳态失活转移到更负的电位，并降低人诱导多能干细胞衍生的心肌细胞中外周电场电位的幅度。我们首次证明天然多不饱和脂肪酸月桂酸作为一种潜在的新型I阻断剂。分子对接和分子动力学模拟表明月桂酸与Na1.5蛋白结合，具有显著的结合亲和力，与功能上必需的残基形成相互作用并阻断Na的内向流动。从机制上讲，月桂酸作用于Na1.5的快速失活，改变人诱导多能干细胞衍生的心肌细胞的电生理传导，并有助于稳心颗粒的抗心律失常作用。
月桂酸是钠通道Na1.5的有效阻断剂，通过抑制I减轻心律失常。
