Sun Yixun, Zhang Mingbo, Zhang Yating, Zheng Yu, Li Jing, Cai Qian, Wang Anqi, Qu Yang
College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
Molecules. 2025 Jun 27;30(13):2764. doi: 10.3390/molecules30132764.
This study systematically investigated the inhibitory mechanism of L. polyphenols (ALP) against human neutrophil elastase (HNE). Molecular docking techniques were employed to predict the binding patterns and inhibition types between polyphenolic components and HNE, complemented by in vitro enzymatic tests to validate inhibitory efficacy. Combination index (CI) analysis was applied to evaluate synergistic effects. Through preliminary in vitro screening, chlorogenic acid, quercetin, and isochlorogenic acid A were identified as key bioactive constituents. Experimental results demonstrated that the half-inhibitory concentration (IC) of individual compounds against HNE ranged from 46.4 to 203.3 μM, while ALP extract exhibited dose-dependent inhibition (IC = 0.99 mg/mL). Drug combination ratios based on individual IC values revealed synergistic effects (CI < 1) in chlorogenic acid-quercetin and isochlorogenic acid A-quercetin combinations, whereas antagonism (CI > 1) was observed in chlorogenic acid-isochlorogenic acid A pairs. The molecular docking results predicted that chlorogenic acid and isochlorogenic acid A competitively occupy the same binding site of the target protein (HNE) to exert inhibitory effects, thereby explaining the antagonism produced by their combination. In contrast, quercetin may inhibit HNE with a binding site different from that of chlorogenic acid or isochlorogenic acid A, which accounts for the observed synergistic effects. This study provides the first systematic elucidation of synergistic mechanisms of ALP as natural HNE inhibitors, providing theoretical foundations for developing novel natural HNE inhibitors with potential applications in acute lung injury, COVID-19-associated inflammatory conditions, and chronic inflammatory diseases.
本研究系统地探究了酸模叶蓼多酚（ALP）对人中性粒细胞弹性蛋白酶（HNE）的抑制机制。采用分子对接技术预测多酚类成分与HNE之间的结合模式和抑制类型，并通过体外酶试验验证抑制效果。应用联合指数（CI）分析评估协同效应。通过初步的体外筛选，确定绿原酸、槲皮素和异绿原酸A为关键生物活性成分。实验结果表明，各化合物对HNE的半数抑制浓度（IC）范围为46.4至203.3μM，而ALP提取物表现出剂量依赖性抑制（IC = 0.99mg/mL）。基于各化合物IC值的药物组合比例显示，绿原酸 - 槲皮素和异绿原酸A - 槲皮素组合具有协同效应（CI < 1），而绿原酸 - 异绿原酸A组合则表现出拮抗作用（CI > 1）。分子对接结果预测，绿原酸和异绿原酸A竞争性占据靶蛋白（HNE）的同一结合位点以发挥抑制作用，从而解释了它们组合产生的拮抗作用。相比之下，槲皮素可能通过与绿原酸或异绿原酸A不同的结合位点抑制HNE，这解释了观察到的协同效应。本研究首次系统阐明了ALP作为天然HNE抑制剂的协同机制，为开发在急性肺损伤、COVID - 19相关炎症病症和慢性炎症疾病中具有潜在应用的新型天然HNE抑制剂提供了理论基础。
