Xiao Xia, Huang Yanhu, Liu Wei, Liu Yuan, Zhang Haijie, Meng Chuang, Wang Zhiqiang
College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
Phytother Res. 2025 Mar;39(3):1372-1387. doi: 10.1002/ptr.8427. Epub 2025 Jan 7.
The rising prevalence of multidrug-resistant (MDR) Gram-positive bacteria threatens the effectiveness of current antibiotic therapies. However, the development of new antibiotics has stagnated in recent years, highlighted the critical need for the discovery of innovative antimicrobial agents. This study aims to evaluate the antibacterial activity of naphthoquinones derived from Arnebia euchroma (Royle) Johnst (ADNs) and elucidate their underlying mechanisms. The antibacterial efficacy of ADNs was assessed using the microbroth dilution method. The antibacterial mechanism of acetylshikonin (ASK) was further explored through scanning electron microscopy, RNA-Seq and transcriptomic analysis, fluorescent probes, high-performance liquid chromatography, qRT-PCR and molecular docking. The results demonstrated that all the ADNs exhibit potent antibacterial activity against MDR Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, and linezolid-resistant Enterococcus. Notably, ASK showed minimum inhibitory concentration of 1-2 μg/mL against MRSA. Mechanistic investigations revealed that ASK operates through a multifaceted antibacterial mechanism. First, ASK disrupts bacterial membrane integrity and dissipates proton motive force by targeting membrane phospholipids. Further analysis demonstrated a significant reduction in oxygen consumption and ATP production, indicative of respiratory chain inhibition. Additionally, ASK interferes with bacterial cell wall synthesis, as evidenced by reduction of peptidoglycan precursors and downregulated expression of genes involved in peptidoglycan synthesis. In conclusion, ASK represents a promising antimicrobial agent with potential efficacy against infections caused by MDR Gram-positive bacteria and offers valuable insights for the development of novel therapeutic strategies.
多重耐药（MDR）革兰氏阳性菌的日益流行威胁着当前抗生素疗法的有效性。然而，近年来新抗生素的研发陷入停滞，凸显了发现创新抗菌剂的迫切需求。本研究旨在评估新疆紫草（Arnebia euchroma (Royle) Johnst）衍生萘醌（ADNs）的抗菌活性，并阐明其潜在机制。采用微量肉汤稀释法评估ADNs的抗菌效果。通过扫描电子显微镜、RNA测序和转录组分析、荧光探针、高效液相色谱、qRT-PCR和分子对接进一步探究乙酰紫草素（ASK）的抗菌机制。结果表明，所有ADNs对多重耐药革兰氏阳性病原体均表现出强大的抗菌活性，包括耐甲氧西林金黄色葡萄球菌（MRSA）、耐万古霉素肠球菌和耐利奈唑胺肠球菌。值得注意的是，ASK对MRSA的最低抑菌浓度为1-2μg/mL。机制研究表明，ASK通过多方面的抗菌机制发挥作用。首先，ASK通过靶向膜磷脂破坏细菌膜完整性并消耗质子动力。进一步分析表明氧气消耗和ATP产生显著减少，表明呼吸链受到抑制。此外，ASK干扰细菌细胞壁合成，这可通过肽聚糖前体减少以及参与肽聚糖合成的基因表达下调得到证明。总之，ASK是一种有前景的抗菌剂，对多重耐药革兰氏阳性菌引起的感染具有潜在疗效，并为新型治疗策略的开发提供了有价值的见解。
