Changchun University of Chinese Medicine, Changchun, 130117, China.
First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
World J Microbiol Biotechnol. 2021 Nov 27;38(1):6. doi: 10.1007/s11274-021-03182-4.
Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant pathogen that poses a significant risk to global health today. In S. aureus, α-hemolysin is an important virulence factor as it contributes to the capacity of the bacteria to infect the host. Here, we showed that biochanin A (bioA), an isoflavone present in red clover, cabbage and alfalfa, effectively inhibited hemolytic activity at a dose as low as 32 μg/mL. Further, western blot and RT-qPCR data showed that bioA reduced the production and expression of MRSA hemolysin in a dose-dependent manner. In addition, when different concentrations of bioA were added to a coculture system of A549 cells and S. aureus, it could significantly decrease cell injury. Importantly, the in vivo study showed that bioA could protect mice from pneumonia caused by a lethal dose of MRSA, as evidenced by improving their survival and reducing the number of bacterial colonies in lung tissues, the secretion of hemolysin into alveolar lavage fluid and the degree of pulmonary edema. In conclusion, biochanin A protected the host from MRSA infection by inhibiting the expression of the hemolysin of MRSA, which may provide experimental evidence for its development to a potential anti-MRSA drug.
耐甲氧西林金黄色葡萄球菌（MRSA）是一种具有多重耐药性的病原体，目前对全球健康构成重大威胁。在金黄色葡萄球菌中，α-溶血素是一种重要的毒力因子，因为它有助于细菌感染宿主的能力。在这里，我们表明，染料木黄酮（bioA），一种存在于红三叶草、卷心菜和紫花苜蓿中的异黄酮，以低至 32μg/mL 的剂量有效抑制溶血活性。此外，Western blot 和 RT-qPCR 数据表明，bioA 以剂量依赖的方式降低了 MRSA 溶血素的产生和表达。此外，当不同浓度的 bioA 被添加到 A549 细胞和金黄色葡萄球菌的共培养系统中时，它可以显著降低细胞损伤。重要的是，体内研究表明，bioA 可以通过提高存活时间和减少肺组织中细菌菌落数量、抑制溶血素分泌到肺泡灌洗液中和减轻肺水肿程度来保护小鼠免受致死剂量 MRSA 引起的肺炎。总之，染料木黄酮通过抑制 MRSA 溶血素的表达来保护宿主免受 MRSA 感染，这可能为其开发为一种潜在的抗 MRSA 药物提供实验依据。
