AUTHOR=Gu Yeqing , Dong Jun , Li Jing , Luo Qianmin , Dong Xianlan , Tang Guowen , Zhang Jiaxiang , Du Xuan , Pu Qiqi , He Lin , Zhao Kaiwei , Han Diangang , Xin Jige 

TITLE=Antibacterial activity and mechanism of sanguinarine against Staphylococcus aureus by interfering with the permeability of the cell wall and membrane and inducing bacterial ROS production

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1121082

DOI=10.3389/fvets.2023.1121082

ISSN=2297-1769

ABSTRACT=<p><italic>Staphylococcus aureus</italic> (<italic>SA</italic>) is representative of gram-positive bacteria. Sanguinarine chloride hydrate (SGCH) is the hydrochloride form of sanguinarine (SG), one of the main extracts of Macleaya cordata (M. cordata). There are few reports on its antibacterial mechanism against <italic>SA</italic>. Therefore, in this study, we investigated the <italic>in vitro</italic> antibacterial activity and mechanism of SGCH against <italic>SA</italic>. The inhibitory zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were measured, and the bactericidal activity curve was plotted. In addition, the micromorphology, alkaline phosphatase (AKP) activity, Na<sup>+</sup>K<sup>+</sup>, Ca<sup>2+</sup>Mg<sup>2+</sup>-adenosine triphosphate (ATP) activity, intracellular reactive oxygen species (ROS), and fluorescein diacetate (FDA) were observed and detected. The results showed that the inhibitory zone of SGCH against <italic>SA</italic> was judged as medium-sensitive; the MIC and MBC were 128 and 256 μg/mL, respectively; in the bactericidal activity curve, SGCH with 8 × MIC could completely kill <italic>SA</italic> within 24 h. SGCH was able to interfere with the integrity and permeability of the <italic>SA</italic> cell wall and membrane, as confirmed by the scanning electron microscopy (SEM) images, the increase in extracellular AKP and Na<sup>+</sup> K<sup>+</sup>, Ca<sup>2+</sup> Mg<sup>2+</sup>-ATP activities as well as the fluorescein diacetate (FDA) staining experiment results. Moreover, a high concentration of SGCH could induce <italic>SA</italic> to produce large amounts of ROS. In summary, these findings revealed that SGCH has a preferable antibacterial effect on <italic>SA</italic>, providing an experimental and theoretical basis for using SG as an antibiotic substitute in animal husbandry and for the clinical control and treatment of diseases caused by <italic>SA</italic>.</p>