Liao Chengshui, Yu Chuan, Guo Jinxiang, Guan Mengxiang
College of Animal Science and Technology/Laboratory of Functional Microbiology and Animal Health, Henan University of Science and Technology, Luoyang, China.
Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Luoyang, China.
Front Microbiol. 2024 Jul 17;15:1388388. doi: 10.3389/fmicb.2024.1388388. eCollection 2024.
Increases in the virulence and survival of some pathogens in the presence of subinhibitory concentrations of antibiotics have been reported. However, research on the effects of subinhibitory concentrations of antimicrobial substances derived from traditional Chinese medicine on pathogens is still insufficient. Glabridin is a well-known active isoflavone found in licorice roots that possesses a wide range of biological activities. Therefore, in this study, () exposed to subinhibitory concentrations of glabridin was used as the research object. The minimum inhibitory concentration (MIC) was determined for . We investigated the impacts of subinhibitory concentrations of glabridin on the morphology, motility, biofilm formation, adherence, and survival of . The results indicated that the MIC of glabridin for was 31.25 μg/mL. At 1/8, 1/4, or 1/2 of the MIC, glabridin did not affect the growth, morphology, flagellar production, or biofilm formation of . However, subinhibitory concentrations of glabridin inhibited bacterial swimming and swarming motility and decreased the hemolytic activity of . Glabridin reduced the hemolytic activity of culture supernatants. The results also showed that subinhibitory concentrations of glabridin had no toxic effect on RAW264.7 cells but decreased the intracellular growth of in RAW264.7 cells. Furthermore, subinhibitory concentrations of glabridin triggered ROS production but did not induce MET formation in macrophages. In addition, glabridin did not enhance the capacity of to trigger METs or the extracellular killing of macrophages by METs. Thus, we conclude that subinhibitory concentrations of glabridin reduce motility and hemolytic activity but do not exhibit antimicrobial activity. Glabridin could be an interesting food additive as a bacteriostatic agent with anti- activity.
据报道，在亚抑菌浓度的抗生素存在下，一些病原体的毒力和存活率会增加。然而，关于源自中药的亚抑菌浓度抗菌物质对病原体影响的研究仍然不足。光甘草定是一种在甘草根中发现的著名活性异黄酮，具有广泛的生物活性。因此，在本研究中，将暴露于亚抑菌浓度光甘草定的（此处原文缺失具体受试对象）用作研究对象。测定了（此处原文缺失具体受试对象）的最低抑菌浓度（MIC）。我们研究了亚抑菌浓度的光甘草定对（此处原文缺失具体受试对象）的形态、运动性、生物膜形成、黏附及存活的影响。结果表明，光甘草定对（此处原文缺失具体受试对象）的MIC为31.25μg/mL。在MIC的1/8、1/4或1/2浓度下，光甘草定不影响（此处原文缺失具体受试对象）的生长、形态、鞭毛产生或生物膜形成。然而，亚抑菌浓度的光甘草定抑制细菌的游动和群集运动，并降低（此处原文缺失具体受试对象）的溶血活性。光甘草定降低了（此处原文缺失具体受试对象）培养上清液的溶血活性。结果还表明，亚抑菌浓度的光甘草定对RAW264.7细胞没有毒性作用，但降低了（此处原文缺失具体受试对象）在RAW264.7细胞内的生长。此外，亚抑菌浓度的光甘草定触发了活性氧（ROS）的产生，但未在巨噬细胞中诱导金属离子嗜中性粒细胞（MET）的形成。另外，光甘草定没有增强（此处原文缺失具体受试对象）触发METs的能力或METs对巨噬细胞的胞外杀伤作用。因此，我们得出结论，亚抑菌浓度的光甘草定降低（此处原文缺失具体受试对象）的运动性和溶血活性，但不表现出抗菌活性。光甘草定作为一种具有抗（此处原文缺失具体活性）活性的抑菌剂，可能是一种有趣的食品添加剂。
