Cui Liyan, Ma Zhennan, Li Wenhui, Ma Haihui, Guo Shang, Wang Defu, Niu Yanbing
College of Grassland Science, Shanxi Agricultural University, Jinzhong, Shanxi, China.
College of Life Sciences, Shanxi Agricultural University, Jinzhong, Shanxi, China.
Front Pharmacol. 2023 Jul 3;14:1183393. doi: 10.3389/fphar.2023.1183393. eCollection 2023.
Fisch. ex Bunge is a traditional botanical drug with antibacterial, antioxidant, antiviral, and other biological activities. In the process of industrialization of , most of the aboveground stems and leaves are discarded without resource utilization except for a small amount of low-value applications such as composting. This study explored the antibacterial activity of stem and leaf extracts to evaluate its potential as a feed antibiotic substitute. The antibacterial activity of the flavonoid, saponin, and polysaccharide fractions in stems and leaves was evaluated by the disk diffusion method. The inhibitory activity of the flavonoid fraction from stems and leaves on was explored from the aspects of the growth curve, cell wall, cell membrane, biofilm, bacterial protein, and virulence factors. On this basis, the flavonoid fraction in stems and leaves were isolated and purified by column chromatography to determine the main antibacterial components. The flavonoid fraction in stems and leaves had significant inhibitory activity against , and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 1.5625 and 6.25 mg/mL, respectively. stem and leaf flavonoid fraction can induce death of in many ways, such as inhibiting growth, destroying cell wall and cell membrane integrity, inhibiting biofilm formation, inhibiting bacterial protein synthesis, and downregulating virulence factor expression. In addition, it was clear that the main flavonoid with antibacterial activity in stems and leaves was isoliquiritigenin. Molecular docking showed that isoliquiritigenin could form a hydrogen bonding force with FtsZ. stem and leaf flavonoid fractions had significant inhibitory activity against , and the main chemical composition was isoliquiritigenin.
地锦草（Fisch. ex Bunge）是一种具有抗菌、抗氧化、抗病毒等生物活性的传统植物药。在地锦草产业化过程中，除了少量如堆肥等低价值应用外，大部分地上茎叶被丢弃而未得到资源利用。本研究探讨了地锦草茎叶提取物的抗菌活性，以评估其作为饲料抗生素替代品的潜力。采用纸片扩散法对地锦草茎叶中黄酮类、皂苷类和多糖类成分的抗菌活性进行了评价。从生长曲线、细胞壁、细胞膜、生物膜、细菌蛋白质和毒力因子方面探讨了地锦草茎叶黄酮类成分对大肠杆菌的抑制活性。在此基础上，通过柱色谱法对地锦草茎叶中的黄酮类成分进行分离纯化，以确定主要抗菌成分。地锦草茎叶黄酮类成分对大肠杆菌具有显著的抑制活性，最低抑菌浓度（MIC）和最低杀菌浓度（MBC）分别为1.5625和6.25mg/mL。地锦草茎叶黄酮类成分可通过抑制生长、破坏细胞壁和细胞膜完整性、抑制生物膜形成、抑制细菌蛋白质合成以及下调毒力因子表达等多种方式诱导大肠杆菌死亡。此外，明确了地锦草茎叶中具有抗菌活性的主要黄酮类成分是异甘草素。分子对接显示异甘草素可与FtsZ形成氢键作用力。地锦草茎叶黄酮类成分对大肠杆菌具有显著的抑制活性，主要化学成分是异甘草素。
