School of Life Science, Liaocheng University, Liaocheng, 252059, China.
School of Pharmacy, Liaocheng University, Liaocheng, 252059, China.
Braz J Microbiol. 2022 Dec;53(4):1789-1797. doi: 10.1007/s42770-022-00807-0. Epub 2022 Jul 28.
Propolis has exhibited effective antibacterial activities in preventing the growth of multiple pathogenic bacteria. However, the antibacterial activity of Chinese propolis against methicillin-resistant Staphylococcus aureus (MRSA) is almost unknown. The present study aimed to explore the antibacterial activity and action mechanism of Chinese propolis ethanol extract (CPEE) against MRSA. Thirteen compounds of CPEE were identified using HPLC-DAD/Q-TOF-MS, and none of them showed better anti-MRSA activity than CPEE. The diameter of inhibition zone (DIZ) of CPEE was 20.1 mm. The minimal inhibitory concentration (MIC) of CPEE was 32 mg/L, while the minimal bactericidal concentration (MBC) against MRSA was 64 mg/L. Moreover, CPEE showed significant synergistic effects with β-lactam antibiotics (ampicillin and oxacillin). Nucleic acid and protein leakage assays showed that CPEE can stimulate the release of intracellular macromolecules by damaging the cell membrane integrity of MRSA. Live/dead-staining and SDS-PAGE assays further confirmed that CPEE could inhibit bacterial activities by disrupting the membrane. The reduction in PBP2a expression and β-lactamase activity, as shown by western blot and β-lactamase detection assays, suggested that CPEE was able to reverse the drug resistance of MRSA. These results demonstrated the anti-MRSA activity of CPEE was mainly due to changing the cell membrane and reversing resistance, which indicates that CPEE could be an attractive candidate for use in future food and medical applications.
蜂胶具有抑制多种病原菌生长的有效抗菌活性。然而，中国蜂胶对耐甲氧西林金黄色葡萄球菌（MRSA）的抗菌活性几乎未知。本研究旨在探索中国蜂胶乙醇提取物（CPEE）对 MRSA 的抗菌活性和作用机制。使用 HPLC-DAD/Q-TOF-MS 鉴定了 CPEE 中的 13 种化合物，它们均未表现出比 CPEE 更好的抗 MRSA 活性。CPEE 的抑菌圈直径（DIZ）为 20.1mm。CPEE 的最小抑菌浓度（MIC）为 32mg/L，而对 MRSA 的最小杀菌浓度（MBC）为 64mg/L。此外，CPEE 与β-内酰胺类抗生素（氨苄西林和苯唑西林）表现出显著的协同作用。核酸和蛋白质渗漏试验表明，CPEE 可以通过破坏 MRSA 细胞膜完整性来刺激细胞内大分子的释放。活/死染色和 SDS-PAGE 试验进一步证实，CPEE 可以通过破坏细胞膜来抑制细菌活性。Western blot 和β-内酰胺酶检测试验显示 PBP2a 表达和β-内酰胺酶活性降低，表明 CPEE 能够逆转 MRSA 的耐药性。这些结果表明，CPEE 的抗 MRSA 活性主要归因于改变细胞膜和逆转耐药性，这表明 CPEE 可能成为未来食品和医疗应用的有吸引力的候选物。
