酸枣果提取物在体内外对抗生素的增效作用及机制研究

作者研究团队先前从酸枣果的氯仿提取物中精制得到其低极性范围的活性组合物Fr.2a，发现Fr.2a与多种抗生素联用显示出广泛的协同抗菌作用。该研究在Fr.2a的基础上利用硅胶柱层析对酸枣果氯仿提取物中其他极性范围内的活性成分进行了分离纯化，得到精制物Fr.B，并对精制物Fr.B进行GC MS、核磁共振氢谱、红外光谱分析，以确定Fr.B的组成成分；通过抗菌谱分析和细胞通透性分析，以明确Fr.B的抗菌增效谱和抗菌增效机制；采用熔和法将精制物Fr.B制备成软膏，通过小鼠伤口感染模型评价该软膏对抗生素的增效效果。结果表明：(1)由酸枣果氯仿提取物进一步精制得到的Fr.B组分，主要包含反油酸、油酸、顺 10 十六碳烯醇、棕榈酸等脂肪酸类化合物。(2)Fr.B分别与庆大霉素、妥布霉素、氨苄青霉素、氯霉素、红霉素、夫西地酸、制霉菌素、酮康唑和两性霉素B等多种抗生素联用时显示出广泛的协同抗菌作用。(3)Fr.B可破坏细胞膜和细胞壁的完整性而增强细菌细胞的通透性。(4)在体内和体外Fr.B均能显著增强红霉素对耐甲氧西林金黄色葡萄球菌(MRSA)的杀菌作用，从而提高红霉素对MRSA菌株引起的伤口感染的治疗效果。研究表明，本研究所得到的Fr.B具有广谱的抗菌增效活性，能够增强红霉素对伤口耐药菌感染的治疗效果。该研究结果为克服微生物对抗生素的耐药性提供了新的思路和解决方案。

Synergistic Effect and Mechanism of Organic Extracts from Ziziphus jujuba Mill. var. spinosa Fruits on Antibiotics in vitro and in vivo

In the previous study, we obtained the low polarity active ingredient Fr.2a from the chloroform extracts of Ziziphus jujuba Mill. var. spinosa fruits, and found that Fr.2a showed a wide range of synergistic antimicrobial effects when used in combination with a variety of antibiotics. On the basis of Fr.2a, the active components in other polar range of the chloroform extracts from Z. jujuba Mill. var. spinosa fruits were separated and purified by silica gel column chromatography, and the refined product Fr.B was obtained. Then, the composition of Fr.B was determined by GC MS, hydrogen nuclear magnetic resonance spectroscopy (1H NMR) and infrared spectroscopy (IR). The synergistic antibacterial spectrum and mechanism of Fr.B were determined by antimicrobial spectrum analysis and cell permeability analysis. The refined Fr.B was prepared into ointment by melting method. The synergistic effect of the ointment on antibiotics was evaluated by wound infection model in mice. The results were as follows: (1) the Fr.B component obtained by further refining the chloroform extracts of Z. jujuba Mill. var. spinosa fruits, mainly contained fatty acid compounds such as elaidic acid, oleic acid, cis 10 hexadecenol, palmitic acid and so on. (2) Fr.B showed extensive synergistic antibacterial action when combined with gentamicin, tobramycin, ampicillin, chloramphenicol, erythromycin, fusidic acid, nystatin, ketoconazole and amphotericin B, respectively. (3) Fr.B can enhance the permeability of bacterial cells by destroying the integrity of cell membrane and cell wall. (4) Fr.B can significantly enhance the bactericidal effect of erythromycin on methicillin resistant Staphylococcus aureus (MRSA) in vivo and in vitro, thereby improving the therapeutic effect of erythromycin on wound infections caused by MRSA strains. In conclusion, Fr.B obtained in this study has a broad spectrum of antimicrobial synergistic activity, which can enhance the efficacy of erythromycin in the treatment of wound drug resistant bacteria infection. This provides new ideas and solutions for overcoming microbial resistance to antibiotics.