Muğla Sıtkı Koçman University, College of Sciences, Department of Chemistry, Muğla, 48000, Turkey.
Muğla Sıtkı Koçman University, College of Sciences, Department of Biology, Muğla, 48000, Turkey.
J Appl Microbiol. 2023 Jan 23;134(1). doi: 10.1093/jambio/lxac031.
Propolis is a resinous bee product containing several hundred biologically active compounds. Although the antibacterial activity of propolis has been demonstrated in many in vitro studies, less is known about its mode of action. In this study, we aimed to shed some light on the antibacterial mechanism of action of propolis against Escherichia coli BW25113 using a nuclear magnetic resonance (NMR) based metabolomics approach.
E. coli BW25113 cells were subjected to different sub-lethal concentrations (0, 2, 4, and 6 mg/mL) of Turkish propolis water extract (PWE). The 500-MHz 1H NMR spectroscopy was then employed to ascertain the metabolic profiles of E. coli extracts.
A total of 52 metabolites were identified from the NMR spectra, belonging to 17 main classes, such as amino acids and peptides, purines, and fatty acids. Twelve out of these 52 metabolites displayed remarkable changes at all tested PWE concentrations when compared to control conditions (P < .05). Levels of 28 more metabolites were significantly altered in at least one of the three PWE treatments. The results of partial least squares discriminant analysis showed that there was a clear separation between control and propolis-treated cells and that putrescine, adenine, adenosine, guanosine, glucose, N6-acetyllysine, and acetamide had the highest effect on group differentiation. Finally, quantitative pathway analysis revealed that purine metabolism was significantly affected by PWE treatments.
Our results suggest that PWE inhibits the growth of E. coli BW25113 by affecting nucleic acid metabolism to a great extent. To the best of our knowledge, this is the first study to evaluate the global metabolic response of a bacterium to propolis.
蜂胶是一种含有数百种具有生物活性的化合物的树脂状蜜蜂产品。尽管蜂胶的抗菌活性已在许多体外研究中得到证实，但对其作用机制的了解较少。在这项研究中，我们旨在使用基于核磁共振（NMR）的代谢组学方法研究蜂胶对大肠杆菌 BW25113 的抗菌作用机制。
用不同的亚致死浓度（0、2、4 和 6mg/ml）的土耳其蜂胶水提物（PWE）处理大肠杆菌 BW25113 细胞。然后采用 500MHz 1H NMR 光谱法确定大肠杆菌提取物的代谢谱。
从 NMR 光谱中鉴定出 52 种代谢物，属于 17 个主要类别，如氨基酸和肽、嘌呤和脂肪酸。与对照条件相比（P<.05），这 52 种代谢物中有 12 种在所有测试的 PWE 浓度下都发生了明显变化。至少有 1 种 PWE 处理中，还有 28 种更多的代谢物发生了显著变化。偏最小二乘判别分析的结果表明，对照和蜂胶处理的细胞之间有明显的分离，腐胺、腺嘌呤、腺苷、鸟苷、葡萄糖、N6-乙酰赖氨酸和乙酰胺对组分化的影响最大。最后，定量途径分析表明，嘌呤代谢受到 PWE 处理的显著影响。
我们的结果表明，PWE 通过极大地影响核酸代谢来抑制大肠杆菌 BW25113 的生长。据我们所知，这是首次评估细菌对蜂胶的整体代谢反应的研究。
