Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, Espinardo, Murcia 30100, Spain.
J Agric Food Chem. 2009 Dec 9;57(23):11186-93. doi: 10.1021/jf9029139.
Bacteria are able to communicate and coordinate certain processes using small secreted signaling molecules called autoinducers. This phenomenon, known as "quorum sensing" (QS), may be essential for the synchronization of virulence factors as well as biofilm development. The interruption of bacterial QS is acknowledged to attenuate virulence and considered to be a potential new therapy to treat infections caused by pathogenic bacteria. N-Acyl-L-homoserine lactones (AHLs) have been identified as the main bacterial signaling molecules in Gram-negative bacteria. This study evaluates the capacity of chestnut honey and its aqueous and methanolic extracts to inhibit bacterial AHL-controlled processes in Erwinia carotovora , Yersinia enterocolitica , and Aeromonas hydrophila . This study is the first in applying liquid chromatography coupled with tandem mass spectrometry to determine the QS inhibitory activity of honey against pathogenic bacteria. The tandem mass spectrometry analysis of culture supernatants confirmed the presence of three main AHLs: N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) and N-hexanoyl-L-homoserine lactone (C6-HSL) in E. carotovora and Y. enterocolitica and N-butanoyl-L-homoserine lactone (C4-HSL) in A. hydrophila. The effect of chestnut honey and its aqueous and methanolic extracts (0.2 g/mL) on AHL concentration and biofilm formation in bacterial cultures was determined. The obtained results revealed their potential use as QS inhibitors or regulators of the degradation of QS signals, with the methanolic extract showing less inhibitory capacity. Thus, the QS inhibitory activity of chestnut honey seems to be related to the aqueous phase, suggesting that the carbohydrate fraction contains an antipathogenic substance responsible for the inhibitory activity.
细菌能够使用称为自动诱导物的小分泌信号分子进行通信和协调某些过程。这种现象称为“群体感应”（QS），对于毒力因子的同步以及生物膜的发展可能是必不可少的。 细菌 QS 的中断被认为会减弱毒力，并被认为是治疗致病性细菌感染的潜在新疗法。已鉴定 N-酰基-L-高丝氨酸内酯（AHL）为革兰氏阴性菌中主要的细菌信号分子。本研究评估了板栗蜂蜜及其水和甲醇提取物抑制欧文氏菌、肠杆菌和嗜水气单胞菌中细菌 AHL 控制过程的能力。这是首次应用液相色谱串联质谱法测定蜂蜜对致病性细菌的 QS 抑制活性。培养上清液的串联质谱分析证实了三种主要 AHL 的存在：N-（3-氧代己酰基）-L-高丝氨酸内酯（3-氧代-C6-HSL）和 N-己酰基-L-高丝氨酸内酯（C6-HSL）在 E. carotovora 和 Y. enterocolitica 中，以及 N-丁酰基-L-高丝氨酸内酯（C4-HSL）在 A. hydrophila 中。测定了板栗蜂蜜及其水和甲醇提取物（0.2 g/mL）对细菌培养物中 AHL 浓度和生物膜形成的影响。获得的结果表明它们可能用作 QS 抑制剂或 QS 信号降解调节剂，其中甲醇提取物的抑制能力较低。因此，板栗蜂蜜的 QS 抑制活性似乎与水相有关，表明碳水化合物部分含有负责抑制活性的抗病原体物质。
