Botany and Microbiology Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
Pharmacognosy Department, Faculty of Pharmacy, Mansoura University, El Mansoura, Egypt.
Sci Rep. 2023 Oct 20;13(1):17942. doi: 10.1038/s41598-023-44063-0.
Antipathogenic drugs are a potential source of therapeutics, particularly following the emergence of multiple drug-resistant pathogenic microorganisms in the last decade. The inhibition of quorum sensing (QS) is an advanced antipathogenic approach for suppression of bacterial virulence and dissemination. This study aimed to investigate the inhibitory effect of some Egyptian medicinal plants on the QS signaling system of Pseudomonas aeruginosa. Among the tested plants, Mangifera indica exhibited the highest quorum sensing inhibition (QSI) activity against Chromobacterium violaceum ATCC 12472. Four pure compounds were extracted and identified; of these, methyl gallate (MG) showed the most potent QSI. MG had a minimum inhibitory concentration (MIC) of 512 g/mL against P. aeruginosa strains PAO1, PA14, Pa21, Pa22, Pa23, Pa24, and PAO-JP2. The virulence factors of PAO1, PA14, Pa21, Pa22, Pa23, and Pa24 were significantly inhibited by MG at 1/4 and 1/2 sub-MICs without affecting bacterial viability. Computational insights were performed by docking the MG compound on the LasR receptor, and the QSI behavior of MG was found to be mediated by three hydrogen bonds: Trp60, Arg61, and Thr75. This study indicates the importance of M. indica and MG in the inhibition and modulation of QS and QS-related virulence factors in P. aeruginosa.
抗菌药物是治疗药物的潜在来源，尤其是在过去十年中出现了多种耐药性致病微生物之后。抑制群体感应（QS）是抑制细菌毒力和传播的一种先进的抗菌方法。本研究旨在研究一些埃及药用植物对铜绿假单胞菌 QS 信号系统的抑制作用。在所测试的植物中，芒果表现出对 Chromobacterium violaceum ATCC 12472 最强的群体感应抑制（QSI）活性。从四种纯化合物中提取并鉴定出四种化合物；其中，没食子酸甲酯（MG）表现出最强的 QSI。MG 对 PAO1、PA14、Pa21、Pa22、Pa23、Pa24 和 PAO-JP2 等铜绿假单胞菌菌株的最小抑菌浓度（MIC）为 512μg/mL。MG 在亚 MIC 的 1/4 和 1/2 浓度下显著抑制了 PAO1、PA14、Pa21、Pa22、Pa23 和 Pa24 的毒力因子，而不影响细菌的活力。通过对接 LasR 受体对 MG 化合物进行计算分析，发现 MG 的 QSI 行为是由三个氢键介导的：Trp60、Arg61 和 Thr75。本研究表明，芒果和 MG 在抑制和调节铜绿假单胞菌的 QS 及其相关毒力因子方面具有重要意义。
