Peerzada Zoya, Kanhed Ashish M, Desai Krutika B
Sunandan Divatia School of Science, SVKM'S NMIMS (Deemed to be University) Mumbai-400056 India.
Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS University Mumbai-400056 India.
RSC Adv. 2022 May 18;12(24):15196-15214. doi: 10.1039/d1ra08351a. eCollection 2022 May 17.
infections are attributed to its ability to form biofilms and are difficult to eliminate with antibiotic treatment. Biofilm formation is regulated by quorum sensing (QS), an intracellular bacterial communication mechanism that allows the activation of numerous virulence factors and secondary metabolites. Targeting the QS pathway is a potential approach that prevents QS-controlled phenotypes and biofilm formation. For the first time, the current work has identified antiquorum sensing activity in the partially purified four fractions from the hot ethyl acetate extract of fruit pods. Of the four fractions, only fraction-1 gave decreased AHL activity; the phytoconstituents in this fraction were identified as rhein, 3-aminodibenzofuran, 5-(hydroxymethyl)-2-(dimethoxymethyl)furan, and dihydrorhodamine. Fraction-1 (1 mg ml) and rhein (0.15 mg ml) showed 63% and 42.7% reduction in short-chain AHL production, respectively, without hindering the bacterial growth. Fraction-1 inhibited QS-mediated extracellular virulence factors protease, elastase, pyocyanin, and rhamnolipid ( < 0.05). Quantitative analysis of biofilm formation showed 77% & 62.4% reduction by fraction-1 (1 mg ml) and rhein (0.15 mg ml) respectively. Confocal laser microscopy (CLMS) & scanning electron microscopy (SEM) confirmed the reduction of biofilm formation in upon treatment with fraction-1 and rhein. Moreover, the study displayed that fraction-1 and rhein (standard) significantly enhanced the survival of by suppressing the potency of virulence factors of . Quantitative real-time polymerase chain reaction results demonstrated the down-regulation of QS-related genes, lasI, lasR, rhlI, and rhlR. In addition, analysis divulged that a component identified by GC-MS displayed a strong affinity towards I and R. These findings suggest that potent phytochemicals from fraction-1, including rhein, could serve as novel phytotherapeutics in controlling emerging infections of antibiotic-resistant bacterial pathogens like .
感染归因于其形成生物膜的能力，并且难以通过抗生素治疗消除。生物膜的形成受群体感应（QS）调节，群体感应是一种细胞内细菌通讯机制，可激活多种毒力因子和次生代谢产物。靶向群体感应途径是一种潜在的方法，可防止群体感应控制的表型和生物膜形成。当前的工作首次在从果荚的热乙酸乙酯提取物中部分纯化的四个馏分中鉴定出抗群体感应活性。在这四个馏分中，只有馏分-1的AHL活性降低；该馏分中的植物成分被鉴定为大黄酸、3-氨基二苯并呋喃、5-（羟甲基）-2-（二甲氧基甲基）呋喃和二氢罗丹明。馏分-1（1 mg/ml）和大黄酸（0.15 mg/ml）分别使短链AHL产量降低了63%和42.7%，且不影响细菌生长。馏分-1抑制了群体感应介导的细胞外毒力因子蛋白酶、弹性蛋白酶、绿脓菌素和鼠李糖脂（P<0.05）。生物膜形成的定量分析表明，馏分-1（1 mg/ml）和大黄酸（0.15 mg/ml）分别使生物膜形成减少了77%和62.4%。共聚焦激光显微镜（CLMS）和扫描电子显微镜（SEM）证实，用馏分-1和大黄酸处理后，生物膜形成减少。此外，该研究表明，馏分-1和大黄酸（标准品）通过抑制某细菌毒力因子的效力，显著提高了某细菌的存活率。定量实时聚合酶链反应结果表明，群体感应相关基因lasI、lasR、rhlI和rhlR下调。此外，气相色谱-质谱分析表明，一种通过气相色谱-质谱鉴定的成分对I和R显示出很强的亲和力。这些发现表明，来自馏分-1的有效植物化学物质，包括大黄酸，可以作为新型植物疗法来控制像某细菌这样的抗生素抗性细菌病原体的新出现感染。
