Quorum Sensing Laboratory, School of Chemical and Biotechnology, SASTRA University, Thirumalaisamudram, Thanjavur - 613 401, Tamil Nadu, India.
Med Chem. 2013 Sep;9(6):819-27. doi: 10.2174/1573406411309060006.
Plants have always been a supreme source of drugs and India is endowed with a wide variety of them with high medicinal values. The Quorum Sensing (QS) quenching efficiency of various solvent extracts of Melia dubia seeds was investigated against uropathogenic Escherichia coli (UPEC) to screen the competitive inhibitor of SdiA, a transcriptional activator of quorum sensing in E. coli. In this study, potentiality of five different extracts of Melia dubia seeds for quorum sensing inhibitory activity was investigated against uropathogenic Escherichia coli (UPEC). Assays such as cell density, swarming motility, protein, protease, hemolysis, hemagglutination, hydrophobicity and biofilm inhibition were performed. Biofilm, hemolysis and swarming motility were found to be inhibited by 92.1%, 20.9 % and 48.52% respectively, when the medium was supplemented with 30 mg/ml of the ethanolic extract. GC-MS spectrum of the ethanolic extract showed an array of 27 structurally unlinked compounds with natural ligand C8HSL. The docking against QS transcriptional regulator SdiA was predicted by in silico studies and the ligand C6 showed significant activity with -10.8 GScore. In vitro and in silico docking analysis showed fairly a good correlation, suggesting that the ethanolic extract showed potency to attenuate quorum sensing of uropathogenic E. coli. Further studies by in vitro and in vivo strategies are necessary to foresee the quorum quenching effect of the ligands.
植物一直是药物的主要来源，印度拥有各种各样具有高药用价值的植物。本研究调查了麻疯树种子不同溶剂提取物对尿路致病性大肠杆菌（UPEC）的群体感应（QS）淬灭效率，以筛选 SdiA 的竞争性抑制剂，SdiA 是大肠杆菌中群体感应的转录激活因子。在这项研究中，研究了麻疯树种子的五种不同提取物对尿路致病性大肠杆菌（UPEC）的群体感应抑制活性的潜力。进行了细胞密度、泳动运动、蛋白质、蛋白酶、溶血、血凝、疏水性和生物膜抑制测定。当培养基中添加 30mg/ml 乙醇提取物时，生物膜、溶血和泳动运动分别被抑制了 92.1%、20.9%和 48.52%。乙醇提取物的 GC-MS 图谱显示了一系列 27 种结构上不相关的化合物，具有天然配体 C8HSL。通过计算机模拟研究预测了对 QS 转录调节剂 SdiA 的对接，配体 C6 显示出显著的-10.8 GScore 活性。体外和计算机模拟对接分析显示出相当好的相关性，表明乙醇提取物具有减弱尿路致病性大肠杆菌群体感应的能力。需要通过体外和体内策略进一步研究配体的群体淬灭效应。
