Zahin Maryam, Hasan Sameena, Aqil Farrukh, Khan Mohd Sajjad Ahmad, Husain Fohad Mabood, Ahmad Iqbal
Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh 202 002, India.
Indian J Exp Biol. 2010 Dec;48(12):1219-24.
Discovery of quorum sensing (QS) system to coordinate virulence and biofilm formation in bacterial pathogens has triggered search for safe, stable and non-toxic anti-QS compounds from natural products. Ethanolic extracts of 24 Indian medicinal plants were tested by agar well and disc diffusion assay for anti-QS activity using Chromobacterium violaceum (CV12472 and CVO26) reporter strains. AHL from C. violaceum CV31532 was isolated and partially purified for its use in CVO26 based bioassay. Effect on swarming-motility of Pseudomonas aeruginosa (PAO1) was also recorded at sub-MIC concentrations of extracts. Of the 24 medicinal plants screened Hemidesmus indicus (L.) Schult (root), Holarrhena antidysenterica (Roth) A.DC. (bark), Mangifera indica L. (seed) Punica granatum L. (pericarp) and Psoralea corylifolia L. (seed) demonstrated varying level of inhibition of violacein production in the reporter strains. Moreover, a significant reduction in swarms was recorded over control. The inhibition of violacein production and swarming motility may be due to direct or indirect interference on QS by active constituents or the interactive effect of different phytocompounds present in the extracts. These plant extracts may be selected for activity guided fractionation to identify and characterize the active principle.
发现群体感应（QS）系统可协调细菌病原体中的毒力和生物膜形成，这引发了人们从天然产物中寻找安全、稳定且无毒的抗QS化合物的研究。使用紫色杆菌（CV12472和CVO26）报告菌株，通过琼脂孔扩散法和纸片扩散法对24种印度药用植物的乙醇提取物进行抗QS活性测试。从紫色杆菌CV31532中分离并部分纯化了AHL，用于基于CVO26的生物测定。在提取物的亚最低抑菌浓度下，还记录了对铜绿假单胞菌（PAO1）群体运动性的影响。在所筛选的24种药用植物中，印度牛弥菜（根）、止泻木（树皮）、芒果（种子）、石榴（果皮）和补骨脂（种子）对报告菌株中紫菌素的产生表现出不同程度的抑制作用。此外，与对照相比，群体数量显著减少。紫菌素产生的抑制和群体运动性的降低可能是由于活性成分对群体感应的直接或间接干扰，或者是提取物中不同植物化合物的相互作用。这些植物提取物可用于活性导向分级分离，以鉴定和表征活性成分。
