Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps/College of Life Sciences, China.
Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang Production & Construction Corps/College of Life Sciences, China; College of Animal Sciences/Key Laboratory of Tarim Animal Husbandry & Science Technology of Xinjiang Production & Construction Corps, Tarim University, Alar, 86-843300, China.
J Ethnopharmacol. 2020 Oct 5;260:113017. doi: 10.1016/j.jep.2020.113017. Epub 2020 May 25.
Coreopsis tinctoria Nutt has various medical and functional properties and its flower is widely used as health-care tea to decrease blood glucose and to lower blood lipids. However, the quorum sensing (QS) inhibition activity of Coreopsis tinctoria Nutt flower remains unclear.
To assess inhibitory activity against quorum sensing by Chromobacterium violaceum, to identify the chemical composition of the extracts and to disclose the action mechanism of separated compound.
Violacein inhibition assays were performed in 96-wells microplates. The compounds extracted from Coreopsis tinctoria Nutt flower were separated and purified by various chromatography techniques. Respectively, thin layer chromatography (TLC, GF254), mass spectrometer (Agilent 1100 Series LC/MSD Trap SL), Medium-pressure automatic purification system (Buscisepacore C 620, Switzerland), High performance liquid chromatography (HPLC, Shimadzu LC-20AD, Japan), Liquid preparation Chromatography (Waters2545, USA). The chemical structures were identified by nuclear magnetic resonance (NMR, Bruker AV-500, Germany) technique. The inhibitory mechanism of okanin against C. violaceum quorum sensing was detected by quantitative real-time PCR (qRT-PCR).
Quorum sensing regulates production of bacterial virulence factors, thereby making it an intriguing target for attenuating bacterial pathogenicity. In this study, anti-QS activity of Coreopsis tinctoria Nutt methanol fraction (CTM) was investigated against C. violaceum ATCC12472. CTM showed an inhibitory effect on the QS-mediated virulence factors production such as violacein in C. violaceum without effect on growth rate. Also, okanin was isolated from CTM and its potential of anti-QS was confirmed after observing a significant reduction of violacein production in C. violaceum. An attempt was made to assess the effect of okanin on vioABCDE expression in C. violaceum to disclose acting mechanisms.
The results of this study contribute to validate an inhibitory effect of Coreopsis tinctoria Nutt flower on quorum sensing by Chromobacterium violaceum and to determine the compound responsible for inhibition. Also, the inhibitory effect was achieved in tandem with the down-regulation of vio operon.
金鸡菊属植物具有多种医学和功能特性，其花被广泛用作保健茶，以降低血糖和降低血脂。然而，金鸡菊属植物花的群体感应（QS）抑制活性尚不清楚。
评估金黄色酿脓葡萄球菌对群体感应的抑制活性，鉴定提取物的化学成分，并揭示分离化合物的作用机制。
在 96 孔微孔板中进行紫胶酮抑制试验。通过各种色谱技术从金鸡菊属植物花中分离和纯化化合物。分别采用薄层色谱（TLC，GF254）、质谱（Agilent 1100 系列 LC/MSD Trap SL）、中压自动纯化系统（Buscisepacore C 620，瑞士）、高效液相色谱（HPLC，Shimadzu LC-20AD，日本）、液相制备色谱（Waters2545，美国）进行分离和纯化。通过核磁共振（NMR，Bruker AV-500，德国）技术鉴定化学结构。通过定量实时 PCR（qRT-PCR）检测奥卡宁对金黄色酿脓葡萄球菌群体感应的抑制机制。
群体感应调节细菌毒力因子的产生，因此成为减弱细菌致病性的一个有趣目标。在这项研究中，研究了金鸡菊甲醇提取物（CTM）对金黄色酿脓葡萄球菌 ATCC12472 的群体感应抑制活性。CTM 对金黄色酿脓葡萄球菌中 QS 介导的毒力因子产生（如紫胶酮）具有抑制作用，而对生长速度没有影响。此外，从 CTM 中分离出奥卡宁，并观察到其对金黄色酿脓葡萄球菌紫胶酮产生的显著减少，证实了其抗 QS 的潜力。还尝试评估奥卡宁对金黄色酿脓葡萄球菌 vioABCDE 表达的影响，以揭示作用机制。
本研究结果验证了金鸡菊属植物花对金黄色酿脓葡萄球菌群体感应的抑制作用，并确定了抑制作用的化合物。此外，抑制作用是与 vio 操纵子的下调同时实现的。
