Amity Institute of Biotechnology, Amity University Haryana, Gurgaon (Manesar) 122413, India.
Amity Institute of Biotechnology, Amity University Haryana, Gurgaon (Manesar) 122413, India.
J Glob Antimicrob Resist. 2017 Sep;10:228-237. doi: 10.1016/j.jgar.2017.06.007. Epub 2017 Jul 19.
Novel strategies to overcome multidrug resistance (MDR) in Tuberculosis (TB) still remain a concern. Usage of natural compounds nowadays to surmount the increasing burden of MDR-TB has shown promising results. The aim of this study was to evaluate the antimycobacterial potential of sesamol (Ses) a natural phenolic compound against Mycobacterium smegmatis, a surrogate for MTB and its underlying mechanism of action along with its effect on mycobacterial virulence traits.
Cell surface phenotypes were estimated microscopically and spectrophotometrically respectively. Membrane parameters were assessed using propidium iodide (PI) uptake, passive diffusion of drug with substrate EtBr and phenotypic susceptibility assay. Changes in lipid profiles were estimated by lipase assay. Oxidative and genotoxic damage were studied using fluorescent probes DCFDA and DAPI. Biofilm formation was studied using crystal violet and calcoflour white staining probes along with biomass measurement. Cell adherence was estimated using buccal epithelial cells.
We observed that antimycobacterial activity of Ses was 6mM and it enhances the efficiency of known anti-TB drugs. Ses affects cell surface phenotypes as displayed by altered colony morphology, impaired sliding motility and enhanced cell sedimentation rate. Membrane perturbation was revealed by hypersensitivity against SDS, reduced PI uptake, enhanced passive diffusion and lipase activity. In addition, Ses leads to oxidative and DNA damage along with abrogated iron homeostasis. Furthermore, we uncover phenotypes related to virulence like inhibited biofilm formation and cell adherence to buccal epithelial cells.
This study for the first time establishes the anti-mycobacterial potential of Ses that may be further exploited for improving the therapeutic strategies and warrants further attention.
克服结核病（TB）多药耐药（MDR）的新策略仍然是一个关注点。如今，使用天然化合物来克服日益增加的 MDR-TB 负担已显示出可喜的结果。本研究旨在评估天然酚类化合物芝麻酚（Ses）对耻垢分枝杆菌（一种 MTB 的替代物）的抗分枝杆菌潜力，及其潜在的作用机制及其对分枝杆菌毒力特征的影响。
分别通过显微镜和分光光度法评估细胞表面表型。使用碘化丙啶（PI）摄取、底物 EtBr 的被动扩散和表型药敏试验评估膜参数。通过脂肪酶测定法评估脂质谱的变化。使用荧光探针 DCFDA 和 DAPI 研究氧化和遗传毒性损伤。通过结晶紫和Calcofluor 白色染色探针以及生物量测量研究生物膜形成。使用口腔上皮细胞评估细胞粘附。
我们观察到 Ses 的抗分枝杆菌活性为 6mM，它增强了已知的抗 TB 药物的效率。Ses 影响细胞表面表型，表现为菌落形态改变、滑动运动受损和细胞沉降率增加。膜扰动通过 SDS 敏感性增加、PI 摄取减少、增强的被动扩散和脂肪酶活性来揭示。此外，Ses 导致氧化和 DNA 损伤，同时破坏铁稳态。此外，我们发现与毒力相关的表型，如抑制生物膜形成和细胞粘附到口腔上皮细胞。
本研究首次确立了 Ses 的抗分枝杆菌潜力，这可能进一步用于改善治疗策略，并值得进一步关注。
