Department of Biotechnology, University of Chemistry and Technology Prague, Technická 5, 166 28, Prague 6, Czech Republic.
World J Microbiol Biotechnol. 2020 Jul 1;36(7):101. doi: 10.1007/s11274-020-02876-5.
Pterostilbene (PTE), a dimethylated analogue of resveratrol, mostly contained in Vitis vinifera leaves or in other plant sources is well-known for its antioxidant activity. Due to its bioavailability, low hydrophilicity and thus ability to penetrate hydrophobic biological membranes it was found to be an antimicrobial agent. These properties of PTE offer the possibility of its use in the treatment of microbial infections. The emergence of antibiotic resistance of microorganisms is often caused by their ability to form biofilm; new substances with antibiofilm activity are therefore sought. The representatives of opportunistic pathogenic gram-positive and gram-negative bacteria as well as fungi were used for the determination of minimum inhibitory concentrations (MIC and MIC), minimum biofilm inhibitory concentrations (MBIC and MBIC) and minimum biofilm eradication concentrations (MBEC and MBEC) of PTE and commonly used antibiotics erythromycin, polymyxin B or antimycotic amphotericin B. Total biofilm biomass was investigated by crystal violet staining, and the results were confirmed using microscopic techniques. The most significant antibiofilm action was proved for gram-positive cocci, e.g., MBEC of PTE for all strains of Staphylococcus epidermidis tested was 25 mg/L. By contrast, the antibiotic ERM did not exhibit antibiofilm activity in most cases. The permeabilization of cell membranes of gram-positive cocci biofilm by MBIC and MBEC of PTE was confirmed by LIVE/DEAD staining using spinning disc confocal microscopy. PTE significantly influenced the ability of gram-positive cocci to form biofilm and it effectively eradicated pre-formed biofilm in vitro; its potential for the treatment of biofilm-associated infections of Staphylococcus spp. or Enterococcus faecalis is thus apparent.
紫檀芪（PTE）是白藜芦醇的二甲基类似物，主要存在于葡萄叶或其他植物源中，以其抗氧化活性而闻名。由于其生物利用度低、亲水性低，因此能够穿透疏水性生物膜，因此被发现具有抗菌活性。PTE 的这些特性为其在治疗微生物感染中的应用提供了可能性。微生物抗生素耐药性的出现通常是由于其形成生物膜的能力；因此，正在寻找具有抗生物膜活性的新物质。使用机会性致病革兰氏阳性和革兰氏阴性细菌以及真菌的代表，来确定 PTE 和常用抗生素红霉素、多粘菌素 B 或抗真菌两性霉素 B 的最小抑菌浓度（MIC 和 MIC）、最小生物膜抑制浓度（MBIC 和 MBIC）和最小生物膜清除浓度（MBEC 和 MBEC）。通过结晶紫染色来研究总生物膜生物量，并使用显微镜技术来验证结果。对革兰氏阳性球菌的抗生物膜作用最为显著，例如，所有测试的表皮葡萄球菌菌株的 PTE 的 MBEC 为 25 mg/L。相比之下，在大多数情况下，抗生素 ERM 没有表现出抗生物膜活性。通过旋转盘共聚焦显微镜的 LIVE/DEAD 染色，证实了 MBIC 和 MBEC 的 PTE 对革兰氏阳性球菌生物膜的细胞膜通透性。PTE 显著影响革兰氏阳性球菌形成生物膜的能力，并有效清除体外已形成的生物膜；因此，它在治疗葡萄球菌或粪肠球菌相关生物膜感染方面具有潜力。
