Mora-Pale Mauricio, Bhan Namita, Masuko Sayaka, James Paul, Wood Julia, McCallum Scott, Linhardt Robert J, Dordick Jonathan S, Koffas Mattheos A G
Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Center for Biotechnology and Interdisciplinary Studies, Troy, New York, 12180-3590.
Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Center for Biotechnology and Interdisciplinary Studies, Troy, New York.
Biotechnol Bioeng. 2015 Dec;112(12):2417-28. doi: 10.1002/bit.25686. Epub 2015 Aug 26.
Plant polyphenols are known to have varying antimicrobial potencies, including direct antibacterial activity, synergism with antibiotics and suppression of bacterial virulence. We performed the in vitro oligomerization of resveratrol catalyzed by soybean peroxidase, and the two isomers (resveratrol-trans-dihydrodimer and pallidol) produced were tested for antimicrobial activity. The resveratrol-trans-dihydrodimer displayed antimicrobial activity against the Gram-positive bacteria Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus (minimum inhibitory concentration (MIC) = 15.0, 125, and 62.0 μM, respectively) and against Gram-negative Escherichia coli (MIC = 123 μM, upon addition of the efflux pump inhibitor Phe-Arg-β-naphthylamide). In contrast, pallidol had no observable antimicrobial activity against all tested strains. Transcriptomic analysis implied downregulation of ABC transporters, genes involved in cell division and DNA binding proteins. Flow cytometric analysis of treated cells revealed a rapid collapse in membrane potential and a substantial decrease in total DNA content. The active dimer showed >90% inhibition of DNA gyrase activity, in vitro, by blocking the ATP binding site of the enzyme. We thus propose that the resveratrol-trans-dihydrodimer acts to: (1) disrupt membrane potential; and (2) inhibit DNA synthesis. In summary, we introduce the mechanisms of action and the initial evaluation of an active bactericide, and a platform for the development of polyphenolic antimicrobials.
已知植物多酚具有不同的抗菌效力，包括直接抗菌活性、与抗生素的协同作用以及对细菌毒力的抑制作用。我们进行了大豆过氧化物酶催化的白藜芦醇体外寡聚反应，并对生成的两种异构体（反式白藜芦醇二氢二聚体和苍白素）进行了抗菌活性测试。反式白藜芦醇二氢二聚体对革兰氏阳性菌蜡样芽孢杆菌、单核细胞增生李斯特菌和金黄色葡萄球菌具有抗菌活性（最低抑菌浓度（MIC）分别为15.0、125和62.0μM），对革兰氏阴性菌大肠杆菌也有抗菌活性（在添加外排泵抑制剂苯丙氨酸-精氨酸-β-萘酰胺后，MIC为123μM）。相比之下，苍白素对所有测试菌株均无明显抗菌活性。转录组分析表明ABC转运蛋白、参与细胞分裂的基因和DNA结合蛋白的表达下调。对处理过的细胞进行流式细胞术分析发现膜电位迅速崩溃，总DNA含量大幅下降。活性二聚体在体外通过阻断该酶的ATP结合位点对DNA回旋酶活性的抑制率>90%。因此，我们认为反式白藜芦醇二氢二聚体的作用机制为：（1）破坏膜电位；（2）抑制DNA合成。总之，我们介绍了一种活性杀菌剂的作用机制和初步评估，以及一种多酚类抗菌剂的开发平台。
