Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA.
Int J Mol Sci. 2022 Feb 15;23(4):2153. doi: 10.3390/ijms23042153.
Theaflavin-3,3'-digallate (TFDG), a polyphenol derived from the leaves of , is known to have many health benefits. In this study, the antibacterial effect of TFDG against nine bacteria and the sporicidal activities on spore-forming spp. have been investigated. Microplate assay, colony-forming unit, BacTiter-Glo, and Live/Dead Assays showed that 250 µg/mL TFDG was able to inhibit bacterial growth up to 99.97%, while 625 µg/mL TFDG was able to inhibit up to 99.92% of the spores from germinating after a one-hour treatment. Binding analysis revealed the favorable binding affinity of two germination-associated proteins, GPR and Lgt (GerF), to TFDG, ranging from -7.6 to -10.3 kcal/mol. Semi-quantitative RT-PCR showed that TFDG treatment lowered the expression of , ranging from 0.20 to 0.39 compared to the control in both spp. The results suggest that TFDG not only inhibits the growth of vegetative cells but also prevents the germination of bacterial spores. This report indicates that TFDG is a promising broad-spectrum antibacterial and anti-spore agent against Gram-positive, Gram-negative, acid-fast bacteria, and endospores. The potential anti-germination mechanism has also been elucidated.
茶黄素-3,3'-双没食子酸酯（TFDG）是一种从茶叶中提取的多酚，具有多种健康益处。本研究探讨了 TFDG 对 9 种细菌的抗菌作用以及对产芽孢细菌的杀菌活性。微量板测定、菌落形成单位、BacTiter-Glo 和 Live/Dead 分析表明，250μg/mL 的 TFDG 可抑制细菌生长达 99.97%，而 625μg/mL 的 TFDG 可抑制 1 小时处理后发芽的孢子达 99.92%。结合分析表明，两种与发芽相关的蛋白 GPR 和 Lgt（GerF）与 TFDG 具有良好的结合亲和力，结合自由能范围为-7.6 至-10.3 kcal/mol。半定量 RT-PCR 显示，与对照相比，TFDG 处理降低了 spp.中两种蛋白的表达水平，分别为 0.20 至 0.39。结果表明，TFDG 不仅抑制营养细胞的生长，还能阻止细菌孢子的发芽。本报告表明，TFDG 是一种有前途的广谱抗革兰氏阳性、革兰氏阴性、抗酸和内生孢子的抗菌和抗孢子剂。还阐明了其潜在的抗发芽机制。
