Abstract

Silver nanoparticles (AgNPs) are used in biomedicine applications. Other drugs combined with the AgNPs can improve efficacy in the treatment of diseases, and most such studies have focused on antibiotics. We determined the synergistic effects of Phyllanthus emblica-derived AgNPs in combination with Vatica diospyroides cotyledon extracts (VCE) against bacteria using agar well diffusion, broth microdilution, and minimum inhibitory concentration (MIC). Synergy of AgNPs and VCE was confirmed with the fractional inhibitory concentration index (FICI). To evaluate patterns of bacterial death, flow cytometry and electron microscopy were used. We found that the effective incubation time of AgNPs against bacteria was highly variable. Increasing AgNPs in the combination influenced antibacterial activity against Staphylococcus aureus and Bacillus subtilis. The MIC values interpreted through FICI showed synergy against S. aureus and indifference against B. subtilis. Flow cytometric profiles confirmed that the fraction of S. aureus that respond to a combination of VCE with AgNPs increased in dose-dependent manner. The response patterns of bacteria proceeded simultaneously as the cells lost intracellular components and suffered membrane damage. Synergy of AgNPs with a plant extract has become a promising approach, as green AgNPs and plant extracts are biocompatible and cost-effective resources that can utilized for the treatment of bacterial infectious diseases.

摘要

银纳米粒子 (AgNPs) 用于生物医学应用。其他药物与 AgNPs 结合可以提高治疗疾病的疗效，大多数此类研究都集中在抗生素上。我们确定了余甘子衍生的AgNPs与Vatica diospyroides的协同作用使用琼脂孔扩散法、肉汤微量稀释法和最低抑菌浓度 (MIC) 对细菌进行子叶提取物 (VCE)。分数抑制浓度指数 (FICI) 证实了 AgNPs 和 VCE 的协同作用。为了评估细菌死亡的模式，使用了流式细胞术和电子显微镜。我们发现 AgNPs 对细菌的有效孵育时间是高度可变的。在组合中增加 AgNPs 会影响对金黄色葡萄球菌和枯草芽孢杆菌的抗菌活性。通过 FICI 解释的 MIC 值显示出对金黄色葡萄球菌的协同作用和对枯草芽孢杆菌的无差异。流式细胞仪分析证实金黄色葡萄球菌的分数对 VCE 与 AgNPs 组合的反应以剂量依赖性方式增加。随着细胞失去细胞内成分并遭受膜损伤，细菌的反应模式同时进行。AgNPs 与植物提取物的协同作用已成为一种很有前途的方法，因为绿色 AgNPs 和植物提取物是生物相容且具有成本效益的资源，可用于治疗细菌性传染病。