Abstract

In the present study, silver nanoparticles were synthesized by aqueous extract of Stachys byzantina K. Koch and characterized by various analytical methods. The formation of AgNPs was confirmed by UV–Visible spectroscopy at 441.75 nm. The XRD study affirmed the crystalline structure of AgNPs. The value of zeta potential was −43.9 mV that showed the stability of nanoparticles. The TEM images revealed well-distributed nanoparticles with spherical shapes and an average size of 17 nm. FT-IR spectra depicted the presence of different functional groups such as hydroxyl and carbonyl substituents of biomolecules. These groups acted as reducing and capping agents which led to the stability and dispersion of AgNPs. The quantitative phytochemical investigations revealed the presence of phenolic compounds and flavonoids in the aqueous extract and on the surface of AgNPs. Also, they indicated strong antioxidant activity (IC₅₀=48.29 µg.ml⁻¹) in the DPPH assay. The AgNPs had the best antibacterial effects against Escherichia coli and Pseudomonas aeruginosa (MIC = 12.5 µg.ml⁻¹). The AgNPs showed remarkable cytotoxic activities against A431, B-CPAP, and HepG2 (IC₅₀=8.16 ± 0.99, 11.39 ± 3.24, and 11.85 ± 0.33 µg.ml⁻¹, respectively). Also, these three cell lines revealed the best selectivity index (≥3) which demonstrated that they are significantly more toxic to cancerous cell lines than the healthy one.

摘要

在本研究中，银纳米粒子是由水苏水提液合成的。K. Koch 并通过各种分析方法进行了表征。通过 441.75 nm 的紫外-可见光谱证实了 AgNPs 的形成。XRD研究证实了AgNPs的晶体结构。zeta电位值为-43.9 mV，表明纳米粒子的稳定性。TEM 图像显示分布良好的球形纳米颗粒，平均尺寸为 17 nm。FT-IR 光谱描绘了不同官能团的存在，例如生物分子的羟基和羰基取代基。这些基团充当还原剂和封端剂，导致 AgNPs 的稳定性和分散性。定量植物化学研究揭示了水提取物中和 AgNPs 表面存在酚类化合物和黄酮类化合物。此外，它们还显示出很强的抗氧化活性（IC ₅₀=48.29 µg.ml ^-1 ) 在 DPPH 测定中。AgNPs 对大肠杆菌和铜绿假单胞菌的抗菌效果最好（MIC = 12.5 µg.ml ^-1）。AgNPs 对 A431、B-CPAP 和 HepG2 显示出显着的细胞毒活性（IC ₅₀ = 8.16 ± 0.99、11.39 ± 3.24 和 11.85 ± 0.33 µg.ml ^-1分别）。此外，这三种细胞系显示出最好的选择性指数（≥3），这表明它们对癌细胞系的毒性明显高于健康细胞系。