Green Synthesis of Silver Nanoparticles Using Astragalus tribuloides Delile. Root Extract: Characterization, Antioxidant, Antibacterial, and Anti-Inflammatory Activities.

Majid Sharifi-Rad,Pawel Pohl,José M Álvarez-Suarez,Francesco Epifano

doi:10.3390/nano10122383

Abstract

Today, the green synthesis of metal nanoparticles is a promising strategy in material science and nanotechnology. In this research, silver nanoparticles (AgNPs) were synthesized through the high-efficient, cost-effective green and facile process, using the Astragalus tribuloides Delile. root extract as a bioreduction and capping agent at room temperature. UV–Vis spectroscopy was applied for the investigation of the reaction proceedings. To characterize the greenly synthesized AgNPs, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), and transmission electron microscopy (TEM) analyses were utilized. In addition, the total phenolics and flavonoids contents, antioxidant, antibacterial, and anti-inflammatory activities of the greenly synthesized AgNPs and the A. tribuloides root extract were evaluated. The results indicated that the AgNPs had spherical morphology and crystalline structure with the average size of 34.2 ± 8.0 nm. The total phenolics and flavonoids contents of the greenly synthesized AgNPs were lower than those for the A. tribuloides root extract. The resultant AgNPs exhibited the appropriate antioxidant activity (64%) as compared to that for the A. tribuloides root extract (47%). The antibacterial test approved the higher bactericidal activity of the resulting AgNPs on the Gram-positive and Gram-negative bacteria in comparison to the A. tribuloides root extract. Considering the anti-inflammatory activity, the greenly synthesized AgNPs showed a stranger effect than the A. tribuloides root extract (82% versus 69% at 500 μg/mL). Generally, the AgNPs that were fabricated by using the A. tribuloides root extract had appropriate antioxidant, antibacterial, and anti-inflammatory activities and, therefore, can be considered as a promising candidate for various biomedical applications.

Highlights

Nanotechnology is considered one of the most important fields of study in material science [1]
The AgNPs synthesis was started at room temperature by adding 10 mL of the A. tribuloides root extract to 90 mL of an aqueous solution of AgNO3 (1 mmol L–1)
This indicated that the useful phytochemical constituents present in the A. tribuloides root extract, including phenolic compounds, flavonoids, and saponins [22], could be responsible for the bioreduction of the Ag (I) ions and the capping of the resultant AgNPs

Summary

Introduction

Nanotechnology is considered one of the most important fields of study in material science [1]. The biological procedure is more promising as compared to physical and chemical methods because it is economical, flexible, and eco-friendly [5] In this method, microorganisms or medicinal plants are used for the nanoparticles’ production [6]. Reduced Ag is toxic to microorganisms because it has the ability to damage their cell walls and disrupt their appropriate functions and development This is because the released Ag ions interact with macromolecules like deoxyribonucleic acid (DNA) and proteins in these cells. They prevent the synthesis of protein, reduce the permeability of the membranes, and lead to the cell death [3,16] Because of their small size and the large surface-area-to-volume ratio, the AgNPs might show the higher biological activity than that exerted by ionic Ag

Methods

Results

Conclusion