Antibacterial activity and characteristics of silver nanoparticles biosynthesized from Carduus crispus

Abstract

In recent years’ synthesis of metal nanoparticle using plants has been extensively studied and recognized as a non-toxic and efficient method applicable in biomedical field. The aim of this study is to investigate the role of different parts of medical plant Carduus crispus on synthesizing silver nanoparticles and characterize the produced nanoparticle. Our study showed that silver nanoparticles (AgNP) synthesized via whole plant extract exhibited a blue shift in absorption spectra with increased optical density, which correlates to a high yield and small size. Also, the results of zeta potential, X-ray diffraction, photon cross-correlation spectroscopy analysis showed the surface charge of − 54.29 ± 4.96 mV (AgNP-S), − 42.64 ± 3.762 mV (AgNP-F), − 46.02 ± 4.17 mV (AgNP-W), the crystallite size of 36 nm (AgNP-S), 13 nm (AgNP-F), 14 nm (AgNP-W) with face-centered cubic structure and average grain sizes of 145.1 nm, 22.5 nm and 99.6 nm. Another important characteristic, such as elemental composition and constituent capping agent has been determined by energy-dispersive X-ray spectroscopy and Fourier transform infrared. The silver nanoparticles were composed of ~ 80% Ag, ~ 15% K, and ~ 7.5% Ca (or ~ 2.8% P) elements. Moreover, the results of the FTIR measurement suggested that the distinct functional groups present in both AgNP-S and AgNP-F were found in AgNP-W. The atomic force microscopy analysis revealed that AgNP-S, AgNP-F and AgNP-W had sizes of 131 nm, 33 nm and 70 nm respectively. In addition, the biosynthesized silver nanoparticles were evaluated for their cytotoxicity and antibacterial activity. At 17 µg/ml concentration, AgNP-S, AgNP-F and AgNP-W showed very low toxicity on HepG2 cell line but also high antibacterial activity. The silver nanoparticles showed antibacterial activity on both gram-negative bacterium Escherichia coli (5.5 ± 0.2 mm to 6.5 ± 0.3 mm) and gram-positive bacterium Micrococcus luteus (7 ± 0.4 mm to 7.7 ± 0.5 mm). Our study is meaningful as a first observation indicating the possibility of using special plant organs to control the characteristics of nanoparticles.

Antibiofilm activity of green synthesized silver nanoparticles against biofilm associated enterococcal urinary pathogens

“…These phytocompounds may play a role in stabilizing the particle size of the prepared silver metals within the nanoparticle ranges. Similar FT-IR results were reported in previous studies of green synthesized AgNPs 16 , 31 , 32 . The chemical AgNPs FT-IR spectrum peaks were corresponding to the O–H stretching/N–H stretching of an amine group and C=O groups.…”

“…The crystalline nature of AgNPs exhibited the FCC crystal nature of metallic silver as (111), (200), (220), and (311) plane lattice observed in the XRD pattern of ginger and chemical AgNPs and (111), (200), and (311) plane lattice in XRD pattern of cinnamon AgNPs. Similar XRD pattern was observed in previous studies of green synthesized AgNPs 32 , 35 .…”

Phytosynthesis of silver nanoparticles from Jatropha integerrima Jacq. flower extract and their possible applications as antibacterial and antioxidant agent

“…So, it is difficult to enter into gram-positive bacteria than gram-negative bacteria ( Erjaee et al, 2017 ). Earlier studies have shown that AgNPs were active against a wide range of pathogenic bacteria due to their effective antibacterial properties ( Gandhi et al, 2021 , Skóra et al, 2021 , Urnukhsaikhan et al, 2021 ).…”

Green Synthesis of Silver Nanoparticles from Root Extracts of Rubus ellipticus Sm. and Comparison of Antioxidant and Antibacterial Activity

“…In this study, we found that our AgNPs showed greater activity against the Gram-negative (E. coli and K. pneumoniae) than Gram-positive (E. faecalis and S. aureus) bacteria. Urnukhsaikhan et al [54] reported contradictory results in which the AgNPs synthesized from the aqueous extracts of Carduus crispus collected from Mongolia exhibited higher potency against Gram-positive bacteria Micrococcus luteus (ZOI = 7 ± 0:4 mm to 7:7 ± 0:5 mm) in comparison to the Gram-negative E. coli (ZOI = 5:5 ± 0:2 mm to 6:5 ± 0:3 mm). They had concluded that the antibacterial activity of different plant-based AgNPs does not depend on the thickness and texture of the bacterial cell wall only.…”