In Vivo and In Vitro Antimicrobial Activity of Biogenic Silver Nanoparticles against Staphylococcus aureus Clinical Isolates

Abstract

Staphylococcus aureus can cause a wide range of severe infections owing to its multiple virulence factors in addition to its resistance to multiple antimicrobials; therefore, novel antimicrobials are needed. Herein, we used Gardenia thailandica leaf extract (GTLE), for the first time for the biogenic synthesis of silver nanoparticles (AgNPs). The active constituents of GTLE were identified by HPLC, including chlorogenic acid (1441.03 μg/g) from phenolic acids, and quercetin-3-rutinoside (2477.37 μg/g) and apigenin-7-glucoside (605.60 μg/g) from flavonoids. In addition, the antioxidant activity of GTLE was evaluated. The synthesized AgNPs were characterized using ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, transmission and scanning electron microscopy (SEM), zeta potential, dynamic light scattering, and X-ray diffraction. The formed AgNPs had a spherical shape with a particle size range of 11.02–17.92 nm. The antimicrobial activity of AgNPs was investigated in vitro and in vivo against S. aureus clinical isolates. The minimum inhibitory concentration (MIC) of AgNPs ranged from 4 to 64 µg/mL. AgNPs significantly decreased the membrane integrity of 45.8% of the isolates and reduced the membrane potential by flow cytometry. AgNPs resulted in morphological changes observed by SEM. Furthermore, qRT-PCR was utilized to examine the effect of AgNPs on the gene expression of the efflux pump genes norA, norB, and norC. The in vivo examination was performed on wounds infected with S. aureus bacteria in rats. AgNPs resulted in epidermis regeneration and reduction in the infiltration of inflammatory cells. Thus, GTLE could be a vital source for the production of AgNPs, which exhibited promising in vivo and in vitro antibacterial activity against S. aureus bacteria.

Investigation of Antimicrobial Activity and Biocompatibility of Biogenic Silver Nanoparticles Synthesized using Syzigyum cymosum Extract

“…Hence, pH 8 solution is highly desirable in order to synthesize small-size nanoparticles. Additionally, our as-prepared bAgNPs demonstrated similar SPR (surface plasmon resonance) bands (ranging from 400 to 450 nm) with those of other AgNPs reported in the literature. , However, the particle size was different, which can be attributed to the presence of different plant secondary metabolites in S. cymosum extract .…”

“…Additionally, our as-prepared bAgNPs demonstrated similar SPR (surface plasmon resonance) bands (ranging from 400 to 450 nm) with those of other AgNPs reported in the literature. 37 , 38 However, the particle size was different, which can be attributed to the presence of different plant secondary metabolites in S. cymosum extract. 39 The average size of bAgNPs synthesized at pH 8 was smaller than most of the bAgNPs reported in the literature.…”

Green Coffee Bean Extract Normalize Obesity-Induced Alterations of Metabolic Parameters in Rats by Upregulating Adiponectin and GLUT4 Levels and Reducing RBP-4 and HOMA-IR

“…The identification and quantitation of phenolic compounds of GCBE were performed using high-performance liquid chromatography (HPLC-DAD) [ 36 , 37 ]. The HPLC-DAD chromatogram for the organic and phenolic compounds present in GCBE is shown in Figure 1 .…”

Encephalartos villosus Lem. Displays a Strong In Vivo and In Vitro Antifungal Potential against Candida glabrata Clinical Isolates

“…Therefore, the impact of EVME on the efflux pump activity was studied, both phenotypically using acridine orange and genotypically [ 56 ]. qRT-PCR is an efficient, cost-effective, and relatively simple technique that can be used to quantify the expression of the genes [ 57 , 58 ]. Therefore, this technique was used to study the genotypic impact of EVME on the efflux genes.…”