Biosynthesis, Characterization, and Antifungal Activity of the Silver Nanoparticles Against Pathogenic Candida species

Abstract

Alcoholic extract of tulsi leaves was used as a reducing and stabilizing agent for the synthesis of silver nanoparticles (AgNPs). The use of plant extract for the synthesis of nanoparticles is cost-effective, single step, and an ecofriendly process. The biosynthesized AgNPs were characterized using UV-Vis, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The AgNPs formed show surface plasmon resonance at 430 nm. They have a smooth surface with an average diameter of 2-7 nm. Their crystalline nature was confirmed by the XRD. The antifungal activity of the AgNPs was evaluated for opportunistic human fungal pathogens Candida albicans, Candida glabrata, and Candida tropicalis. The antifungal effect was determined by minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and disk diffusion assay. Further, to assess the pathogenicity, proteinase and phospholipase assays were performed. TEM analysis of treated Candida cells reveals that the AgNPs may be exerting antifungal activity by disrupting the cell membrane structure and integrity. Cytotoxicity of AgNPs was checked by performing hemolytic assay against human erythrocytes. At MIC values, AgNPs caused only 5.6 % lysis in RBCs which was very low in comparison to conventional antifungal agents. Hence, biosynthesized AgNPs using plant extracts have immense antifungal potential and can be used in the management of fungal infections. Further studies have to be done to understand their mode of action.

The Biological Synthesis of Silver Nanoparticles by Mango Plant Extract and Its Anti-Candida Effects

“…These findings are in line with the results of a study by Nafisa et al which had been conducted on fungal pathogens of C. albicans, C. glabrata, and C. tropicalis. 17 Furthermore, in another study, Asghari et al investigated the antifungal effects of silver nanoparticles on Candida vulvovaginal factors in vitro. The results of this study showed that silver spherical nanoparticles with a diameter of 10 nm had antifungal activity against C. albicans to some degree.…”

Inhibition of secreted aspartyl proteinase activity in biofilms of Candida species by mycogenic silver nanoparticles

“…Candida spp. have also developed a battery of putative virulence factors which include adherence to host tissues, yeast hyphal transitions, and secretion of hydrolytic enzymes especially secretion of proteinases and phospholipases known to be frequently associated with pathogenicity [2]. Secreted aspartyl proteinases (S aspartyl proteinases) by Candida spp.…”

Bifunctional Fe3O4/Ag nanoparticles obtained by two-step laser ablation in pure water

“…Here, we present the synthesis and characterization of Fe 3 O 4 /Ag nanoparticles obtained by two-step laser ablation of iron and silver targets in pure water, in order to obtain colloidal suspensions with magnetic properties, along with spectral tests demonstrating their SERS activity. Silver is by far the most suitable metal to provide SERS intensification, apart from marked anti-bacterial, antifungal and anti-inflammatory activities [12][13][14][15], as previously said. Fe 3 O 4 magnetic nanoparticles present good biocompatibility and low toxicity [16][17][18] and are therefore widely used in biomedical applications.…”