<p>Silver nanoparticles induce reactive oxygen species-mediated cell cycle delay and synergistic cytotoxicity with 3-bromopyruvate in <em>Candida</em> <em>albicans</em>, but not in <em>Saccharomyces</em> <em>cerevisiae</em></p>

Abstract

Background: Silver nanoparticles (AgNPs) inhibit the proliferation of various fungi; however, their mechanisms of action remain poorly understood. To better understand the inhibitory mechanisms, we focused on the early events elicited by 5 nm AgNPs in pathogenic Candida albicans and non-pathogenic Saccharomyces cerevisiae. Methods: The effect of 5 nm and 100 nm AgNPs on fungus cell proliferation was analyzed by growth kinetics monitoring and spot assay. We examined cell cycle progression, reactive oxygen species (ROS) production, and cell death using flow cytometry. Glucose uptake was assessed using tritium-labeled 2-deoxyglucose. Results: The growth of both C. albicans and S. cerevisiae was suppressed by treatment with 5 nm AgNPs but not with 100 nm AgNPs. In addition, 5 nm AgNPs induced cell cycle arrest and a reduction in glucose uptake in both fungi after 30 minutes of culture in a dose-dependent manner ( P <0.05). However, in C. albicans only, an increase in ROS production was detected after exposure to 5 nm AgNPs. Concordantly, an ROS scavenger blocked the effect of 5 nm AgNPs on the cell cycle and glucose uptake in C. albicans only. Furthermore, the growth-inhibition effect of 5 nm AgNPs was not greater in S. cerevisiae mutant strains deficient in oxidative stress response genes than it was in wild type. Finally, 5 nm AgNPs together with a glycolysis inhibitor, 3-bromopyruvate, synergistically enhanced cell death in C. albicans ( P <0.05) but not in S. cerevisiae . Conclusion: AgNPs exhibit antifungal activity in a manner that may or may not be ROS dependent, according to the fungal species. The combination of AgNPs with 3-bromopyruvate may be more useful against infection with C. albicans .

Silver Nanoparticles Addition in Poly(Methyl Methacrylate) Dental Matrix: Topographic and Antimycotic Studies

“…However, the concentration of ions released from PMMA was very low and it was not considered toxic to human cells [28]. The disruption of C. albicans instead occurred even at slight Ag + concentration [51,52,53].…”

Hepatic histopathological and ultrastructural alterations induced by 10 nm silver nanoparticles

“…Other studies showed that Ag NPs exposure could induce mitochondrial damage, glutathione depletion membranes integrity and inflammatory cytokines release [17,18]. Other studies reported that Ag NPs could cause DNA damage, reduce metabolic activity, lower ATP production, arrest cell cycle, and induce chromosomal aberrations, cytotoxic and genotoxic alterations [11,[19][20][21].…”

Evaluation of different antioxidants during in vitro establishment of allspice (Pimenta dioica L. Merrill): a recalcitrant species

“…ex Andrews) and by por Vitali et al [21] in black poplar (Populus nigra L.). AgNPs have been reported to bind to bacteria producing cell cycle arrest [22], caused by toxicity due to ROS production [23]. In addition, Kim et al [24] demonstrated that AgNPs have an antimicrobial effect bacterial cell membrane surface and modifying the cell potential.…”

“…In fungi, AgNPs break the cell membrane of hyphae altering the mechanisms of infection [27]. Lee et al [22] report that AgNPs that penetrate the cell increase Ag+ cations, which could affect the electrical potential of the membrane, denaturing proteins, leading to cell cycle arrest. On the other hand, Rónavári et al [28] report growth inhibition of fungi such as Candida, Criptococcus, Microsporum and Trichophyton.…”