Antifungal activity of ZnO nanoparticles—the role of ROS mediated cell injury

Abstract

Metal oxide nanoparticles have marked antibacterial activity. The toxic effect of these nanoparticles, such as those comprised of ZnO, has been found to occur due to an interaction of the nanoparticle surface with water, and to increase with a decrease in particle size. In the present study, we tested the ability of ZnO nanoparticles to affect the viability of the pathogenic yeast, Candida albicans (C. albicans). A concentration-dependent effect of ZnO on the viability of C. albicans was observed. The minimal fungicidal concentration of ZnO was found to be 0.1 mg ml(-1) ZnO; this concentration caused an inhibition of over 95% in the growth of C. albicans. ZnO nanoparticles also inhibited the growth of C. albicans when it was added at the logarithmic phase of growth. Addition of histidine (a quencher of hydroxyl radicals and singlet oxygen) caused reduction in the effect of ZnO on C. albicans depending on its concentration. An almost complete elimination of the antimycotic effect was achieved following addition of 5 mM of histidine. Exciting the ZnO by visible light increased the yeast cell death. The effects of histidine suggest the involvement of reactive oxygen species, including hydroxyl radicals and singlet oxygen, in cell death. In light of the above results it appears that metal oxide nanoparticles may provide a novel family of fungicidal compounds.

Antifungal, optical, and mechanical properties of polymethylmethacrylate material incorporated with silanized zinc oxide nanoparticles

“…This metal oxide varies in particle size, with sizes ranging from microns to nanometers. 8,10,11 Many studies demonstrated the effectiveness of these particles on inhibiting the growth of fungi 7,10 and bacteria. [11][12][13][14][15] The inhibition depended on particle size, concentration, and type of microbes.…”

Development of Antibacterial Composite Films Based on Isotactic Polypropylene and Coated ZnO Particles for Active Food Packaging

“…The mechanisms responsible for the antibacterial activity are not fully understood. Distinctive mechanisms that have been put forward in the literature are listed as the following: direct contact of ZnO with cell walls, resulting in destructing bacterial cell integrity [6][7][8], liberation of antimicrobial ions, mainly Zn 2+ ions [8], and reactive oxygen species formation [9][10][11].…”

Resistance of extremely halophilic archaea to zinc and zinc oxide nanoparticles

“…ZnO NPs have been extensively studied for their antifungal (Candida albicans), antibacterial (Escherichia coli) and antiviral (bacteriophages MS2) effect (Lipovsky et al 2011;You et al 2011). There are numerous reports on resistance and/or tolerance of metals by bacterial strains either individually or in consortium (non halophilic) (Gadd 2009).…”