title: 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.
authors.affiliation: Department of Chemistry, Kanbar Laboratory for Nanomaterials, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Lipovsky
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Nitzan
authors.forename: Aharon
authors.initials: A
authors.lastname: Gedanken
authors.forename: Rachel
authors.initials: R
authors.lastname: Lubart
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects; D004578:Electron Spin Resonance Spectroscopy; D006639:Histidine / Q000494:pharmacology; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism*; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D017382:Reactive Oxygen Species; D006639:Histidine; D015034:Zinc Oxide