Synergistic Anticandidal Activities of Greenly Synthesized ZnO Nanomaterials with Commercial Antifungal Agents against Candidal Infections

Abstract

The high occurrence of mycological resistance to conventional antifungal agents results in significant illness and death rates among immunodeficient patients. In addition, the underprivileged therapeutic results of conventional antifungal agents, besides the potential toxicity resulting from long term therapy necessitate the fabrication of efficient antimicrobial combinations. Hence, the objective of the present investigation is to synthesize, characterize and investigate the anticandidal action of green zinc oxide nanoparticles (ZnO-NPs) formulated using Camellia sinensis leaf extract against three candidal pathogens. The eco-friendly synthesized ZnO-NPs were characterized utilizing different physicochemical methods and their anticandidal potency was tested utilizing a disk diffusion assay. In this setting, the size of the biofabricated ZnO-NPs was detected using transmission electron microscope (TEM) micrographs, recording an average particle size of 19.380 ± 2.14 nm. In addition, zeta potential analysis revealed that the ZnO-NPs surface charge was −4.72 mV. The biogenic ZnO-NPs reveal the highest anticandidal activity against the C. tropicalis strain, demonstrating relative suppressive zones measured at 35.16 ± 0.13 and 37.87 ± 0.24 mm in diameter for ZnO-NPs concentrations of 50 and 100 μg/disk, respectively. Excitingly, Candida glabrata showed a high susceptibility to the biofabricated ZnO nanomaterials at both ZnO-NPs’ concentrations (50 and 100 μg/disk) compared to the control. Moreover, the biosynthesized ZnO-NPs revealed potential synergistic effectiveness with nystatin and terbinafine antifungal agents against the concerned strains. The maximum synergistic efficiency was noticed against the C. glabrata strain, demonstrating relative synergistic percentages of 23.02 and 45.9%, respectively. The biogenic ZnO-NPs revealed no hemolytic activity against human erythrocytes revealing their biosafety and hemocompatibility. Finally, the high anticandidal effectiveness of biogenic ZnO-NPs against the concerned candidal pathogens, as well as potential synergistic patterns with conventional antifungal agents such as nystatin and terbinafine, emphasize the prospective application of these combinations for the fabrication of biocompatible and highly efficient antifungal agents.