Evaluation fungicidal property of itraconazole against Candida albicans biofilm in order to suggests a suitable treatment approach in cases of recalcitrant onychomycosis

Candida albicans have the ability to colonize living and non-living surfaces and form biofilms that are very resistant to common antifungals. The present study was designed to evaluate the fungicidal activity of itraconazole on Candida albicans biofilm.

The present study was conducted on 10 nail samples. Routine mycological and molecular tests were performed to identify and determine the type of fungus. Biofilm was formed in the 96-well plate and was subjected to the itraconazole. ROS accumulation was measured. ROS levels were determined in biofilms treated with itraconazole in the presence of antioxidants.The minimum inhibitory concentration of itraconazole was measured in the presence of ascorbic acid (10 mM) according to the protocol of the previous step. Annexin V-FITC apoptosis detection kit was used to investigate the possibility of apoptosis induction following itraconazole use. 

Mann-Whitney showed a significant difference between biofilms treated with itraconazole and untreated biofilms for 10 tested strains. Treatment with itraconazole resulted in a significant reduction in the number of biofilms. Ascorbic acid significantly reduced ROS accumulation caused by itraconazole for biofilms of all Candida albicans strains. The findings show that itraconazole induces ROS-dependent apoptosis in a dose-dependent manner in biofilm cells.

In this study, it was found that the presence of intracellular ROS is the main cause of the apoptosis mechanism of itraconazole. The ability of itraconazole to induce ROS in Candida cells appears to be a very effective fungicidal strategy.