Background: The increasing incidence of invasive forms of candidiasis and resistance to antifungal
therapy leads us to seek new and more effective antifungal compounds.
Objective: To investigate the antifungal activity and toxicity as well as to evaluate the potential targets of 2-
cyclohexylidenhydrazo-4-phenyl-thiazole (CPT) in Candida albicans.
Methods: The antifungal activity of CPT against the survival of C. albicans was investigated in Caenorhabditis
elegans. Additionally, we determined the effect of CPT on the inhibition of C. albicans adhesion
capacity to buccal epithelial cells (BECs), the toxicity of CPT in mammalian cells, and the potential
targets of CPT in C. albicans.
Results: CPT exhibited a minimum inhibitory concentration (MIC) value of 0.4-1.9 µg/mL. Furthermore,
CPT at high concentrations (>60 x MIC) showed no or low toxicity in HepG2 cells and <1% haemolysis
in human erythrocytes. In addition, CPT decreased the adhesion capacity of yeasts to the BECs and prolonged
the survival of C. elegans infected with C. albicans. Analysis of CPT-treated cells showed that
their cell wall was thinner than that of untreated cells, especially the glucan layer. We found that there
was a significantly lower quantity of 1,3-β-D-glucan present in CPT-treated cells than that in untreated
cells. Assays performed on several mutant strains showed that the MIC value of CPT was high for its antifungal
activity on yeasts with defective 1,3-β-glucan synthase.
Conclusion: In conclusion, CPT appears to target the cell wall of C. albicans, exhibits low toxicity in
mammalian cells, and prolongs the survival of C. elegans infected with C. albicans.