Inhibitory effect of menthol on expression of aspartyl proteinase 1 in fluconazole-resistant Candida albicans

Fluconazole-resistant Candida albicans is one of the biggest problems faced in clinical practice. Using of natural pure compounds such as menthol could be one of the most frequently ways to solve this problem. The aims of this study were to investigate the hypha formation and gene expression profiling of fluconazole-resistant C. albicans treated by menthol. Colonizing vaginal isolates of C. albicans were recognized and fluconazole-resistant detected by WHONET software. The relative MICs of menthol were determined by broth microdilution for fluconazole-resistant isolates. The potency of menthol to inhibit hypha formation exploited using a light microscopy. Finally, the expression of SAP1 was measured using quantitative Real Time RT- PCR. Out of colonizing vaginal isolates of C. albicans, 100% were found to be fluconazol-resistant. MIC90 for menthol was reported in fluconazol-resistant isolates at 1.6 to 25 μg/mL. Additionally, all isolates treated with menthol showed the significant reduction in hyphae and number of planktonic cells. Furthermore, the expression levels of SAP1 were increased by 1.53- and 1.43-fold at concentrations of 2 × MIC and 1 × MIC, respectively, in the fluconazol-resistance C. albicans cells treated with fluconazol. While, treatment with menthol was down regulated of SAP1 expression by 2.02- and 1.85-fold at concentrations of 2 × MIC and 1 × MIC, respectively (P ≤ 0.05). These findings suggest that menthol could has potential applications in the treatment of infections due to fluconazole-resistance C. albicans. In addition, SAP1 could be probable molecular target of menthol in C. albicans.