Antifungal activity of Thymus kotschyanus extract: An in vitro study on the expression of CDR1 and CDR2 genes in clinical isolates of Candida albicans

Introduction: Thymus kotschyanus (T. kotschyanus) belongs to the Lamiaceae family that are medicinal plants used in traditional medicine. In this study, the aim was to evaluate the antifungal activity of T. kotschyanus extract and its effects on the expression of CDR1 and CDR2 genes associated with drug resistance genes of Candida albicans (C. albicans).Methods: T. kotschyanus crude extract was prepared using percolation method. Different concentrations of the extract (2-500 mg/ml) were utilized for determination of the minimal inhibitory concentrations (MICs) and minimal fungicidal concentration (MFC) of T. kotschyanus using broth microdilution method. The expression level of CDR1 and CDR2 genes was evaluated in C. albicans isolates before and after the treatment with MIC concentration, using Quantitative real-time PCR (qRT-PCR).Results: T. kotschyanus extract showed an inhibitory effect on Candida growth with MIC and MFC of 75 and 125 mg/ml, respectively. Real-time PCR findings indicated that mRNA expression level of CDR1 and CDR2 genes were significantly reduced after exposure to MIC concentration of T. kotschyanus (p < 0.01).Conclusion: The findings demonstrate that T. kotschyanus extract has anti-Candida activity and reduces mRNA levels of CDR1 and CDR2 genes as drug-resistance genes of clinical isolates of C. albicans.