Investigation of antifungal potential of aqueous and ethanolic extracts of the plant Cota tinctoria on selected isolates of yeasts and dermatomycetes

Abstract

Fungal infections are a serious health related burden. The increasing and non-selective use of commercial antimicrobial therapeutics, due to numerous infections and diseases, causes an increase in the resistance of pathogenic microorganisms to synthetic antimicrobial drugs. Although a large number of plant species used in traditional medicine, have been well phytochemically and pharmacologically investigated and therefore recognized in modern medicine, large number still remains unexplored. The aim of this study was to examine the antifungal potential of aqueous and ethanolic extracts of the plant golden marguerite - Cota tinctoria on the certain yeasts and dermatomycetes. The aerial parts of the Cota tinctoria plant were used for the extract preparation. The microdilution method was used to examine antifungal activity. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of the tested extracts were determined. The following fungal species were used: Candida albicans (clinical isolate), Candida albicans (ATCC 10231), Candida krusei (clinical isolate), Microsporum gypseum (clinical isolate), Trichophyton rubrum (ATCC 28188) and Trichophyton mentagrophytes (clinical isolate). Aqueous extracts, except for the inhibitory effect on C. albicans, had no effect on the tested yeasts and dermatomycetes. Ethanol extracts showed different antifungal activity. The most sensitive species were: T. mentagrophytes (MIC 0.50 mg/mL, MFC 1.00 mg/mL) and T. rubrum (MIC 0.75 mg/mL, MFC 2.00 mg/mL), while the most resistant species was C. krusei (MIC 8.00 mg/ml). Commercial antifungals, ketoconazole (MIC 0.003 - 0.05 mg/mL) and fluconazole (MIC 0.006 - 0.05 mg/mL) showed better antifungal activity compared to the tested extracts. The results of this investigation showed good antifungal characteristics of C. tinctoria plant extracts and may have potential application as an adjunct in the treatment of superficial infections caused by certain micromycetes.