Antifungal Activities of Curcuminoids and Difluorinated Curcumin Against Clinical Dermatophyte Isolates

Dermatophytes are a group of fungal agents that can invade humans' keratinized tissues such as skin, nail, and hair, thereby causing dermatophyte infection (dermatophytosis) or ringworm. Some natural products have been reported to possess fungicidal effects. Hence, the present study investigated the effect of curcuminoids (CUR) and difluorinated curcumin (CDF) against clinical isolates of dermatophytes. CUR and CDF powders were evaluated against dermatophyte species including Trichophyton tonsurans (n = 21), T. mentagrophytes (n = 19), T. interdigitale (n = 18), Microsporum canis (n = 4), T. benhamiae (n = 1), and T. verrucosum (n = 1), based on the CLSI M38-A2 guideline. The minimum inhibitory concentration (MIC) ranges of CUR were 4-16, 8-16, 4-16, 8, 8, and 16 μg/ml for T. tonsurans, T. mentagrophytes, T. interdigitale, M. canis, T. benhamiae, and T. verrucosum, respectively. In addition, MIC ranges of CDF were obtained as 2-32, 4-16, 0.125-16, 8-16, 8, and 16 μg/ml, for T. tonsurans, T. mentagrophytes, T. interdigitale, M. canis, T. benhamiae, and T. verrucosum, respectively. CUR and CDF showed an inhibitory effect against dermatophyte isolates. CDF showed a stronger effect than CUR, especially against T. interdigitale. CUR and CDF have the capacity to be developed for use in dermatophytosis to augment existing preventative/therapeutic strategies.