Antifungal activity of Cleome gynandra L. aerial parts for topical treatment of Tinea capitis: an in vitro evaluation

BACKGROUND: Cleome gynandra L. (Capparaceae) is an edible weed used in Uganda topically for its presumed antifungal activity against Tinea capitis. The goal of this study was to determine if this plant possesses antifungal activity in vitro, since T. capitis is a pervasive infection among especially rural children. METHODS: Antifungal activity assay was performed by Broth dilution method, and testing done on clinical isolates of three common Tinea capitis-causing fungal strains. Evaluation of in vitro antifungal activity of the ethanol and water extracts of C. gynandra was done to determine the minimum inhibitory concentrations (MICs) and the minimum fungicidal concentrations (MFCs) of the extracts. RESULTS: The MIC of C. gynandra ethanol extract ranged from 0.0313 to 0.0625 mg/ml for Trichophyton rubrum, and from 0.25 to 0.5 mg/ml for both Microsporum canis and Trichophyton mentagrophytes. The MICs of C. gynandra aqueous extract ranged between 0.125 to 0.25 mg/ml for T. rubrum, and 0.25 to 0.5 mg/ml for both M. canis and T. mentagrophytes. T. rubrum was more sensitive than M. canis (p < 0.002) and more sensitive than T. mentagrophytes (p < 0.035) to the antifungal activity of C. gynandra. T. rubrum was 6.9 times (95 % CL: 1.15 – 41.6) more likely to have a better outcome (more sensitive) than T. mentagrophytes. Cleome gynandra aqueous extract had MFC of ≥0.0313 mg/ml for M. canis, ≥0.0156 mg/ml for T. mentagropyhtes, and ≥0.0625 mg/ml for T. rubrum. Cleome gynandra ethanol extract showed MFCs of ≥0.5 mg/ml for M. canis and T. mentagrophytes, and ≥0.125 mg/ml for T. rubrum. CONCLUSION: Both plant extracts demonstrated antifungal activity, shown by the MIC and MFC for the different extracts, which varied with the type of organism of the clinical fungal isolates. The ethanol extract exhibited comparable antifungal activity to the aqueous extract indicated by the MIC values seen. Conversely, after subculturing the fungal isolates, MFCs were lower for the aqueous than for the ethanol extract.