Enhancement of antidermatophytic activities of Citrullus colocynthis Schrad collected from different ecological habitats in Egypt using fluconazole

Abstract

BackgroundDermatophytes may cause various and severe types of fungal infections in several communities. Herbal plant extracts may be inhibitory against cutaneous fungi related to Epidermophyton, Microsporum, and Trichophyton. The extract may be more efficient by its mixing with a low concentration of the antifungal agent. PurposeThis study demonstrates the antidermatophytic activities of seed methanol extract of Citrullus colocynthis from different habitats in Egypt, namely Sinai desert, El-Wadi El-Gadid, and Wadi Qena. MethodsA broth microdilution assay was used to determine the MIC and MFC of the extracts against the investigated fungal strains according to the Clinical and Laboratory Standards Institute (CLSI) M38-Ed3 guidelines. GC/MS was employed for the identification of the active constituents. Keratinase, lipase, phospholipase, and protease were measured spectrophotometrically or by determining the diameter of the reaction zone according to standard methods using a specific medium. ResultsC.colocynthis seed methanol extract from Sinai desert combined with 0.5 μg/ml of the antifungal drug fluconazole (FLU) was more effective than the extract or FLU, each on its own, in decreasing spore viability and reduction of fungal enzyme activities. The phytochemical analyses of the methanolic seed extract of the three cultivars show the presence of three common main compounds, namely, (9Z,12Z)-methyl octadeca-9,12-dienoate, (9Z,12E)-methyl octadeca-9,12-dienoate, and (9E,12E)-methyl octdeca-9,12-dienoate. The in-silico docking activity of the main compounds toward fungal enzymes showed a high binding affinity between the first compound and lipase enzymes of Microsporum canis and Trichophyton mentagrophytes. ConclusionsThe variation in the bioactivity of the plant extracts of a certain species may be varied due to the difference of the active constituents that are formed under specific conditions or stress. The inhibitory action of the extract to a certain pathogen could be improved when combined with lower drug concentration. Longer chain carbon compounds were frequently detected in the cultivar of Sinai compared to the compounds identified from the other localities suggesting that there was a variation in the active constituents according to the surveyed habitat although the main core of the constituents is maintained.