Chemical profiling of antifungal Dicerocaryum senecioides and Diospyros mespiliformis extracts using TLC-p-iodonitrotetrazolium violet assay and GC–MS/MS

Abstract

BackgroundDespite the availability of conventional medication for fungal skin diseases, dermatophytic infections are now a major crisis in the whole world due to multidrug resistance. In an effort to search for complementary and alternative remedies, this study evaluated the chemical composition of Dicerocaryum senecioides and Diospyros mespiliformis leaf and fruit extracts, respectively, exhibiting significant in vitro antifungal activity. Ethyl acetate extracts of each plant were screened for antifungal activity against three fungi species: Candida albicans, Trichophyton rubrum and Epidermophyton floccosum using disc diffusion and poisoned food assays. Gas chromatography–tandem mass spectrometry (GC–MS/MS) was used to evaluate the chemical composition after isolation of active bands by thin-layer chromatography-p-iodonitrotetrazolium chloride assay.ResultsThe composite crude ethyl acetate extracts of D. mespiliformis and D. senecioides (1:1) exhibited concentration-dependent antifungal potencies. C. albicans was susceptible to the crude extracts up to a minimum concentration of 6.25%. E. floccosum and T. rubrum were more susceptible up to a minimum extract concentrations of 1%. GC–MS/MS analysis of the isolated active TLC bands revealed bioactive compounds including flavonoids (quercetin, luteolin), together with their O-glycosylated counter parts and the C-monoglycosylated flavonoids (vitexin, orientin, isovitexin and isoorientin), terpenoids, esters and other phenolic acids. Some of the compounds were common to both plants.ConclusionThe findings of this study show that D. senecioides and D. mespiliformis extracts consist of important bioactive compounds to warrant their use in complementary and alternative poly-herbal formulations against fungal infections.