Abstract Objectives This study aims to determine the in vitro antifungal activity of heptane, dichloromethane, ethyl acetate and methanol extracts from eight medicinal plants species against pathogenic yeast strains involved in candidiasis, including Candidozyma auris whose multidrug-resistant strains represent a serious global threat. Methods Forty extracts from selected plant species: Combretum micranthum (leaf), Elaeis guineensis (leaf), Erigeron floribundus (aerial parts), Oldfieldia africana (stem bark), Octoknema borealis (leaf and stem bark), Omphalocarpum ahia (leaves and stem bark), Omphalocarpum elatum (stem bark) and Tristemma coronatum (entire plant), were screened against Candidozyma auris, Candida albicans, Candida parapsilosis, C. tropicalis, Pichia kudriavzevii (Candida krusei), and Cryptococcus neoformans. The most active extract was subsequently subjected to 13C-NMR dereplication and bioactivity-guided fractionation. Key findings Twenty plant extracts exhibited antifungal activity against at least one of the strains tested. The ethyl acetate extract of Octoknema borealis stem bark inhibited all yeasts strains, with growth inhibition rates of 71–97% at 25 μg/mL. Bioactivity-guided fractionation and 13C-NMR analysis identified thirteen compounds, including four previously unreported. Conclusion Among the forty plant extracts tested, only the EtOAc extract of O. borealis stem bark showed bioactivity against C. albicans. Ethyl acetate extracts from O. borealis leaves and stem bark were the most effective against clinical strains of Corynebacterium auris. Gallic tannins and a flavonoid were identified as major contributors to the observed antifungal activity.
Ouattara et al. (Fri,) studied this question.