n -butanol fraction of Terminalia catappa possesses anti-Candida albicans properties and in vivo action on Tenebrio molitor alternative infection model.

Current treatment of Candida infections is threatened by antifungal drug resistance. Thus, medicinal plants have been studied to identify new and highly effective antifungal substances with low toxicity. Here, we showed that the tannin-rich n-butanol fraction of Terminalia catappa (FBuOH) possesses antifungal and antibiofilm properties and protects Tenebrio molitor larvae against Candida albicans infection. FBuOH showed antifungal activity against Candida spp. vaginal isolates (MIC values ranged from 7 to 500 μg/mL). Moreover, a combination of FBuOH with fluconazole (FICI ≤0.5) showed considerably increased anti-yeast, anti-biofilm activity and significantly improved the survival rate (up to 100 %) of T. molitor larvae against C. albicans infection. Furthermore, FBuOH acted synergistically with fluconazole by reducing C. albicans membrane ergosterol content. These results could also explain the synergistic activity between FBuOH and fluconazole, indicating that FBuOH exerted its effects on C. albicans membrane integrity, increasing its permeability. Our findings provide insights into the antifungal activity and low cytotoxicity of FBuOH, showing its potential use as a new antimycotic.