CAY-I, a novel antifungal compound from cayenne pepper

CAY-1, a novel saponin from Capsicum frutescens(commercially known as cayenne pepper) was investigated to determine its in vitroantifungal activity, mechanism of action and mammalian cell cytotoxicity. CAY-1 was active against 16 different fungal strains, including Candidaspp. and Aspergillus fumigatus[minimum inhibitory concentrations (MIC) ranging from 4 to 16 µg ml−1], and was especially active against Cryptococcus neoformans(90% inhibition at 1 µg ml−1). Synergistic activity was also observed between CAY-1 and amphotericin B against Candida albicansand A. fumigatus. No significant cytotoxicity was demonstrated when CAY- 1 was tested against 55 mammalian cell lines at up to 100 µg ml−1. Importantly, CAY-1 appears to act by disrupting the membrane integrity of fungal cells.