Study of the action of alpha-hederin on the ultrastructure of Candida albicans

alpha-Hederin, a saponin isolated from Hedera helix (L.) (Araliaceae), was tested on Candida albicans ultrastructure. The concentrations used were 6.2 5, 12.5, and 25 mu g ml(-1) for an exposure time of 24 h. Transmission elec tron microscopy observations indicated that compared with untreated control yeasts, alpha-hederin induced modifications of cellular contents and alter ations of cell envelope with degradation and death of the yeasts. The impac t of alpha-hederin on the biomembranes and in particular on the plasmalemma is discussed. The antifungal activity of alpha-hederin was confirmed, as w as the minimal inhibitory concentration (25 mu g ml(-1)).