Saliva affects the antifungal activity of exogenously added histatin 3 towards Candida albicans.

Antifungal activity of histatin 3 against two Candida albicans clinical isolates was determined in assays containing rabbit submandibular gland saliva. Histatin 3 inhibited the cell growth and germination of both isolates dose-dependently (10-100 microg ml(-1)) with maximum inhibition occurring after 60 min incubation. Adding fresh histatin 3 after 60 min caused further reduction in the viable cell count. Higher histatin 3 concentrations (50-100 microg ml(-1)) and prolonged exposure to peptide were required to inhibit germination. Histatin 3 was rapidly degraded in rabbit submandibular gland saliva and this may explain why fresh addition of histatin 3 increases candidacidal activity.