Postantifungal-like effect of sublethal treatment of Candida albicans with acid-electrolyzed water.

OBJECTIVE: Acid-electrolyzed water (AEW) has been applied to the treatment of oral candidiasis. We evaluated the postantifungal effect (PAFE)-like activity of AEW against Candida albicans under sublethal conditions by exposing C. albicans to dilute AEW. DESIGN: The growth of C. albicans after a short-term exposure to dilute AEW was evaluated in broth and on agar culture. The involvement of reactive oxygen species (ROS) in the PAFE was examined by flow cytometric analysis with hydroxyphenyl fluorescein (HPF) as a fluorescence probe. RESULTS: The dilute AEW exerted PAFE-like activity against C. albicans. ROS were produced in the cells treated with AEW diluted 16 times or fewer. The increase in HPF fluorescence after treatment with dilute AEW was cancelled by dimethyl sulfoxide, a hydroxyl radical (OH) scavenger. CONCLUSION: It would be expected that the ROS, especially OH, produced in the C. albicans cells treated with sublethal dilutions of AEW could exert PAFE-like activity against the fungal cells.