Effects of Storage Temperature and pH on the Antifungal Effects of Commercial Oral Moisturizers against Candida albicans and Candida glabrata

Abstract

Background and objectives: Oral moisturizers have been used to treat dry mouth. This study aimed to investigate the effects of storage temperature and pH on the antifungal effects of oral moisturizers against Candida albicans and Candida glabrata. Materials and Methods: Thirty-one oral moisturizers and amphotericin B (AMPH-B) were stored at 25 and 37 °C for 1 week. Subsequently, they were added to cylindrical holes in 50% trypticase soy agar plates inoculated with C. albicans and C. glabrata (107 cells/ml). The antifungal effects were evaluated based on the sizes of the growth-inhibitory zones formed. Two-way analysis of variance was used to determine the effects of storage temperature and pH on the growth-inhibitory zones. Results: Significant differences in the effects of storage temperature and pH of the moisturizers were observed against C. albicans and C. glabrata. The growth-inhibitory zones of samples stored at 37 °C and with neutral pH were significantly larger than those stored at 25 °C and with acidic pH, respectively. The sizes of the zones formed by most of the oral moisturizers were larger than those formed by AMPH-B (concentration, 0.63 µg/ml). Conclusion: The antifungal effects of oral moisturizers against C. albicans and C. glabrata were affected by their storage temperature and pH.