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

• Published in: Medicina
• Main Authors: Mamoru Murakami, Kae Harada, Yasuhiro Nishi, Takaharu Shimizu, Sara Motoyama, Masahiro Nishimura
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Subjects: oral moisturizer; <i>C. albicans</i>; <i>C. glabrata</i>; pH; xerostomia
• Online Access: https://www.mdpi.com/1648-9144/56/10/525
• ISSN: 1010-660X; 1648-9144

<i>Background and objectives</i>: 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 <i>Candida albicans</i> and <i>Candida glabrata</i>. <i>Materials and Methods</i>: 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 <i>C. albicans</i> and <i>C. glabrata</i> (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. <i>Results</i>: Significant differences in the effects of storage temperature and pH of the moisturizers were observed against <i>C. albicans</i> and <i>C. glabrata</i>. 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). <i>Conclusion</i>: The antifungal effects of oral moisturizers against <i>C. albicans</i> and <i>C. glabrata</i> were affected by their storage temperature and pH.