Combined Effects of Zinc Compounds and Xylitol on the Enzymatic and Anticandidal Activities of Salivary Antimicrobials

OBJECTIVES: To investigate the combined effects of zinc compounds and xylitol on the enzymatic and anticandidal activities of salivary antimicrobials. METHODS: Four zinc compounds and/or xylitol were incubated with hen egg-white lysozyme (HEWL), bovine lactoperoxidase, the glucose oxidase-mediated peroxidase (GO-PO) system, and human whole saliva. Their enzymatic activities were then assessed. The effects of xylitol on the minimum inhibitory concentration (MIC) and fungicidal activities of zinc compounds were tested against Candida albicans strains. The combined effects of zinc compounds and xylitol on the candidacidal activities of HEWL, the peroxidase system, and the GO-PO system were also evaluated. RESULTS: Zinc compounds increased lysozyme activity but reduced peroxidase activity. Xylitol exerted opposite effects, although it did not reverse the effects of zinc compounds. While xylitol had no effect on the MIC results of zinc compounds against C albicans, it significantly increased their candidacidal activities. Furthermore, the fungicidal activities of HEWL and the peroxidase system were significantly increased when zinc compounds were combined with xylitol. CONCLUSIONS: Zinc compounds combined with xylitol increased lysozyme activity but reduced peroxidase activity. The combination synergistically increased the fungicidal activities of HEWL and the peroxidase system. CLINICAL RELEVANCE: The combination of zinc compounds and xylitol may represent a potential candidate for topical antifungal strategies for preventing or managing oral candidiasis, especially in geriatric populations.