Antifungal activity of lawsone methyl ether in comparison with chlorhexidine

Objective: The aim of this study was to determine the antifungal activity of lawsone methyl ether mouthwash (LME) in comparison with chlorhexidine mouthwash (CHX) in vitro and in vivo. Materials and methods: For in vitro study, each mouthwash preparation was added into the inoculum of Candida. The turbidity was recorded after incubation at 37 degrees C for 48 h. Candidal culture was performed and the number of colony of Candida albicans was recorded. For in vivo study, a crossover clinical trial was conducted in 22 HIV-infected subjects and 32 denture wearers. Clinical examination was performed and oral rinse technique was carried out immediately before and 0, 1, 2 h after using each mouthwash. Allergy and subjective assessment of the mouthwashes were recorded. Statistical analysis was performed using one-way ANOVA and linear mixed effect modeling. Results: In vitro, antifungal activity of 0.25% LME was significantly greater than that of 0.12% CHX (P < 0.05) and comparable with that of 0.2% CHX. In vivo, antifungal activity up to 2 hours of 0.025% LME mouthwash was evidenced in both groups of subjects, although significantly lower than that of 0.12% CHX. No allergic reaction was reported. LME mouthwash was graded to have less bitter taste than that of CHX. Subjects' satisfaction on taste and smell of LME mouthwash was significantly greater than that of CHX (P < 0.05). Conclusions: Lawsone methyl ether mouthwash possesses potent antifungal activity both in vitro and in vivo. However, concentration of the mouthwash needs to be adjusted in addition to further clinical trials on long-term use.