Evaluation of in vitro antifungal effects of synthetic and herbal mouth rinses on oral Candida albicans and Candida glabrata

Abstract

Mouth rinses which function as breath fresheners, medicaments, and antiseptics can also deliver oral therapeutic agents. This study evaluated and compared the antifungal effects of synthetic and herbal mouth rinses on oral C. albicans and C. glabrata via disk diffusion, minimal inhibition concentration (MIC), minimum fungicidal concentration (MFC), time-kill assay, and growth profile tests. The four chemical mouth rinses, namely Brand O (A), Brand M (B), Brand H (C), and Brand B (D) used in the study showed positive antifungal activity in these two species. The average diameter of the inhibition zones obtained from the disk diffusion test was higher in mouth rinse B (C. albicans = 12.0 ± 0.9 mm, C. glabrata = 13.5 ± 0.8 mm) compared to those in C, A and D. Both Candida species exhibited similar MIC and MFC values, ranging from 1.63 ± 0.5 to 18.75 ± 0.0 µg/mL and 6.51 ± 2.01 to 50.00 ± 9.36 µg/mL, respectively. These synthetic mouth rinses had efficient killing activity eliminating 50% of the growing population of both Candida spp. following 15 seconds exposure time. Analyses of the growth profile curves showed that mouth rinses B and A resulted in rapid growth depletion of both Candida spp. Meanwhile, three herbal mouth rinses, namely Brand S (E), Brand C (F), and Brand P (G), were less effective against C. albicans and C. glabrata. Mouth rinses B and A contained cetylpyridinium chloride and chlorhexidine, respectively, and could be an effective alternative for controlling and preventing oral candidiasis.