Multitarget Anti-Candida Activity of Thai Plant Extracts and Essential Oils: Inhibiting Biofilm Formation, Denture...

This study aimed to evaluate the efficacy of Thai plant extracts (PEs) and essential oils (EOs) against reference and clinical isolate strains of Candida albicans, focusing on their ability to inhibit biofilm formation, cell adhesion to denture acrylic, and germ tube formation. The minimum biofilm inhibition concentration (MBIC) and the minimum biofilm eradication concentration (MBEC) were determined. The impact on adhesion to denture acrylic was determined by XTT assay, and germ tube inhibition was evaluated using the counting chamber. The results revealed that cinnamon bark oil exhibited the lowest MBIC₉₀ and MBEC₉₀ values (0.156 mg/mL and 0.313 mg/mL, respectively) against both C. albicans strains, followed by lemongrass oil, clove bud oil, Alpinia galanga extract, and Piper betle extract. A similar inhibitory trend was observed for cell adhesion to denture acrylic and germ tube formation. In particular, A. galanga extract (2.50 mg/mL) significantly reduced C. albicans adhesion to denture acrylic by over 80%. Additionally, cinnamon bark oil, lemongrass oil, and A. galanga extract could inhibit the germination of C. albicans at 0.5×MIC. In conclusion, this study indicates that all tested agents possessed anti-C. albicans biofilm activity through decreasing adhesion and yeast-hyphae transition of C. albicans cells. Therefore, these EO and PE could serve as alternative antifungals for treating oral candidiasis.