Inhibition of Candida Adhesion to Denture Acrylic by Boesenbergia pandurata

Boesenbergia pandurata is a medicinal and culinary herb, commonly used in Southeast Asia. Rhizome of this plant was shown to have antifungal activity against food spoilage fungi. Candida albicans is the predominant fungus found in the oral cavity and associated with denture stomatitis. Adhesion of candida to denture acrylic surface is considered an essential step in the development of infection. Objective: The effect of B. pandurata rhizome extract on adhesion of C. albicans to acrylic surface was investigated. Methods: Dried rhizome of B. pandurata was extracted with 95% ethanol at room temperature for 48 h. After freeze drying, the extract was dissolved in distilled water and further diluted with normal saline solution (NSS). Transparent acrylic strips were prepared and pretreated with extract solution, at concentrations ranging from 25-100 mg/ml, for 30 min at room temperature. After washing with phosphate buffered saline solution (PBS), the strips were then inoculated with C. albicans ATCC13803 (10⁷cells/ml) for 1 h at 37 °C with gentle agitation at 120 rev/min. Non adherent cells were removed by washing with PBS. NSS and 0.2% chlorhexidine gluconate were used as negative and positive controls, respectively. The strips were then stained with modified Gram stain without counterstain. Adherent yeast cells were direct counted under microscope (Olympus-CX31, Japan) in 20 randomly selected fields on each strip. The statistical significance was calculated by Kruskal-Wallis and Mann-Whitney non-parametric tests at a significance level of p < 0.05. Results: Pretreatment with 25, 50 and 100 mg/ml of B. pandurata extract significantly reduced the adhesion of C. albicans to acrylic surfaces by 43.84%, 65.97% and 74.90 %, respectively. Conclusion: This observation indicates that B. pandurata extract has an inhibitory effect on the ability of C. albicans to adhere to denture acrylic and could be employed as an antifungal agent for preventing denture stomatitis.