Effects of Terminalia catappa Linn. Extract on Candida albicans biofilms developed on denture acrylic resin discs.

Background: Considering the prevalence of denture stomatitis and the challenge of controlling this pathology using conventional therapies, natural products have been suggested as important therapeutic alternatives due to their antifungal and anti-biofilm properties. Thus, this study investigated if immersion in Terminalia Catappa Linn. extract (TCE) affects Candida albicans biofilms developed on denture acrylic resin discs.

Material and Methods: The minimal inhibitory and minimal fungicidal concentrations (MIC and MFC, respectively) tests were performed for TCE against suspensions of C. albicans . For the biofilm assay, discs (10 x 2 mm) were fabricated using a denture acrylic resin with surface roughness standardized. The biofilms were allowed to develop for 24 hours. Then, they were immersed in the following treatments overnight (8 hours): phosphate-buffered saline (PBS, control), TCE at MIC, 5XMIC or 10XMIC. The biofilms were analyzed for cell counts and microscopy. Data were analyzed by ANOVA followed by a Tukey test at a 5% significance level.

Results: The minimal concentration of TCE required to inhibit C. albicans was 6.25 mg/mL, while MFC was 12.5 mg/mL. Immersion in TCE at MIC was sufficient to reduce 80% of the biofilm viable cells compared to the control group ( p < 0.001). Microscopic images confirm that immersion at 5XMIC and 10XMIC had a fungicidal activity with no significant differences between the concentrations regarding viable cells counts ( p > 0.05).

Conclusions: Within the limitations of this study, it was possible to conclude that immersion in TCE reduced the C. albicans biofilms cells developed on the denture acrylic surface. Key words: Terminalia catappa Linn, Biofilm, Candida albicans.