Comparison of antibacterial efficacy between xanthorrhizol (Curcuma xanthorrhiza roxb.) and chlorhexidine 2% against enterococcus faecalis clinical isolate biofilm

Objective: In root canal treatments, chlorhexidine (CHX) is widely used for irrigation and is effective in killing Enterococcus faecalis. CHX is a synthetic chemical and is toxic to host cells; therefore, natural or herbal irrigation solutions, which are safer but still effective, are necessary. The aim of this study is to analyze the effect of xanthorrhizol (XNT) derived from Curcuma xanthorrhiza Roxb. on E. faecalis clinical isolate biofilm formation (0.5%, 0.75%, 1%, 1.25%, and 1.5%). Methods: The MTT assay and total plate count were performed for assessing the effectiveness of herbal ingredients, while CHX (2%) was used as a positive control. Data were analyzed using one-way ANOVA and Bonferroni post-hoc tests for analyzing differences between groups. Results: Xanthorrhizol concentrations of 0.5%, 0.75%, 1%, 1.25%, and 1.5% reduced the amount of bacteria that grew as biofilms in vitro. We found that the ability of xanthorrhizol 1% to inhibit E. faecalis biofilm formation was not significantly different compared with that of CHX 2% (p>0.05). Conclusion: Xanthorrhizol 1% can inhibit biofilm formation by E. faecalis. Further studies are required to confirm this preliminary result.