Objectives. The aim of this study was to evaluate the antibacterial effect caused by a combination of Xanthorrhizol (Xan) and
several surfactants on planktonic and biofilm of S. mutans. An additional aim was to confirm the safety of a combined solution
as a MTT cell viability assay.
Methods. The Xan, isolated from Indonesian folk medicinal plants, was used at concentrations of 12.5 and 25 ppm. Ethanol (12.5%)
was used as a solvent, while sodium lauryl sulfate (SLS; 200, 250 ppm) and sodium methyl cocoyl taurate (Tau; 250, 300 ppm)
were used as surfactants. The planktonic S. mutans ATCC 25175 (2×107 CFU/ml) was mixed with Xan containing surfactant
and ethanol for 5 minutes, and counted as colonies of live cells. The antibacterial effect of Xan was tested by a biofilm model
with S. mutans, which was used with the saliva-media, hydroxyapatite (HA) disc and BHI broth. The cultured biofilm on HA
disc was exposed to the treatment solutions mixed with Xan, surfactants, and ethanol for 5 minutes. This process was repeated
at 16, 40, 64 hours later. MTT assays were carried out to evaluate cell viability and cell proliferation after exposure of Xan.
Results. Antibacterial effect of Xan on planktonic S. mutans significantly increased when applied with 200 ppm SLS and 300 ppm
Tau (p<0.05). The formation of S. mutans biofilm was inhibited by 25 ppm Xan mixed with 250 ppm SLS or 300 ppm Tau.
In addition, the cytotoxicity of Xan was similar to that of 0.2% chlorhexidine oral rinse.
Conclusions. The solutions of Xanthorrhizol with surfactants such as SLS and Tau showed significant antimicrobial effect on
planktonic and biofilm cells of S. mutans (p<0.05). These solutions also exhibited biological safety similar to chlorhexidine oral
rinse