Inhibition of microbial adhesion to plastic surface and human buccal epithelial cells by Rhodomyrtus tomentosa leaf extract

- Rhodomyrtus tomentosa leaf extract and rhodomyrtone inhibit oral microbial adhesion.
- Rhodomyrtus tomentosa and rhodomyrtone are useful in therapy or prophylaxis for oral infections.
- Rhodomyrtus tomentosa is a Thai medicinal plant with anti-adherence activity.

ObjectiveThe adherence of oral pathogenic microorganisms to host tissues is the initial step for successful process of oral diseases. This study aimed to determine the effect of the Rhodomyrtus tomentosa leaf extract and rhodomyrtone, an antibacterial compound from R. tomentosa leaf, on adhesion of some oral pathogens to polystyrene plastic surface and human buccal epithelial cells.MethodsThe minimum inhibitory concentration (MIC) was evaluated using broth microdilution method. The microbial adhesion to the plastic surface and buccal cells was determined using microtiter plate method and microscopy technique.ResultsThe ethanol extract of leaf demonstrated antibacterial activity against oral microorganisms including Staphylococcus aureus ATCC 25923, Streptococcus mutans (clinical isolate), and Candida albicans ATCC 90028 with the MIC values of 31.25, 15.62, and 1000 μg/ml, respectively. Rhodomyrtone displayed activity with the MIC values of 0.78 and 0.39 μg/ml against S. aureus ATCC 25923 and S. mutans, respectively. The MIC value of the compound against C. albicans ATCC 90028 was more than 100 μg/ml which was the highest test concentration. All pathogenic microorganisms treated with the extract and rhodomyrtone at their subinhibitory concentrations resulted in a decrease in their adherence ability to both plastic surface and buccal cells.ConclusionIt is suggested that R. tomentosa extract and rhodomyrtone may be useful in therapy or as prophylaxis in infections involving oral pathogens.