Indonesian Mangosteen Fruit (Garcinia mangostana L.) Peel Extract Inhibits Streptococcus mutans and Porphyromonas gingivalis in Biofilms In vitro.

Streptococcus mutans and Porphyromonas gingivalis are caries and periodontal disease-related bacteria. The mangosteen fruit (Garcinia mangostana L.) peel contains flavonoids, tannins, saponins, and xanthones that have antibacterial properties.

The aim of this study is to analyze mangosteen peel extracts' ability to inhibit S. mutans and P. gingivalis has biofilms growth in vitro.

Mangosteen peel extract effects on the S. mutans ATCC-3198 and P. gingivalis ATCC-3327 in biofilms growth were evaluated by a crystal violet biofilm assay. Each bacterium was inoculated into a brain-heart infusion broth for 24 h at 37°C anaerobic conditions. A volume of 200 μL (10⁷ colony-forming unit/mL) of bacterial suspension were distributed in microplate wells and incubated for 24 h. Mangosteen peel extracts with different concentrations were added into biofilm wells. Biofilm without treatment was used as negative control. Biofilm mass was calculated by 0.5% crystal violet staining, and optical density was measured at 600 nm using microplate reader. All obtained data were statistically analyzed using one-way analysis of variance test with P < 0.05 set as the level of significance.

The results showed that mangosteen peel extract could inhibit the growth of S. mutans and P. gingivalis in biofilms significantly compared to the negative control (P < 0.05). The most effective concentration and incubation time for inhibiting biofilm growth was 100% in 6 h for S. mutans and 100% in 24 h for P. gingivalis.

Mangosteen peel extract is effective at inhibiting S. mutans and P. gingivalis biofilms, and this antibiofilm agent can be an alternative therapy in preventing caries and periodontal disease. Future studies are needed to explore this effect.