Antibacterial Effects of Paeonia lactiflora Extract on Oral Microcosm Biofilms

The aim of this study was to evaluate the antibacterial effects of Paeonia lactiflora (PL) extract on oral microcosm biofilms and determine its usefulness as a natural alternative to current antimicrobial agents. Oral biofilms were cultivated on hydroxyapatite disks using human saliva for 2 days, following which they were treated with 1.5 mL of distilled water (DW), 30 μg/mL of PL extract, or 0.12% chlorhexidine gluconate (CHX) once daily for 3 days. Antibacterial effects were assessed by measuring red fluorescence intensity (RatioR/G), bacterial viability (RatioG/G+R), and aciduric bacterial counts. RatioR/G was evaluated using quantitative light-induced fluorescence digital imaging. RatioR/G and RatioG/G+R in the PL group were 0.94-fold and 0.73-fold lower than those in the DW group (p < 0.001 and p = 0.011, respectively) and comparable to those in the CHX group (p = 0.356 and p = 0.964, respectively). Aciduric bacterial counts in the PL group were 0.97-fold lower than those in the DW group (p < 0.001), with no significant difference from those in the CHX group (p = 0.892). Thus, the antibacterial effect of PL extract was comparable to that of CHX; this suggests its potential as a natural alternative for managing oral biofilm-associated diseases.