Ursolic acid disrupts cariogenic biofilms with selective antibacterial activity against Streptococcus mutans and Streptococcus sobrinus
Issued Date
2026-02-04
Resource Type
eISSN
26300087
Scopus ID
2-s2.0-105040167485
Journal Title
Science Engineering and Health Studies
Volume
20
Rights Holder(s)
SCOPUS
Bibliographic Citation
Science Engineering and Health Studies Vol.20 (2026)
Suggested Citation
Klaophimai A., Klaophimai S., Pattamadilok C., Pouyfung P., Chairatvit K. Ursolic acid disrupts cariogenic biofilms with selective antibacterial activity against Streptococcus mutans and Streptococcus sobrinus. Science Engineering and Health Studies Vol.20 (2026). doi:10.69598/sehs.20.26050007 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/117079
Title
Ursolic acid disrupts cariogenic biofilms with selective antibacterial activity against Streptococcus mutans and Streptococcus sobrinus
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Abstract
Prevention of dental caries requires effective control of biofilm-forming Streptococcus spp. The present study evaluated the antimicrobial and antibiofilm properties of ursolic acid (UA) and beta-sitosterol against cariogenic bacteria. UA demonstrated selective antimicrobial activity, with MIC/MBC values of 8 and 16 μM against Streptococcus mutans and Streptococcus sobrinus, respectively. At 16 μM, UA reduced biofilm adherence by 95% and 90% in S. mutans and S. sobrinus, respectively. Confocal microscopy revealed a dose-dependent reduction in biofilm thickness, decreasing from 35.2 ± 2.3 μm to 17.3 ± 1.5 μm for S. mutans and from 64.3 ± 1.8 μm to 42.1 ± 1.2 μm for S. sobrinus following treatment with 64 μM UA. At this concentration, bacterial viability decreased to 40% and 62% for S. mutans and S. sobrinus, respectively. In comparison, 0.12% chlorhexidine (positive control) reduced biofilm thickness to 15.1 ± 2.5 μm and 32.5 ± 1.9 μm, with viability decreasing to 36% and 52% for S. mutans and S. sobrinus, respectively. Unlike UA, beta-sitosterol showed negligible antibacterial activity. These findings demonstrate the potential of UA as a promising natural therapeutic agent against cariogenic biofilms, although its efficacy remains lower than that of chlorhexidine.