Related Experiment Video
Updated: Aug 6, 2026
Systematic Approach to Identify Novel Antimicrobial and Antibiofilm Molecules from Plants' Extracts and Fractions to Prevent Dental Caries
Published on: March 31, 2021
In vitro inhibitory effects of Polygonum cuspidatum on bacterial viability and virulence factors of Streptococcus
Ju-Hee Song1, Shin-Kyu Kim, Kee-Wan Chang
1Department of Preventive Dentistry, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea.
Objectives:
Polygonum cuspidatum has been used in Korean folk medicine to improve oral hygiene. This study was performed to evaluate the effects of methanol extract from root of P. cuspidatum (MEP) on bacterial viability and the virulence factors of Streptococcus mutans and Streptococcus sobrinus.
Methods:
To test the effects of MEP on bacterial viability, we determined the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 20 bacterial strains, including S. mutans and S. sobrinus, using a micro-dilution assay. In case of S. mutans and S. sobrinus, the assays for time-kill and bacterial growth rate at sub-MIC concentrations were also performed. To determine effects of the extract on the virulence factors of S. mutans and S. sobrinus, the assays for sucrose-dependent adherence, water-insoluble glucan formation, glycolytic acid production, and acid tolerance were performed at sub-MIC levels. Phytochemical analysis for constituents of MEP was carried out.
Results:
MEP showed a broad antibacterial range (MIC 0.5-4 mg/ml). The MBC was two to four times higher than the MIC. The time-kill curves showed S. mutans and S. sobrinus were significantly killed after 1h of incubation. At sub-MIC levels, doubling times of S. mutans and S. sobrinus dose-dependently increased up to 211% and 123%, respectively. At sub-MIC levels, MEP also showed inhibitory effects on the virulence factors of S. mutans and S. sobrinus in a dose-dependent fashion. Phytochemical analysis revealed the presence of alkaloids, sterol/terpenes, tannins, flavonoids, and carbohydrates.
Conclusion:
These data indicate that MEP has inhibitory effects on bacterial viability at higher concentrations (> or =MIC) and the virulence factors of S. mutans and S. sobrinus at sub-MIC concentrations, suggesting that it might be useful for the control of dental plaque formation and subsequent dental caries formation.
Insights
Methanol extract from Polygonum cuspidatum root (MEP) effectively inhibits oral bacteria like Streptococcus mutans and Streptococcus sobrinus. This natural compound shows potential for controlling dental plaque and preventing cavities.
Area of Science:
- Microbiology
- Pharmacology
- Natural Products Chemistry
Background:
- Polygonum cuspidatum is traditionally used for oral hygiene.
- Streptococcus mutans and Streptococcus sobrinus are key pathogens in dental caries.
- Understanding natural compounds' effects on oral bacteria is crucial for developing new treatments.
Purpose of the Study:
- To evaluate the antibacterial and anti-virulence effects of Polygonum cuspidatum root methanol extract (MEP).
- To assess MEP's impact on the viability and virulence factors of Streptococcus mutans and Streptococcus sobrinus.
Main Methods:
- Determined Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against oral bacteria.
- Assessed time-kill kinetics and growth rates at sub-MIC levels.
- Investigated effects on sucrose-dependent adherence, glucan formation, acid production, and acid tolerance.
Main Results:
- MEP exhibited broad-spectrum antibacterial activity (MIC 0.5-4 mg/ml).
- Significant bacterial killing observed within 1 hour; growth rates were inhibited at sub-MIC levels.
- MEP dose-dependently inhibited virulence factors, including adherence and glucan formation.
Conclusions:
- MEP demonstrates potent antibacterial effects and inhibits key virulence factors of S. mutans and S. sobrinus.
- These findings suggest MEP's potential utility in managing dental plaque and preventing dental caries.
- Phytochemical analysis confirmed the presence of bioactive compounds like flavonoids and tannins in MEP.
Related Concept Videos
01:28Antimicrobial Effectiveness
01:25Clinical Significance of Antibiotic Resistance