The inhibitory effects of Rheum palmatum extract on the growth of oral streptococci and biofilm formation
10.11149/jkaoh.2022.46.3.129
- Author:
Si Yeong KIM
1
;
Yuri SONG
;
Hyun Ah LEE
;
Hee Sam NA
;
Jin CHUNG
Author Information
1. Department of Oral Microbiology, School of Dentistry, Pusan National University, Yangsan, Korea
- Publication Type:Original Article
- From:Journal of Korean Academy of Oral Health
2022;46(3):129-134
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objectives:Oral streptococci play a significant role in the development of dental caries. Among them, Streptococcus mutans and Streptococcus sobrinus are the principal causative agents of dental caries. Rheum palmatum is a flowering plant of the family Polygonaceae with several known medicinal properties. However, its effects on oral streptococci have yet to be established. Therefore, we investigated the effects of Rheum palmatum for its potential use as an anticaries agent in inhibiting the growth of streptococci and preventing biofilm formation.
Methods:Rheum palmatum extract was diluted with sterile distilled water to obtain various extract concentrations. Several strains of oral bacteria, including S. mutans and S. sobrinus, were treated with the varying concentrations. The effects of the extract on bacterial growth was examined using the viable cell count method. Glucan synthesis was measured using a spectrophotometer at 650 nm optical density. Crystal violet staining was also carried out to observe the effect of the extract on biofilm formation.
Results:The growth of S. mutans and S. sobrinus was significantly inhibited by the Rheum palmatum solution at concentrations of 0.3% or more compared to the control group. The viable cell count results indicated that the number of bacterial colonies decreased 1.2-fold and 1.7-fold at concentrations of 1.25% and 2.5%, respectively, compared to the control group. Biofilm formation by S. mutans and S. sobrinus was suppressed more than 20-fold compared to the control group at extract concentrations of 1.25% or more.
Conclusions:The extract inhibited the growth of caries-causing bacteria, namely S. mutans and S. sobrinus. Furthermore, the extract inhibited the synthesis of glucan and biofilm formation by S. mutans and S. sobrinus. Therefore, this study suggests that the extract is a potential candidate as a therapeutic agent for controlling dental caries.
