Anti-biofilm Activities from Bergenia crassifolia Leaves against Streptococcus mutans

Abstract

Streptococcus mutans has been reported as a primary cariogenic pathogen associated with dental caries. The bacteria can produce glucosyltransferases (Gtfs) to synthesize extracellular polysaccharides (EPSs) that are known as virulence factors for adherence and formation of biofilms. Therefore, an ideal inhibitor for dental caries is one that can inhibit planktonic bacteria growth and prevent biofilm formation. Bergenia crassifolia (L.), widely used as a folk medicine and tea beverage, has been reported to have a variety of bioactivities. The present study aimed to explore the effect of B. crassifolia (L.) leaf extracts on the biofilm of Streptococcus mutans. The B. crassifolia (L.) leaf extracts showed inhibitory effects by decreasing viability of bacteria within the biofilm, as evidenced by the XTT assay, live/dead staining assay and LDH activity assay, and could decrease the adherence property of S. mutans through inhibiting Gtfs to synthesize EPSs. In addition, the reduced quantity of EPSs and the inhibition of Gtfs were positively correlated with concentrations of test samples. Finally, the MTT assay showed that the extracts had no cytotoxicity against normal oral cells. In conclusion, the extracts and sub-extracts of B. crassifolia leaves were found to be antimicrobial and could reduce EPS synthesis by inhibiting activities of Gtfs to prevent bacterial adhesion and biofilm formation. Therefore, B. crassifolia leaves have potential to be developed as a drug to prevent and cure dental caries.

Developing natural products as potential anti-biofilm agents

“…Other natural products or components such as polyphenolic extract from Rosa rugose tea, methanolic fraction of Zingiber officinale or kinds of leaves extract, were also demonstrated to display inhibitory effect on QS and biofilm development [53][54][55]. It was reported that ethanol extract from Rhodomyrtus tomentosa (Aiton) Hassk.…”

Evaluation of total phenol and flavonoid content and antimicrobial and antibiofilm activities of Trollius chinensis Bunge extracts on Streptococcus mutans

“…The results showed that with the increase of drug concentration, the thickness of bacterial biofilm gradually decreased; there is a concentration‐dependent effect between thickness and concentration (Table 3). The formation of bacterial biofilm is a three‐step dynamic process, followed by adhesion, aggregation, and maturity; the first step of adhesion is crucial to the formation of biofilm, which determines the subsequent development and maturity of biofilm (Liu et al, 2017). Our research shows that the T. chinensis Bunge can inhibit the growth of S. mutans and the formation of its biofilm.…”

Antibacterial and Antibiofilm Activity of Temporin-GHc and Temporin-GHd Against Cariogenic Bacteria, Streptococcus mutans

“…Minimum bactericidal concentrations (MBCs) were determined by plating the bacterial suspensions from the MIC assay wells at the peptide concentrations equal to or higher than the MIC values on solid agars. The lowest peptide concentrations at which there was no bacterial growth on plates after incubation were taken as the MBC (Liu et al, 2017). Resazurin microtiter assay was also performed as previously described to determine the MIC (Palomino et al, 2002).…”

“…Human oral epithelial cells (HOECs) were purchased from Shrdio Company (Nanjing, China). The cytotoxicity of GHc or GHd on HOECs was evaluated by a Cell Counting Kit-8 (CCK-8) assay (Beyotime Biotechnology, China) (Alaufi et al, 2017;Liu et al, 2017). HOECs were grown in Dulbecco's modified Eagle's medium (DMEM) containing 10% fatal bovine serum (FBS) and cultured in a humidified atmosphere of 5% CO 2 at 37°C.…”