In vitro anti-cariogenic activity of dichloromethane fraction fromRheum undulatum L. root

Abstract

This study aimed to evaluate in vitro effects of Rheum undulatum L. root on the development of dental caries, especially its effects on viability, dental plaque formation, and glycolytic acid production of Streptococcus mutans and Streptococcus sobrinus. Methanol extract of Rheum undulatum L. root and its fractions were prepared and tested. Among the test extract and fractions, dichloromethane fraction (DF) showed the most active antibacterial activity (inhibition zone: 13-17 mm) against S. mutans and S. sobrinus in a disc diffusion method. Minimal inhibitory concentrations (MICs) of DF against these bacteria ranged from 0.25 to 0.5 mg/mL. Furthermore, DF significantly inhibited the caries-inducing factors of these bacteria. At sub-MIC levels, DF inhibited in vitro dental plaque formation by S. mutans and S. sobrinus (IC50= 0.079 and 0.142 mg/mL, respectively), which was caused, in part, by the inhibitory effect on the activity of glucosyltransferases. A significant reduction of glycolytic acid production was found at the concentration as low as 0.032 mg/mL for S. mutans and 0.063 mg/mL for S. sobrinus. The possible bioactive compounds that are inducing in vitro anti-cariogenic activity of DF are unknown. Based on the preliminary phytochemical analysis, the activity of DF may be related to the presence of anthraquinones, cardiac glycosides, coumarines, sterols/terpenes, and phenolics. These results indicate that DF is probably useful for the control of dental plaque formation and subsequent dental caries development.

Effects of Japanese traditional herbal medicines (Kampo) on growth and virulence properties ofPorphyromonas gingivalisand viability of oral epithelial cells

“…Anthraquinones are important phytochemicals in rhubarb and were found to be highly inhibitory for P. gingivalis growth, more specifically aloe-emodin and rhein possessed an MIC of 0.75 mg/ml. The above results are in agreement with previous studies that showed that an anthraquinone-rich extract of another species of rhubarb (Rheum undulatum) exhibited antibacterial activity towards the cariogenic bacterium Streptococcus mutans (Song et al, 2006;Kim et al, 2011). Moreover, synergistic effects of anthraquinones (emodin, rhein) in combination with antibiotics (ampicillin, oxacillin) have been reported for methicillin-resistant Staphylococcus aureus (Joung et al, 2012;Lee et al, 2010).…”

Anticariogenic Activity of <i>Lagerstroemia speciosa</i> (L.)

“…Chung et al (2006) isolated macelignan from the methanol extract of Myristica fragrans and showed its potent anticariogenic activity against S. mutans and other oral pathogens. The inhibitory activity of methanol extract of Rheum undulatum root against S. mutans and S. sorbinus was investigated by Song et al (2006). The dichloromethane fraction showed the most active antibacterial activity.…”

Antimicrobial activity and total content of polyphenols of Rheum L. species growing in Poland

“…on the growth of other Gram-positive bacteria, e.g. Streptococcus mutans and S. sobrinus [9]. It is worth noting that the reported MIC value of plant extracts is often in the range of 100 -1000 mg/mL [30,36].…”

“…The use of plants or plant preparations to treat infections has been a common practice in virtually all cultures for a long time [6,7]. Several plant species have been a subject of scientific investigation for many years in order to learn about the biological activity of their compounds, allowing in the future development of alternative, natural antimicrobial compounds [1,2,6,8,9].…”