Inhibitory effect of Aralia continentalis on the cariogenic properties of Streptococcus mutans.

ETHNOPHARMACOLOGICAL RELEVANCE: Aralia continentalis has been used in traditional Korean medicine for dental diseases such as toothache, dental caries, periodontal disease and gingivitis, and also has been used for neuralgia, analgesia, sweating, and as an antirheumatic. AIM OF THE STUDY: The present study was designed to investigate the inhibitory effect of Aralia continentalis extract on cariogenic properties of Streptococcus mutans, which is one of the most important bacteria in the formation of dental caries and dental plaque. MATERIALS AND METHODS: The inhibitory effects of Aralia continentalis extract on the growth, acid production, water-insoluble glucan synthesis, and adhesion were investigated in Streptococcus mutans. The biofilm formation of Streptococcus mutans was determined by scanning electron microscopy (SEM) and safranin staining. RESULTS: The ethanol extract of Aralia continentalis showed concentration dependent inhibitory activity on the growth of Streptococcus mutans and significant inhibition of acid production at the concentrations of 0.25, 0.5, 1, 2 and 4 mg/ml compared to the control group. The synthesis of water-insoluble glucan by glucosyltransferase (GTFase) was decreased in the presence of 0.5-4 mg/ml of the extract of Aralia continentalis. The extract markedly inhibited Streptococcus mutans adherence to saliva-coated hydroxyapatite beads (S-HAs). The extract of Aralia continentalis has an inhibitory effect on the formation of Streptococcus mutans biofilms at the concentrations higher than 2mg/ml. CONCLUSIONS: These results suggest that Aralia continentalis may inhibit cariogenic properties of Streptococcus mutans, and also may support the scientific rationale that native inhabitants used the extract for the treatment of dental diseases.

Anticariogenic properties of the extract of Cyperus rotundus.

Streptococcus mutans (S. mutans) is known as the causative bacteria in the formation of dental plaque and dental caries. The aim of this experiment was to investigate the effects of Cyperus rotundus (C. rotundus) tuber extract on the growth, acid production, adhesion, and water-insoluble glucan synthesis of S. mutans. The growth and acid production were reduced by the extract of C. rotundus in a dose dependent manner. The extract of C. rotundus markedly inhibited the adherence of S. mutans to saliva-coated hydroxyapatite beads (HAs). The adherence was repressed by more than 50% at the concentration of 0.5 mg/ml of the extract and complete inhibition was observed at the concentration of 4 mg/ml of the extract. On the activity of glucosyltransferase (GTFase) which synthesizes water-insoluble glucan from sucrose, the extract of C. rotundus showed more than 10% inhibition at a concentration of 2 mg/ml. These results suggest that C. rotundus may inhibit cariogenic properties of S. mutans. Further studies are necessary to clarify the active constituents of C. rotundus responsible for such biomolecular activities.

Rehmannia glutinosa activates intracellular antioxidant enzyme systems in mouse auditory cells.

Steamed roots of Rehmannia glutinosa (R. glutinosa) have been traditionally used in Oriental medicine for the treatment of auditory diseases such as tinnitus and hearing loss. To investigate whether the ethanol extract of steamed roots of R. glutinosa (SRG) increases activity of antioxidant enzymes and the level of glutathione (GSH), we measured activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR) and GSH level in HEI-OC1 cells after treatment with 5-50 microg/ml of SRG. The SOD and CAT activities were significantly increased in the presence of SRG compared to the control group. Maximal activities of SOD and CAT were observed in these cells exposed to 10 microg/ml of SRG. The GPX activity also increased dramatically in response to the treatment with SRG in a dose-dependent manner. The GR activity was only increased in the presence of 50 microg/ml of SRG compared to the control group. The level of GSH gradually increased in the presence of 5-50 microg/ml of SRG. In the cytotoxicity test, 5-50 microg/ml of SRG did not show any significant cytotoxicity. These results suggest that the traditional use of R. glutinosa for the treatment of auditory diseases may be explained, in part, by activation of intracellular antioxidant enzyme systems. Further studies are necessary to clarify the active constituents of SRG responsible for such biomolecular activities.