In vitro antibacterial activity and major bioactive components of Cinnamomum verum essential oils against cariogenic bacteria,Streptococcus mutans and Streptococcus sobrinus

Objective:To evaluate the antibacterial activity of Cinnamomum verum(C.verum) from32 different essential oils against cariogenic bacteria,Streptococcus mutans(S.mutans)and Streptococcus sobrinus(S.sobrinus).Methods:The antibacterial activities of each essential oil were individually investigated against S.mutans and S.sobrinus.The essential oil of C.verum was selected for further evaluation against S.mutans and S.sobrinus.Gas chromatography mass spectrometry was used to determine the major constituents of C.verum essential oil.In addition,the minimum inhibitory concentration(MIC) and minimum bactericidal concentration of the most effective constituent was investigated.Results:The essential oil from C.verum exhibited the greatest antibacterial activity.Gas chromatography mass spectrometry analysis revealed that the major components of C.verum essential oil were cinnamaldehyde(56.3%),cinnamyl acetate(7.1%) and bphellandrene(6.3%).The MIC of cinnamaldehyde was measured using broth dilution assays.The MIC of cinnamaldehyde was 0.02%(v/v) against both bacterial strains tested.The minimum bactericidal concentration of cinnamaldehyde against S.mutans and S.sobrinus were 0.2% and 0.1%(v/v),respectively.Conclusions:The essential oil of C.verum and its major component cinnamaldehyde possessed considerable in vitro antibacterial activities against cariogenic bacteria,S.mutans and S.sobrinus strains.These results showed that the essential oil of C.verum and its bioactive component,cinnamaldehyde,have potential for application as natural agents for the prevention and treatment of dental caries.

THE ADHERENCE OF CARIOGENIC BACTERIA TO PELLICLE FORMED IN VITRO FROM MIXED AND DELIPIDATED SALIVA

Objective To study the influence of salivary lipids on the adherence of cariogenic bacteria (S.mutans Ingbritt and BF; S.sobrinus OMZ176 and 6715). Methods Mixed saliva was collected from 10 healthy subjects (5 males and 5 females, aged 21～23). The salivary lipids was depleted under nondenatural condition (-10℃, ethanol∶ether 3∶2 V∶V ). The adherence of S.mutans and S.sobrinus to the experimental pellicles formed from mixed saliva or lipids-depleted saliva was investigated with 3H-TdR incorperation assay. Results The amount of S.mutans Ingbritt and BF adhered to lipids-depleted pellicle were significantly increased ( P <0.05). The amount of experimental bacteria adhered to lipids-depleted pellicle or mixed salivary pellicle were following the regular pattern: Ingbritt>BF>OMZ176>6715. Conclusion Salivary lipids significantly decreased the number of S.mutans adhered to pellicle.

STUDY ON ADHERENCE ABILITY OF PERIODONTAL PATHOGENS AND CARIOGENIC BACTERIA TO HYDROXYAPATITE DISKS

Objective To study the adherence activity of six representative periodontopathic and cariogenic bacteria to hydroxyapatite disks. Methods Six periodontopathic and cariogenic bacteria of P. gingivalis, A. actinomycetemcomitans, F. nucleatum, S. sanguis, A. viscosus and S. mutans were cultured in modified MD-300 chemostat according to total fifteen experimental groups of single-specie and each pair of periodontal pathogens and cariogenic bacteria, respectively. After 1h attached live bacteria on removable hydroxyapatite disks was analyzed by culture technologies to evaluate the adherence level. Results The adherence activity of periodontopathic and cariogenic bacteria to HA was in the following order: S. sanguis > A. viscosus> S. mutans> A. actinomycetemcomitans > F. nucleatum > P. gingivalis. The number of periodontopathic bacteria to HA was enhanced by S. sanguis and A. viscosus,respectively.When mix-cultivated with S. mutans, the colonization of P. gingivalis was reduced significantly(P<0.001). Periodontopathic bacteria had no effect on the adherence activity of S. mutans and A. viscosus, except S. sanguis. Conclusion It was showed that the adherence activity of periodontal pathogens was weaker than that of cariogenic bacteria and emphasized the importance of bacterial adherence in determining the level of bacterial colonization on tooth surfaces. It was suggested that periodontopathic bacteria can utilize initial colonizers to become those predominant bacteria in periodontal ecosystem, which maybe have close relation to the periodontopathic mechanism.

Effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria in vitro

Background CecropinXJ belongs to cecropinB, which is the most potent antibacterial peptide found naturally The aim of this study was to investigate the effects of cecropinXJ on growth and adherence of oral cariogenic bacteriaMethods Four oral cariogenic bacteria (Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscosus and Actinomyces naeslundii) were chosen for this experiment The minimal inhibitory concentrations (MICs) and reductive percent of bacterial growth were used to assay the antibacterial activity of cecropinXJ Mammalian cytotoxicity of cecropinXJ was tested with human periodontal membrane fibroblasts by tetrazolium (MTT) colorimetric assay The bacterial morphological changes induced by cecropinXJ were examined on scanning electron microscope (SEM) The influence of cecropinXJ on bacterial adhesion to salivacoated hydroxyapatite (SHA) was measured by scintillation countingResults The MICs of cecropinXJ for inhibition of the growth of four bacteria ranged from 40 to 428 μmol/L with the highest susceptible to A naeslundii and the lowest susceptible to L acidophilus At pH 68, 55 and 82, 1/2 MIC of cecropinXJ reduced the number of viable bacteria by 409%, 678% and 328% for S mutans and by 281%, 572% and 379% for L acidophilus The activities against Smutans and L acidophilus increased at pH 55 compared with pH 68 (P<001, respectively) In present of 50% saliva, 1/2 MIC of the peptide decreased the direct count of viable cells by 292% and 144% for S mutans and L acidophilus, respectively (P<001 and P>005, respectively), whereas almost no reduction counts were detected in the presence of 20% serum for both bacteria (P>005, respectively) Mammalian cytotoxicity of cecropinXJ from 10 to 100 μmol/L exhibited no cytotoxicity against human periodontal membrane fibroblasts (P>005) Bacterial morphological changes induced by MIC of cecropinXJ examined on SEM showed cell surface disruption Furthermore, the ability of A naeslundii adhesion to SHA decreased significantly with MIC of cecropinXJ for 10 and 20 minutes (P=0001 and 0000, respectively), and S mutans, A viscosus to SHA decreased significantly with MIC of cecropinXJ for 20 minutes( P=0000, respectively) Conclusions CecropinXJ exhibited bactericidal action against cariogenic pathogens, and the antibacterial activity enhanced in the acid environment The results also demonstrate that cecropinXJ prevents S mutans and actinomyces adsorption to SHA These findings suggest that CecropinXJ may have potential to prevent caries

The Antibacterial Effect of CMCTS-Containing Chewing Gum

Objective： This paper was designed to confirm the efficacy of chewing carboxymethyl chitosan（CMCTS）-containing gum in suppressing the growth of oral bacteria when compared to a CMCTS-containing mouth rinse. Methods：Fourteen healthy subjects were recruited from among the staff and students of Qingdao University Dentistry Department. Before the experiments saliva was collected from all subjects and bacteria counts determined. For the gum study, the subjects chewed CMCTS-containing gum for 5 min and then rested for 5 min. When testing the CMCTS mouth rinse, the subjects gargled with 10 mL of solution for 30 s, followed by resting for 9rain 30 s. These protocols were repeated five times over a 50 min period on the same day. Post-experiment saliva samples were then collected at the following times： 0, 30 and 60 min. Results： Chewing gum containing CMCTS or rinsing with a CMCTS-containing rinse significantly decreased oral bacteria counts. The total bacteria counts, total Streptococci counts, and mutans streptococci counts of saliva from subjects who chewed CMCTS-containing gum were significantly lower than saliva from subjects in the rinse group in all three sampling periods, except in the case of the total bacteria count in the 60 min samples. Conclusion：CMCTS-containing gum chewing has a greater antibac- terial effect than using a CMCTS-containing mouth rinse. The present findings strongly indicate that the application of natural materials such as chitosan and its derivatives is useful for better oral health.

Ozone action on Streptococcus mutans and Lactobacillus fermentum : A pilot study

AIM: To study the effectiveness of ozone in the elimination of cariogenic bacteria, followed with fluoride supplements.METHODS: Sixty extracted teeth free of caries were used, and five groups were constituted. In Group Ⅰ,the teeth were immersed in artificial saliva. In Group Ⅱ,the teeth were inoculated with Streptococcus mutans(S. mutans) and immersed in artificial saliva. In GroupⅢ the teeth were inoculated with Lactobaccilus fermentum(L. fermentum) and immersed in artificial saliva.In Group Ⅳ the teeth were inoculated with S. mutans and L. fermentum and immersed in artificial saliva and the teeth in Group Ⅴ were inoculated with S. mutans and L. fermentum, and were subjected to the application of ozone and to the action of a fluoride mineralizing gel. DIAGNOdent was used to evaluate the caries of the teeth 3 wk after inoculation of bacteria and after that the teeth of Group Ⅴ were subjected to the application of ozone during 60 s, by HealO zone. After the application of ozone, products of the remineralization kit supplied by the manufacturer were applied daily, during 30 d. At the end samples were collected for analysis and evaluation of bacterial activity by polymerase chain reaction. RESULTS: Regarding the value of caries, obtained via DIAGNOdent, in the initial measurement the groups are homogeneous(P = 0.730). There was an increase in DIAGNOdent values, presenting statistical significant difference regarding the initial measurement in all groups(P < 0.001), except in group Ⅰ- only artificial saliva- which shows that the artificial carie model was effective. Comparing the initial and final measurements for each of the 60 teeth, it can be observed that in 9 teeth(15.0%) there was a decrease in values between the two measurements, one(1.7%) retained the same values in the two measurements and in the remaining 50 cases(83.3%) there was increase in values between the initial and final measurements. It should also be noted that in the teeth inoculated with S. mutans + L. fermentum, there was an increase of the values in 100% of cases, and in all groups except the group with artificial saliva, there is a more frequent increase in the values. In group Ⅴ, subject to the application of ozone, bacterial DNA was not detected, in group Ⅳ, bacterial DNA was detected.CONCLUSION: Ozone was effective in the elimination of the study bacteria.