抄録
Extract of Eucalyptus globulus showed antibacterial activity against several oral bacteria such as Streptococcus mutans, Streptococcus sobrinus and Streptococcus sanguis. It also showed inhibitory effect on glycosyltransferase (GTase of mutans streptococci) in vitro.
In this study, anti-caries activity of extract of E. globulus on S. mutans-infected gnotobiotic BALB/cA mouse model was investigated.
Germ-free BALB/cA mice (5 weeks old) were divided into 1 control group and 3 experimental groups. The control group were fed Diet 2000 (D#2000) containing 30% sucrose and experimental groups were fed D#2000 containing extract of E. globulus at levels of 0.5%, 0.1% and 0.05%. All groups were inoculated with S. mutans ATCC 25175.
The number of S. mutans on the teeth of the experimental groups 0.5% and 0.1% were significantly lower than that of the control group (p<0.01) . That of the 0.5% group was also significantly lower than that of 0.05% group (p<0.05) .
The number of S. mutans in the cecum contents of the experimental groups 0.5% (p<0.01) and 0.1% (p<0.05) were significantly lower than that of the control group. That of the 0.5% group was also significantly lower than those of the 0.1% (p<0.05) and 0.05% groups (p<0.01) .
Caries developed in all mice, however, the mean caries scores of the experimental groups 0.5% and 0.1% were significantly lower than that of the control group (p<0.01) . Further, the mean caries score of the 0.5% group was significantly lower than those of the 0.1% and 0.05% groups (p<0.01) .
The results suggested that extract of E. globulus showed anti-caries activity in gnotobiotic BALB/cA mouse model. This anti-caries activity of extract of E. grobulus might be due to bacteriostatic action of S. mutans, and extract of E. grobulus has an inhibitory effect on GTase of S. mutans.
