Antibacterial Activity of Licorice Extract on Streptococcus mutans and Cytotoxic Effect and Cytotoxic Effect on Human Gingival Fibroblast Cells
The purpose of this study were to examine the antibacterial activity of licorice extract against Streptococcus mutans ptococcus mutans, bacteria associated dental caries development, and examine the cytotoxic effect of licorice extract on human gingival fibroblast cells. The results of licorice extract against Streptococcus mutans showed the MIC and MBC of licorice extract were 781 and 3,125 µg/ml, respectively. The licorice extract strongly decreased a viable count of bacteria in 30 minutes and further decreased 30 minutes and further decreased to an almost to an almost undetectable level in 90 minutes. The cytotoxic effect of licorice extract on human gingival fibroblast cells was significantly found when cells treated by 3,125 µg/ml, while no significant cytotoxicity of licorice extract was found when cells were treated by 781 µg/ml. The results suggested the concentration of licorice extract against Streptococcus mutans and would be safe for oral tissue is 781 µg/ml.
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