Antimicrobial effect of sophoraflavanone G isolated from Sophora flavescens against mutans streptococci

In this study, the antibacterial properties of sophoraflavanone G isolated from the methanol extract of Sophora flavescens were tested against 16 strains of mutans streptococci to screen and determine the optimal concentration of anti-caries natural extract. The antimicrobial activity was evaluated by measuring minimum bactericidal concentration (MBC). The cell viability of normal human gingival fibroblast (NHGF) cells was tested using the methyl thiazolyl tetrazolium assay after exposure to sophoraflavanone G. The data showed that sophoraflavanone G had a remarkable antimicrobial effect on the bacteria tested with an MBC ranging from 0.5 μg/ml to 4 μg/ml. Sophoraflavanone G had no cytotoxic effect on NHGF cells at concentrations where it produced an antimicrobial effect. These findings demonstrate that sophoraflavanone G has strong antimicrobial activity against mutans streptococci and could be useful in the development of novel oral hygiene products, such as a gargle solution or dentifrice.