Inhibitory effect of baicalin on Streptococcus mutans UA159 in vitro

Abstract

Objective To investigate the inhibitory effect of baicalin on Streptococcus mutans UA159 in vitro.Methods The minimum inhibitory concentration (MIC) of baicalin on Streptococcus mutans UA159 was determined by the liquid multiple dilution method combined with the OD600 value measured by microplate. The OD600 value of Streptococcus mutans UA159 in different concentrations of baicalin was measured by an enzyme mapping instrument. A growth curve was drawn, and the adhesion rate and adhesion inhibition rate were calculated. The effect of baicalin on the formation of Streptococcus mutans UA159 biofilms was observed by the crystal violet quantitative method and scanning electron microscopy. The effect of baicalin on the total number of Streptococcus mutans UA159 bacteria was observed by scanning electron microscopy.Results The MIC of baicalin on Streptococcus mutans UA159 was 12 mg/mL. With increasing baicalin concentration, the growth rate of Streptococcus mutans UA159 was slowed, the adhesion rate of Streptococcus mutans UA159 decreased and the adhesion inhibition rate increased（P < 0.05）. The results of crystal violet quantitative method showed that compared with the bacterial control group, the biofilm formation of Streptococcus mutans UA159 was significantly reduced after adding baicalin at 0 h, 6 h and 12 h (P < 0.001). Under a scanning electron microscope, the total number of bacteria decreased significantly after adding baicalin at 0 h, 6 h and 12 h.Conclusion Baicalin can inhibit the growth and reproduction of Streptococcus mutans UA159 in vitro as well as the adhesion and biofilm formation of Streptococcus mutans UA159.

Keywords

• baicalin，
• natural medicine，
• streptococcus mutans ua159，
• caries，
• minimum inhibitory concentration，
• growth curve，
• adhesion rate，
• adhesion inhibition rate，
• biofilm formation ，
• in vitro study，