Antibacterial activity of Salvia hydrangea extract against oral bacteria and comparison with vancomycin antibiotic in vitro

The three oral bacteria (members of the normal flora in the mouth) including Streptococcus mutans, Lactobacillus and Streptococcus sanguis play a major role in the production of dental caries so that the first two bacteria accelerate dental caries but the third reduce this process. The purpose of this study was to determine the antibacterial activity of hydro and methanolic extract from Salvia hydrangea DC. ex Benth. against the three oral bacteria and comparison with vancomycin antibiotic in vitro.

At First, a sample of hydro and methanolic extract of the Salvia hydrangea was prepared and then its antibacterial activity against S. mutans (PTCC 1601), Lactobacillus (PTCC 1608) and S. sanguis (PTCC 1449) was evaluated by well diffusion (with concentration of 100mg/ml) and agar serial dilution methods for determining of MIC (minimum inhibitory concentration) with dilution of 0.195 to 100mg/ml. Also, we studied the antibacterial activity of vancomycin antibiotic on them by disk diffusion method.

The results from the antibacterial tests Salvia hydrangea hydro and methanolic extract had not been affected against any of the bacteria. While S. mutans was sensitive to vancomycin and Lactobacillus and strep. Sanguis were resistant to it.

This study demonstrated that hydro and methanolic extract of Salvia hydrangea may not be an effective antibacterial medication in the prevention of dental caries.

Keywords: Salvia hydrangea, hydro and methanolic extract, antibacterial activity, vancomycin, oral bacterial