Antibacterial and therapeutic effects of a combination of Sophora flavescens and Glycyrrhiza uralensis Fischer ethanol extracts on mice infected with Streptococcus pyogenes

Abstract

This study evaluated the antibacterial effects of a mixture of Sophorae radix and Glycyrrhiza uralensis Fischer (1: 1) ethanol extracts (SGE) on mice infected with Streptococcus (S.) pyogenes. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of SGE necessary for antibacterial effects against S. pyogenes were 20 μg/mL. Based on the time-kill curves for S. pyogenes, SGE was effective at 4× MIC after 16 h. On Day 12 after challenge, the survival rate of mice treated with 2.0 mg/kg SGE was 60%. In conclusion, SGE had potent in vitro and in vivo antibacterial activities against S. pyogenes.