Panax Notoginseng Extract Possesses Significant Antibacterial Activity against Pathogenic Streptococci

Abstract

Background: In traditional Chinese medicine, Panax notoginseng is used to treat inflammation and bleeding but has not been shown to affect bacterial pathogens. Objectives: Our aim was to assess the antibacterial potential of Panax notoginseng extract (PNE) against bacterial pathogens. Methods: PNE was dissolved in autoclaved distilled water. Antimicrobial activity was measured by the disc diffusion test and bacterial growth curve assays, in which the concentration of bacterial colony forming units was monitored at several time points in the presence or absence of PNE. Results: Disc diffusion and growth curve assays demonstrated that PNE significantly inhibited the growth of Streptococcus pyogenes, Streptococcus pneumoniae, and Haemophilus influenzae (p < 0.05). In contrast, the growth of the oral commensal bacteria Streptococcus intermedius, Streptococcus salivarius, and Streptococcus anginosus was not inhibited. Therefore, S. pyogenes clinical isolates were analyzed. PNE had antimicrobial effects on all tested isolates in both aerobic and anaerobic conditions. In addition, when S. pyogenes was co-cultured with S. intermedius in the presence of PNE, PNE inhibited the growth of S. pyogenes, but did not inhibit the growth of S. intermedius. Conclusion: Our findings suggested that PNE inhibited S. pyogenes without affecting oral commensal bacteria. Therefore, PNE could be used for the treatment of S. pyogenes infections.