Effect of Traditional Chinese Herbal Medicine with Antiquorum Sensing Activity onPseudomonas aeruginosa
Traditional Chinese herbal medicines (TCHMs) were tested for their ability of antiquorum sensing. Water extracts ofRhubarb, Fructus gardeniae, and Andrographis paniculatashow antiquorumsensing activity when usingChromobacterium violaceumCV12472 as reporter; the sub-MIC concentrations of these TCHMs were tested against AHL-dependent phenotypic expressions of PAO1. Results showed significant reduction in pyocyanin pigment, protease, elastase production, and biofilm formation in PAO1 without inhibiting the bacterial growth, revealing that the QSI by the extracts is not related to static or killing effects on the bacteria. The results indicate a potential modulation of bacterial cell-cell communication,P. aeruginosabiofilm, and virulence factors by traditional Chinese herbal medicine. This study introduces not only a new mode of action for traditional Chinese herbal medicines, but also a potential new therapeutic direction for the treatment of bacterial infections, which have QSI activity and might be important in reducing virulence and pathogenicity of pathogenic bacteria.