Comparison on Antimicrobial Activity of Different Solvent Extracts from Aerial Stem and Rhizome of Douttuynia cordata

The 95% of ethanol crude extract of aerial stem and rhizome of houttuynia cordata was sequentially extracted with petroleum ether, ethyl acetate, n-butyl alcohol and water. Antimicrobial activity and minimum inhibitory concentration (MIC) of the different extracts against Staphylococlus aureus, Escherichia coli, Bacillus subtilis, Aspergillus niger and Saccharomycetes were examined with filter paper method. And antimicrobial activity between aerial stem and rhizome was compared. The result showed that, among the extracts of aerial stem and rhizome of houttuynia cordata, with regard to antimicrobial activity, water extract was strongest against Staphylococlus aureus, and ethyl acetate extract was strongest against Escherichia coli, and n-butyl alcohol extract was strongest against Bacillus subtilis and Saccharomycetes, while each extract had no significant antimicrobial activity against Aspergillus niger. Moreover, the antimicrobial activity of rhizome was stronger than that of the aerial stem.