Abstract:

In order to validate the applicability of synergistic index (SI) decision criteria on mutual compatibility antibacterial activity of clearing heat and removing toxicity traditional Chinese medicine in vitro, antibacterial activity to streptococcus was detected by the microtube-flat method on water extract and ethanol extract from the Radix glycyrrhiza, Rhizoma coptidis, Flos lonicerae japonicae, Cortex phellodendri chinensis and Cortex fraxini. SI was detected by the board trace broth dilution. SI was calculated by the formula. And then two Chinese herbs were matched into compound. The compound was extracted by water and ethanol solution. The minimum antibacterial concentration (MIC) of the extraction to streptococcus was determined. The results showed that SI of Rhizoma coptidis and Cortex fraxini compatibility was 0.5, while SI of Radix glycyrrhiza and Cortex fraxini, Radix glycyrrhiza and Flos lonicerae japonicae was both 0.75. MIC of ethanol-extraction to streptococcus, suis Ⅱ was 7.81 mg/mL. MIC of Radix glycyrrhiza and Rhizoma coptidis, Radix glycyrrhiza and Cortex fraxini ethanol-extraction was both 1.95 mg/mL. MIC of Rhizoma coptidis and Cortex phellodendri chinensis water-extract was 0.98 mg/mL. MIC of Coptis chinensis franch and Cortex fraxini water was 1.95 mg/mL. This showed that the compatibility on Rhizoma coptidis ethanol-extraction content and Cortex fraxini water extraction was present synergy obviously in vitro, the antibacterial activity of water-extraction on Rhizoma coptidis and Cortex phellodendri chinensis to streptococcus suis Ⅱ was the strongest.