Antibacterial activities, antioxidant contents and antioxidant properties of three traditional Chinese medicinal extracts

The present study was carried out to identify antibacterial and antioxidant characteristics of traditional aqueous extracts derived from three traditional Chinese medicinal plants (Scutellaria baicalensis, Coptis chinensis and Sonchus oleraceus). It was indicated that the Sonchus oleraceus showed the highest antibacterial efficacy, especially against Staphylococcus aureus. The minimum inhibitory concentration (MIC) of the Sonchus oleraceus was 5.0 mg/mL what was in correlation with the high total phenolic and flavonoid contents and CUPRAC value, and MIC of both Scutellaria baicalensis and Coptis chinensis was 7.5 mg/mL. The rational pH of the working Sonchus oleraceus was acidic, while the other two preferred to neutral or alkaline environment. The reasonable preservation temperature of Scutellaria baicalensis should not beyond 60 degrees C, while the other two below 90 degrees C. Meanwhile, Scutellaria baicalensis had significant antioxidant activity with the highest CUPRAC and center dot OH scavenging activity. These results had provided useful information on further drug discovery.