Abstract:

Objectives: To evaluate the antibacterial activities of 80% ethanol extract of Syringa reticulate stem bark against 5 common bacteria and its antioxidant activity and analyze trace elements. Methods: The minimal inhibitory concentrations (MICs) of Syringa reticulata extract against bacteria tested were determined by filter paper method. The effects of temperature, pressure, pH and ultraviolet irradiation on antibacterial activity of the extract were also investigated. DPPH free radical scavenging assay was used for antioxidant activity evaluation. The contents of trace elements such as iron, manganese, zinc and copper were determined using atomic absorption spectrophotometry. Results: The MICs of the extract was 1.563 mg/mL against Staphylococcus aureus, and 6.25 mg/mL against both Pasteurella and Salmonella enterica. The extract exhibited stable antibacterial activity when exposed to high temperature, ultraviolet light and acidic environment. The EC50 (median effective concentration) of the extract for scavenging DPPH free radicals was 0.042 mg/mL. The contents of trace elements such as Fe, Mn, Zn and Cu were 880.5, 26.03, 60.9μg/g and 10.13 μg/g, respectively. Conclusion: Syringa reticulata stem bark has an excellent antibacterial activity and antioxidant activity and exhibits high levels of trace elements. This demonstrates its promising development potential.

Key words: Syringa reticulata, antibacterial activity, antioxidant activity, trace elements