Antioxidant Properties of Ethanolic Extract from Ramulus mori (Sangzhi)

The antioxidant properties and total phenolic contents of four fractions of ethanolic extract from Ramulus mori were examined. Various experimental models including superoxide radical, hydroxyl radical, 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) scavenging activity, metal chelating activity, and reducing power were used for characterization of their antioxidant activity. The four fractions showed various degrees of efficacy in each assay in a dose-dependent manner. The third fraction with the highest amount of total phenolics was the most potent antioxidant in all assays used. In addition, the most powerful compound (oxyresveratrol) was isolated and identified followed by on-line HPLC method and characterized by different spectral analysis. Oxyresveratrol exhibited impressive antioxidant activities in scavenging the superoxide radical, hydroxide radical, and DPPH. On the basis of the results obtained, Ramulus mori may serve as a potential source of natural antioxidant due to its significant antioxidant activity and oxyresveratrol may be the most powerful antioxidant in ethanolic extracts of Ramulus mori.