The present paper presents the comparison on antioxidant capabilities of Acanthopanax species, including Acanthopanax trifoliatus (L.) MERR., Acanthopanax trifoliatus var. setosus and Acanthopanax senticosus RUPER. et MAXIM.. Previous pharmacological study on A. senticosus reported antiinflammatory, immunostimulatory and good antioxidant activity. A. trifoliatus , a species endemic to Taiwan, can be found in the Taiwan coteau and Acanthopanax trifoliatus var. setosus is another variety. The antioxidative activities assays include 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging effect, Fe2+ chelating power, reducing power and the inhibition of Butylated hydroxyanisole crystalline (BHT) induced lipid peroxidation in a liposome model system. Some extracts were good antioxidants by comparison with reference molecules, such as vitamin E and quercetin. Results indicated that the scavenging action of the DPPH free radical were just as efficient and effective as when the synthetic antioxidant BHT is used. As for the reducing actions of the extracts of Acanthopanax trifoliatus (L.) MERR. and BHT as indicated by the formation of Prussian blue, extracts of optimum concentration displayed relative activity at 100% of BHT. The results showed that all extracts obtained antioxidative abilities and their abilities depended strongly on their concentrations.
