Abstract: BACKGROUND AND AIM: To study the antioxidative activities of different concentrations of ethanol and water extracts of Acanthopanax in several free radical models in vitro and their dose-effect relationships. MATERIALS AND METHODS: The DPPH system model was built to study the inhibitive rates of DPPH radicals by different concentrations of Acanthopanax extracts. Two chemiluminescence system models for determination of ·OH and O2 were set up to examine the inhibitive rates of luminous intensity by different concentrations of Acanthopanax extracts. The lipid microsomal peroxidation model stimulated by CHP, VC／Fe2＋ and CC14／NADP were used to assess the inhibitive rates of MDA by different concentrations of Acanthopanax extracts. RESULTS: In the DPPH system, the inhibitive rates of DPPH radicals by the two Acanthopanax extracts were significantly higher than that in control group which showed an evident dose-effect relationship. The IC50 of DPPH radicals by the ethanol and water extracts of Acanthopanax was 0.18 mg/ml and 0.09 mg/ml, respectively. In the two chemiluminescence systems, except the ethanol extract of 0.625 mg/ml (P=0.102), the inhibitive rates of ·OH and O2 by different concentrations of Acanthopanax extracts were significantly higher than that in control group and showed an evident dose-effect relationship. The IC50 of O2 and ·OH by ethanol extracts of Acanthopanax were 0.488 mg/ml and 1.29 mg/ml, respectively, and the IC50 were 0.24 mg/ml and 0.37 mg/ml, respectively, by the water extracts. In the CHP model, the water extracts of Acanthopanax showed an activity of promoting oxidation when the concentration was 1.25 mg/ml. But the variance didn't reach statistical significance. Compared with that in control group, the content of MDA in the three LPO models decreased significantly(P<0.05) at different concentrations and had a dose-effect relationship. CONCLUSION: In several in vitro models described above, the ethanol and water extracts of Acanthopanax demonstrated effective antioxidative effects. In DPPH and two chemiluminescence systems, the antioxidative activities of the water extracts were stronger than that of the ethanol extracts; whilst in the three LPO models, the results were opposite.

Key words: acanthopanax, DPPH, chemiluminescence, antioxidative activities, lipid peroxidation