Objective:To study the antioxidant activity of different polarity chemical constituents from Tetrastigma planicaule. Method: The capacity of ferric reducing antioxidant power (FRAP) and scavenging hydroxyl free radical (OH·) and·) of the total extracts

petroleum ether fraction

ethylacetate fraction

n-butanol fraction and water fraction from T. planicaule were evaluated by FRAP assay

OH·scavenging assay

and ABTS+·scavenging assay at different concentration (0.005-0.050 g·L-1). Results were compared with that of positive control vitamin C(VC) and tea polyphenol. Result: First

ferric reducing antioxidant power of different polarity chemical constituents from T. planicaule were weaker than VC

but higher than tea polyphenol except water fraction. When the concentration of different polarity chemical constituents was 0.050 g·L-1

ferric reducing antioxidant power was as follows: VC (FRAP value 2 377.8)>total extracts (FRAP value 683.8)>ethyl acetate (FRAP value 419.8)>petroleum ether (FRAP value 201.8)>n-butanol (FRAP value 185.8)>tea polyphenol (FRAP value 73.8)>water (FRAP value 63.8). Secondly

the results demonstrated that OH·scavenging activity in ethylacetate fraction (IC50 0.028 g·L-1) was higher than VC (IC50 0.044 g·L-1) and tea polyphenol (IC50 0.032 g·L-1). Finaly

different polarity chemical constituents showed higher ABTS+·scavenging activity than tea polyphenol (IC50 0.416 g·L-1)

also ethylacetate fraction (IC50 0.008 g·L-1) was higher than VC (IC50 0.011 g·L-1). Conclusion: T. planicaule has a strong antioxidative activity

which provides scientific basis for exploiting functional antioxidant.