Objective: To study the antioxidant activity of different fractions from Solanum rostratum in vitro. Method: Antioxidant activities of different extraction fractions of S. rostratum

with vitamin C(VC) as positive control

were evaluated by methods of the 1

1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging

radical scavenging and ferric reducing antioxidant power (FRAP). Result: The results of these methods were similar

and different extraction fractions of S. rostratum had highly antioxidant activities. The antioxidant activity of ethyl acetate extraction was the strongest. Its 50% scavenging rates (IC50) on DPPH and ABTS were 38.428

29.175 mg·L-1

respectively

and the ferric reducing antioxidant power value was 3.774 mmol·g-1 FeSO4 equivalent weight

which were weaker than positive control VC (10.551

8.570 mg·L-1

22.795 mmol·g-1). Antioxidant activity of n-butanol extraction was secondly strong

and the IC50 values on DPPH and ABTS were 53.142

57.895 mg·L-1

respectively

and the ferric reducing antioxidant power value was 1.936 mmol·g-1 FeSO4 equivalent weight. The antioxidant activities of different extraction fractions from strong to weak were as follows:VC>ethyl acetate extraction>n-butanol extraction>the total extraction>petroleum ether extraction>water extraction. The antioxidant properties of different fractions were dose-dependent. With the increasing of the concentrations of various fractions

the antioxidant capacities were enhanced. Conclusion: Ethyl acetate extraction

n-butanol extraction and the total extract of S. rostratum had strong antioxidant activity. The results will be benefit for the exploitation and utilization of S. rostratum.