刺萼龙葵不同萃取物抗氧化活性研究

Antioxidative Properties of Different Extraction Fractions from Solanum rostratum

目的:研究刺萼龙葵Solanum rostratum Dunal不同萃取物的体外抗氧化活性。方法:采用清除二苯代苦味酰基(DPPH)自由基、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法,对刺萼龙葵不同萃取物的体外抗氧化活性进行评价,并与阳性对照药维生素C(VC)进行比较。结果:3种方法测得的抗氧化活性结果趋势一致,刺萼龙葵总浸膏及各萃取物都有较强的抗氧化活性,其中乙酸乙酯萃取物抗氧化活性最强,对DPPH,ABTS自由基清除率的IC50值分别为38.428,29.175 mg·L-1,对Fe3+还原性相当于3.774 mmol·g-1的FeSO4当量,弱于VC(IC50值分别为10.551,8.570 mg·L-1,FeSO4当量为22.795 mmol·g-1);其次是正丁醇萃取物,对DPPH,ABTS自由基清除率的IC50值分别为53.142,57.895 mg·L-1,对Fe3+还原性相当于1.936 mmol·g-1的FeSO4当量。刺萼龙葵不同萃取物和VC体外抗氧化活性的强弱顺序为:VC>乙酸乙酯萃取物>正丁醇萃取物>总浸膏>石油醚萃取物>剩余水部位,随着各萃取物浓度的增加,抗氧化能力增强。结论:刺萼龙葵乙酸乙酯萃取物、正丁醇萃取物及总浸膏均有较强的抗氧化活性,本研究为恶性杂草刺萼龙葵的开发利用提供理论依据。

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.