乌饭树果乙醇提取物不同极性分部的体外抗氧化活性研究

目的筛选乌饭树果乙醇提取物中抗氧化活性最强的极性分部。方法采用石油醚、乙酸乙酯、氯仿、正丁醇和水等5种不同极性溶剂对乌饭树果乙醇提取物进行进一步梯度萃取,并分析比较其总抗氧化能力(total antioxidant capacity,T_(AC))、抗脂质过氧化能力及对羟基自由基OH·、超氧阴离子自由基O_2~-·的清除效果。结果乌饭树果乙醇提取物的5个不同极性分部均具有一定的抗氧化活性,但其活性大小差异极显著(P0.01),T_(AC)大小依次为:乙酸乙酯部氯仿部正丁醇部石油醚部水部。同时,在OH·、O_2~-·自由基清除能力和抗脂质过氧化能力上,乙酸乙酯部均优于氯仿部和正丁醇部,且呈明显的量效关系。结论乌饭树果乙醇提取物的乙酸乙酯部具有最强的抗氧化活性,且对OH·、O_2~-·的清除能力及抗脂质过氧化能力均强于L-抗坏血酸及其它部位,可作为天然抗氧化剂的潜在有效来源。

Study on the in vitro antioxidant activity of different polarity fractions of ethanol extract obtained from Vaccinium bracteatum Thunb. fruits

Objective To screen the strongest antioxidant activities of polarity fraction of ethanol extract obtained from Vaccinium bracteatum Thunb. fruits. Methods Totally 5 different polarity solvents (petroleum ether, ethyl acetate, chloroform, n-butanol and water) were used to furtherly fractionate ethanol extracts from Vaccinium bracteatum Thunb. fruits. Moreover, the total antioxidant capacity (TAC), anti-lipid peroxidation and scavenging effect of 5 kinds of polarity fractions on hydroxyl radical (OH?) and superoxide radical (O2-?) were studied and compared. Results A total of 5 polarity fractions of ethanol extract obtained from Vaccinium bracteatum Thunb. fruits were showed antioxidant activity while exhibited significant differences (P<0.01), among which the ethyl acetate fraction had the strongest TAC, following by the chloroform, n-butanol fractions and the petroleum ether, the water fraction was the weakest. Furthermore, the ethyl acetate fraction had better scavenging capacities of OH?, O2-? and anti-lipid peroxidation than n-butanol fraction and chloroform fraction, and also showed a significant dose-response relationship. Conclusion The ethyl acetate fraction exhibited the strongest of antioxidant capacity, was superior to L-ascorbic acid and other fractions on the scavenging effects of OH?, O2-? and anti-lipid peroxidation, which could be used as a potential effective source of natural antioxidants.