连香树水提物和乙醇提取物的体外抗氧化研究

In vitro antioxidant activity of aqueous extract and ethanol extract of Cercidiphyllum japonicum

关键词:  连香树, 水提物, 乙醇提取物, 抗氧化作用

Key words:  Cercidiphyllum japonicum, aqueous extract, ethanol extract, antioxidant

摘要:

为了探究连香树水提物和乙醇提取物的主要成分和抗氧化作用,该研究采用水提和醇提两种方法提取连香树叶片中的代谢物并测定其主要成分,通过体外抗氧化实验,即清除羟自由基(·OH)、DPPH自由基(DPPH·)、超氧阴离子(O₂^-·)和还原铁离子(Fe³⁺)的能力等四个指标来评价其抗氧化作用。结果表明:连香树水提物和乙醇提取物中均含有山萘酚。此外,水提物中还含有苜蓿素和异槲皮苷等黄酮类物质; 乙醇提取物中还含有柚皮素和槲皮素3-O-β-D-葡萄糖苷等黄酮类物质。水提物和乙醇提取物均有清除羟自由基、DPPH自由基、超氧阴离子及还原三价铁离子的能力。抗氧化的作用随提取物浓度的增大而增强,其中清除超氧阴离子(IC₅₀值分别为0.092、0.002 mg·mL^-1)的能力强于阳性对照Vc(IC₅₀值为0.241 mg·mL^-1)且铁离子还原力的IC₅₀值(水提物为0.014 mg·mL^-1,乙醇提取物为0.001 mg·mL^-1)相对较小,说明其总抗氧化活性较强。由此可见,连香树水提物和乙醇提取物均具有良好的抗氧化作用,可作为一种潜在的天然抗氧化剂。

Abstract:

In order to study on the main components and antioxidation of Cercidiphyllum japonicum aqueous extract and ethanol extract, the secondary metabolites of C. japonicum leaf were extracted by aqueous extraction and ethanol extraction and the main components of aqueous extract and ethanol extract of C. japonicum were determined. The antioxidant effects of aqueous extract and ethanol extract of C. japonicum were evaluated by in vitro antioxidant assays, such as the ability of scavenging hydroxyl radical(·OH), the ability of scavenging DPPH free radical(DPPH·), the ability of scavenging superoxide anion(O₂^-·)and the ability of reducing iron ion(Fe³⁺). The results showed that the main components of the aqueous extract and the ethanol extract of C. japonicum both contain kaempferol. In addition, the main components of the aqueous extract of C. japonicum also contained flavonoids such as alfalfa and isoquercetin, and the main components of the ethanol extract of C. japonicum also contained flavonoids such as naringin and quercetin 3-O- β -dglucoside. The aqueous extract and the ethanol extract of C. japonicum both had the ability of scavenge hydroxyl radicals, DPPH free radicals, superoxide anions and the ability of reducing iron ion. The antioxidant effects of the aqueous extract and the ethanol extract of C. japonicum increased with the increasing concentrations, which was dose-dependent. Speci-fically, the ability of the aqueous extract and the ethanol extract of C. japonicum to scavenge superoxide anion(IC₅₀ values were 0.092 mg·mL^-1 and 0.002 mg·mL^-1 respectively)was stronger than that of positive control Vc(IC₅₀ value was 0.241 mg·mL^-1). Furthermore, the IC₅₀ value of the aqueous extract and the ethanol extract of C. japonicum on iron ion reducing power was relatively small(the IC₅₀ value of the aqueous extract was 0.014 mg·mL^-1; the IC₅₀ value of the ethanol extract was 0.001 mg·mL^-1), which indicated that the total antioxidant activity of C. japonicum extracts were strong. It can be seen that the aqueous extract and the ethanol extract of C. japonicum both have good antioxidant effects, and it can be used as a potential source of natural antioxidants.