Div of Biochemistry and Plant Physiology, SK Univ of Agricultural Sciences and Technology, Chatha 180 009, Jammu, India.
J Food Sci. 2011 Sep;76(7):C959-64. doi: 10.1111/j.1750-3841.2011.02284.x. Epub 2011 Aug 1.
The antioxidant activity of methanol extract/fractions of leaf, bark, and heartwood of Acacia catechu was evaluated by various antioxidant assays, including free radical, superoxide and hydroxyl radical, reducing power, metal ion chelation, as well as hydroxyl radical induced DNA strand scission. The leaf, bark, and heartwood powder was extracted in methanol and the lyophilized methanol extract was fractionated with different solvents in the order of increasing polarity. The results indicate that ethyl acetate fraction of heartwood has the highest antioxidant capacities, presenting lower EC(50) values particularly in free radical scavenging activity, including DPPH radicals (4.76 ± 0.14 μg/mL), superoxide anions (26.21 ± 0.79 μg/mL), and hydroxyl radicals (33.69 ± 1.42 μg/mL), in direct assay systems. Reducing power was also highest in ethyl acetate fraction of heartwood (EC(50) of 79.05 ± 1.02 μg/mL). As for the chelating power on ferrous ions, leaf extract was more effective than bark and heartwood extracts. Furthermore, the ethyl acetate and acetone fractions of heartwood significantly protected pBR322 supercoiled plasmid DNA against strand scission induced by hydroxyl radicals in a Fenton's reaction mixture.
The present investigation suggests that the three organs of A. catechu differ significantly in their antioxidant potential as seen in the DPPH radical scavenging assay, reducing power assay, metal ion chelating assay, superoxide radical scavenging assay and hydroxyl radical scavenging assay. Further, our results showed that crude methanol extract and ethyl acetate fraction of heartwood of A. catechu might have a good potential as a source for natural health products due to its antioxidant and DNA protective activities.
通过各种抗氧化测定法，包括自由基、超氧阴离子和羟自由基、还原能力、金属离子螯合以及羟自由基诱导的 DNA 链断裂，评估了金合欢树叶、树皮和心材甲醇提取物/馏分的抗氧化活性。将叶、皮和心材粉末用甲醇提取，并用不同溶剂按极性增加的顺序对冻干甲醇提取物进行馏分分离。结果表明，心材的乙酸乙酯馏分具有最高的抗氧化能力，在自由基清除活性中表现出较低的 EC50 值，特别是 DPPH 自由基（4.76±0.14μg/mL）、超氧阴离子（26.21±0.79μg/mL）和羟自由基（33.69±1.42μg/mL），在直接测定系统中。心材乙酸乙酯馏分的还原能力也最高（EC50为 79.05±1.02μg/mL）。就螯合亚铁离子的能力而言，叶提取物比树皮和心材提取物更有效。此外，心材的乙酸乙酯和丙酮馏分可显著保护 pBR322 超螺旋质粒 DNA 免受 Fenton 反应混合物中羟自由基诱导的链断裂。
本研究表明，A. catechu 的三个器官在 DPPH 自由基清除测定、还原能力测定、金属离子螯合测定、超氧阴离子清除测定和羟自由基清除测定中抗氧化能力有显著差异。此外，我们的结果表明，由于其抗氧化和 DNA 保护活性，A. catechu 的粗甲醇提取物和心材乙酸乙酯馏分可能具有作为天然保健品的良好潜力。
