4种海藻膳食纤维清除自由基的比较研究

采用羟基自由基体系、超氧阴离子自由基体系、烷基自由基引发的亚油酸氧化体系和DPPH体系对江蓠(Gracilaria)、麒麟菜(Eucheuma)、马尾藻(Sargassum)、海带(Laminaria)4种膳食纤维清除自由基的活性进行研究。结果表明，在羟基自由基体系中，江蓠、麒麟菜、马尾藻、海带4种膳食纤维的IC50分别为5．2mg／mL、5．5mg／mL、4．4mg／mL和4．1mg/mL；在超氧阴离子自由基体系中，江蓠、麒麟菜膳食纤维的IC50分别为4．8mg/mL和5．3mg/mL，而马尾藻、海带膳食纤维的最高清除率分别为36％和42％；在烷基自由基引发的亚油酸氧化体系中，江蓠、麒麟菜膳食纤维的最高清除率分别为36％和26％，马尾藻、海带膳食纤维的IC50分别为4．1mg/mL和3．5mg/mL；在DlPIH体系中，江蓠、麒麟菜、马尾藻膳食纤维的最高清除率分别为31％、11％和26％，海带膳食纤维的IC50为6．2mg/mL。在各体系中，与相应的专一性阳性参照物对比，证明这4种海藻膳食纤维对自由基有一定的清除作用。

Scavenging effect of dietary fibers from four seaweeds on free radical

Free radical scavenging capacities of four dietary fibers from Gracilaria, Eucheuma, Sargassum and Laminaria were studied. The assay system included hydroxyl radical system,superoxide radical system,alkyl radical oxidation system and DPPH system. The results showed that IC_(50)s of dietary fibers from Gracilaria ,Eucheuma, Sargassum and Laminaria were 5.2?mg/mL,5.5?mg/mL,4.4?mg/mL and (4.1?mg/mL,)respectively in hydroxyl radical assay system. In superoxide radical assay system, the IC_(50) of Gracilaria and Eucheuma was 4.8?mg/mL and 5.3?mg/mL respectively, while for Sargassum and Laminaria, free radical scavenging ratio were as high as 36% and 42% respectively. In linoleic acid oxidation system, free radical scavenging capacities of Gracilaria and Eucheuma were about 36% and 26%,respectively,which were lower than those of Sargassum and Laminaria, and IC_(50) were 4.1?mg/mL and (3.5?mg/mL,)respectively. In DPPH system, free radical scavenging capacities for Gracilaria and Eucheuma dietary fiber were 31%, 11% and 26%, respectively, while for Laminaria dietary fiber, IC_(50) was about 6.2?mg/mL. It was proved that dietary fibers from the four seaweeds had effects on free radical scavenging compared with special positive contrast in these systems.