南极磷虾蛋白水解产物超滤组分的抗氧化活性评价

目的 对南极磷虾(Euphausia superba)蛋白水解产物超滤组分进行系统的抗氧化活性评价。方法 利用胃蛋白酶和胰蛋白酶制备南极磷虾蛋白水解物(antioxidant hydrolysate of Euphausia superba protein, EPAH), 利用超滤技术制备抗氧化组分。以自由基清除实验、脂质过氧化抑制实验、体外DNA氧化损伤保护实验以及氧化损伤张氏肝细胞(Chang liver)模型进行抗氧化组分的活性研究。结果 利用超滤技术将EPAH按照分子量(molecular weight, MW)分为三个肽组分EPAH-I(MW<3.5 KDa)、EPAH-II(3.5 KDa5 KDa)。其中, EPAH-I显示出强的DPPH自由基和羟基自由基清除活性、脂质过氧化抑制作用和质粒DNA的氧化损伤保护作用以及对H2O2氧化损伤的张氏肝细胞显示出较强的保护作用。在5.0 mg/mL浓度下, EPAH-I可将氧化损伤张氏肝细胞(Chang liver)的活力由模型组的(49.51±4.18 )%显著提升至(70.58±4.52)% (P<0.05); 超氧化物歧化酶和谷胱甘肽过氧化物酶活力分别提高至(176.34±10.92) U/mg prot和(35.83±2.55) U/mg prot, 活性氧自由基含量降至2.76±0.18%, 膜脂质氧化产物丙二醛的含量降至(5.75±0.16) nmol/mg prot。结论 本实验制备的南极磷虾抗氧化组分(EPAH-I)具有显著的生物活性, 可用于抗氧化相关功能产品的研发。

Antioxidant activity evaluation of ultra filtration fraction of protein hydrolysate from Antarctic krill (Euphausia superba)

Objective To evaluate the antioxidant activity of ultra filtration fraction of protein hydrolysate from Antarctic krill (Euphausia superba). Methods The antioxidant hydrolysate of Euphausia superba protein (EPAH) was prepared using pepsin and trypsin, and the hydrolysate was fractionated using ultra filtration method. The antioxidant activity of ultra filtration fraction was evaluated by radical scavenging assay, lipid peroxidation inhibition assay, DNA oxidative damage protection assay, and oxidative damage model of Chang liver cells. Results Using molecular weight (MW) cut-off membranes of 3.5 KDa and 5 KDa, 3 kinds of peptide fractions, defined as EPAH-I (MW<3.5 KDa), EPAH-II (3.5KDa5 KDa) were prepared from EPAH. Among them, EPAH-I showed the strongest scavenging activity of DPPH radical and hydroxyl radical, inhibition ability of lipid peroxidation, and protection function against oxidative damage of plasmid DNA. Moreover, EPAH-I showed high protective effect on Chang liver cells damaged by H2O2 oxidation. At the concentration of 5.0 mg/mL, the cell viability of EPAH-I group was (70.58±4.52)%, which was significantly higher than that ((49.51±4.18)%) of model groups (P<0.05). In addition, EPAH-I could increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) to (176.34±10.92) U/mg prot and (35.83±2.55) U/mg prot, and decrease the contents of ROS and MDA to (2.76±0.18)% and (5.75±0.16) nmol/mg prot. Conclusion These results suggested that EPAH-I could decrease the H2O2-induced stress injury in Chang liver cells and might be used as a potential natural antioxidant in the functional products.