甲鱼肽对果蝇寿命及其抗氧化活性的影响

Effect of Soft-shelled Turtle Peptide on the Lifespan and Antioxidant Activities of Drosophila melanogaster

目的:探讨甲鱼肽(soft-shelled turtle peptide,STP)对果蝇寿命及其抗氧化活性的影响。方法:通过酶解甲鱼肉得到甲鱼肽,测定其分子量和氨基酸组成。以不同剂量(0.2%、0.4%和0.8%)的甲鱼肽饲喂果蝇,通过生存试验以及测定果蝇体内超氧化物歧化酶(superoxide dismutase,SOD)活力、过氧化氢酶(catalase,CAT)活力和丙二醛(malondialdehyde,MDA)含量,评价甲鱼肽的抗氧化作用。结果:甲鱼肽以相对分子质量介于180~500 Da的肽段为主,含有较为丰富的脯氨酸、赖氨酸和亮氨酸等。以甲鱼肽饲喂果蝇,与对照组相比,高剂量组雌、雄果蝇的平均寿命分别显著延长了10.80%(P<0.05)和14.01%(P<0.01),平均最高寿命分别显著延长了6.35%(P<0.01)和13.22%(P<0.01)。抗氧化实验结果表明,高剂量组雌、雄果蝇的SOD活力分别显著提高了28.40%(P<0.01)和15.08%(P<0.01),CAT活力分别显著提高了33.50%(P<0.05)和38.05%(P<0.01),MDA含量分别显著下降了33.33%(P<0.01)和34.62%(P<0.01)。结论:甲鱼肽可以提高雌、雄果蝇体内抗氧化酶活力,缓解脂质过氧化作用,从而延长果蝇寿命,具有潜在抗衰老作用。

Objective:To investigate the effect of soft-shelled turtle peptide(STP)on the lifespan and antioxidant activities of Drosophila melanogaster.Methods:The soft-shelled turtle peptide was prepared by enzymatic digestion.The molecular mass distribution and amino acid composition of STP were measured.Male and female Drosophila melanogaster were fed on a diet supplemented with different doses of soft-shelled turtle peptide(0.2%,0.4%,0.8%).The antioxidant effect of softshelled turtle peptide was evaluated by analyzing the survival rate and measuring the activity of superoxide dismutase(SOD),catalase(CAT)and the content of malondialdehyde(MDA)of D.melanogaster.Results:The results showed that STP were mainly constituted with peptides which had relative molecular weight between 180 and 500 Da.Moreover,STP were rich in proline,lysine and leucine.After treating with STP,compared with the control group,mean life span in highdose group were significantly increased by 10.80%(P<0.05)and 14.01%(P<0.01)for female and male flies.Maximum mean life-span in high-dose group were significantly increased by 6.35%(P<0.01)and 13.22%(P<0.01)for female and male flies.The activity of SOD in high-dose group were significantly increased by 28.40%(P<0.01)and 15.08%(P<0.01)for female and male flies.The activity of CAT was increased by 33.50%(P<0.05)and 38.05%(P<0.01)while the content of MDA was decreased by 33.33%(P<0.01)and 34.62%(P<0.01),respectively.Conclusion:Soft-shelled turtle peptide can increase a series of antioxidant enzyme activities and decrease lipid peroxidation to prolong life span of D.melanogaster.Thus,STP may have potential anti-aging effect.