紫山药多糖抗氧化及延长果蝇寿命的作用

EFFECTS OF PURPLE YAM POLYSACCHARIDES ON ANTIOXIDANT FUNCTION AND LIFESPAN IN DROSOPHILA MELANOGASTER

目的探究紫山药多糖(PYP)抗氧化活性与延长寿命作用。方法将2 d龄雌性果蝇随机分成4组,采用生存实验与急性氧化应激损伤实验测定喂饲不同浓度(0、1.0、2.0、4.0 mg/ml)PYP对果蝇寿命的影响,并测定果蝇体内抗氧化酶活力及抗氧化相关基因表达水平。结果添加2.0、4.0 mg/ml PYP可显著延长果蝇的平均寿命和最长寿命,急性氧化应激损伤实验中,各PYP组果蝇的寿命均明显延长。添加4.0 mg/ml PYP可显著提高果蝇过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活力,显著降低丙二醛(MDA)含量,同时,Mn-SOD、CAT、Cu,Zn-SOD m RNA表达水平显著上调,G蛋白偶联受体基因(MTH)m RNA表达水平显著下降。结论 PYP在体内具有较强的抗氧化作用,并可能通过上调抗氧化基因的表达实现延长果蝇寿命的作用。

Objectives To investigate the effects of purple yam polysaccharides （PYP） on antioxidant function and lifespan in Drosophila melanogaster. Methods Two daysold female Drosophila melanogasler were divided into four groups randomly, and fed with different doses （0, 1.0, 2.0, 4.0 mg/ml） of PYP. The life span was detected by survival test and acute oxidative stress-induced damage test, and the activities of antioxidant enzymes and their encoding genes expressions were detected. Results Compared with the control Drosophila melanogaster, the average and longest lifespans of 2.0 or 4.0 mg/ml PYP groups were significantly prolonged, and the lifespan was also obviously prolonged for all PYP groups in acute oxidative stress-induced damage test. In the 4.0 mg/ml PYP group, the activities of catalase （CAT） and superoxide dismutase （SOD） were significantly increased, while the level of malondialdehyde （MDA） was obviously decreased, Meanwhile, the mRNA expressions of Mn-SOD, CAT, and Cu, Zn-SOD were significantly up-regulated, while the G protein-coupled receptors （MTH） mRNA expression was significantly decreased. Conclusion There is a strong antioxidant capacity of PYP in vivo. It can prolong the lifespan of Drosophila melanogaster by up-regulating the expression of antioxidant genes.