龟肉蛋白肽延缓果蝇衰老的作用及机制研究

目的:探究龟肉蛋白肽（pond turtle protein-derived peptides，PTPDP）延缓果蝇衰老的作用和机制。方法:酶解乌龟肉得到PTPDP，测定其营养成分、分子质量分布以及氨基酸组成；分别以0.2%、0.4%和0.8%的PTPDP喂养果蝇，通过生存实验和测定体内超氧化物歧化酶（superoxide dismutase，SOD）、过氧化氢酶（catalase，CAT）活性和丙二醛（malondialdehyde，MDA）含量来分析其抗衰老功能；通过测定0.8% PTPDP喂养的雌性果蝇抗氧化相关基因Sod1、Sod2、Cat和寿命相关基因mth、Rpn11的表达来探究其抗衰老机制。结果:龟肉酶解产物以1000 Da以下的小分子肽段为主，富含甘氨酸、谷氨酸和脯氨酸等具有抗氧化活性的氨基酸。生存实验和抗氧化活性实验中，0.8% PTPDP组雌雄果蝇的平均寿命分别显著延长了18.92%和9.37%（P<0.01)；SOD活性分别显著提高了7.13%和7.37%（P<0.05）；CAT活性分别极显著提高了42.14%和84.66%（P<0.01）；MDA含量分别显著下降了22.22%和23.08%（P<0.05）。基因表达结果显示，0.8% PTPDP喂养显著上调了抗氧化相关基因Sod1，Sod2（P<0.05）和Cat（P<0.01）的表达，同时对寿命相关基因mth和Rpn11（P<0.01）的表达也表现出显著的调节作用。结论:PTPDP通过影响果蝇抗氧化和寿命相关基因的表达，提高其体内抗氧化活性，延长果蝇寿命，有潜在的抗衰老功效。

Research on Anti-aging Function and Mechanism of Pond Turtle Protein-derived Peptides on Drosophila melanogaster

Objective: To explore the anti-aging function and mechanism of pond turtle protein-derived peptides (PTPDP) on Drosophila melanogaster. Methods: PTPDP were obtained by enzymatic hydrolysis of turtle meat. Nutrients content, molecular weight distribution and amino acid composition of PTPDP were determined. D. melanogaster were fed with 0.2%, 0.4%, and 0.8% PTPDP. The activities of superoxide dismutase (SOD) and catalase (CAT), along with the content of malondialdehyde (MDA) were determined to analyze the anti-aging function of PTPDP. The anti-aging mechanism was explored by measuring the expression of antioxidant genes (Sod1, Sod2 and Cat) and lifespan-related genes (mth and Rpn11) in female D. melanogaster fed with 0.8% PTPDP. Results: The enzymatic hydrolysis products of turtle meat were mainly composed of small molecule peptides less than 1000 Da. PTPDP were rich in amino acids with antioxidant activity, such as glycine, glutamic acid and proline. In the survival experiment, the average lifespans of female and male D. melanogaster were significantly prolonged by 18.92% and 9.37% (P<0.01), respectively. In the antioxidant activity experiment, the SOD activity of female and male D. melanogaster increased significantly by 7.13% and 7.37% (P<0.05); the CAT activity of female and male D. melanogaster increased significantly by 42.14% and 84.66% (P<0.01); the MDA content of female and male D. melanogaster decreased significantly by 22.22% and 23.08% (P<0.05). In female D. melanogaster fed with 0.8% PTPDP, the expression of anti-oxidant related genes Sod1, Sod2 (P<0.05) and Cat (P<0.01) were significantly up-regulated, and genes (mth and Rpn11) related to lifespan also showed different degrees of regulation (P<0.01). Conclusion: PTPDP increase the antioxidant activity of D. melanogaster by affecting the expression of antioxidant genes and lifespan-related genes, thereby prolonging the lifespan of D. melanogaster. This mechanism implies that PTPDP has potential anti-aging effects.