Laboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichenxi Road, Beijing 100101, China.
Food Chem Toxicol. 2013 Oct;60:385-90. doi: 10.1016/j.fct.2013.07.074. Epub 2013 Aug 6.
Housefly (Musca domestica) is an important medical insect and its larva is an ideal high protein food source. We isolated from housefly larvae the polypeptides hydrolyzed by neutral protease (PHNP), and investigated the protective effect of PHNP on hydrogen peroxide (H₂O₂)-induced oxidative damage in HepG2 cells. Cells exposed to H₂O₂ showed a marked decrease in proliferation and intracellular superoxide dismutase (SOD) activity, and a significant increase in reactive oxygen species (ROS) level and malondialdehyde (MDA) content. H₂O₂ also caused apoptosis and mitochondrial dysfunction including mitochondrial fragmentation and the loss of mitochondrial membrane potential. Pretreatment with PHNP at concentrations of 2.5, 5, 10 μg/mL blocked these H₂O₂-induced cellular events in a dose-dependent manner. The effect of PHNP at 10 μg/mL is equal to that of ascorbic acid at 10 μM. In summary, PHNP has a protective effect against H₂O₂-induced oxidative injury in cells due to its ability to decrease intracellular ROS and elevate antioxidant enzyme activities.
家蝇（Musca domestica）是一种重要的医学昆虫，其幼虫是一种理想的高蛋白食物源。我们从家蝇幼虫中分离出中性蛋白酶（PHNP）水解的多肽，并研究了 PHNP 对 HepG2 细胞中过氧化氢（H₂O₂）诱导的氧化损伤的保护作用。暴露于 H₂O₂的细胞增殖明显下降，细胞内超氧化物歧化酶（SOD）活性降低，活性氧（ROS）水平和丙二醛（MDA）含量显著升高。H₂O₂还导致细胞凋亡和线粒体功能障碍，包括线粒体片段化和线粒体膜电位丧失。用 2.5、5、10 μg/mL 的 PHNP 预处理以剂量依赖性方式阻断了这些 H₂O₂诱导的细胞事件。PHNP 在 10 μg/mL 的作用与 10 μM 的抗坏血酸相当。综上所述，PHNP 通过降低细胞内 ROS 和提高抗氧化酶活性对 H₂O₂诱导的氧化损伤具有保护作用。
