中文摘要：

[目的]探究丝素肽（SF）对过氧化氢（H2O2）致人肺癌（A549）细胞损伤的修复作用。[方法]将细胞分为空白对照组,H2O2组（600μmol/L）,SF前处理组（10、20、30、50 mg/m L SF预孵育24 h再加600μmol/L H2O2损伤24 h）,SF后处理组（600μmol/L H2O2损伤24 h再加10、20、30、50 mg/m L SF孵育24 h）及阳性对照前、后处理组[抗氧化剂N-乙酰半胱氨酸（NAC）]。用MTT法测定细胞活力,生物化学法测定细胞中丙二醛（MDA）、超氧化物岐化酶（SOD）、过氧化氢酶（CAT）的含量和总抗氧化能力（T-AOC）。[结果]H2O2组细胞活力为（46.67±2.19）%,MDA含量为（64.31±3.22）nmol/mg（以蛋白计）。与H2O2组相比,前处理组和后处理组中细胞活力增加,而MDA含量降低（P〈0.05）;SF后处理组细胞活力的增加和MDA含量的降低更明显（P〈0.05）;尤其50 mg/m L SF后处理组比前处理组细胞活力增加值高2.33%,而MDA含量降低值少44.51 nmol/mg（以蛋白计）。H2O2组中SOD、CAT活性和T-AOC都明显降低（P〈0.05）,SF后处理明显提高SOD、CAT活性和T-AOC水平（P〈0.05）。[结论]SF对H2O2致A549细胞损伤有修复作用,部分原因可能是由于其可增加细胞活力和提高细胞中抗氧化酶活性。

英文摘要：

[Objective] To assess the restoration effect of silk fibroin peptide（SF） on hydrogen dioxide（H2O2） induced human lung cancer cell（A549） injury.[Methods] The A549 cells were divided into blank（without drug treatment）,H2O2（600 μmol/L）,pretreatment（10,20,30,and 50 mg/m L SF pretreatment for 24 h plus 600 μmol/L H2O2 treatment for another 24 h）,post-treatment（600 μmol/L H2O2 treatment for 24 h and 10,20,30,and 50 mg/m L SF treatment for another 24 h）,and positive control pretreatment and post-treatment groups [antioxidant,N-acetylcysteine（NAC）].Cell viability was measured by MTT assay,and levels of malondialdehyde（MDA）,super oxide dismutase（SOD）,catalase（CAT）,and total antioxidant capacity（T-AOC） by biochemical methods.[Results] The cell viability was（46.67±2.19）% and the content of MDA was（64.31±3.22）nmol/mg（protein） after H2O2 treatment.Compared with the H2O2 group,the cell viability increased and the content of MDA decreased（P 〈 0.05） in the pretreatment groups and the post-treatment groups,and the post-treatment groups showed greater effects（P 〈 0.05）.Especially when comparing the 50 mg/m L SF treatment effects,post-treatment increased cell viability by 2.33% and decreased MDA content by 44.51 nmol/mg（protein） than the pretreatment did.The activities of SOD,CAT,and T-AOC were all decreased in the H2O2 group（P 〈 0.05）,but the activities were increased after post-treatment with SF（P 〈 0.05）.[Conclusion] The study demonstrates that SF could promote cell viability and intracellular antioxidase activity to ameliorate A549 cell injury induced by H2O2.