Restoration Effect of Silk Fibroin Peptide on Hydrogen Dioxide Induced Human Lung Cancer Cell Injury

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/mL SF pretreatment for 24 h plus 600 μmol/L H₂O₂ treatment for another 24 h), post-treatment (600μmol/L H₂O₂ treatment for 24 h and 10, 20, 30, and 50 mg/mL 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/mL 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.