This study investigates the protective effect of small peptides from Periplaneta americana (SPPA) on hydrogen peroxide (H₂O₂)–induced apoptosis of ovarian granular cells. H₂O₂ was applied to human ovarian granular cells (KGN cell strains). Cell viability was tested by cell counting Kit-8 (CCK-8). Cell apoptosis was tested by flow cytometry, and a cell apoptosis model was established. The model cells were treated with SPPA, and the cell survival rate was monitored using the CCK-8 method. The oxidative stress state of cells was examined using SOD, ROS, MDA, and NO kits. The protein expression levels of SIRT1, p53, and the apoptosis-related gene Caspase3 were measured using Western Blot methodology. Relative to the control group, cell viability declined significantly after the H₂O₂ treatment only (P < 0.01), while the apoptosis rate increased significantly (P < 0.01). The activity of SOD was weakened significantly (P < 0.01), while the cell levels of ROS, MDA, and NO increased dramatically (P < 0.01). Cell viability dramatically recovered (P < 0.01), and the SOD activity is hugely increased (P < 0.01) after SPPA treatment. In contrast, contents of ROS, MDA, and NO decreased sharply (P < 0.01), and significant dose-response relationships are characterized. Moreover, the H₂O₂ treatment group showed significantly downregulated expression of SIRT1 (P < 0.01) but significantly upregulated expressions of p53 and Caspase3 (P < 0.01) compared to the control group. Following the SPPA treatment of apoptosis cells, expression of SIRT1 increased significantly, while expressions of p53 and Caspase3 declined significantly (P < 0.01). This study suggests that SPPA inhibits H₂O₂-induced human KGN cell apoptosis through antioxidation, and the SIRT1/p53 signal pathway mediates the antioxidation.

本研究探讨美洲大蠊小肽(SPPA) 对过氧化氢 (H ₂ O ₂ ) 诱导的卵巢颗粒细胞凋亡的保护作用。H ₂ O ₂应用于人卵巢颗粒细胞（KGN细胞株）。通过细胞计数 Kit-8 (CCK-8) 测试细胞活力。流式细胞仪检测细胞凋亡，建立细胞凋亡模型。SPPA处理模型细胞，CCK-8法监测细胞存活率。使用 SOD、ROS、MDA 和 NO 试剂盒检测细胞的氧化应激状态。使用蛋白质印迹方法测量 SIRT1、p53 和凋亡相关基因 Caspase3 的蛋白质表达水平。与对照组相比，H ₂ O ₂处理后细胞活力显着下降（P < 0.01），而细胞凋亡率显着增加（P< 0.01)。SOD活性显着减弱（P < 0.01），而细胞内ROS、MDA和NO水平显着升高（P < 0.01）。SPPA处理后细胞活力显着恢复（P <0.01），SOD活性显着增加（P <0.01）。相比之下，ROS、MDA 和 NO 的含量急剧下降（P < 0.01），并具有显着的剂量反应关系。此外，H ₂ O ₂处理组 SIRT1 表达显着下调（P < 0.01），而 p53 和 Caspase3 表达显着上调（P< 0.01) 与对照组相比。SPPA处理凋亡细胞后，SIRT1的表达显着升高，而p53和Caspase3的表达显着下降（P < 0.01）。本研究提示SPPA通过抗氧化抑制H ₂ O ₂诱导的人KGN细胞凋亡，SIRT1/p53信号通路介导抗氧化作用。