The protective effect of small peptides from Periplaneta americana on hydrogen peroxide-induced apoptosis of granular cells.

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.