Sea Cucumber-Derived Peptides Alleviate Oxidative Stress in Neuroblastoma Cells and Improve Survival in C. elegans Exposed to Neurotoxic Paraquat

Figure 3

Sea cucumber-derived peptides reduce superoxide levels in mitochondria. (a) Detection of mitochondrial ROS by MitoSOX using confocal microscopy: SH-SY5Y cells were grown in glass-bottomed MatTek dishes until they reached partial confluency (50-70%). Cells were then treated with 50 μM peptides and were incubated for 24 h at 37°C. As a positive control, cells were also treated with 50 μM glutathione (GSH). After incubation, cellular oxidative stress was induced by treating cells with 2 mM H₂O₂ for 3 h at 37°C. Cells were then washed three times with PBS before labelling them with 2 μM MitoSOX Red dye for 30 min at 37°C. MitoSOX Red fluorescence intensity was then detected by confocal microscopy. (b) Detection of mitochondrial ROS by flow cytometry: cells were grown and treated as described in (a) except that the cells were cultured in 24-well plates until they reach ~80% confluency. After incubation with MitoSOX Red, cells were washed with PBS and harvested for fluorescence measurements by flow cytometry. In the bar diagram, “control” refers to the negative control where ROS are not induced, and “no peptide” represents the positive control where cells were treated with H₂O₂ in culture medium without any peptide treatment. Samples were compared with “no peptide,” and statistical significance was determined by Tukey one-way ANOVA. , , , and . Error bars show SD (). Experiments were repeated 3 times.

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