Delta Sleep-Inducing Peptide Protects Liver from Chronic Stress in Rats

The liver is highly susceptible to damage from various stressors, including psychological stress, which can induce oxidative stress and impair hepatocyte function. Understanding how to mitigate this damage is crucial for maintaining liver health. This study specifically investigates the protective effects of Delta Sleep-Inducing Peptide (DSIP) on liver cells during both acute and chronic restraint stress.

Under conditions of acute restraint stress, 40 μg/kg DSIP led to a complex response, increasing both antioxidant enzyme activities (catalase and superoxide dismutase, SOD) and malonic dialdehyde (MDA) concentration, a marker of oxidative damage. However, the effects were markedly different and more protective under chronic stress. In chronic stress, 40 μg/kg DSIP demonstrated the most pronounced protective effect, significantly decreasing catalase and SOD activities, and notably reducing MDA concentration, indicating reduced oxidative stress. At a dose of 120 μg/kg DSIP during chronic stress, rats showed a decrease in SOD activity and MDA concentration, an increase in total protein content, and a reduction in AST activity, suggesting improved liver function. Interestingly, increasing the dose to 360 μg/kg DSIP completely abolished these beneficial effects, highlighting a dose-dependent response.