Anti-oxidative damage effect in Schisandrin B in mice of Alzheimer's disease and its mechanism / 吉林大学学报(医学版)

ABSTRACT

Objective:To investigate the preventive and protective effects of Schisandrin B in the mice of Alzheimer's disease (AD),and to clarify its mechanism.Methods:Fifty Balb/c mice were randomly divided into blank group,model group,pasitive control group,low dose of Schisandrin B group(0.1 g·kg-1)and high dose of Schisandrin B group(0.5 g·kg-1);there were 10 mice in each group.Step-through test was conducted after last administration to detect the latencies and number of errors of the mice in various groups,and the brain tissue was taken.Congo red staining was to detect the morphology changes of cells and neuronal amyloidosis in brain tissue of the mice.The levels of ROS in brain tissue of the mice were tested by Flow Cytometry.The contents of MDA,the levels of LDH,and the activities of CAT,GSH-Px and SOD in brain tissue of the mice were tested by biochemical method.Western blotting method was used to detect the expression levels of signaling pathway proteins Nrf2 and Keap1 in brain tissue of the mice.Results:Compared with model group,the latencies of the mice in low and high dose of Schisandrin B groups were increased (P<0.01) and the number of errors in step-through tests was decreased (P<0.05 or P<0.01).The Congo red staining results showed that compared with model group,the neuronal amyloidosis in brain tissue of the mice in Schisandrin B groups was decreased significantly.Compared with model group,the levels of ROS,LDH and the contents of MDA in brain tissue of the mice in low and high doses of Schisandrin B groups were decreased (P<0.05 or P<0.01),and the activities of CAT,SOD and GSH-Px were increased (P<0.01).Compared with low dose of Schisandrin B group,the content of MDA and the activities of SOD and GSH-Px in brain tissue of the mice in high dose of Schisandrin B group were increased (P<0.001).Compared with model group,the expression level of Nrf2 protein in brain tissue of the mice in low dose of Schisandrin B group was increased (P<0.01),while the expression level of Nrf2 protein in brain tissue of the mice in high dose of Schisandrin B group was decreased (P<0.01);the expression levels of Keap1 protein in brain tissue of the mice in low and high doses of Schisandrin B groups was decreased (P<0.01).Conclusion:Schisandrin B could decrease the level of peroxidation in brain tissue of the mice and reduce the oxidative damage and improve the memory function of the AD mice.The mechanism is related to the activation of Nrf2 signaling pathway which improve the activity of antioxidant enzymes.