Abstract:

Abstract:Objective  To copy the mouse aging model with D-galactose,and to investigate the role of Schisandra total lignin (SCL) in the  mouse brain tissue aging and its mechanism.Methods 50 mice were radomly divided into control group,model group (100 mg?kg-1?d-1),low dose (35 mg/kg/d) of SCL group (SCL-L)， middle dose  (70 mg/kg/d) of SCL group (SCL-M) and high dose (140 mg?kg-1?d-1) of SCL group (SCL-H)（n=10）.D- galactose ( 100 mg?kg-1?d-1 ) was injected into the mice hypodermically for 10 weeks to induce aging models in all the groups except control group,and 35,70, and 140 mg/kg/d  SCL were administered for 10 weeks in SCL groups.The learning and memory abilities were measured by the Water Maze test.The expression levels of Bax,Bcl-2,ubiquitin (Ub),microtubule-associated protein light chain 3 (LC3) in the brain tissue of  the mice in various groups were observed by Western blotting method.The LC3 protein expressions in mouse brain cortex and hippocampus were observed by immunohistochemistry.Results  In learning and memory test,compared with control group,the swimming time of the mice in model group was increased (P<0.05),and the number of errors was increased (P<0.05);compared with model group,the swimming time in SCL-L,SCL-M and SCL-H groups was decreased (P<0.05) and the number of errors was also decreased (P<0.05). Compared with control group，the expression level of Bax was increased (P<0.05),the expression level of Bcl-2 was decreased (P<0.05),the expression levels of Ub and LC3-Ⅱ/LC3-Ⅰ proteins were increased (P<0.05) in model group;compared with model group,the expression level of Bax was decreased (P<0.05),the expression level of Bcl-2 was incerased (P<0.05),and the expression levels of Ub and LC3-Ⅱ/LC3-Ⅰ proteins were decreased (P<0.05) in SCL-L,SCL-M and SCL-H groups.In control group,the neuronal morphology was normal,and none of brown granules were visible in the cytoplasm of mouse brain cortex and hippocampus and the expression of LC3 protein was negative.In model group,the neurons were degeneration,and the number of LC3 protein positive cells in the cerebral cortex and hippocamptal tissue was increased (P<0.05).In SCL-L,SCL-M and SCL-H groups,the number of degenerative neurons was decreased,and the number of LC3 protein positive cells was decreased (P<0.05).Conclusion SCL can inhibit the D-galactose-induced brain tissue aging in the mice,and the mechanism is related to regulating autophagy and inhibiting apoptosis.

Key words: Schisandra total lignin, aging, autophagy, apoptosis