Effect and Mechanism of Lily Polysaccharide Combined with Astragalus Polysaccharide on Depressive Behavior in Chronic Stress Mice / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore the mechanism of antidepressant effect of lily polysaccharide （LLP）and astragalus polysaccharide（APS）. MethodSixty KM mice were randomly divided into blank group， model group， fluoxetine hydrochloride （8 mg·kg-1）group， LLP （0.2 g·kg-1）group， APS （0.2 g·kg-1）group and polysaccharide combination （LLP+APS，0.1 g·kg-1+0.1 g·kg-1）group， with 10 mice in each group. Except the blank group， the other groups were given chronic unpredictable mild stress （CUMS） induced mouse depression model. On the 29th day of modeling，fluoxetine hydrochloride group was given corresponding dose of fluoxetine hydrochloride， and polysaccharide groups were given corresponding drug. The depressive behavior of mice was evaluated by behavioral indexes such as body mass change， open field test. The morphological changes of hippocampal CA1 neurons were observed by Nissl staining. The contents of 5-hydroxytryptamine （5-HT）， adrenocorticotropic hormone （ACTH）， and corticosterone （CORT）， in brain tissue and plasma were measured by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the expression levels of related proteins in adenylate cyclase/cyclic adenylate phosphate/protein kinase A （AC/cAMP/PKA） signal pathway. ResultCompared with the blank group， mice in the model group gained weight slowly， the total distance， central distance and sugar water preference rate decreased significantly （P<0.01）， the depressive behavior was significant， the hippocampal neurons were seriously damaged， the content of 5-HT decreased （P<0.01）， the contents of ACTH and CORT increased significantly （P<0.01）， adenylate cyclase 6（ADCY6）， PKA and cAMP response element binding protein-1 （CREB-1） and brain-derived neurotrophic factor （BDNF） protein expression decreased significantly （P<0.01）. Compared with the model group， depressive behavior of mice in LLP group， APS group and LLP+APS group was significantly improved （P<0.01）. The antidepressant effect of LLP+APS was better than that of LLP and APS. Each administration group could alleviate the damage of hippocampal neurons in varying degrees， significantly increase the content of 5-HT in brain tissue （P<0.01）， and reduce the levels of ACTH and CORT in plasma （P<0.05）. The protein levels of ADCY6， PKA， CREB-1 and BDNF were significantly increased （P<0.05）. ConclusionThe antidepressant effect of LLP+APS is significantly enhanced and has a synergistic effect. The mechanism may be closely related to affecting the content of neurotransmitters， inhibiting HPA axis activity and activating AC/cAMP/PKA signal transduction pathway.