RESUMO
Aim To investigate the effects of astragalus polysaccharide (APS) on depressive behaviors, hippocampal damage and Nrf2-ARE signaling pathway in rats. Methods Wistar rats were randomly divided into control group, depression group, APS low dose group and APS high dose group. Rats (except the control group) underwent chronic unpredictable mild stress (CUMS) for 28 days. The depressive behaviors were assessed by tail suspension test, forced swim test and sucrose preference test. The histopathological changes of the hippocampus were valuated by HE staining. Levels of nuclear factor erythroid 2-related factor 2 (Nrf2) protein and Nrf2 mRNA were measured. The hippocampal levels of oxidative stress were evaluated. Results Compared with the control group, the depression group showed significant depressive behaviors and hippocampal damage. The depression group had higher levels of Nrf2 and MDA, but lower levels of HO-1, SOD, CAT and GSH-Px than the control group. However, APS does-dependently attenuated the hippocampal damage and depressive behaviors, increased hippocampal levels of Nrf2, HO-1, SOD, CAT and GSH-Px, but decreased hippocampal levels of MDA in rats. Conclusions APS can attenuate CUMS-induced hippocampal damage and depressive behaviors in rats, and the effects may be associated with the activation of Nrf2-ARE signaling pathway.