Abstract: Objective The effects of Astragalus polysaccharides on learning and memory ability and depression-like behavior in rats with post-stroke depression (PSD) model were observed and analyzed. Methods Forty-eight Wistar rats were randomly divided into sham operation group, depression model group, astragalus polysaccharide low dose group and high dose group (n=12). PSD models were constructed except for the sham operation group. Rats in the low-dose group and the high-dose group were intragastrically administered with the corresponding dose of Astragalus polysaccharide. The depression model group and the sham operation group were given the same volume of saline as the control, and the 4 groups were all treated for 4 weeks. The edema intake experiment and Zero water maze analysis system were used to evaluate the depression behavior of rats. The patch clamp technique was used to record the spontaneous action potential (AP) and group peak potential (PS) in hippocampal CA1 area to evaluate the learning ability of Astragalus polysaccharides in PSD model rats. Behavioral effects; serum cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6) levels were detected by double antibody sandwich ELISA; nuclear transcription factor-κB (NF-κB) was detected by Western blotting in hippocampal CA1 region Peroxisome proliferator-activated receptor-gamma (PPAR-γ) protein expression, real-time quantitative (RT-PCR) detection of NF-κB and PPAR-γ gene expression. Results In the low-dose and high-dose groups of Astragalus polysaccharides, the sucrose intake increased significantly, the escape latency was shortened, and the number of crossovers increased. The AP and PS membrane voltages and serum IL-1β and IL-6 levels in CA1 area were significantly decreased. NF-κB protein and NF-κB mRNA were down-regulated in CA1 region, while PPAR-γ protein and PPAR-γ mRNA were highly expressed, and the difference was statistically significant (P<0.05). The difference was statistically significant (P<0.05). Conclusion Astragalus polysaccharide can alleviate the depression-like behavior of PSD model rats and improve learning and memory ability. The mechanism may be to reduce the release of cytokines IL-1β and IL-6 regulated by NF-κB signaling pathway and reduce middle cerebral artery occlusion (MCAO). Traumatic stress and inflammatory response are associated with increased membrane stability in the CA1 region.

Key words: Astragalus polysaccharide, Post-stroke depression (PSD), Nuclear factor kappa B (NF-κB) signaling pathway, Cytokines, Learning ability, Behavior