Atractylenolide I Suppresses A1 Astrocyte Activation to Improve Depression in Mice

This work aimed to investigate the role of atractylenolide I (ATR) in resisting depression and its mechanism of action. The mouse model of depression was constructed through chronic unpredictable mild stress (CUMS) method. After ATR intervention, changes in the depression-related behaviors of mice were detected through open field test and elevated plus maze. In addition, enzyme-linked immunosorbent assay (ELISA) was conducted to detect inflammatory factor levels. Real-time fluorescence quantitative PCR (RT-qPCR) was performed to measure the mRNA levels of A1/A2 astrocyte markers. Furthermore, primary astrocytes were induced in vitro, and the A1 differentiation level was detected by ELISA and RT-qPCR assays. ATR improved the behaviors of CUMS mice and alleviated the depression symptoms. Moreover, it reduced tissue inflammation, inhibited the A1 differentiation of astrocytes, and decreased the mRNA levels of A1 markers. After NLRP3 knockout, the effects of ATR were suppressed. Similarly, in vitro experimental results also revealed that ATR suppressed the A1 differentiation of astrocytes. Based on molecular dynamics and small molecule-protein docking results, ATR mainly targeted NLRP3 and suppressed the NLRP3-mediated A1 differentiation. We discover that ATR can target NLRP3 to suppress A1 differentiation of astrocytes, restrain tissue inflammation, and improve the depression symptoms in mice.