Abstract: Objective To explore the mechanism of the effect of magnoflorine on the behavior of mice with depression caused by chronic unpredictable mild stress. Methods The ICR mice were randomly divided into normal control group (control group), positive depression group (PG group), high dose of magnoflorine group (MH group) and low dose of magnoflorine group (ML group). Depression mouse model was established by chronic unpredictable mild stress method. The behavioral changes of mice were detected. The expressions of lysine specific demethylase 1 (LSD1) mRNA and protein in brain of mice were detected by real-time quantitative PCR, Western blot assay and immunohistochemistry. Results Magnoflorine improved the depression in mice. Compared with the PG group, the motionless time of tail suspension and motionless time of forced swimming were significantly shorter in the MH group and the ML group (P＜0.05). Real-time quantitative PCR and Western blot assay showed that there was no significant difference in LSD1 mRNA expression between the PG group and the control group. The protein expression was significantly decreased (P＜0.05). The expressions of LSD1 mRNA and protein were significantly increased in the ML group compared with those of control group (P＜0.05). Compared with the PG group, the expressions of LSD1 mRNA and protein were significantly increased in the ML group (P＜0.05). The results of immunohistochemistry showed that the number of positive cells in brain was decreased in the PG group compared with that of the control group, while it was increased in the ML group compared with that of PG group. Conclusion LSD1 may play an important role in the treatment with magnoflorine for depressed mice.

Key words: depression, chronic unpredictable mild stress, magnoflorine, lysine specific demethylase 1