ObjectiveTo investigate the effects of Schisandrae Chinensis Fructus lignans on schizophrenia induced by dizocilpine maleate （MK-801） in mice and to clarify its mechanism. MethodsMale mice of 4-6 weeks old were randomized into blank， model， positive drug， and low-， medium-， and high-dose （40， 80， 160 mg·kg^-1， respectively） Schisandrae Chinensis Fructus lignans groups. The blank group was administrated with distilled water， and the other groups were injected with 0.5 mg·kg^-1 MK-801 to induce schizophrenia symptoms. Meanwhile， risperidone was injected at 0.2 mg·kg^-1 in the positive drug group， and mice in the intervention groups were injected with corresponding drugs for 14 consecutive days. The behavioral changes of mice were observed by autonomous activity test， open field test， forced swimming test， and water maze test. The levels of dopamine （DA） and 5-hydroxytryptamine （5-HT） in the brain and tumor necrosis factor-α （TNF-α） and nuclear factor-κB （NF-κB） in peripheral blood were quantified by enzyme-linked immunosorbent assay （ELISA）. The changes in the prefrontal lobe of mice were observed by hematoxylin-eosin staining， and the changes of the hippocampal tissue were observed by Nissl staining. The protein levels of silencing information regulatory factor 1 （SIRT1） and forkhead box protein O3a （FoxO3a） in the hippocampus of mice were determined by Western blot. ResultsCompared with the model group， low， medium， and high doses of Schisandrae Chinensis Fructus lignans reduced the total number of autonomous activities， total distance in the open field test， immobile time in the forced swimming test， and levels of TNF-α and NF-κB in peripheral blood （P<0.05）， while increasing the number of platform crossings in the water maze test and DA and 5-HT levels in the brain tissue （P<0.05）. Compared with the model group， risperidone and low， medium， and high doses of Schisandrae Chinensis Fructus lignans improve the neural cell morphology in the CA1 region， with full cells in neatly dense arrangement and exhibiting clear membrane boundary. Schisandrae Chinensis Fructus lignans inhibited the expression of SIRT 1 and FoxO3a in the hippocampus （P<0.05）. ConclusionTo sum up， Schisandrae Chinensis Fructus lignans may improve the behavior of schizophrenic mice by activating the SIRT1/FoxO3a signaling pathway to exert neuroprotective effects.