Changes of serum level of acetylcholinesterase enzyme in lipopolysaccharide-induced model of depression in mice

Background and Objective: Depression is a common disorder, especially in developed countries. Functional changes of cholinesterase are involved in pathogenesis of some brain disorders. Until now, exact association of these changes with depression has not been determined. This study was conducted to evaluate the changes of serum cholinesterase in lipopolysaccharide (LPS)-induced model of depression in male mice. Materials and Methods: Male mice (n = 48) were divided into 2 groups of control and LPS. For induction of depression, LPS (0.5 mg/kg; i.p.) was injected 24 h before the experiments. Open field, forced swimming, and tail suspension tests were used for behavioral assessment. Finally, serum cholinesterase activity was determined using biochemical method. Results: LPS injection significantly decreased travelled distance in open field test (p < 0.05) and increased immobility duration in forced swimming and tail suspension tests (p < 0.01). In addition, serum cholinesterase showed a significant decrease in LPS subgroups versus control (p < 0.05). Conclusion: Our data showed that LPS could induce a valid model of depression and changes of cholinesterase are in part involved in development of its complications.