Abstract:

Objective To analyze the effects of curcumin on cognitive function，anxiety like behavior，and synaptic protein expression in hippocampal tissue of sleep deprived mice，and explore the mechanism by which curcumin improves cognitive impairment and anxiety like behavior caused by sleep deprivation. Methods Establish a sleep deprivation mouse model using the "improved platform water environment" experimental method，which was divided into four groups：normal group，model group，curcumin group，and Western medicine intervention group. Curcumin group：gavage of curcumin 200 mg/kg/d. Western medicine intervention group：gavage of zolpidem 0.54 mg/kg/d. Normal group and model group：daily gavage of equal volume of physiological saline. Continuous processing for 21 days. Analysis of cognitive function in mice using water maze experiment，the open field experiment was used to detect anxiety like behavior in mice，quantification of melatonin content in mouse serum by enzyme-linked immunosorbent assay，Western blot was used to evaluate the relative values of synaptic proteins in hippocampal tissue，including postsynaptic membrane dense substance 95（PSD-95），synaptophysin（SYN），and brain-derived neurotrophic factor（BDNF）. Results Compared with the normal group，the escape latency[（43.07±6.26）s] of model group mice was prolonged，and the number of platform crossings[（9.70±1.89）times] was reduced（both P<0.01）. The number of upright movements[（27.48±3.32）times] and the total distance traveled[（7 038.90±912.62）cm] significantly increased（both P<0.01），while the resting time[（19.12±2.28）s] was obviously shortened（P<0.01）. The levels of melatonin[（35.15±4.84）ng/L] in serum and the relative values of synaptic-related proteins[PSD-95（1.14±0.23），SYN（1.38±0.23），and BDNF（0.69±0.10）] in hippocampal tissue were all reduced（all P<0.01）. Compared with the model group，the escape latency of mice in curcumin group was shortened[（31.66±4.18）s]，and the number of crossing platforms was increased[（18.96±2.60）times]（both P<0.01）. The number of upright movements[（21.48±3.01）times] and total distance traveled[（5 445.85±737.16）cm] were obviously reduced（both P<0.01），while the resting time[（25.63±3.46）s] was obviously increased（both P<0.01）. The levels of melatonin（43.25±6.27）ng/L） in serum and the relative values of synaptic-related proteins[PSD-95（1.48±0.21），SYN（1.75±0.23），and BDNF（0.90±0.13）] in hippocampal tissue increased（all P<0.05）. There were no statistically significant differences in cognitive function，anxiety like behavior，serum melatonin content，and relative values of synaptic proteins in the hippocampus between curcumin group and Western medicine intervention group（all P>0.05）. Conclusion Curcumin can improve cognitive function and anxiety like behavior in sleep deprived mice，which is closely related to its increased content of synaptic-related proteins in hippocampal tissue.

Key words: Mice, Curcumin, Sleep deprivation, Cognitive function, Anxiety like behavior, Synaptic-related proteins