Melatonin upregulates BMAL1 to attenuate chronic sleep deprivation‐related cognitive impairment by alleviating oxidative stress

PURPOSE: To investigate the mechanism underlying the regulatory effect of melatonin on chronic sleep deprivation‐related cognitive impairment. METHODS: Chronic sleep deprivation (CSD) model was established using the MMPM method. After the model was established, melatonin receptor agonist and inhibitor were given, respectively. Water maze was conducted to record the escape latency and the duration of crossing the platform of space exploration. The concentration of TNF‐α, IL‐6, MDA, and SOD was measured by ELISA. Immunofluorescence was used to determine the expression level of CD86 and CD206, while the mRNA expression of Bax, Bcl‐2, P65, IκB, and BMAL1 was detected by qPCR. Western blotting assay was utilized to determine the protein expression of Bax, Bcl‐2, P65, p‐P65, IκB, p‐I κB, and BMAL1. RESULTS: Compared with the control, the escape latency was greatly increased on the second and third day, accompanied by the increased expression of TNF‐α, IL‐6, MDA, and SOD in serum. Furthermore, dramatically upregulated Bax, Bcl‐2, P65, IκB, and CD86 were observed in the model group, accompanied by the declined expression level of BMAL1 and CD206. Compared with the model group, the escape latency was declined, the concentration of TNF‐α, IL‐6, MDA, and SOD was decreased, the expression level of Bax, Bcl‐2, P65, IκB, and CD86 was declined, and the level of BMAL1 and CD206 was promoted by the treatment of the melatonin agonist, while the opposite results were observed under the treatment of the melatonin inhibitor. CONCLUSION: Melatonin upregulates BMAL1 to attenuate chronic sleep deprivation‐related cognitive impairment by alleviating oxidative stress.