Sepsis is a systemic inflammatory response to
infection that causes severe neurological complications. Previous studies have suggested that
melatonin is protective during
sepsis. Additionally, silent information regulator 1 (
SIRT1) was reported to be beneficial in
sepsis. However, the role of
SIRT1 signaling in the protective effect of
melatonin against septic
encephalopathy remains unclear. This study aimed to investigate the role of
SIRT1 in the protective effect of
melatonin. EX527, a
SIRT1 inhibitor, was used to reveal the role of
SIRT1 in
melatonin's action. Cecal
ligation and
puncture or
sham operation was performed in male C57BL/6J mice.
Melatonin was administrated intraperitoneally (30 mg/kg). The survival rate of mice was recorded for the 7-day period following the
sham or CLP operation. The blood-brain barrier (BBB) integrity, brain water content, levels of inflammatory
cytokines (TNF-α, IL-1β, and
HMGB1), and the level of oxidative stress (
superoxide dismutase (SOD),
catalase (CAT), and
malondialdehyde (MDA)) and apoptosis were assessed. The expression of
SIRT1, Ac-FoxO1, Ac-p53, Ac-NF-κB, Bcl-2, and Bax was detected by Western blot. The results suggested that
melatonin improved survival rate, attenuated
brain edema and neuronal apoptosis, and preserved BBB integrity.
Melatonin decreased the production of TNF-α, IL-1β, and
HMGB1.
Melatonin increased the activity of SOD and CAT and decreased the MDA production. Additionally,
melatonin upregulated the expression of
SIRT1 and Bcl-2 and downregulated the expression of Ac-FoxO1, Ac-p53, Ac-NF-κB, and Bax. However, the protective effects of
melatonin were abolished by EX527. In conclusion, our results demonstrate that
melatonin attenuates
sepsis-induced
brain injury via
SIRT1 signaling activation.