In a review article, Esther M Speksnijder and colleagues state that using hormones such as adrenal glucocorticoids and melatonin and the autonomic nervous system, the SCN modulates critical processes such as glucose production and insulin sensitivity. (1) Thus, it is interesting to understand how melatonin acts on glucose homeostasis or related issues.
According to the research titled “Melatonin Improves Glucose Homeostasis and Insulin Sensitivity by Mitigating Inflammation and Activating AMPK Signaling in a Mouse Model of Sleep Fragmentation,” melatonin appears to play a crucial role in glucose homeostasis and metabolic health. Here are the key findings from the study conducted by Seok Hyun Hong and colleagues:
Sleep Fragmentation (SF) and Metabolic Dysfunction:
Sleep fragmentation, characterized by disrupted sleep patterns, can lead to inflammation and increased production of reactive oxygen species (ROS). Sleep Fragmentation is associated with inflammation in adipose tissue and insulin resistance.
Melatonin’s Potential Beneficial Effects:
Previous studies have suggested that melatonin might have metabolic benefits due to its ability to activate AMP-activated protein kinase (AMPK). AMPK is a key cellular energy-sensing complex that plays a role in maintaining metabolic homeostasis.
The Experiment:
The researchers conducted an experiment using adult male C57BL/6 mice. The mice were divided into three groups: Control group (no SF), SF group (housed in SF chambers), SF+Mel group (SF mice with daily oral melatonin treatment) After 12 weeks, various assessments were performed, including glucose tolerance tests, insulin tolerance tests, and AMPK assessments.
Results:
SF mice showed increased weight gain, impaired glucose regulation, inflammation, and decreased AMPK expression in white adipose tissue (WAT) compared to the controls. Melatonin treatment significantly improved these outcomes by mitigating SF-induced metabolic dysfunction, inflammation, and AMPK downregulation in adipose tissue.
Therapeutic Efficacy of Melatonin:
The study suggests that melatonin’s ability to restore adipose tissue homeostatic pathways may contribute to its therapeutic efficacy against cardiometabolic impairments induced by SF. In summary, melatonin appears to positively impact glucose homeostasis by restoring AMPK expression and related pathways in adipose tissue. Its potential as a therapeutic agent for metabolic dysfunction warrants further investigation.
REFERENCES
1. Esther M Speksnijder et al, Circadian desynchrony and glucose metabolism, J Pineal Res. 2024 May;76(4):e12956. doi: 10.1111/jpi.12956.
2. Seok Hyun Hong et al, Melatonin Improves Glucose Homeostasis and Insulin Sensitivity by Mitigating Inflammation and Activating AMPK Signaling in a Mouse Model of Sleep Fragmentation, Cells. 2024 Mar 7;13(6):470. doi: 10.3390/cells13060470.