📋 Browse Articles

Gestational intermittent hypoxia (GIH), which serves as a model for obstructive sleep apnea (OSA), is associated with adverse maternal and neonatal outcomes, especially cognitive impairments in offspring. Growing evidence supports that the anti-inflammatory actions of melatonin significantly influence the peripartum environment and contribute to the mitigation of neurodegeneration. However, the full impact of GIH on offspring cognition and the molecular mechanisms by which melatonin modulates these effects remain uncertain. Thus, in this study, we explored the neurobiological changes in GIH-exposed offspring and the mechanism underlying maternal melatonin supplementation in preventing these alterations using a murine model. C57BL/6J mice were exposed to GIH between gestational Days 15 and 21. Concurrently, dams received either vehicle or melatonin. The Morris water maze test was employed to evaluate offspring cognitive function, after which the offspring were euthanized at 2 months of age. The hippocampal levels of glial markers (ionized calcium-binding adapter molecule 1 [Iba-1], glial fibrillary acidic protein [GFAP]), NOD-like receptor thermal protein domain-associated protein 3 [NLRP3], nuclear factor-kappa B [NF-κB], tight-junction proteins (zonula occludens-1 [ZO-1], occludin), and synaptic plasticity-related proteins (brain-derived neurotrophic factor [BDNF], tropomyosin receptor kinase B [TrkB], postsynaptic density protein 95 [PSD-95], synaptophysin [SYN]) were quantified by enzyme-linked immunosorbent assay and western blot. Maternal melatonin supplementation significantly attenuated learning and memory impairments, reduced the protein levels of Iba-1 and GFAP by suppressing NLRP3/NF-κB signaling, and elevated those of ZO-1, occludin, BDNF, TrkB, PSD-95, and SYN. Additionally, melatonin mitigated inflammatory responses, glial cell activation, blood-brain barrier (BBB) leakage, and synaptic dysfunction induced by GIH in mice. Our results demonstrated that GIH-exposed mice exhibit cognitive deficits, alongside neuroinflammatory responses, leading to inflammasome activation, glial reactivity, BBB breakdown, and synaptic deficits. However, melatonin exerted significant protective effects against these deleterious effects. Show less

Melatonin, a key regulator of circadian rhythms and sleep-wake cycles, is implicated in the pathophysiology of major depressive disorder (MDD). Emerging evidence supports its anti-inflammatory, cytoprotective, and neuroprotective roles, including promotion of neuroplasticity. This study aims to investigate alterations in serum melatonin, interleukin-6 (IL-6), and brain-derived neurotrophic factor (BDNF) levels in first-episode MDD patients, and explores their clinical correlations. A total of 74 first-episode patients diagnosed with MDD and 72 healthy controls were enrolled in this study. The severity of depressive symptoms was assessed using the 24-item Hamilton Depression Rating Scale (HAMD-24). All blood samples were collected in the morning, and serum levels of melatonin, IL-6, and BDNF were quantified via enzyme-linked immunosorbent assay (ELISA). Baseline serum concentrations of melatonin, IL-6, and BDNF were compared between the MDD group and the control group. Additionally, the discriminative ability of these biomarkers (melatonin, IL-6, and BDNF) in distinguishing MDD patients from healthy controls was evaluated using receiver operating characteristic (ROC) curve analysis. Pearson correlation analysis or Spearman's rank correlation analysis was performed to explore the relationships between serum melatonin levels and clinical disease severity, as well as with IL-6 and BDNF levels, in patients with MDD. Compared with the control group, the MDD group showed significantly higher serum levels of melatonin (Z = -3.861, P < 0.001) and IL-6 (Z = -4.240, P < 0.001), but significantly lower serum BDNF levels (t = 9.537, P < 0.001). Moreover, the combined panel of BDNF, IL-6, and melatonin achieved high accuracy in distinguishing MDD patients from healthy controls, with an area under the curve (AUC) of 0.905. Additionally, no significant correlations were found between serum melatonin levels and clinical disease severity (assessed by HAMD-24 scores), IL-6 levels, or BDNF levels in MDD patients (all P > 0.05). These findings suggest that dysregulation of melatonin, IL-6, and BDNF may contribute to the pathophysiology of first-episode MDD, with their combined measurement offering strong diagnostic potential. Show less

This study aims to investigate the radioprotective effects of melatonin (MEL) against oxidative damage that may be caused by flattening filter (FF) and flattening filter-free (FFF) beam in the cerebrum and cerebellum of rat using various genetic markers. Forty female Wistar albino rats were randomly assigned to five groups. The control group received no intervention. The FF group received a single 16 Gy fraction at 600 MU/min. The FF+MEL group received the same FF protocol, preceded by melatonin (50 mg/kg, intraperitoneal) administered 15 min before irradiation. The FFF group received a single dose of 16 Gy at 2,400 MU/min. The FFF+MEL group received the same FFF protocol with melatonin administered as above. After treatment, cerebrum and cerebellum tissues were harvested, and mRNA expression levels of BDNF, CREB, BAX, BCL2 and IL6 were measured. Both FF and FFF radiotherapy treatments significantly increased BDNF, CREB, IL6, and BAX gene expression in cerebrum and cerebellum tissues, while decreasing BCL2 levels (P < 0.05). Melatonin treatment increased BDNF and CREB expression, significantly attenuated radiation-induced increases in IL6 and BAX, and partially reversed the decrease in BCL2 (P < 0.05). The increase in the BAX/BCL2 ratio after radiotherapy was significantly attenuated by melatonin treatment. Overall, FFF irradiation induced a stronger oxidative, inflammatory, and pro-apoptotic response than FF, whereas melatonin exhibited potent neuroprotective and anti-apoptotic effects. In conclusion, MEL demonstrates potential as a protective agent for healthy tissues during irradiations, owing to its antiapoptotic, anti-inflammatory, and neurotrophic properties. Show less