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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

Chaihu Shugan San (CSS), a classical Traditional Chinese Medicine (TCM) formula, was first recorded in Jingyue Quanshu (1624 AD) for treating "liver qi stagnation" (Yu Syndrome), a TCM diagnostic pattern analogous to modern mood disorders. Although CSS has been prescribed for emotional distress, irritability, and depressive symptoms for centuries, the neurobiological mechanisms underlying its antidepressant efficacy, particularly in the context of gender-specific pathology, remain poorly revealed. The present study probed the antidepressant effects of CSS in female mice, while elucidating the underlying molecular mechanisms involving hippocampal neuroinflammation and neuroplasticity. We hypothesized that CSS reverses chronic stress-induced depressive phenotypes by suppressing interleukin-6 (IL-6), which in turn facilitates cAMP-CaMKII-BDNF signaling pathway in the hippocampus. Adult female C57BL/6J mice were subjected to a 5-week chronic unpredictable mild stress (CUMS) regimen to evoke depressive-like behaviors. During the final 2 weeks of the regimen, CSS was administered intragastrically at 0.5, 1.0, or 1.5 g/kg, with fluoxetine (10 mg/kg) as the positive control. Behavioral assessments included forced swimming test (FST), sucrose preference test (SPT), open field test (OFT), and tail suspension test (TST). Hippocampal IL-6, cAMP, CaMKII, and BDNF levels were quantified by ELISA. Mechanistic validation employed acute hippocampal microinjection of recombinant IL-6 (1 μg/site) and systemic administration of the CaMKII inhibitor KN-93 (6 mg/kg). Chemical constituents were identified by UHPLC-QTOF MS. CSS alleviated CUMS-induced depressive-like behaviors in a dose-dependent manner, cutting down immobility time in TST/FST and reinstating sucrose preference, similar to the action of fluoxetine. CSS significantly suppressed hippocampal IL-6 while upregulating cAMP, CaMKII activity, and BDNF expression. Acute IL-6 elevation completely abolished both the behavioral antidepressant effects and molecular actions of CSS. Pharmacological inhibition of CaMKII blocked CSS-induced behavioral improvement and its upregulation of cAMP-BDNF signaling, without affecting basal behaviors. CSS exhibited no anxiogenic or locomotor side effects. CSS exerts potent antidepressant effects in female mice through coordinated suppression of hippocampal IL-6 and activation of the cAMP-CaMKII-BDNF neuroplasticity-related pathway, with CaMKII playing a critical role in this process. These findings offer scientific evidence for the traditional use of CSS in addressing emotional disorders and highlight its therapeutic potential as a multi-targeted, anti-inflammatory botanical medicine for female-specific depression. Show less

To investigate longitudinal changes in neuroimmune biomarkers during acute exacerbations of chronic obstructive pulmonary disease (AECOPD), their modulation by standard therapy, and prognostic implications for 90-day outcomes. In a prospective cohort, 266 hospitalized AECOPD patients were stratified into worsened ( Compared with controls, AECOPD patients exhibited higher IL-6, TNF-α, PD-1, and MMP-9, alongside reduced BDNF and IL-10. Stable patients demonstrated partial biomarker normalization, whereas worsened patients retained a pro-inflammatory profile. Corticosteroids and antibiotics attenuated cytokine elevations, and oxygen therapy facilitated BDNF recovery. Low BDNF and high MMP-9 predicted spirometric decline, while elevated PD-1 and MMP-9 were associated with increased 90-day readmission risk. A dual-axis model incorporating neurotrophic and immune exhaustion markers outperformed GOLD classification for risk prediction. Neuroimmune biomarkers capture recovery heterogeneity in AECOPD. The proposed dual-axis model improves prognostic accuracy and may inform personalized management strategies. Show less