Modulatory effect of n-3 polyunsaturated fatty acids on depressive-like behaviors in rats with chronic sleep deprivation: potential involvement of melatonin receptor pathway and brain lipidome

Exploring Crocin's Role in Alleviating Memory Impairments and Depression-like Behaviors Induced by REM Sleep Deprivation, Focusing on BDNF and GSK-3β in Male Rats

Rapid-eye movement sleep deprivation (REM SD) drastically alters behavioral functions and the mood state. Evidence demonstrates that the effects of REM SD on cognition and mood vary significantly based on the duration of deprivation. On the other hand, crocin (as a natural therapeutic compound found in Saffron) may be beneficial for the alleviation of SD effect. The present research aimed to explore the effects of REM SD of varying durations on behavioral functions and the expression levels of brain-derived neurotrophic factor (BDNF) and glycogen synthase kinase-3 beta (GSK-3β) in the prefrontal cortex. REM SD was conducted for 1, 5, or 10 days (6 h per day). Crocin was injected intraperitoneally at the dose of 50 mg/kg. The results showed that REM SD for 5- and 10-days increased locomotor activity and rearing, decreased pain threshold, and impaired passive avoidance memory performance. REM SD for 5- and 10-days increased the expression levels of GSK-3β, while only REM SD for 5 days decreased BDNF levels. Crocin (only in rats exposed to REM SD for 5 days) restored behavioral alterations, while in rats exposed to REM SD for 10 days had no effect. Interestingly, crocin in rats exposed to REM SD for 5- and 10-days attenuated GSK-3β upregulation. In addition, crocin in rats exposed to REM SD for 5 but not 10 days attenuated BDNF down regulation. In conclusion, the duration of REM SD is a crucial determinant of its impact on cognitive and mood functions.

Omega-3 fatty acids and sleep: recent advances in understanding effects and mechanisms

PURPOSE OF REVIEW

Sleep disturbance and low dietary intake of omega-3 fatty acids are common in modern society. Previous research shows that omega-3 fatty acids play an integral role in the regulation of sleep processes, but efficacy data in adults have been equivocal to date. This review examines recent studies highlighting the effects of omega-3 fatty acids on sleep quality and circadian processes.

RECENT FINDINGS

Two randomized controlled trials in healthy adults found that supplementation with DHA-rich interventions improved sleep quality, though effects may vary depending on age, current sleep habits and habitual omega-3 intake. Conversely, EPA-rich interventions in menopausal women, men with prostate cancer and people experiencing episodic migraines did not improve sleep quality. Advances in lipidomics reveal a bidirectional relationship between sleep disturbance and lipid metabolism, to some extent underpinned by activity of omega-3 fatty acids in circadian processes. Therefore, adequate omega-3 fatty acid intake is both a preventive and therapeutic approach to sleep quality and health.

SUMMARY

Omega-3 fatty acids and DHA in particular show promise for improving sleep quality and limiting the adverse effects of sleep disturbance on health. Future research should focus on developing sex-specific and age-specific recommendations for omega-3 fatty acid intake to optimize sleep health.

Bone-brain communication mediates the amelioration of Polgonatum cyrtonema Hua polysaccharide on fatigue in chronic sleep-deprived mice

This study aimed to investigate the anti-fatigue efficacy and underlying mechanisms of Polygonatum cyrtonema Hua polysaccharide (PCP) in chronic sleep-deprived mice. Following three weeks of oral administration, PCP demonstrated significant efficacy in alleviating fatigue symptoms. This was evidenced by the prolonged swimming and rotarod time in the high-dose group of PCP, which increased by 73 % and 64 %, respectively. Additionally, serum activities of CAT, GSH-Px, and SOD enzymes rose by 53.56 %, 37.69 % and 53.67 %, respectively, while MDA, lactic acid and BUN levels decreased by 22.90 %, 17.48 % and 24.61 %. The crosstalk between bone and brain is crucial for maintaining energy homeostasis. Molecular docking studies indicated a spontaneous and strong mutual binding between PCP and the bone-promoting target protein BMPR1A. Furthermore, it was observed that PCP enhanced osteogenic differentiation via the BMP-2/Smad1 pathway, leading to an upregulation of osteocalcin expression, which in turn regulated neurotransmitter balance and improved central arousal capacity. Moreover, PCP treatment stimulated neurogenesis by activating the CREB/BDNF/Akt signaling cascade, exhibiting neurotrophic effects. Additionally, PCP increased AMPK phosphorylation and destabilized TXNIP, facilitating astrocyte glucose uptake, glycolysis, and lactate conversion to support neuronal activity. These findings suggested that PCP could effectively respond to energy demands through bone-brain crosstalk, ultimately exerting anti-fatigue properties.

DHA and EPA alleviate depressive-like behaviors in chronic sleep-deprived mice: Involvement of iron metabolism, oligodendrocyte-lipids peroxidation and the LCN2-NLRP3 signaling axis

Mounting evidence suggests that eicosapentaenoic acid (EPA) is superior to docosahexaenoic acid (DHA) in the treatment of depression, but the underlying mechanisms remain elusive. In the present study, the effect of DHA and EPA on depressive-like behaviors was investigated in chronic sleep-deprived (CSD) mice. Following the administration of EPA or DHA, investigations were conducted on depression-like behavior, myelin damage, iron dyshomeostasis, oligodendrocyte-lipids peroxidation, and neuroinflammation. As anticipated, EPA was more effective than DHA in ameliorating CSD-induced depression by increasing center preference and immobility time and concurrently shortening immobility latency. Both DHA and EPA mitigated myelin damage with EPA demonstrating superior benefits characterized by higher levels of Olig2, MBP, and FTH, as well as decreased oligodendrocyte-lipid peroxidation. The inhibition of activated astrocytes and the associated LCN2-NLRP3 signaling pathway was observed following both EPA and DHA supplementation. However, the inhibitory effect was more pronounced with EPA. Additionally, EPA outperformed DHA in mitigating microglial activation and M1/M2 polarization imbalance. Overall, this present study provides valuable insights into the anti-depressive effects of DHA and EPA, highlighting their role in inhibiting oligodendrocyte-lipids peroxidation and the LCN2-NLRP3 axis and corroborating the superiority of EPA in mediating antidepressant effects.

Eicosapentaenoic Acid Modulates Transient Receptor Potential V1 Expression in Specific Brain Areas in a Mouse Fibromyalgia Pain Model

Pain is an unpleasant sensory and emotional experience accompanied by tissue injury. Often, an individual's experience can be influenced by different physiological, psychological, and social factors. Fibromyalgia, one of the most difficult-to-treat types of pain, is characterized by general muscle pain accompanied by obesity, fatigue, sleep, and memory and psychological concerns. Fibromyalgia increases nociceptive sensations via central sensitization in the brain and spinal cord level. We used intermittent cold stress to create a mouse fibromyalgia pain model via a von Frey test (day 0: 3.69 ± 0.14 g; day 5: 2.13 ± 0.12 g). Mechanical pain could be reversed by eicosapentaenoic acid (EPA) administration (day 0: 3.72 ± 0.14 g; day 5: 3.69 ± 0.13 g). A similar trend could also be observed for thermal hyperalgesia. The levels of elements in the transient receptor potential V1 (TRPV1) signaling pathway were increased in the ascending pain pathway, including the thalamus, medial prefrontal cortex, somatosensory cortex, anterior cingulate cortex, and cerebellum. EPA intake significantly attenuated this overexpression. A novel chemogenetics method was used to inhibit SSC and ACC activities, which presented an analgesic effect through the TRPV1 downstream pathway. The present results provide insights into the role of the TRPV1 signaling pathway for fibromyalgia and its potential as a clinical target.