Opioid System Contributes to the Trifluoromethyl-Substituted Diselenide Effectiveness in a Lifestyle-Induced Depression Mouse Model

(m-CF3-PhSe)2 benefits against anxiety-like phenotype associated with synaptic plasticity impairment and NMDAR-mediated neurotoxicity in young mice exposed to a lifestyle model

Lifestyle habits including energy-dense foods and ethanol intake are associated with anxiety disorders. m-Trifluoromethyl-diphenyl diselenide [(m-CF₃-PhSe)₂] has been reported to modulate serotonergic and opioidergic systems and elicit an anxiolytic-like phenotype in animal models. This study investigated if the modulation of synaptic plasticity and NMDAR-mediated neurotoxicity contributes to the (m-CF₃-PhSe)₂ anxiolytic-like effect in young mice exposed to a lifestyle model. Swiss male mice (25-days old) were subjected to a lifestyle model, an energy-dense diet (20:20% lard: corn syrup) from the postnatal day (PND) 25-66 and sporadic ethanol (2 g/kg) (3 x a week, intragastrically, i.g.) from PND 45 to 60. From PND 60 to 66, mice received (m-CF₃-PhSe)₂ (5 mg/kg/day; i.g). The corresponding vehicle (control) groups were carried out. After, mice performed anxiety-like behavioral tests. Mice exposed only to an energy-dense diet or sporadic ethanol did not show an anxiety-like phenotype. (m-CF₃-PhSe)₂ abolished the anxiety-like phenotype in young mice exposed to a lifestyle model. Anxious-like mice showed increased levels of cerebral cortical NMDAR2A and 2B, NLRP3 and inflammatory markers, and decreased contents of synaptophysin, PSD95, and TRκB/BDNF/CREB signaling. (m-CF₃-PhSe)₂ reversed cerebral cortical neurotoxicity, the increased levels of NMDA2A and 2B, and decreased levels of synaptic plasticity-related signaling in the cerebral cortex of young mice exposed to a lifestyle model. In conclusion, the (m-CF₃-PhSe)₂ anxiolytic-like effect was associated with the modulation of NMDAR-mediated neurotoxicity and synaptic plasticity in the cerebral cortex of young mice exposed to the lifestyle model.

(m-CF3-PhSe)2 counteracts metabolic disturbances and hypothalamic inflammation in a lifestyle rodent model

An unhealthy lifestyle is associated with metabolic disorders and neuroinflammation. In this study, the efficacy of m-trifluoromethyl-diphenyl diselenide [(m-CF₃-PhSe)₂] against lifestyle model-related metabolic disturbances and hypothalamic inflammation in young mice was investigated. From postnatal day 25 (PND25) to 66, male Swiss mice were subjected to a lifestyle model, an energy-dense diet (20:20% lard: corn syrup) and sporadic ethanol (3x/week). Ethanol was administrated intragastrically (i.g., 2g/kg) to mice from PND45 to 60. From PND60 to 66, mice received (m-CF₃-PhSe)₂ (5mg/kg/day; i.g). (m-CF₃-PhSe)₂ reduced relative abdominal adipose tissue weight, hyperglycemia, and dyslipidemia in mice exposed to the lifestyle-induced model. (m-CF₃-PhSe)₂ normalized hepatic cholesterol and triglyceride levels, and the activity of G-6-Pase increased in lifestyle-exposed mice. (m-CF₃-PhSe)₂ was effective in modulating hepatic glycogen levels, citrate synthase and hexokinase activities, protein levels of GLUT-2, p-IRS/IRS, p-AKT/AKT, redox homeostasis, and inflammatory profile of mice exposed to a lifestyle model. (m-CF₃-PhSe)₂ counteracted hypothalamic inflammation and the ghrelin receptor levels in mice exposed to the lifestyle model. (m-CF₃-PhSe)₂ reversed the decreased levels of GLUT-3, p-IRS/IRS, and the leptin receptor in the hypothalamus of lifestyle-exposed mice. In conclusion, (m-CF₃-PhSe)₂ counteracted metabolic disturbances and hypothalamic inflammation in young mice exposed to a lifestyle model.

Resistance Training Modulates Hippocampal Neuroinflammation and Protects Anxiety-Depression-like Dyad Induced by an Emotional Single Prolonged Stress Model

Stress is a triggering factor for anxious and depressive phenotypes. Exercise is known for its action on the central nervous system. This study aimed to evaluate the role of resistance exercise in an anxiety-depression-like dyad in a model of stress. Male Swiss mice (35-day-old) were exercised, three times a week for 4 weeks on nonconsecutive days. The resistance exercise consisted of climbing a 1-m-high ladder 15 times. After mice were subjected to an emotional single prolonged stress (Esps) protocol. Seven days later, they were subjected to anxiety and depression predictive behavioral tests. The results showed that exercised mice gain less weight than sedentary from weeks 3 to 5. Resistance exercise was effective against an increase in immobility time in the forced swim test and tail suspension test and a decrease in grooming time of mice subjected to Esps. Resistance exercise protected against the decrease in the percentage of open arms time and open arm entries, and the increase in the anxiety index in Esps mice. Four-week resistance exercise did not elicit an antidepressant/anxiolytic phenotype in non-stressed mice. Esps did not alter plasma corticosterone levels but increased the hippocampal glucocorticoid receptor content in mice. Resistance exercise protected against the decrease in hippocampal levels of tropomyosin kinase B (TRκB), the p-Akt/Akt, and the p-mTOR/mTOR ratios of Esps mice. Resistance exercise proved to be effective in decreasing hippocampal neuroinflammation in Esps mice. Resistance exercise protected against the increase in the hippocampal Akt/mTOR pathway and neuroinflammation, and anxiety/depression-like dyad in Esps exposed mice.

Selenium in Bodily Homeostasis: Hypothalamus, Hormones, and Highways of Communication

The ability of the body to maintain homeostasis requires constant communication between the brain and peripheral tissues. Different organs produce signals, often in the form of hormones, which are detected by the hypothalamus. In response, the hypothalamus alters its regulation of bodily processes, which is achieved through its own pathways of hormonal communication. The generation and transmission of the molecules involved in these bi-directional axes can be affected by redox balance. The essential trace element selenium is known to influence numerous physiological processes, including energy homeostasis, through its various redox functions. Selenium must be obtained through the diet and is used to synthesize selenoproteins, a family of proteins with mainly antioxidant functions. Alterations in selenium status have been correlated with homeostatic disturbances in humans and studies with animal models of selenoprotein dysfunction indicate a strong influence on energy balance. The relationship between selenium and energy metabolism is complicated, however, as selenium has been shown to participate in multiple levels of homeostatic communication. This review discusses the role of selenium in the various pathways of communication between the body and the brain that are essential for maintaining homeostasis.

p-Chloro-diphenyl diselenide modulates Nrf2/Keap1 signaling and counteracts renal oxidative stress in mice exposed to dexamethasone repeated administrations

Dexamethasone is a synthetic glucocorticoid that has been associated with oxidative stress in central and peripheral tissues. p-Chloro-diphenyl diselenide (p-ClPhSe)2 is an antioxidant organoselenium compound. The present study aimed to evaluate whether Nrf2/Keap-1 signaling contributes to the (p-ClPhSe)2 antioxidant effects in the kidney of mice exposed to dexamethasone. Adult Swiss mice received dexamethasone (i.p) at a dose of 2 mg/kg or its vehicle for 21 days. After, mice were treated with (p-ClPhSe)2 (i.g)(1, 5, or 10 mg/kg) for 7 days. Samples of kidneys were collected for biochemical assays. (p-ClPhSe)2 at dose of 1 mg/kg reversed the renal reactive oxygen species (ROS) and carbonyl protein (CP) levels increased by dexamethasone. (p-ClPhSe)2 at doses of 5 and 10 mg/kg was effective against the increase of TBARS (thiobarbituric acid reactive substances), ROS, and CP as well as the decrease of δ-aminolevulinic acid dehydratase (δ-ALA-D) activity and non-protein SH (NPSH) levels induced by dexamethasone. At 5 mg/kg, (p-ClPhSe)2 reduced the renal levels of 4-OH-2-HNE and HO-1 as well as modulated the Nrf2/Keap-1 signaling in mice exposed to dexamethasone. The present findings revealed that (p-ClPhSe)2 antioxidant effects were associated with the modulation of Nrf2/Keap-1 signaling pathway in the kidney of mice exposed to dexamethasone.

Baicalin ameliorates chronic unpredictable mild stress-induced depression through the BDNF/ERK/CREB signaling pathway

Brain-derived neurotrophic factor (BDNF) can activate the extracellular regulated protein kinase (ERK)/cAMP response element binding protein (CREB) cascade revealing an important role in antidepressant effects. Here, we studied the neuroprotective effect of baicalin (BA) in mice with chronic unpredictable mild stress (CUMS)-induced via a BDNF/ERK/CREB signaling pathway. Depression was induced via six weeks of CUMS in male ICR mice, and drug therapy was given simultaneously for the last three weeks. Cognitive dysfunctions were then evaluated via sucrose preference test (SPT), open field test (OFT), Morris water maze test (MWM), tail suspension test (TST), and novelty suppressed feeding test (NSF). Western blot and real-time PCR were then used to detect the relative expression of ERK, CREB, p-ERK, and p-CREB. Integrated optical density (IOD) tests of p-ERK and p-CREB were then evaluated via immunofluorescence. The behavior results showed that the cognitive dysfunctions increased in the CUMS group versus the control (CON) group (p < 0.01). There were decreases in fluoxetine (FLU) and BA groups (p < 0.05, p < 0.01). The protein ratios of p-ERK/ERK, p-CREB/CREB and ERK mRNA, and CREB mRNA expression decreased in the CUMS group (p < 0.01) and markedly increased in the FLU and BA groups (p < 0.05, p < 0.01). The IOD value of the p-ERK and p-CREB in the CUMS group was decreased versus the CON group (p < 0.01), and these changes were improved via BA and FLU treatment (p < 0.05, p < 0.01). This study indicated that BA can improve cognitive functions and has antidepressant effects in mice, which may be associated with activation of the BDNF/ERK/CREB signaling pathway in the hippocampus.