Lithium ameliorates lipopolysaccharide-induced neurotoxicity in the cortex and hippocampus of the adult rat brain

Ambroxol attenuates detrimental effect of LPS-induced glia-mediated neuroinflammation, oxidative stress, and cognitive dysfunction in mice brain

Neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), are multifactorial. Among various factors, lipopolysaccharides (LPSs) from Gram-negative bacteria, such as E. coli, are considered potential causative agents. Despite significant advancements in the field, there is still no cure. In this study, we investigated the neuroprotective effects of ambroxol against LPS-induced neuroinflammation, oxidative stress, neurodegeneration, and the associated cognitive dysfunction. Intraperitoneal injection of LPS (250 µg/kg every alternative day for a total of seven doses over 14 days) triggered glial cell activation, neuroinflammation, oxidative stress, and neurodegeneration in the mouse brain. Ambroxol treatment (30 mg/kg/day for 14 days) significantly reduced neuroinflammation and oxidative stress compared to LPS-treated mice. Immunoblotting and immunofluorescence results showed that ambroxol reduced levels of Toll-like receptor 4 (TLR4) and oxidative stress kinase phospho-c-Jun N-terminal Kinase 1 (p-JNK). It also decreased astrocyte and microglia activation in the cortex and hippocampus of LPS+ Amb-treated mice, as indicated by the downregulation of GFAP and Iba-1. Furthermore, ambroxol-reversed LPS-induced neuroinflammation by inhibiting inflammatory mediators, such as IL-1β and TNF-α, through regulation of the transcription factor p-NFkB. Persistent neuroinflammation disrupted the natural antioxidant mechanisms, leading to oxidative stress. Ambroxol treatment upregulated antioxidant markers, including Nrf-2, HO-1, and SOD, which were downregulated in the LPS-treated group. Additionally, ambroxol-inhibited lipid peroxidation, maintaining malondialdehyde levels in the mouse brain. Ambroxol also improves synaptic integrity by upregulating synaptic biomarkers, including PSD-95 and SNAP-23. Overall, ambroxol demonstrated anti-inflammatory, antioxidant, and neuroprotective effects in LPS-treated mice, highlighting its potential benefits in neurological disorders.

Immunomodulatory effect of lithium treatment on in vitro model of neuroinflammation

Bipolar disorder (BD) is psychiatric disorder of not fully acknowledged pathophysiology. Studies show the involvement of innate-immune system activation and inflammation in BD course and treatment efficiency. Microglia are crucial players in the inflammatory response possibly responsible for BD innate-immune activity. Lithium is a mood stabilizer used in treatment for 75 years. Immunomodulation was previously described as one of the potential modes of its action. We hypothesized that lithium might modulate the microglia response to innate-immune-associated cytokines (10 ng/mL TNF-α, 50 ng/mL IL-1β, 20 ng/mL IFN-γ). We aimed to investigate whether lithium treatment and pretreatment of microglia modify the expression of genes associated with NLRP3 inflammasome. We also aimed to verify lithium treatment effect on caspase activity and extracellular IL-1β concentration. For the first time, our study used human microglial cell line - HMC3, the cytokine stimuli and lithium in concentration corresponding to that in the brains of patients. To analyze lithium mode of action, we analyzed the short- and long-term treatment and pretreatment. To assess the influence on microglia responding to innate-immune cytokines, we analyzed the expression of genes involved in innate-immune and inflammasome (TSPO, TLR4, NFKB1, CASP1, CASP4, NLRP3, IL-1β, IL-6), caspase activity, extracellular IL-1β concentration, phospho-GSK-3β(Ser9) expression and lactate concentration. We found that lithium treatment significantly reduced NLRP3 inflammasome-related genes expression. We observed that lithium treatment reduces inflammasome activity, which may attenuate the inflammatory state. Interestingly, the lithium pretreatment resulted in significantly elevated inflammasome activity, suggesting that lithium does not impair the immune response to additional stimuli.

Application of an in vitro neuroinflammation model to evaluate the efficacy of magnesium-lithium alloys

Mg-Li alloys can be promising candidates as bioresorbable Li-releasing implants for bipolar disorder and other neurodegenerative disorders. In order to compare the therapeutic efficacy of conventional Li salts and Li delivered through Mg-Li alloy extracts, we tested an in vitro model based on the neuroinflammation hypothesis of mood disorders (peripheral inflammation inducing neuroinflammation) wherein, a coculture of microglia and astrocytes was treated with conditioned medium from pro-inflammatory macrophages. Two alloys, Mg-1.6Li and Mg-9.5Li, were tested in the form of material extracts and well-known outcomes of Li treatment such as GSK3β phosphorylation (indirect flow cytometry) and influence on inflammation-related gene expression (qPCR) were compared against Li salts. This is the first study demonstrating that Li can increase the phosphorylation of GSK3β in glial cells in the presence of excess Mg. Furthermore, Mg-Li alloys were more effective than Li salts in downregulating IL6 and upregulating the neurotrophin GDNF. Mg had no antagonistic effects toward Li-driven downregulation of astrogliosis markers. Overall, the results provide evidence to support further studies employing Mg-Li alloys for neurological applications.

A Selective Nuclear Factor-κB Inhibitor, JSH-23, Exhibits Antidepressant-like Effects and Reduces Brain Inflammation in Rats

BACKGROUND

Accumulating evidence suggests that nuclear factor (NF)-κB is involved in the pathophysiology of mood disorders.

OBJECTIVES AND METHODS

We conducted two experimental protocols in rats to investigate the effects of a selective NF-κB inhibitor (JSH-23) on (i) lipopolysaccharide (LPS)-induced inflammation and (ii) on behavioral phenotypes in rat models of depression (sucrose consumption test and forced swim test) and mania (amphetamine-induced hyperactivity test). Additionally, we tested the effects of JSH-23 on levels of inflammatory components (interleukin-6, prostaglandin E2, nuclear phospho-p65, and tumor necrosis factor-α) in the brain.

RESULTS

Acute treatment with JSH-23 (10 mg/kg, intraperitoneally [ip]) led to potent anti-inflammatory effects in LPS-treated rats, including a diminished hypothermic response to LPS and a reduction in pro-inflammatory mediators' levels in the brain. Chronic treatment with JSH-23 (3 mg/kg, ip, once daily, for 14 days) resulted in robust antidepressant-like effects (increased sucrose consumption and decreased immobility time). The antidepressant-like effects of JSH-23 were mostly accompanied by a reduction in levels of pro-inflammatory mediators in the brain. On the other hand, JSH-23 did not reduce amphetamine-induced hyperactivity.

CONCLUSIONS

Altogether, these data suggest that NF-κB may be a potential therapeutic target for pharmacological interventions for depression.

Lupeol protect against LPS-induced neuroinflammation and amyloid beta in adult mouse hippocampus

Neuroinflammation includes the activation of immune glial cells in the central nervous system, release pro-inflammatory cytokines, which disrupt normal neural function and contribute to various neurological disorders, including Alzheimer's disease (AD), Parkinson's disease, multiple sclerosis, and stroke. AD is characterized by various factors including amyloidogenesis, synaptic dysfunction, memory impairment and neuroinflammation. Lipopolysaccharide (LPS) constitutes a vital element of membrane of the gram-negative bacterial cell, triggering vigorous neuroinflammation and facilitating neurodegeneration. Lupeol, a naturally occurring pentacyclic triterpene, has demonstrated several pharmacological properties, notably its anti-inflammatory activity. In this study, we evaluated the anti-inflammatory and anti-Alzheimer activity of lupeol in lipopolysaccharide (LPS)-injected mice model. LPS (250ug/kg) was administered intraperitoneally to C57BL/6 N male mice for 1 week to induce neuroinflammation and cognitive impairment. For biochemical analysis, acetylcholinesterase (AChE) assay, western blotting and confocal microscopy were performed. AChE, western blot and immunofluorescence results showed that lupeol treatment (50 mg/kg) along with LPS administration significantly inhibited the LPS-induced activation of neuroinflammatory mediators and cytokines like nuclear factor (NF-κB), tumor necrosis factor (TNF-α), cyclooxygenase (COX-2) and interleukin (IL-1β). Furthermore, we found that LPS-induced systemic inflammation lead to Alzheimer's symptoms as LPS treatment enhances level of amyloid beta (Aβ), amyloid precursor protein (APP), Beta-site APP cleaving enzyme (BACE-1) and hyperphosphorylated Tau (p-Tau). Lupeol treatment reversed the LPS-induced elevated level of Aβ, APP, BACE-1 and p-Tau in the hippocampus, showing anti-Alzheimer's properties. It is also determined that lupeol prevented LPS-induced synaptic dysfunction via enhanced expression of pre-and post-synaptic markers like SNAP-23, synaptophysin and PSD-95. Overall, our study shows that lupeol prevents memory impairment and synaptic dysfunction via inhibition of neuroinflammatory processes. Hence, we suggest that lupeol might be a useful therapeutic agent in prevention of neuroinflammation-induced neurological disorders like AD.

Abelson Helper Integration Site 1 haplotypes and peripheral blood expression associates with lithium response and immunomodulation in bipolar patients

RATIONALE

In bipolar disorder (BD), immunological factors play a role in the pathogenesis and treatment of the illness. Studies showed the potential link between Abelson Helper Integration Site 1 (AHI1) protein, behavioural changes and innate immunity regulation. An immunomodulatory effect was suggested for lithium, a mood stabilizer used in BD treatment.

OBJECTIVES

We hypothesized that AHI1 may be an important mediator of lithium treatment response. Our study aimed to investigate whether the AHI1 haplotypes and expression associates with lithium treatment response in BD patients. We also examined whether AHI1 expression and lithium treatment correlate with innate inflammatory response genes.

RESULTS

We genotyped seven AHI1 single nucleotide polymorphisms in 97 euthymic BD patients and found that TG haplotype (rs7739635, rs9494332) was significantly associated with lithium response. We also showed significantly increased AHI1 expression in the blood of lithium responders compared to non-responders and BD patients compared to healthy controls (HC). We analyzed the expression of genes involved in the innate immune response and inflammatory response regulation (TLR4, CASP4, CASP5, NLRP3, IL1A, IL1B, IL6, IL10, IL18) in 21 lithium-treated BD patients, 20 BD patients treated with other mood stabilizer and 19 HC. We found significantly altered expression between BD patients and HC, but not between BD patients treated with different mood stabilizers.

CONCLUSIONS

Our study suggests the involvement of AHI1 in the lithium mode of action. Moreover, mood-stabilizing treatment associated with the innate immunity-related gene expression in BD patients and only the lithium-treated BD patients showed significantly elevated expression of anti-inflammatory IL10, suggesting lithium's immunomodulatory potential.

Cerebrolysin potentiates the antidepressant effect of lithium in a rat model of depression

RATIONALE

Depression is the most prevalent psychiatric disorder worldwide. Although numerous antidepressant treatments are available, there is a serious clinical concern due to their severe side effects and the fact that some depressed patients are resistant to them. Lithium is the drug of choice for bipolar depression and has been used as adjunct therapy with other groups of antidepressants.

OBJECTIVES

The present study aims to investigate the effect of lithium augmentation with cerebrolysin on the neurochemical, behavioral and histopathological alterations induced in the reserpine model of depression.

METHODS

The animals were divided into control and reserpine-induced model of depression. The model animals were further divided into rat model of depression, rat model treated with lithium, rat model treated with cerebrolysin and rat model treated with a combination of lithium and cerebrolysin.

RESULTS

Treatment with lithium, cerebrolysin, or their combination alleviated most of the changes in behavior, oxidative stress parameters, acetylcholinesterase and monoamines in the cortex and hippocampus of the reserpine-induced model of depression. It also improved the alterations in brain-derived neurotrophic factor (BDNF) and histopathology induced by reserpine.

CONCLUSIONS

The augmentation of lithium with cerebrolysin showed a clear beneficial effect in the present model of depression suggesting the use of cerebrolysin as an adjuvant in antidepressant treatment.

Common changes in rat cortical gene expression after valproate or lithium treatment particularly affect pre- and post-synaptic pathways that regulate four neurotransmitters systems

OBJECTIVES

We have postulated that common changes in gene expression after treatment with different therapeutic classes of psychotropic drugs contribute to their common therapeutic mechanisms of action.

METHODS

To test this hypothesis, we measured levels of cortical coding and non-coding RNA using GeneChip® Rat Exon 1.0 ST Array after treatment with vehicle (chow only), chow containing 1.8 g lithium carbonate/kg (n = 10) or chow containing 12 g sodium valproate/kg (n = 10) for 28 days. Differences in levels of RNA were identified using JMP Genomics 13 and the Panther Gene Ontology Classification System was used to identify potential consequences of RNA.

RESULTS

Compared to vehicle treatment, levels of cortical RNA for 543 and 583 coding and non-coding RNAs were different after treatment with valproate and lithium, respectively. Moreover, levels of 323 coding and non-coding RNAs were altered in a highly correlated way by treatment with valproate and lithium, changes that would impact on cholinergic, glutamatergic, serotonergic and dopaminergic neurotransmission as well as on voltage gated ion channels.

CONCLUSIONS

Our study suggests that treating with mood stabilisers cause many common changes in levels of RNA which will impact on CNS function, particularly affecting post-synaptic muscarinic receptor functioning and the release of multiple neurotransmitters.

The Protective Effect of Lithium Against Rotenone may be Evolutionarily Conserved: Evidence from Eisenia fetida, a Primitive Animal with a Ganglionic Brain

Chronic exposure to stress is a non-adaptive situation that is associated with mitochondrial dysfunction and the accumulation of reactive oxygen species (ROS), especially superoxide anion (SA). This accumulation of ROS produces damage-associated molecular patterns (DAMPs), which activate chronic inflammatory states and behavioral changes found in several mood disorders. In a previous study, we observed that an imbalance of SA triggered by rotenone (Ro) exposure caused evolutionarily conserved oxi-inflammatory disturbances and behavioral changes in Eisenia fetida earthworms. These results supported our hypothesis that SA imbalance triggered by Ro exposure could be attenuated by lithium carbonate (LC), which has anti-inflammatory properties. The initial protocol exposed earthworms to Ro (30 nM) and four different LC concentrations. LC at a concentration of 12.85 mg/L decreased SA and nitric oxide (NO) levels and was chosen to perform complementary assays: (1) neuromuscular damage evaluated by optical and scanning electron microscopy (SEM), (2) innate immune inefficiency by analysis of Eisenia spp. extracellular neutrophil traps (eNETs), and (3) behavioral changes. Gene expression was also evaluated involving mitochondrial (COII, ND1), inflammatory (EaTLR, AMP), and neuronal transmission (nAchR α5). LC attenuated the high melanized deposits in the circular musculature, fiber disarrangement, destruction of secretory glands, immune inefficiency, and impulsive behavior pattern triggered by Ro exposure. However, the effects of LC and Ro on gene expression were more heterogeneous. In summary, SA imbalance, potentially associated with mitochondrial dysfunction, appears to be an evolutionary component triggering oxidative, inflammatory, and behavioral changes observed in psychiatric disorders that are inhibited by LC exposure.

Lithium co-administration with rutin improves post-stroke neurological outcomes via suppressing Gsk-3β activity in a rat model

Cerebral ischemic stroke is one of the leading causes of adult disability worldwide. Reperfusion is the only therapeutic option with a lot of side effects. In the current study, we investigated the efficacy of rutin and lithium co-treatment in improving post-stroke neurological outcomes in a transient global cerebral ischemia-reperfusion injury rat model. Middle-aged male rats were subjected to transient global cerebral ischemia-reperfusion. NORT and Y-maze were used to assess the cognitive processes. Lipid peroxidation, protein carbonylation, and nitric oxide assays were performed to study oxidative stress. The excitotoxicity index was calculated by HPLC. Real time-PCR and western blotting were performed to study gene and protein expressions. The co-administration of rutin and lithium improved the overall survival, recognition memory, spatial working memory, and neurological score following cerebral ischemia-reperfusion in rats. Further, a marked decrease in malonaldehyde, protein carbonyls, and nitric oxide levels was observed following combined treatment. The mRNA expression of antioxidant (Hmox1 and Nqo1) and pro-inflammatory (Il2, Il6, and Il1β) markers were significantly attenuated in the rutin and lithium co-administrated group. The treatment inhibited the Gsk-3β and maintained a normal pool of the downstream β-catenin and Nrf2 proteins. The results revealed that co-administration of rutin and lithium had a neuroprotective potential, suggesting it to be a viable treatment to overcome post-stroke deaths and neurological complications.

Vitamin E Analog Trolox Attenuates MPTP-Induced Parkinson's Disease in Mice, Mitigating Oxidative Stress, Neuroinflammation, and Motor Impairment

Trolox is a potent antioxidant and a water-soluble analog of vitamin E. It has been used in scientific studies to examine oxidative stress and its impact on biological systems. Trolox has been shown to have a neuroprotective effect against ischemia and IL-1β-mediated neurodegeneration. In this study, we investigated the potential protective mechanisms of Trolox against a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. Western blotting, immunofluorescence staining, and ROS/LPO assays were performed to investigate the role of trolox against neuroinflammation, the oxidative stress mediated by MPTP in the Parkinson's disease (PD) mouse model (wild-type mice (C57BL/6N), eight weeks old, average body weight 25-30 g). Our study showed that MPTP increased the expression of α-synuclein, decreased tyrosine hydroxylase (TH) and dopamine transporter (DAT) levels in the striatum and substantia nigra pars compacta (SNpc), and impaired motor function. However, Trolox treatment significantly reversed these PD-like pathologies. Furthermore, Trolox treatment reduced oxidative stress by increasing the expression of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Lastly, Trolox treatment inhibited the activated astrocytes (GFAP) and microglia (Iba-1), also reducing phosphorylated nuclear factor-κB, (p-NF-κB) and tumor necrosis factor-alpha (TNF-α) in the PD mouse brain. Overall, our study demonstrated that Trolox may exert neuroprotection on dopaminergic neurons against MPTP-induced oxidative stress, neuroinflammation, motor dysfunction, and neurodegeneration.

Evaluation of the therapeutic potential of cerebrolysin and/or lithium in the male Wistar rat model of Parkinson's disease induced by reserpine

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease worldwide and represents a challenge for clinicians. The present study aims to investigate the effects of cerebrolysin and/or lithium on the behavioral, neurochemical and histopathological alterations induced by reserpine as a model of PD. The rats were divided into control and reserpine-induced PD model groups. The model animals were further divided into four subgroups: rat PD model, rat PD model treated with cerebrolysin, rat PD model treated with lithium and rat PD model treated with a combination of cerebrolysin and lithium. Treatment with cerebrolysin and/or lithium ameliorated most of the alterations in oxidative stress parameters, acetylcholinesterase and monoamines in the striatum and midbrain of reserpine-induced PD model. It also ameliorated the changes in nuclear factor-kappa and improved the histopathological picture induced by reserpine. It could be suggested that cerebrolysin and/or lithium showed promising therapeutic potential against the variations induced in the reserpine model of PD. However, the ameliorating effects of lithium on the neurochemical, histopathological and behavioral alterations induced by reserpine were more prominent than those of cerebrolysin alone or combined with lithium. It can be concluded that the antioxidant and anti-inflammatory effects of both drugs played a significant role in their therapeutic potency.

Nose-to-brain delivery of galantamine loaded nanospray dried polyacrylic acid/taurodeoxycholate mixed matrix as a protective therapy in lipopolysaccharide-induced Alzheimer's in mice model

One of the promising drug delivery approaches is performed by nanosizing the administered drug product using the nanospray drying technique. In this study, a combination of several formulation factors was integrated and exploited to augment the bioavailability of galantamine hydrobromide (GAL) via the intranasal route. Nanosized polymeric particles were fabricated using the mucoadhesive polymer, polyacrylic acid (PAA), and the permeability booster, sodium taurodeoxycholate (TDC). First, a preliminary study was conducted to adjust the nanospray drying conditions. Then, formulations were prepared on the basis of a mixed factorial experimental design and further analyzed using Design Expert® software. Different responses were investigated: particle size, polydispersity index, spray rate, drying efficiency, and percent yield. The optimized formulation was further assessed for physical morphology using the scanning electron microscope, flowability, in vitro drug release, and in vivo brain cell uptake using confocal laser scanning microscopy. The promising formulation (F6), composed of equal ratio of PAA and TDC and 20 mg GAL, exhibited a particle size of 185.55 ± 4.3 nm, polydispersity index of 0.413 ± 0.02, and yield-value of 69.58 ± 5.82 %. It also displayed good flowability, complete drug release within 2 h, and enhanced in vivo fluorescent dye uptake and penetration in brain cells. The efficacy of the optimized formulation was examined using lipopolysaccharide-induced Alzheimer's in mice. Results revealed the advantageous influence of the optimized formulation (F6) through downregulation of NF-κβ, IL-1β and GFAP as well as upregulating TGF-1β in adult mice.

Is lithium neuroprotective? An updated mechanistic illustrated review

Neurodegeneration is a pathological process characterized by progressive neuronal impairment, dysfunction, and loss due to mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Many studies have shown that lithium protects against neurodegeneration. Herein, we summarize recent clinical and laboratory studies on the neuroprotective effects of lithium against neurodegeneration and its potential to modulate mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Recent findings indicate that lithium regulates critical intracellular pathways such as phosphatidylinositol-3 (PI3)/protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3β) and PI3/Akt/response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF). We queried PubMed, Web of Science, Scopus, Elsevier, and other related databases using search terms related to lithium and its neuroprotective effect in various neurodegenerative diseases and events from January 2000 to May 2022. We reviewed the major findings and mechanisms proposed for the effects of lithium. Lithium's neuroprotective potential against neural cell degeneration is mediated by inducing anti-inflammatory factors, antioxidant enzymes, and free radical scavengers to prevent mitochondrial dysfunction. Lithium effects are regulated by two essential pathways: PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF. Lithium acts as a neuroprotective agent against neurodegeneration by preventing inflammation, oxidative stress, apoptosis, and mitochondrial dysfunction using PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF signaling pathways.

GSK3β Inhibition by Phosphorylation at Ser389 Controls Neuroinflammation

The inhibition of Glycogen Synthase Kinase 3 β (GSK3β) by Ser⁹ phosphorylation affects many physiological processes, including the immune response. However, the consequences of GSK3β inhibition by alternative Ser³⁸⁹ phosphorylation remain poorly characterized. Here we have examined neuroinflammation in GSK3β Ser³⁸⁹ knock-in (KI) mice, in which the phosphorylation of Ser³⁸⁹ GSK3β is impaired. The number of activated microglia/infiltrated macrophages, astrocytes, and infiltrated neutrophils was significantly higher in these animals compared to C57BL/6J wild-type (WT) counterparts, which suggests that the failure to inactivate GSK3β by Ser³⁸⁹ phosphorylation results in sustained low-grade neuroinflammation. Moreover, glial cell activation and brain infiltration of immune cells in response to lipopolysaccharide (LPS) failed in GSK3β Ser³⁸⁹ KI mice. Such effects were brain-specific, as peripheral immunity was not similarly affected. Additionally, phosphorylation of the IkB kinase complex (IKK) in response to LPS failed in GSK3β Ser³⁸⁹ KI mice, while STAT3 phosphorylation was fully conserved, suggesting that the NF-κB signaling pathway is specifically affected by this GSK3β regulatory pathway. Overall, our findings indicate that GSK3β inactivation by Ser³⁸⁹ phosphorylation controls the brain inflammatory response, raising the need to evaluate its role in the progression of neuroinflammatory pathologies.

Low-Dose Aspirin Augments the Anti-Inflammatory Effects of Low-Dose Lithium in Lipopolysaccharide-Treated Rats

Mounting evidence suggests that immune-system dysfunction and inflammation play a role in the pathophysiology and treatment of mood-disorders in general and of bipolar disorder in particular. The current study examined the effects of chronic low-dose aspirin and low-dose lithium (Li) treatment on plasma and brain interleukin-6 and tumor necrosis factor-α production in lipopolysaccharide (LPS)-treated rats. Rats were fed regular or Li-containing food (0.1%) for six weeks. Low-dose aspirin (1 mg/kg) was administered alone or together with Li. On days 21 and 42 rats were injected with 1 mg/kg LPS or saline. Two h later body temperature was measured and rats were sacrificed. Blood samples, the frontal-cortex, hippocampus, and the hypothalamus were extracted. To assess the therapeutic potential of the combined treatment, rats were administered the same Li + aspirin protocol without LPS. We found that the chronic combined treatment attenuated LPS-induced hypothermia and significantly reduced plasma and brain cytokine level elevation, implicating the potential neuroinflammatory diminution purportedly present among the mentally ill. The combined treatment also significantly decreased immobility time and increased struggling time in the forced swim test, suggestive of an antidepressant-like effect. This preclinical evidence provides a potential approach for treating inflammation-related mental illness.

Sex-specific responses of the pubertal neuroimmune axis in CD-1 mice

The mechanistic relationship between the sexually dimorphic neuroimmune system and the sex-specific outcomes of a pubertal immune challenge is unclear. Therefore, we examined sex differences in the progression of cytotoxic microglial responses and blood-brain barrier (BBB) disruption to a peripubertal lipopolysaccharide (LPS) treatment in brain regions relevant to stress responses and cognitive function. Six-week-old (i.e., stress-sensitive pubertal period) male and female CD-1 mice were treated with LPS (1.5 ​mg/kg body weight, ip) or 0.9% saline (LPS-matched volume, ip). Sex and treatment differences in microglial (Iba1⁺) and apoptotic neuronal (caspase-3⁺/NeuN⁺) and non-neuronal (caspase-3⁺/NeuN⁻) expression were examined in the hippocampus, medial prefrontal cortex (mPFC), and paraventricular nucleus 24 ​h (sickness), one week (symptomatic recovery) and four weeks (early adulthood) post-treatment (n ​= ​8/group). Microglial morphology was quantified with fractal analyses. Group differences in BBB permeability to ¹⁴C-sucrose were examined 24 ​h (whole-brain, hippocampus, prefrontal cortex, hypothalamus, and cerebellum) and one week (whole-brain) post-treatment. The acute effects of pubertal LPS were specific to females (i.e., global BBB disruption, altered microglial expression and morphology in the mPFC and hippocampus, increased hippocampal apoptosis). The residual effects of pubertal LPS-induced sickness observed in microglia persisted into adulthood in a sex- and region-specific manner. In addition to highlighting these sex-specific responses of the pubertal neuroimmune system, we report baseline region-specific sex differences in microglia spanning puberty through adulthood. We propose that these sex differences in neuroimmune-neurovascular interactions during the stress-sensitive pubertal period create sex biases in stress-related disorders of brain and behaviour.

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Pubertal LPS alters baseline sex differences in microglial numbers and morphology.

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Pubertal CD-1 mice mount sexually dimorphic neuroimmune responses to systemic LPS.

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Treatment effects on microglial expression and morphology differ by sex and region.

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The acute LPS-induced effects were specific to females.

Cadmium, an Environmental Contaminant, Exacerbates Alzheimer's Pathology in the Aged Mice's Brain

Cadmium (Cd) is an environmental contaminant, which is a potential risk factor in the progression of aging-associated neurodegenerative diseases. Herein, we have assessed the effects of chronic administration of Cd on cellular oxidative stress and its associated Alzheimer's disease (AD) pathologies in animal models. Two groups of mice were used, one group administered with saline and the other with Cd (1 mg/kg/day; intraperitoneally) for 3 months. After behavioral studies, molecular/biochemical (Immunoblotting, ELISAs, ROS, LPO, and GSH assays) and morphological analyses were performed. We observed an exacerbation of memory and synaptic deficits in chronic Cd-injected mice. Subacute and chronic Cd escalated reactive oxygen species (ROS), suppressed the master antioxidant enzymes, e.g., nuclear factor-erythroid 2-related factor 2 and heme oxygenase-1, and evoked the stress kinase phospho-c-Jun N-terminal kinase 1 signaling pathways, which may escalate AD pathologies possibly associated with amyloidogenic processes. These findings suggest the regulation of oxidative stress/ROS and its associated amyloid beta pathologies for targeting the Cd-exacerbated AD pathogenesis. In addition, these preclinical animal studies represent a paradigm for epidemiological studies of the human population exposed to chronic and subacute administration of Cd, suggesting avoiding environmental contaminants.

Nicotinamide Ameliorates Amyloid Beta-Induced Oxidative Stress-Mediated Neuroinflammation and Neurodegeneration in Adult Mouse Brain

Alzheimer’s disease (AD) is the most predominant age-related neurodegenerative disease, pathologically characterized by the accumulation of aggregates of amyloid beta Aβ_1–42 and tau hyperphosphorylation in the brain. It is considered to be the primary cause of cognitive dysfunction. The aggregation of Aβ_1–42 leads to neuronal inflammation and apoptosis. Since vitamins are basic dietary nutrients that organisms need for their growth, survival, and other metabolic functions, in this study, the underlying neuroprotective mechanism of nicotinamide (NAM) Vitamin B3 against Aβ_1–42 -induced neurotoxicity was investigated in mouse brains. Intracerebroventricular (i.c.v.) Aβ_1–42 injection elicited neuronal dysfunctions that led to memory impairment and neurodegeneration in mouse brains. After 24 h after Aβ_1–42 injection, the mice were treated with NAM (250 mg/kg intraperitoneally) for 1 week. For biochemical and Western blot studies, the mice were directly sacrificed, while for confocal and “immunohistochemical staining”, mice were perfused transcardially with 4% paraformaldehyde. Our biochemical, immunofluorescence, and immunohistochemical results showed that NAM can ameliorate neuronal inflammation and apoptosis by reducing oxidative stress through lowering malondialdehyde and 2,7-dichlorofluorescein levels in an Aβ_1–42-injected mouse brains, where the regulation of p-JNK further regulated inflammatory marker proteins (TNF-α, IL-1β, transcription factor NF-kB) and apoptotic marker proteins (Bax, caspase 3, PARP1). Furthermore, NAM + Aβ treatment for 1 week increased the amount of survival neurons and reduced neuronal cell death in Nissl staining. We also analyzed memory dysfunction via behavioral studies and the analysis showed that NAM could prevent Aβ_1–42 -induced memory deficits. Collectively, the results of this study suggest that NAM may be a potential preventive and therapeutic candidate for Aβ_1–42 -induced reactive oxygen species (ROS)-mediated neuroinflammation, neurodegeneration, and neurotoxicity in an adult mouse model.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

Vanillic Acid, a Bioactive Phenolic Compound, Counteracts LPS-Induced Neurotoxicity by Regulating c-Jun N-Terminal Kinase in Mouse Brain

The receptor for advanced glycation end products (RAGE), a pattern recognition receptor signaling event, has been associated with several human illnesses, including neurodegenerative diseases, particularly in Alzheimer’s disease (AD). Vanillic acid (V.A), a flavoring agent, is a benzoic acid derivative having a broad range of biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. However, the underlying molecular mechanisms of V.A in exerting neuroprotection are not well investigated. The present study aims to explore the neuroprotective effects of V.A against lipopolysaccharides (LPS)-induced neuroinflammation, amyloidogenesis, synaptic/memory dysfunction, and neurodegeneration in mice brain. Behavioral tests and biochemical and immunofluorescence assays were applied. Our results indicated increased expression of RAGE and its downstream phospho-c-Jun n-terminal kinase (p-JNK) in the LPS-alone treated group, which was significantly reduced in the V.A + LPS co-treated group. We also found that systemic administration of LPS-injection induced glial cells (microglia and astrocytes) activation and significantly increased expression level of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-KB) and secretion of proinflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1 β (IL1-β), and cyclooxygenase (COX-2). However, V.A + LPS co-treatment significantly inhibited the LPS-induced activation of glial cells and neuroinflammatory mediators. Moreover, we also noted that V.A treatment significantly attenuated LPS-induced increases in the expression of AD markers, such as β-site amyloid precursor protein (APP)–cleaving enzyme 1 (BACE1) and amyloid-β (Aβ). Furthermore, V.A treatment significantly reversed LPS-induced synaptic loss via enhancing the expression level of pre- and post-synaptic markers (PSD-95 and SYP), and improved memory performance in LPS-alone treated group. Taken together; we suggest that neuroprotective effects of V.A against LPS-induced neurotoxicity might be via inhibition of LPS/RAGE mediated JNK signaling pathway; and encourage future studies that V.A would be a potential neuroprotective and neurotherapeutic candidate in various neurological disorders.

Anxiogenic-like effect of chronic lipopolysaccharide is associated with increased expression of matrix metalloproteinase 9 in the rat amygdala

Pathways by which inflammatory stimuli influence behaviors can involve changes in neuronal plasticity, however, the evidence for this is still insufficient. This study aimed to evaluate the effects of chronic lipopolysaccharide (LPS) injected alone or together with tetracycline antibiotic doxycycline (Dox) on the levels of Iba-1, BDNF, Bcl-xL and MMP-9 in brain regions in relation to stress-induced behaviors in the elevated plus-maze (EPM). LPS injected to adult rats every 2 days for a total of 7 injections reduced body weight gain, increased spleen and adrenal weights, decreased locomotor activity, and increased anxiety-like behavior. These effects were associated with increased expression of Iba-1, a well-known marker for activated microglia, in most brain regions investigated. Co-treatment of LPS with Dox attenuated LPS-induced microglial activation and behavioral changes, supporting their relation to the neuroinflammation. LPS administration also produced pro-apoptotic changes in the brain. In the hypothalamus and striatum, the levels of anti-apoptotic protein Bcl-xL were decreased, whereas in the amygdala, a significant increase in MMP-9 protein levels was observed. The levels of Iba-1 as well as MMP-9 in the amygdala positively correlated with the numbers of defecation. The data suggest that mechanisms of anxiety associated with neuroinflammation may involve the increase in MMP-9 levels in the amygdala.

TLR4-mediated hippocampal MMP/TIMP imbalance contributes to the aggravation of perioperative neurocognitive disorder in db/db mice

Although type 2 diabetes is an important predictor of perioperative neurocognitive disorder (PND), little is currently known about its mechanism of action. Adult male db/db and db/m mice were subjected to four different treatments, including either sham or tibial fracture surgery as well as intraperitoneal injection of vehicle or TAK-242 (the selective inhibitor of TLR4) at 1, 24, and 48 h after surgery. The fear conditioning test was performed to detect cognitive impairment on post-operative day (POD) 3. The hippocampus was collected on POD 1 for western-blots and on POD 3 for western-blots, transmission electron microscopy, and electrophysiological experiments. Toll-like receptor 4 (TLR4) inhibition reversed more profound decline in the freezing behavior of db/db mice on POD 3. The surgery reduced the slope of hippocampal field excitatory postsynaptic potentials, and induced blood-brain barrier (BBB) damage in db/db mice on POD 3. The surgery also increased protein levels of TLR4, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, albumin, matrix metalloproteinase (MMP)-2, and MMP-9, and decreased protein levels of claudin-5, occludin, tissue inhibitor of matrix metalloproteinase (TIMP)-1, and TIMP-2 in the hippocampus of db/db and db/m mice. These changes were all reversed by TAK-242 treatment. At last, compared with those in post-operative db/m mice, the surgery increased protein levels of TLR4, TNF-α, and IL-1β, decreased protein levels of claudin-5 and occludin, and sustained the MMP/TIMP imbalance in the hippocampus of db/db mice on POD 3. Our results suggest that TLR4-mediated aggravated hippocampal MMP/TIMP imbalance, BBB disruption, sustained inflammatory cytokine release, and impairment of long-term potentiation play a key role in tibial fracture surgery-induced persistent PND in db/db mice.

Structural and biochemical imaging reveals systemic LPS-induced changes in the rat brain

Despite mounting evidence for the role of inflammation in Major Depressive Disorder (MDD), in vivo preclinical investigations of inflammation-induced negative affect using whole brain imaging modalities are scarce, precluding a valid model within which to evaluate pharmacological interventions. Here we used an E. coli lipopolysaccharide (LPS)-based model of inflammation-induced depressive signs in rats to explore brain changes using multimodal neuroimaging methods. During the acute phase of the LPS response (2 h post injection), prior to the emergence of a task-quantifiable depressive phenotype, striatal glutamine levels and splenial, retrosplenial, and peri-callosal hippocampal cortex volumes were greater than at baseline. LPS-induced depressive behaviors observed at 24 h, however, occurred concurrently with lower than control levels of striatal glutamine and a reversibility of volume expansion (i.e., shrinkage of splenial, retrosplenial, and peri-callosal hippocampal cortex to baseline volumes). In both striatum and hippocampus at 24 h, mRNA expression in LPS relative to control animals demonstrated alterations in enzymes and transporters regulating glutamine homeostasis. Collectively, the observed behavioral, in vivo structural and metabolic, and mRNA expression alterations suggest a critical role for astrocytic regulation of inflammation-induced depressive behaviors.

Taxane-induced neurotoxicity: Pathophysiology and therapeutic perspectives

Taxane-derived drugs are antineoplastic agents used for the treatment of highly common malignancies. Paclitaxel and docetaxel are the most commonly used taxanes; however, other drugs and formulations have been used, such as cabazitaxel and nab-paclitaxel. Taxane treatment is associated with neurotoxicity, a well-known and relevant side effect, very prevalent amongst patients undergoing chemotherapy. Painful peripheral neuropathy is the most dose-limiting side effect of taxanes, affecting up to 97% of paclitaxel-treated patients. Central neurotoxicity is an emerging side effect of taxanes and it is characterized by cognitive impairment and encephalopathy. Besides impairing compliance to chemotherapy treatment, taxane-induced neurotoxicity (TIN) can adversely affect the patient's life quality on a long-term basis. Despite the clinical relevance, not many reviews have comprehensively addressed taxane-induced neurotoxicity when they are used therapeutically. This article provides an up-to-date review on the pathophysiology of TIN and the novel potential therapies to prevent or treat this side effect.

The Neuroprotective Effect of Zingiber cassumunar Roxb. Extract on LPS-Induced Neuronal Cell Loss and Astroglial Activation within the Hippocampus

The systemic administration of lipopolysaccharide (LPS) has been recognized to induce neuroinflammation which plays a significant role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In this study, we aimed to determine the protective effect of Zingiber cassumunar (Z. cassumunar) or Phlai (in Thai) against LPS-induced neuronal cell loss and the upregulation of glial fibrillary acidic protein (GFAP) of astrocytes in the hippocampus. Adult male Wistar rats were orally administered with Z. cassumunar extract at various doses (50, 100, and 200 mg/kg body weight) for 14 days before a single injection of LPS (250 μg/kg/i.p.). The results indicated that LPS-treated animals exhibited neuronal cell loss and the activation of astrocytes and also increased proinflammatory cytokine interleukin- (IL-) 1β in the hippocampus. Pretreatment with Z. cassumunar markedly reduced neuronal cell loss in the hippocampus. In addition, Z. cassumunar extract at a dose of 200 mg/kg BW significantly suppressed the inflammatory response by reducing the expression of GFAP and IL-1ß in the hippocampus. Therefore, the results suggested that Z. cassumunar extract might be valuable as a neuroprotective agent in neuroinflammation-induced brain damage. However, further investigations are essential to validate the possible active ingredients and mechanisms of its neuroprotective effect.

Dihydroartemisinin ameliorates LPS-induced neuroinflammation by inhibiting the PI3K/AKT pathway

Neuroinflammation can cause multiple neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Recent studies have shown that the artemisinin derivative dihydroartemisinin (DHA) can be used as an immunomodulatory, anti-inflammatory and anti-tumor agent. The anti-neuroinflammatory effects of DHA were evaluated in our study, and the underlying mechanisms were explored using the Morris water maze test (MWMT), Open-field test (OFT) and Closed-field test (CFT), Elevated plus maze test (EPMT), Nissl Staining, Immunofluorescence analysis, RT-PCR, and Western Blot. Our results show that DHA significantly inhibits LPS-induced inflammation and attenuates LPS-induced behavioral and memory disorders. 1. Behavioral test results: 1) in the water maze test, the mice in the LPS group showed increased escape latency and length of the movement path on the third day; they also had a decreased number of crossings of the target quadrant after the platform was removed on the 5th day and remained in the target quadrant for less time; 2) in the open- and closed-field experiment, the number of activities and activities in the open-field were significantly reduced; 3) in the elevated cross maze experiment, LPS-treated mice exhibited a significant reduction in the number of times and the time to enter the open arm; the above behavior was reversed after DHA treatment. 2. Nissl staining results: compared with the Control group, the LPS group showed significant damage, and the number of damaged cells in the hippocampal CA1, CA2, CA3 and DG regions was increased; DHA treatment reduced cell damage. 3. RT-PCR results: compared with the Control group, the LPS group showed increased expression of IL-1β and IL-6 but decreased expression after DHA treatment. 4. GFAP fluorescent staining: compared with the control group, the corresponding reactivity of positive cells in the LPS-induced group was increased in the CA1-CA3 and DG regions of the hippocampus; compared with the LPS-induced mice, cells in the LPS + DHA group showed significantly reduced reactivity (GFAP). 5. Western blot results: compared with the Control group, the LPS group showed increased expression of P-PI3K/PI3K, P-AKT/AKT, IL-6 and TNFα and a decreased expression of P-PI3K/PI3K, IL-6, TNF and P-AKT/AKT after DHA treatment. Our findings provide direct evidence for the potential use of DHA in the treatment of neuroinflammatory diseases.

Inhibition of HDAC6 alleviating lipopolysaccharide-induced p38MAPK phosphorylation and neuroinflammation in mice

Context: Researchers in a variety of fields have extensively focused on histone deacetylase 6 (HDAC6) due to its aggravation of inflammatory reaction. However, relevant studies examining whether HDAC6 could exacerbate lipopolysaccharide (LPS)-induced inflammation are still lacking. Objective: We assessed the role of HDAC6 in LPS-induced brain inflammation and used the HDAC6-selective inhibitor Tubastatin A (TBSA) to investigate the potential mechanisms further. Materials and methods: Brain inflammation was induced in Kunming (KM) mice via intraperitoneal (I.P.), injection of Lipopolysaccharide (LPS) (1 mg/kg), the TBSA (0.5 mg/kg) was delivered via intraperitoneal. The phosphorylated p38 (p-p38) Mitogen-activated protein kinases (MAPK) and expression of typical inflammatory mediators, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in both the hippocampus and cortex, were examined by immunoblotting. Nissl staining was used to detect the neuronal damage in the hippocampus and the cortex. Results: About 1 mg/kg LPS via daily intraperitoneal (I.P.) injections for 12 days significantly increased p38 MAPK phosphorylation, TNF-α and IL-6 expression, and neuronal loss. However, 0.5 mg/kg TBSA (three days before LPS treatment) by I.P. injections for 15 days could reverse the above results. Conclusions: This present study provided evidence that TBSA significantly suppressed LPS-induced neuroinflammation and the expression of p-p38. Results derived from our study might help reveal the effective targeting strategies of LPS-induced brain inflammation through inhibiting HDAC6.

Ameliorative effect of lithium chloride against d-galactose induced behavioral and memory impairment, oxidative stress and alteration in serotonin function in rats

BACKGROUND

Aging is a phenomenon that all living organisms surely face. d-galactose (D-gal) has been used to develop an aging model of brain. Lithium (Li) has been proposed to have neuroprotective properties in relation to several neurological disorders. The goal of the current studyis to evaluate the effect of Lithium Chloride (LiCl) on D-gal induced neurological disorders and oxidative stress.

METHODS

Rats were treated with D-gal at a dose of 300 mg/ml/kg and various doses of LiCl (20, 40 and 80 mg/ml/kg) for 14 days. After that behavioral analysis (Elevated plus maze (EPM); Light dark box test (LDT); Morris water maze (MWM); Forced swim test (FST)) were performed. Animals were decapitated after behavioral tests and brain samples were collected for biochemical (malondialdehyde (MDA); superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase (GPx); acetylcholiesterase (AChE)) and neurochemical analysis (5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA)).

RESULTS

The results showed that administration of LiCl at all doses ameliorates D-gal induced, decreased time spent in the open arm and light box in EPM and LDT respectively, increased immobility in FST, increased latency escape in MWM, increased MDA levels, decreased antioxidant enzyme, increased AChE activity and decreased 5-HT metabolism.

CONCLUSIONS

In conclusion, the present study indicated that D-gal induced anxiety/depression like symptoms and memory impairment were ameliorated by LiCl (at all doses) possibly via its antioxidant effects and normalizing 5-HT function.

Putative neuroprotective pharmacotherapies to target the staged progression of mental illness

AIM

Neuropsychiatric disorders including depression, bipolar and schizophrenia frequently exhibit a neuroprogressive course from prodrome to chronicity. There are a range of agents exhibiting capacity to attenuate biological mechanisms associated with neuroprogression. This review will update the evidence for putative neuroprotective agents including clinical efficacy, mechanisms of action and limitations in current assessment tools, and identify novel agents with neuroprotective potential.

METHOD

Data for this review were sourced from online databases PUBMED, Embase and Web of Science. Only data published since 2012 were included in this review, no data were excluded based on language or publication origin.

RESULTS

Each of the agents reviewed inhibit one or multiple pathways of neuroprogression including: inflammatory gene expression and cytokine release, oxidative and nitrosative stress, mitochondrial dysfunction, neurotrophin dysregulation and apoptotic signalling. Some demonstrate clinical efficacy in preventing neural damage or loss, relapse or cognitive/functional decline. Agents include: the psychotropic medications lithium, second generation antipsychotics and antidepressants; other pharmacological agents such as minocycline, aspirin, cyclooxygenase-2 inhibitors, statins, ketamine and alpha-2-delta ligands; and others such as erythropoietin, oestrogen, leptin, N-acetylcysteine, curcumin, melatonin and ebselen.

CONCLUSIONS

Signals of evidence of clinical neuroprotection are evident for a number of candidate agents. Adjunctive use of multiple agents may present a viable avenue to clinical realization of neuroprotection. Definitive prospective studies of neuroprotection with multimodal assessment tools are required.

Lithium chloride with immunomodulatory function for regulating titanium nanoparticle-stimulated inflammatory response and accelerating osteogenesis through suppression of MAPK signaling pathway

Background

Wear particle-induced inflammatory osteolysis and the consequent aseptic loosening constitute the leading reasons for prosthesis failure and revision surgery. Several studies have demonstrated that the macrophage polarization state and immune response play critical roles in periprosthetic osteolysis and tissue repair, but the immunomodulatory role of lithium chloride (LiCl), which has a protective effect on wear particle-induced osteolysis by suppressing osteoclasts and attenuating inflammatory responses, has never been investigated.

Methods

In this work, the immunomodulatory capability of LiCl on titanium (Ti) nanoparticle-stimulated transformation of macrophage phenotypes and the subsequent effect on osteogenic differentiation were investigated. We first speculated that LiCl attenuated Ti nanoparticle-stimulated inflammation responses by driving macrophage polarization and generating an immune micro-environment to improve osteogenesis. Furthermore, a metal nanoparticle-stimulated murine air pouch inflammatory model was applied to confirm this protective effect in vivo.

Results

The results revealed that metal nanoparticles significantly activate M1 phenotype (proinflammatory macrophage) expression and increase proinflammatory cytokines secretions in vitro and in vivo, whereas LiCl drives macrophages to the M2 phenotype (anti-inflammatory macrophage) and increases the release of anti-inflammatory and bone-related cytokines. This improved the osteogenic differentiation capability of rat bone marrow mesenchymal stem cells (rBMSCs). In addition, we also provided evidence that LiCl inhibits the phosphorylation of the p38 mitogen-activated protein kinase (p38) and extracellular signal-regulated kinase (ERK) pathways in wear particle-treated macrophages.

Conclusion

LiCl has the immunomodulatory effects to alleviate Ti nanoparticle-mediated inflammatory reactions and enhance the osteogenic differentiation of rBMSCs by driving macrophage polarization. Thus, LiCl may be an effective therapeutic alternative for preventing and treating wear debris-induced inflammatory osteolysis.

Astrocytes are direct cellular targets of lithium treatment: novel roles for lysyl oxidase and peroxisome-proliferator activated receptor-γ as astroglial targets of lithium

Astrocytes are multifunctional glial cells that play essential roles in supporting synaptic signalling and white matter-associated connectivity. There is increasing evidence that astrocyte dysfunction is involved in several brain disorders, including bipolar disorder (BD), depression and schizophrenia. The mood stabiliser lithium is a frontline treatment for BD, but the mechanisms of action remain unclear. Here, we demonstrate that astrocytes are direct targets of lithium and identify unique astroglial transcriptional networks that regulate specific molecular changes in astrocytes associated with BD and schizophrenia, together with Alzheimer's disease (AD). Using pharmacogenomic analyses, we identified novel roles for the extracellular matrix (ECM) regulatory enzyme lysyl oxidase (LOX) and peroxisome proliferator-activated receptor gamma (PPAR-γ) as profound regulators of astrocyte morphogenesis. This study unravels new pathophysiological mechanisms in astrocytes that have potential as novel biomarkers and potential therapeutic targets for regulating astroglial responses in diverse neurological disorders.

Phytomedicine-Based Potent Antioxidant, Fisetin Protects CNS-Insult LPS-Induced Oxidative Stress-Mediated Neurodegeneration and Memory Impairment

Phytomedicine based natural flavonoids have potent antioxidant, anti-inflammatory, and neuroprotective activities against neurodegenerative diseases. The aim of the present study is to investigate the potent neuroprotective and antioxidant potential effects of fisetin (natural flavonoid) against central nervous system (CNS)-insult, lipopolysaccharide (LPS)-induced reactive oxygen species (ROS), neuroinflammation, neurodegeneration, and synaptic/memory deficits in adult mice. The mice were injected intraperitoneally (i.p.) with LPS (250 μg/kg/day for 1 week) and a fisetin dosage regimen (20 mg/kg/day i.p. for 2 weeks, 1 week pre-treated to LPS and 1 week co-treated with LPS). Behavioral tests, and biochemical and immunofluorescence assays were applied. Our results revealed that fisetin markedly abrogated the LPS-induced elevated ROS/oxidative stress and activated phosphorylated c-JUN N-terminal Kinase (p-JNK) in the adult mouse hippocampus. Fisetin significantly alleviated LPS-induced activated gliosis. Moreover, fisetin treatment inhibited LPS-induced activation of the inflammatory Toll-like Receptors (TLR4)/cluster of differentiation 14 (CD14)/phospho-nuclear factor kappa (NF-κB) signaling and attenuated other inflammatory mediators (tumor necrosis factor-α (TNF-α), interleukin-1 β (IL1-β), and cyclooxygenase (COX-2). Furthermore, immunoblotting and immunohistochemical results revealed that fisetin significantly reversed LPS-induced apoptotic neurodegeneration. Fisetin improved the hippocampal-dependent synaptic and memory functions in LPS-treated adult mice. In summary, our results strongly recommend that fisetin, a natural potent antioxidant, and neuroprotective phytomedicine, represents a promising, valuable, and therapeutic candidate for the prevention and treatment of neurodegenerative diseases.

Caffeine Modulates Cadmium-Induced Oxidative Stress, Neuroinflammation, and Cognitive Impairments by Regulating Nrf-2/HO-1 In Vivo and In Vitro

Cadmium (Cd), a nonbiodegradable heavy metal and one of the most neurotoxic environmental and industrial pollutants, promotes disturbances in major organs and tissues following both acute and chronic exposure. In this study, we assessed the neuroprotective potential of caffeine (30 mg/kg) against Cd (5 mg/kg)-induced oxidative stress-mediated neuroinflammation, neuronal apoptosis, and cognitive deficits in male C57BL/6N mice in vivo and in HT-22 and BV-2 cell lines in vitro. Interestingly, our findings indicate that caffeine markedly reduced reactive oxygen species (ROS) and lipid peroxidation (LPO) levels and enhanced the expression of nuclear factor-2 erythroid-2 (Nrf-2) and hemeoxygenase-1 (HO-1), which act as endogenous antioxidant regulators. Also, 8-dihydro-8-oxoguanine (8-OXO-G) expression was considerably reduced in the caffeine-treated group as compared to the Cd-treated group. Similarly, caffeine ameliorated Cd-mediated glial activation by reducing the expression of glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), and other inflammatory mediators in the cortical and hippocampal regions of the mouse brain. Moreover, caffeine markedly attenuated Cd-induced neuronal loss, synaptic dysfunction, and learning and cognitive deficits. Of note, nuclear factor-2 erythroid-2 (Nrf-2) gene silencing and nuclear factor-κB (NF-κB) inhibition studies revealed that caffeine exerted neuroprotection via regulation of Nrf-2- and NF-κB-dependent mechanisms in the HT-22 and BV-2 cell lines, respectively. On the whole, these findings reveal that caffeine rescues Cd-induced oxidative stress-mediated neuroinflammation, neurodegeneration, and memory impairment. The present study suggests that caffeine might be a potential antioxidant and neuroprotective agent against Cd-induced neurodegeneration.

Probiotic mixture of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 attenuates hippocampal apoptosis induced by lipopolysaccharide in rats

In recent years, the beneficial impact of targeted gut microbiota manipulation in various neurological disorders has become more evident. Therefore, probiotics have been considered as a promising approach to modulate brain gene expression and neuronal pathways even in some neurodegenerative diseases. The purpose of this study was to determine the effect of probiotic biotherapy with combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on the expression levels of proteins critical to neuronal apoptosis in hippocampus of lipopolysaccharide (LPS)-exposed rats. Four groups of animals (Control, LPS, Probiotic + LPS, and Probiotic) were treated with maltodextrin (placebo) or probiotic (10⁹ CFU/ml/rat) for 2 weeks by gavage. On the 15th day, a single intraperitoneal dose of saline or LPS (1 mg/kg) was injected and 4 h later, protein assessment was performed by western blotting in hippocampal tissues. LPS significantly increased the Bax, Bax/Bcl-2 ratio, and cleaved caspase-3 expression along with decreased the Bcl-2 and procaspase-3 protein levels. However, probiotic pretreatment (L. helveticus R0052 + B. longum R0175) significantly downregulated the Bax and Bax/Bcl-2 ratio accompanied with upregulated Bcl-2 expression. Prophylactic treatment with these bacteria also attenuated LPS-induced caspase-3 activation by remarkably increasing the expression of procaspase-3 while reducing the level of cleaved caspase-3 in target tissues. Our data indicate that probiotic formulation (L. helveticus R0052 + B. longum R0175) alleviated hippocampal apoptosis induced by LPS in rats via the gut-brain axis and suggest that this probiotic could play a beneficial role in some neurodegenerative conditions.

Neuroprotective Effect of Quercetin Against the Detrimental Effects of LPS in the Adult Mouse Brain

Chronic neuroinflammation is responsible for multiple neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. Lipopolysaccharide (LPS) is an essential component of the gram-negative bacterial cell wall and acts as a potent stimulator of neuroinflammation that mediates neurodegeneration. Quercetin is a natural flavonoid that is abundantly found in fruits and vegetables and has been shown to possess multiple forms of desirable biological activity including anti-inflammatory and antioxidant properties. This study aimed to evaluate the neuroprotective effect of quercetin against the detrimental effects of LPS, such as neuroinflammation-mediated neurodegeneration and synaptic/memory dysfunction, in adult mice. LPS [0.25 mg/kg/day, intraperitoneally (I.P.) injections for 1 week]-induced glial activation causes the secretion of cytokines/chemokines and other inflammatory mediators, which further activate the mitochondrial apoptotic pathway and neuronal degeneration. Compared to LPS alone, quercetin (30 mg/kg/day, I.P.) for 2 weeks (1 week prior to the LPS and 1 week cotreated with LPS) significantly reduced activated gliosis and various inflammatory markers and prevented neuroinflammation in the cortex and hippocampus of adult mice. Furthermore, quercetin rescued the mitochondrial apoptotic pathway and neuronal degeneration by regulating Bax/Bcl2, and decreasing activated cytochrome c, caspase-3 activity and cleaving PARP-1 in the cortical and hippocampal regions of the mouse brain. The quercetin treatment significantly reversed the LPS-induced synaptic loss in the cortex and hippocampus of the adult mouse brain and improved the memory performance of the LPS-treated mice. In summary, our results demonstrate that natural flavonoids such as quercetin can be beneficial against LPS-induced neurotoxicity in adult mice.

Anthocyanins Improve Hippocampus-Dependent Memory Function and Prevent Neurodegeneration via JNK/Akt/GSK3β Signaling in LPS-Treated Adult Mice

Microglia plays a critical role in the brain and protects neuronal cells from toxins. However, over-activation of microglia leads to deleterious effects. Lipopolysaccharide (LPS) has been reported to affect neuronal cells via activation of microglia as well as directly to initiate neuroinflammation. In the present study, we evaluated the anti-inflammatory and anti-oxidative effect of anthocyanins against LPS-induced neurotoxicity in an animal model and in cell cultures. Intraperitoneal injections of LPS (250 μg/kg/day for 1 week) induce ROS production and promote neuroinflammation and neurodegeneration which ultimately leads to memory impairment. However, anthocyanins treatment at a dose of 24 mg/kg/day for 2 weeks (1 week before and 1 week co-treated with LPS) prevented ROS production, inhibited neuroinflammation and neurodegeneration, and improved memory functions in LPS-treated mice. Both histological and immunoblot analysis indicated that anthocyanins reversed the activation of JNK, prevented neuroinflammation by lowering the levels of inflammatory markers (p-NF-kB, TNF-α, and IL-1β), and reduced neuronal apoptosis by reducing the expression of Bax, cytochrome c, cleaved caspase-3, and cleaved PARP-1, while increasing the level of survival proteins p-Akt, p-GSK3β, and anti-apoptotic Bcl-2 protein. Anthocyanins treatment increased the levels of memory-related pre- and post-synaptic proteins and improved the hippocampus-dependent memory in the LPS-treated mice. Overall, this data suggested that consumption of naturally derived anti-oxidant agent such as anthocyanins ameliorated several pathological events in the LPS-treated animal model and we believe that anthocyanins would be a safe therapeutic agent for slowing the inflammation-induced neurodegeneration in the brain against several diseases such as Alzheimer's disease and Parkinson's disease.

β-elemene attenuates macrophage activation and proinflammatory factor production via crosstalk with Wnt/β-catenin signaling pathway

β-elemene, extracted from Rhizoma zedoariae, has been widely used as a traditional medicine for its antitumor activity against a broad range of cancers. However, the effect of β-elemene in inflammation disorders has yet to be determined. The present study was designed to investigate the anti-inflammatory effects and potential molecular mechanisms of β-elemene in lipopolysaccharide (LPS)-induced murine macrophage cells RAW264.7. We found that the production of pro-inflammatory mediators, including interleukin-6(IL-6), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), induced by LPS was significantly suppressed by β-elemene in a dose-dependent manner in RAW264.7 macrophage cell line. Also, β-elemene inhibited LPS-induced nitric oxide synthase (iNOS) and interleukin-10 (IL-10) expression by RAW264.7, which was related to the down-regulation of Wnt/β-catenin signaling pathway. Importantly, this study demonstrates that β-catenin was significantly inhibited by β-elemene, which appeared to be largely responsible for the down-regulation of Wnt/β-catenin signaling pathway. Accordingly, the deletion of β-catenin in primary macrophages reversed β-catenin-elicited inhibition of immune response. Furthermore, β-catenin expression and Wnt/β-catenin signaling pathway induced by LPS in RAW264.7 was also significantly inhibited by α-humulene, one isomeric sesquiterpene of β-elemene. α-humulene was also found to significantly inhibit LPS-induced production of proinflammatory cytokines. However, α-humulene showed more cytotoxic ability than β-elemene. Collectively, our data illustrated that β-elemene exerted a potent inhibitory effect on pro-inflammatory meditator and cytokines production via the inactivation of β-catenin, and also demonstrated the protective functions of β-elemene in endotoxin-induced inflammation. β-elemene may serve as potential nontoxic modulatory agents for the prevention and treatment of inflammatory diseases.