Excessive intragastric alcohol administration exacerbates hepatic encephalopathy and provokes neuronal cell death in male rats with chronic liver disease.

Hepatic encephalopathy (HE) is defined as decline in neurological function during chronic liver disease (CLD). Alcohol is a major etiological factor in the pathogenesis of fibrosis/cirrhosis and has also been documented to directly impact the brain. However, the role of alcohol in the development of HE in CLD remains unclear. Here, we investigated the impact of excessive alcohol administration on neurological deterioration in rats with CLD. Starting day 7 post-BDL surgery, rats were administered alcohol twice daily (51% v/v ethanol, 3 g/kg, via gavage) for 4 weeks. Motor coordination was assessed weekly using rotarod and anxiety-like behavior was evaluated with open field and elevated plus maze at 5 weeks. Upon sacrifice, brains were collected for western blot and immunohistochemical analyses to investigate neuronal integrity and oxidative stress status. Alcohol worsened motor coordination performance and increased anxiety-like behavior in BDL rats. Impairments were associated with decreased neuronal markers of NeuN and SMI311, increased apoptotic markers of cleaved/pro-caspase-3 and Bax/Bcl2, increased necroptosis markers of pRIP3 and pMLKL, decreased total antioxidant capacity (TAC), and increased 4-hydroxynonenal (4-HNE)modified proteins in the cerebellum of BDL-alcohol rats when compared to respective controls. Immunofluorescence confirmed the colocalization of cleaved caspase-3 and pMLKL in the granular neurons of the cerebellum of BDL-alcohol rats. Excessive alcohol consumption exacerbates HE which leads to associated apoptotic and necroptotic neuronal loss in the cerebellum of BDL-alcohol rats. Additionally, higher levels of 4-HNE and decreased TAC in the cerebellum of BDL-alcohol rats suggest oxidative stress is the triggering factor of apoptotic and necroptotic neuronal loss/injury.

Flaxseed Oil (Linum usitatissimum) Prevents Cognitive and Motor Damage in Rats with Hyperammonemia.

Hyperammonemia is characterized by the excessive accumulation of ammonia in the body as a result of the loss of liver detoxification, leading to the development of hepatic encephalopathy (HE). These metabolic alterations carry cognitive and motor deficits and cause neuronal damage, with no effective treatment at present. In this study, we aimed to evaluate the effect of two subacute oral administrations of flaxseed oil (0.26 and 0.52 mL/kg) on short- and long-term memory, visuospatial memory, locomotor activity, motor coordination, and the neuronal morphology of the prefrontal cortex (PFC) via tests on Wistar rats with hyperammonemia. The goal was to identify its role in the regulation of cerebral edema, without liver damage causing cerebral failure. In contrast with an ammonium-rich diet, flaxseed oil and normal foods did not cause cognitive impairment or motor alterations, as evidenced in the short-term and visuospatial memory tests. Furthermore, the flaxseed oil treatment maintained a regular neuronal morphology of the prefrontal cortex, which represents a neuroprotective effect. We conclude that the oral administration of flaxseed oil prevents cognitive and motor impairments as well as neuronal alterations in rats with hyperammonemia, which supports the potential use of this oil to ameliorate the changes that occur in hepatic encephalopathy.

TNF-α blockage by etanercept restores spatial learning and reduces cellular degeneration in the hippocampus during liver cirrhosis.

Hepatic encephalopathy (HE) is one of the most debilitating cerebral complications of liver cirrhosis. The one-year survival of patients with liver cirrhosis and severe encephalopathy is less than 50%. Recent studies have indicated that neuroinflammation is a new player in the pathogenesis of HE, which seems to be involved in the development of cognitive impairment. In this study, we demonstrated neurobehavioral and neuropathological consequences of liver cirrhosis and tested the therapeutic potential of the tumor necrosis factor-α (TNF-α) inhibitor, etanercept. Sixty male adult Wistar albino rats (120-190 g) were allocated into four groups, where groups I and IV served as controls. Thioacetamide (TAA; 300 mg/kg) was intraperitoneally injected twice a week for five months to induce liver cirrhosis in group II (n = 20). Both TAA and etanercept (2 mg/kg) were administered to group III (n = 20). At the end of the experiment, spatial learning was assessed using Morris water maze. TNF-α was detected in both serum and hippocampus. The excised brains were also immunohistochemically stained with glial fibrillary acidic protein (GFAP) to estimate both the number and integrity of hippocampal astrocytes. Ultrastructural changes in the hippocampus were characterized by transmission electron microscopy. The results showed that blocking TNF-α by etanercept was accompanied by a lower TNF-α expression and a higher number of GFAP-positive astrocytes in the hippocampus. Etanercept intervention alleviated the neuronal and glial degenerative changes and impeded the deterioration of spatial learning ability. In conclusion, TNF-α is strongly involved in the development of liver cirrhosis and the associated encephalopathy. TNF-α blockers may be a promising approach for management of hepatic cirrhosis and its cerebral complications.

Extracellular vesicles from hyperammonemic rats induce neuroinflammation in hippocampus and impair cognition in control rats.

Patients with liver cirrhosis show hyperammonemia and peripheral inflammation and may show hepatic encephalopathy with cognitive impairment, reproduced by rats with chronic hyperammonemia. Peripheral inflammation induces neuroinflammation in hippocampus of hyperammonemic rats, altering neurotransmission and leading to cognitive impairment. Extracellular vesicles (EVs) may transmit pathological effects from the periphery to the brain. We hypothesized that EVs from peripheral blood would contribute to cognitive alterations in hyperammonemic rats. The aims were to assess whether EVs from plasma of hyperammonemic rats (HA-EVs) induce cognitive impairment and to identify the underlying mechanisms. Injection of HA-EVs impaired learning and memory, induced microglia and astrocytes activation and increased TNFα and IL-1ß. Ex vivo incubation of hippocampal slices from control rats with HA-EVs reproduced these alterations. HA-EVs increased membrane expression of TNFR1, reduced membrane expression of TGFßR2 and Smad7 and IκBα levels and increased IκBα phosphorylation. This led to increased activation of NF-κB and IL-1ß production, altering membrane expression of NR2B, GluA1 and GluA2 subunits, which would be responsible for cognitive impairment. All these effects of HA-EVs were prevented by blocking TNFα, indicating that they were mediated by enhanced activation of TNFR1 by TNFα. We show that these mechanisms are very different from those leading to motor incoordination, which is due to altered GABAergic neurotransmission in cerebellum. This demonstrates that peripheral EVs play a key role in the transmission of peripheral alterations to the brain in hyperammonemia and hepatic encephalopathy, inducing neuroinflammation and altering neurotransmission in hippocampus, which in turn is responsible for the cognitive deficits.

Ferrous sulfate reverses cerebral metabolic abnormality induced by minimal hepatic encephalopathy.

Orally administered ferrous iron was previously reported to significantly improve the cognition and locomotion of patients with minimal hepatic encephalopathy (MHE). However, the metabolic mechanisms of the therapeutic effect of ferrous iron are unknown. In this study, MHE was induced in rats by partial portal vein ligation (PPVL), and was treated with ferrous sulfate. The Morris water maze was used to evaluate the cognitive condition of the rats. The metabolites observed by NMR and validated by liquid chromatography-mass spectrometry were defined as the key affected metabolites. The enzyme activities and trace element contents in the rat brains were also investigated. The Mn content was found to be increased but the ferrous iron content decreased in the cortex and striatum in MHE. Decreased oxoglutarate dehydrogenase activity and increased glutamine synthetase (GS) and pyruvate carboxylase (PC) activity were observed in the cortex of MHE rats. Decreased pyruvate dehydrogenase activity and increased GS and PC activity were observed in the striatum of MHE rats. The levels of BCAAs and taurine were significantly decreased, and the contents of GABA, lactate, arginine, aspartate, carnosine, citrulline, cysteine, glutamate, glutamine, glycine, methionine, ornithine, proline, threonine and tyrosine were significantly increased. These metabolic abnormalities described above were restored after treatment with ferrous sulfate. Pathway enrichment analysis suggested that urea cycle, aspartate metabolism, arginine and proline metabolism, glycine and serine metabolism, and glutamate metabolism were the major metabolic abnormalities in MHE rats, but these processes could be restored and cognitive impairment could be improved by ferrous sulfate administration.

Sustained Hyperammonemia Activates NF-κB in Purkinje Neurons Through Activation of the TrkB-PI3K-AKT Pathway by Microglia-Derived BDNF in a Rat Model of Minimal Hepatic Encephalopathy.

Chronic hyperammonemia is a main contributor to the cognitive and motor impairment in patients with hepatic encephalopathy. Sustained hyperammonemia induces the TNFα expression in Purkinje neurons, mediated by NF-κB activation. The aims were the following: (1) to assess if enhanced TrkB activation by BDNF is responsible for enhanced NF-κB activation in Purkinje neurons in hyperammonemic rats, (2) to assess if this is associated with increased content of NF-κB modulated proteins such as TNFα, HMGB1, or glutaminase I, (3) to assess if these changes are due to enhanced activation of the TNFR1-S1PR2-CCR2-BDNF-TrkB pathway, (4) to analyze if increased activation of NF-κB is mediated by the PI3K-AKT pathway. It is shown that, in the cerebellum of hyperammonemic rats, increased BDNF levels enhance TrkB activation in Purkinje neurons leading to activation of PI3K, which enhances phosphorylation of AKT and of IκB, leading to increased nuclear translocation of NF-κB which enhances TNFα, HMGB1, and glutaminase I content. To assess if the changes are due to enhanced activation of the TNFR1-S1PR2-CCR2 pathway, we blocked TNFR1 with R7050, S1PR2 with JTE-013, and CCR2 with RS504393. These changes are reversed by blocking TrkB, PI3K, or the TNFR1-SP1PR2-CCL2-CCR2-BDNF-TrkB pathway at any step. In hyperammonemic rats, increased levels of BDNF enhance TrkB activation in Purkinje neurons, leading to activation of the PI3K-AKT-IκB-NF-κB pathway which increased the content of glutaminase I, HMGB1, and TNFα. Enhanced activation of this TrkB-PI3K-AKT-NF-κB pathway would contribute to impairing the function of Purkinje neurons and motor function in hyperammonemic rats and likely in cirrhotic patients with minimal or clinical hepatic encephalopathy.

Extracellular Vesicles From Hyperammonemic Rats Induce Neuroinflammation in Cerebellum of Normal Rats: Role of Increased TNFα Content.

Hyperammonemia plays a main role in the neurological impairment in cirrhotic patients with hepatic encephalopathy. Rats with chronic hyperammonemia reproduce the motor incoordination of patients with minimal hepatic encephalopathy, which is due to enhanced GABAergic neurotransmission in cerebellum as a consequence of neuroinflammation. Extracellular vesicles (EVs) could play a key role in the transmission of peripheral alterations to the brain to induce neuroinflammation and neurological impairment in hyperammonemia and hepatic encephalopathy. EVs from plasma of hyperammonemic rats (HA-EVs) injected to normal rats induce neuroinflammation and motor incoordination, but the underlying mechanisms remain unclear. The aim of this work was to advance in the understanding of these mechanisms. To do this we used an ex vivo system. Cerebellar slices from normal rats were treated ex vivo with HA-EVs. The aims were: 1) assess if HA-EVs induce microglia and astrocytes activation and neuroinflammation in cerebellar slices of normal rats, 2) assess if this is associated with activation of the TNFR1-NF-kB-glutaminase-GAT3 pathway, 3) assess if the TNFR1-CCL2-BDNF-TrkB pathway is activated by HA-EVs and 4) assess if the increased TNFα levels in HA-EVs are responsible for the above effects and if they are prevented by blocking the action of TNFα. Our results show that ex vivo treatment of cerebellar slices from control rats with extracellular vesicles from hyperammonemic rats induce glial activation, neuroinflammation and enhance GABAergic neurotransmission, reproducing the effects induced by hyperammonemia in vivo. Moreover, we identify in detail key underlying mechanisms. HA-EVs induce the activation of both the TNFR1-CCL2-BDNF-TrkB-KCC2 pathway and the TNFR1-NF-kB-glutaminase-GAT3 pathway. Activation of these pathways enhances GABAergic neurotransmission in cerebellum, which is responsible for the induction of motor incoordination by HA-EVs. The data also show that the increased levels of TNFα in HA-EVs are responsible for the above effects and that the activation of both pathways is prevented by blocking the action of TNFα. This opens new therapeutic options to improve motor incoordination in hyperammonemia and also in cirrhotic patients with hepatic encephalopathy and likely in other pathologies in which altered cargo of extracellular vesicles contribute to the propagation of the pathology.

SB332235, a CXCR2 antagonist, ameliorates thioacetamide-induced hepatic encephalopathy through modulation of the PI3K/AKT pathways in rats.

RATIONALE: Hepatic encephalopathy (HE) is a neuropsychiatric disorder that results from either acute or chronic liver failure. CXCR2 plays an essential role in the pathophysiology of liver and brain diseases. In the present study, the potential beneficial effects of SB332235, a selective inhibitor of CXCR2, against HE were evaluated. METHODS: HE was induced in male rats by thioacetamide injection (200 mg/kg, i.p.) at three alternative days. SB332235 was injected in rats 1 h before TAA at a dose of 1 and 3 mg/kg i.p. RESULTS: SB332235 alleviated oxidative stress as shown by the decreased serum NO and reduced MDA, elevated GSH and SOD levels, and reduced TNF-α and NF-κB levels in both brain and liver tissues of rats. Additionally, SB332235 suppressed brain ASK-1, JNK, IL-8, and caspase-3 expression, and activated PI3K/AKT expression in brain tissues. Markers of brain dysfunction, such as ammonia, and markers of hepatic injury, such as LDH, albumin, bilirubin, γGT, AST, ALT, and ALP, were significantly ameliorated. Also, the protective effect of SB332235 was confirmed by histological examination of both brain and liver tissues. CONCLUSIONS: Both doses (1 and 3 mg/kg) of SB332235 revealed significant hepatic/neuroprotective effects due to their anti-inflammatory, antioxidant, and antiapoptotic activities via activation of the PI3K/AKT pathway. Between the two, the 1 mg/kg dose provided significantly improved outcomes.

Thymol ameliorated neurotoxicity and cognitive deterioration in a thioacetamide-induced hepatic encephalopathy rat model; involvement of the BDNF/CREB signaling pathway.

In the present study, we aimed to delineate the neuroprotective potential of thymol (THY) against neurotoxicity and cognitive deterioration induced by thioacetamide (TAA) in an experimental model of hepatic encephalopathy (HE). Rats received TAA (100 mg kg-1, intraperitoneally injected, three times per week) for two weeks. THY (30 and 60 mg kg-1), and Vit E (100 mg k-1) were administered daily by oral gavage for 30 days after HE induction. Supplementation with THY significantly improved liver function, reduced serum ammonia level, and ameliorated the locomotor and cognitive deficits. THY effectively modulated the alteration in oxidative stress markers, neurotransmitters, and brain ATP content. Histopathology of liver and brain tissues showed that THY had ameliorated TAA-induced damage, astrocyte swelling and brain edema. Furthermore, THY downregulated NF-kB and upregulated GFAP protein expression. In addition, THY significantly promoted CREB and BDNF expression at both mRNA and protein levels, together with enhancing brain cAMP level. In conclusion, THY exerted hepato- and neuroprotective effects against HE by mitigating hepatotoxicity, hyperammonemia and brain ATP depletion via its antioxidant, anti-inflammatory effects in addition to activation of the CREB/BDNF signaling pathway.

Construction and comprehensive analysis of a lncRNA-mRNA interactive network to reveal a potential lncRNA for hepatic encephalopathy development.

Little is known about the role of lncRNA-mRNA regulatory relationships in hepatic encephalopathy (HE). Here, we aimed to construct the potential lncRNA and mRNA interactive network in forecasting HE development in patients with liver cirrhosis using different bioinformatic analysis method. Through analyses, we found that AL137857.1 had the most connections with other mRNAs and was deemed as a hub lncRNA. It was obviously upregulated in HE patients, which was also validated by another independent dataset. GO and KEGG analyses suggested that AL137857.1 was involved in microglial cell activation, phagocytosis, cytokine biosynthetic process, interleukin-6 production and tumor necrosis factor production. In vitro experiments suggested LPS could stimulate microglia to generate AL137857.1. In addition, we found that inhibition of AL137857.1 suppressed the expression of a series of inflammatory cytokines, including IL-1, IL-6, TNF-α, Cox2 and iNOS. Conversely, AL137857.1 over-expression induced a marked increase in these factors. Finally, AL137857.1 was demonstrated to be highly associated with the ability of microglial phagocytosis. Taken together, we have constructed a lncRNA-mRNA regulatory network associated with HE and explored the biological significance of mRNAs in the network, then discovered a novel lncRNA AL137857.1 in HE that might act as a potential regulator of the downstream inflammatory cytokines.

Molecular mechanisms involved in the effects of morin in experimental hepatic encephalopathy.

This study aimed to investigate the possible usefulness of morin flavonoid in comparison to silymarin as a hepatic/neuronal-supportive agent with similar effects and higher bioavailability in a rat model of hepatic encephalopathy (HE). Morin effects on rat liver and brain were evaluated post-induction of HE by thioacetamide (TAA; 200 mg/kg/day for 3 successive days). Then, the serum activities of aspartate transaminase (AST) and alanine transaminase (ALT) together with ammonia concentration were estimated to assess the liver function. Also, the degree of brain effects was evaluated via the assessment of brain contents of reduced glutathione (GSH), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and interleukin (IL-1ß) together with glutathione peroxidase (GPx) activity. In addition, the apoptotic and inflammatory changes in brain and liver tissues were also assessed via immunohistochemical examination. Our findings revealed a promising effect of morin against HE complications; as it corrected the liver functions, attenuated the brain/liver tissue injuries, and reduced the apoptotic and inflammatory insults of HE on both organs. These effects are comparable to those of silymarin. Morin could be introduced as a promising hepato- and neuro-therapeutic adjuvant in HE-associated neuronal complications especially in cases like silymarin intolerance.

Phytochemical constituents and protective efficacy of Schefflera arboricola L. leaves extract against thioacetamide-induced hepatic encephalopathy in rats.

CONTEXT: Hepatic encephalopathy (HE) is a severe neuropsychiatric syndrome resulting from liver failure. OBJECTIVE: To evaluate the protective effect of Schefflera arboricola L. leaves methanol extract against thioacetamide (TAA) induced HE in rats. MATERIALS AND METHODS: GC/MS, LC-ESI-MS, and the total phenolic and flavonoid contents were determined. The methanol extract was orally administrated (100 and 200 mg/kg body weight) for 21 days. TAA (200 mg/kg body weight) was given intraperitoneally on day 19 and continued for three days. The evaluation was done by measuring alanine aminotransferase (ALT), alkaline phosphatase (ALP), ammonia, reduced glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), tumour necrosis factor-alpha (TNF-α), toll-like receptor 4 (TLR4), interleukin-1 beta (IL-1ß), interlukin-6 (IL-6), cyclooxygenase 2 (COX2), B cell lymphoma 2 (BCL2), alpha-smooth muscle actin (α-SMA), and the cluster of differentiation 163 (CD163). The histological features of the liver and brain were conducted. RESULTS: Forty-five compounds were identified from the n-hexane fraction, while twenty-nine phenolic compounds were determined from the methanol extract. Pre-treatment with the plant extract returned most of the measurements under investigation to nearly normal. CONCLUSION: Due to its richness with bioactive compounds, Schefflera arboricola L. leaves methanolic extract succeeded to exert anti-fibrotic, anti-inflammatory, and antioxidants properties in TAA-induced HE in rats with more efficacy to its high protective dose.

Cerebellar spongiform degeneration is accompanied by metabolic, cellular, and motor disruption in male rats with portacaval anastomosis.

The episodes of cerebral dysfunction, known as encephalopathy, are usually coincident with liver failure. The primary metabolic marker of liver diseases is the increase in blood ammonium, which promotes neuronal damage. In the present project, we used an experimental model of hepatic encephalopathy in male rats by portacaval anastomosis (PCA) surgery. Sham rats had a false operation. After 13 weeks of surgery, the most distinctive finding was vacuolar/spongiform neurodegeneration exclusively in the molecular layer of the cerebellum. This cerebellar damage was further characterized by metabolic, histopathological, and behavioral approaches. The results were as follows: (a) Cellular alterations, namely loss of Purkinje cells, morphological changes, such as swelling of astrocytes and Bergmann glia, and activation of microglia; (b) Cytotoxic edema, shown by an increase in aquaporin-4 and N-acetylaspartate and a reduction in taurine and choline-derivate osmolytes; (c) Metabolic adjustments, noted by the elevation of circulating ammonium, enhanced presence of glutamine synthetase, and increase in glutamine and creatine/phosphocreatine; (d) Inflammasome activation, detected by the elevation of the marker NLRP3 and microglial activation; (e) Locomotor deficits in PCA rats as assessed by the Rotarod and open field tests. These results lead us to suggest that metabolic disturbances associated with PCA can generate the cerebellar damage that is similar to morphophysiological modifications observed in amyloidogenic disorders. In conclusion, we have characterized a distinctive cerebellar multi-disruption accompanied by high levels of ammonium and associated with spongiform neurodegeneration in a model of hepatic hypofunctioning.

MR T1 mapping for quantifying brain manganese deposition in type C hepatic encephalopathy rats.

To evaluate magnetic resonance (MR) T1 mapping for quantifying brain manganese (Mn) deposition in type C hepatic encephalopathy (CHE) rats and to investigate the mechanism of magnesium sulfate (MgSO4) therapy. Thirty Sprague-Dawley rats were randomly assigned into normal control group (NC, n = 6) and CHE groups (n = 24). Thioacetamide (TAA) was used for modeling CHE rats. CHE groups were further divided into 4 subgroups: TAA group, MgSO4 low dose (Mg-L) group, MgSO4 high dose (Mg-H) group and deionized water (DW) group (n = 6 for each group). TAA, Mg-L, Mg-H and DW groups were received intraperitoneal injections of 250 mg TAA/kg, twice a week for 8 weeks. Mg-L and Mg-H groups were orally received MgSO4 of 124 and 248 mg/kg daily, respectively, for another 8 weeks (without TAA). MR T1 mapping was performed in NC, TAA, Mg-L, Mg-H and DW groups at various time points. T1 value and Mn content in basal ganglia, hippocampus, cerebral cortex and cerebellum were evaluated. Morris water maze (MWM) and narrow beat test (NBT) were utilized to evaluate rats' learning, memory and motor ability. Contents of interleukin-6 (IL-6), tumor necrosis factor-a (TNF-a) and calcium-binding adaptor 1 protein (Iba1) were evaluated. Reduced T1 values in basal ganglia, hippocampus and cerebral cortex (P < 0.01, P < 0.05 and P < 0.05, respectively); increased Mn content in basal ganglia, hippocampus and cerebral cortex (all P < 0.05); reduced times of head contacting with region of interest (ROI), reduced times of entrance into the target quadrant (both P < 0.05); increased NBT total time (P < 0.05); increased brain contents of IL-6 (P < 0.001), TNF-α (P < 0.01) and over-expression of Iba1 were found in TAA group compared to NC group. After treated by MgSO4, increased T1 value and reduced Mn content in basal ganglia, hippocampus and cerebral cortex (all P < 0.01); increased times of head contacting with ROI, increased times of entrance into the target quadrant (both P < 0.05); reduced NBT total time (P < 0.01); reduced brain content of IL-6, TNF-α (both P < 0.05) and reduced expression of Iba1 were found. T1 values were negatively correlated with Mn contents in basal ganglia (r = - 0.834, P < 0.01), hippocampus (r = - 0.739, P < 0.05), cortex (r = - 0.801, P < 0.05) and cerebellum (r = - 0.788, P < 0.05). T1 mapping could quantify brain Mn deposition in CHE rats. MgSO4 could improve cognition and motor ability of CHE rats by reducing brain Mn deposition, alleviating neurological inflammation and achieve the effective therapy for CHE. Mn may participate in the pathogenesis of CHE through neuroinflammation.

The effects of thymoquinone on memory impairment and inflammation in rats with hepatic encephalopathy induced by thioacetamide.

Hepatic encephalopathy (HE) is a prevalent complication of the central nervous system (CNS) that is caused by acute or chronic liver failure. This study was designed to evaluate the effects of thymoquinone (TQ) on thioacetamide (TAA)-induced HE in rats, and determine the consequential behavioral, biochemical, and histological changes. HE was induced in male Wistar rats by intraperitoneal (i.p.) injection of 200 mg/kg TAA once every 48 h for 14 consecutive days. Control groups received the normal saline containing 5 % DMSO. Thymoquinone (5, 10, and 20 mg/kg) was administered for ten consecutive days intraperitoneally (i.p.) after HE induction and it was continued until the end of the tests. Then, the passive avoidance memory, extracellular single unit, BBB permeability, and brain water content were evaluated. Moreover, hippocampal tissues were used for evaluation of oxidative stress index, inflammatory biomarkers, and histological parameters following HE. As result of the treatment, TQ improved passive avoidance memory, increased the average number of simultaneous firing of spikes/bins, improved the integrity of BBB, and decreased brain water content in the animal model of HE. Furthermore, the results indicated that treatment with TQ decreased the levels of inflammatory cytokines (TNF-α and IL-1ß) but increased the levels of glutathione (GSH) and anti-inflammatory cytokine (IL-10) of the surviving cells in the hippocampal tissues. This study demonstrates that TQ may have beneficial therapeutic effects on cognitive, oxidative stress, neuroinflammatory, and histological complications of HE in rat.

Babao Dan improves neurocognitive function by inhibiting inflammation in clinical minimal hepatic encephalopathy.

BACKGROUND AND PURPOSE: Inflammation has been considered a precipitating event that contributes to neurocognitive dysfunction in minimal hepatic encephalopathy (MHE). Inhibition TLR-4 related inflammation can effectively improve neurocognitive dysfunction of MHE. Our previous study showed that Babao Dan (BBD) effectively inhibited inflammation and ameliorated neurocognitive function in rats with acute hepatic encephalopathy (HE) and chronic HE. The mechanism may lie in the regulation of TLR4 signaling pathway. Therefore, this study aimed to evaluate the role of BBD in the treatment of MHE patients with cirrhosis and to elucidate the underlying mechanism by which BBD regulated TLR4 pathway to alleviate inflammation. METHODS: A randomized controlled trial (n = 62) was conducted to evaluate the clinical efficacy between BBD plus lactulose (n = 31) and lactulose alone (n = 31) in MHE patients by testing neurocognitive function (NCT-A and DST), blood ammonia, liver function (ALT, AST and TBIL) and blood inflammation (IL-1ß, IL-6 and TNF-α). Afterward, we detected NO, inflammatory cytokines (IL-1ß, IL-6 and TNF-α) and the phosphorylation of P65, JNK, ERK as well as P38 in LPS-activated rat primary bone marrow-derived macrophages (BMDMs), peritoneal macrophages (PMs), and mouse primary BMDMs/PMs/microglia/astrocytes, to investigate the underlying mechanism of BBD inhibiting inflammation through TLR4 pathway. Also, the survival rate of mice, liver function (ALT, AST), blood inflammation (IL-1ß, IL-6 and TNF-α), inflammatory cytokines (IL-1ß, IL-6 and TNF-α) and histopathological changes in the liver, brain and lung were measured to assess the anti-inflammatory effect of BBD on neurocognitive function in endotoxin shock/endotoxemia mice. RESULTS: BBD combined with lactulose significantly ameliorated neurocognitive function by decreasing NCT-A (p＜0.001) and increasing DST (p＜0.001); inhibited systemic inflammation by decreasing IL-1ß (p＜0.001), IL-6(p＜0.001) and TNF-α (p＜0.001); reduced ammonia level (p = 0.005), and improved liver function by decreasing ALT(p = 0.043), AST(p = 0.003) and TBIL (p = 0.026) in MHE patients. Furthermore, BBD inhibited gene and protein expression of IL-1ß, IL-6 and TNF-α as well as NO in rat primary BMDMs/PMs, and mouse primary BMDMs/PMs/microglia/astrocytes in a dose-dependent manner. BBD inhibited the activation of mouse primary BMDMs/PMs/microglia/astrocytes by regulating TLR4 pathway involving the phosphorylation of P65, JNK, ERK and P38. Also, BBD reduced the mortality of mice with endotoxin shock/endotoxemia; serum levels of ALT, AST, IL-1ß, IL-6 and TNF-α; gene expression of IL-1ß, IL-6 and TNF-α in the liver, brain and lung, and tissue damage in the liver and lung. CONCLUSION: Our study provided for the first time clinical and experimental evidence supporting the use of BBD in MHE, and revealed that BBD could play a crucial role in targeting and regulating TLR4 inflammatory pathway to improve neurocognitive function in MHE patients.

Hydrogen sulphide ameliorates dopamine-induced astrocytic inflammation and neurodegeneration in minimal hepatic encephalopathy.

It has been demonstrated that the action of dopamine (DA) could enhance the production of tumour necrosis factor-α (TNF-α) by astrocytes and potentiate neuronal apoptosis in minimal hepatic encephalopathy (MHE). Recently, sodium hydrosulfide (NaHS) has been found to have neuroprotective properties. Our study addressed whether NaHS could rescue DA-challenged inflammation and apoptosis in neurons to ameliorate memory impairment in MHE rats and in the neuron and astrocyte coculture system. We found that NaHS suppressed DA-induced p65 acetylation, resulting in reduced TNF-α production in astrocytes both in vitro and in vivo. Furthermore, decreased apoptosis was observed in neurons exposed to conditioned medium from DA + NaHS-challenged astrocytes, which was similar to the results obtained in the neurons exposed to TNF-α + NaHS, suggesting a therapeutic effect of NaHS on the suppression of neuronal apoptosis via the reduction of TNF-α level. DA triggered the inactivation of p70 S6 ribosomal kinase (S6K1) and dephosphorylation of Bad, resulting in the disaggregation of Bclxl and Bak and the release of cytochrome c (Cyt. c), and this process could be reversed by NaHS administration. Our work demonstrated that NaHS attenuated DA-induced astrocytic TNF-α release and ameliorated inflammation-induced neuronal apoptosis in MHE. Further research into this approach may uncover future potential therapeutic strategies for MHE.

Curcumin prevents cognitive deficits in the bile duct ligated rats.

RATIONALE: Bile duct ligation (BDL) in rodents can cause impaired liver function and cognition deficits. Curcumin has shown a preventive and therapeutic role in memory impairment. OBJECTIVES: Therefore, this study aimed to explore the effect of curcumin on the performance of male adult Wistar rats that underwent BDL, a model of hepatic encephalopathy (HE) in the Morris water maze (MWM). METHODS: Four weeks after surgery, sham (manipulation of common bile duct without ligation) and BDL rats underwent the MWM test. RESULTS: The representative data showed that BDL rats exhibited impairments in spatial learning and reference memory in the MWM compared with the sham rats. Treatment of BDL rats with curcumin (40 mg/kg, i.p., for 4 weeks) prevented these impairments, while it did not affect spatial learning and memory in the sham rats, by itself. Curcumin increased expression levels of the pro-survival B cell lymphoma extra-large (Bcl-xL) gene and two genes involved in mitochondrial function, peroxisome proliferative-activated receptor-γ co-activator 1α (PGC-1α) and mitochondrial transcription factor A (TFAM), in the hippocampus of BDL rats compared with the vehicle-treated sham or BDL rats, while it decreased the pro-apoptotic Bcl-2-associated X protein (Bax) gene expression level. BDL up-regulated Bax and down-regulated TFAM, by itself. Furthermore, curcumin reduced the mRNA level of Bax, while it increased Bcl-2 and TFAM mRNA levels. CONCLUSIONS: These findings demonstrate the beneficial effect of curcumin on cognitive function in BDL rats of the HE model. The curcumin effect may be related to mitochondrial function improvement in the HE.

Encephalopathy in cystic fibrosis.

Cystic fibrosis liver disease (CFLD) affects a large proportion of cystic fibrosis (CF) patients; however encephalopathy is a rare complication. While classical hepatic encephalopathy can be a feature of end-stage liver disease, "hyperammonemic encephalopathy" can be precipitated in previously stable CFLD by various triggers including systemic corticosteroids. We describe one such case and review the relevant literature.

S-Adenosylmethionine Deficiency and Brain Accumulation of S-Adenosylhomocysteine in Thioacetamide-Induced Acute Liver Failure.

BACKGROUND: Acute liver failure (ALF) impairs cerebral function and induces hepatic encephalopathy (HE) due to the accumulation of neurotoxic and neuroactive substances in the brain. Cerebral oxidative stress (OS), under control of the glutathione-based defense system, contributes to the HE pathogenesis. Glutathione synthesis is regulated by cysteine synthesized from homocysteine via the transsulfuration pathway present in the brain. The transsulfuration-transmethylation interdependence is controlled by a methyl group donor, S-adenosylmethionine (AdoMet) conversion to S-adenosylhomocysteine (AdoHcy), whose removal by subsequent hydrolysis to homocysteine counteract AdoHcy accumulation-induced OS and excitotoxicity. METHODS: Rats received three consecutive intraperitoneal injections of thioacetamide (TAA) at 24 h intervals. We measured AdoMet and AdoHcy concentrations by HPLC-FD, glutathione (GSH/GSSG) ratio (Quantification kit). RESULTS: AdoMet/AdoHcy ratio was reduced in the brain but not in the liver. The total glutathione level and GSH/GSSG ratio, decreased in TAA rats, were restored by AdoMet treatment. CONCLUSION: Data indicate that disturbance of redox homeostasis caused by AdoHcy in the TAA rat brain may represent a deleterious mechanism of brain damage in HE. The correction of the GSH/GSSG ratio following AdoMet administration indicates its therapeutic value in maintaining cellular redox potential in the cerebral cortex of ALF rats.