Rimonabant ameliorates hepatic ischemia/reperfusion injury in rats: Involvement of autophagy via modulating ERK- and PI3K/AKT-mTOR pathways.

Hepatic ischemia/reperfusion (HIR), which can result in severe liver injury and dysfunction, is usually associated with autophagy and endocannabinoid system derangements. Whether or not the modulation of the autophagic response following HIR injury is involved in the hepatoprotective effect of the cannabinoid receptor 1(CB1R) antagonist rimonabant remains elusive and is the aim of the current study. Rats pre-treated with rimonabant (3 mg/kg) or vehicle underwent 30 min hepatic ischemia followed by 6 hrs. reperfusion. Liver injury was evaluated by serum ALT, AST, bilirubin (total and direct levels) and histopathological examination. The inflammatory, profibrotic and oxidative responses were investigated by assessing hepatic tumor necrosis factor α (TNFα), nuclear factor kappa B (NF-κB), transforming growth factor (TGF-ß), lipid peroxidation and reduced glutathione. The hepatic levels of CB1R and autophagic markers p62, Beclin-1, and LC3 as well as the autophagic signaling inhibitors ERK1/2, PI3K, Akt and mTOR were also determined. Rimonabant significantly attenuated HIR-induced increases in hepatic injury, inflammation, profibrotic responses and oxidative stress and improved the associated pathological features. Rimonabant modulated the expression of p62, Beclin-1, and LC3, down-regulated CB1R, and dcreased pERK1/2, PI3K, Akt, and mTOR activities. The current study suggests that rimonabant can protect the liver from IR injury at least in part by inducing autophagy, probably by modulating ERK- and/or PI3K/AKT-mTOR signaling.

DNA methyltransferase 3B plays a protective role against hepatocarcinogenesis caused by chronic inflammation via maintaining mitochondrial homeostasis.

Most hepatocellular carcinomas (HCCs) develop on the basis of chronic hepatitis, but the mechanism of epigenetic regulation in inflammatory hepatocarcinogenesis has yet to be elucidated. Among de novo DNA methyltransferases (DNMTs), DNMT3B has lately been reported to act specifically on actively transcribed genes, suggesting the possibility that it plays a role in the pathogenesis of cancer. We confirmed that DNMT3B isoforms lacking its catalytic domain were highly expressed in HCCs compared with non-tumorous liver tissue. To elucidate the role of DNMT3B in hepatocarcinogenesis, we generated a genetically engineered mouse model with hepatocyte-specific Dnmt3b deletion. The liver of the Dnmt3b-deficient mice exhibited an exacerbation of thioacetamide-induced hepatitis, progression of liver fibrosis and a higher incidence of HCC compared with the liver of the control mice. Whole-genome bisulfite sequencing verified a lower CG methylation level in the Dnmt3b-deficient liver, demonstrating differentially methylated regions throughout the genome. Transcriptome analysis revealed decreased expression of genes related to oxidative phosphorylation in the Dnmt3b-deficient liver. Moreover, primary hepatocytes isolated from the Dnmt3b-deficient mice showed reduced mitochondrial respiratory capacity, leading to the enhancement of oxidative stress in the liver tissue. Our findings suggest the protective role of DNMT3B against chronic inflammation and HCC development via maintaining mitochondrial homeostasis.

Preparation and antagonistic effect of ACE inhibitory peptide from cashew.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitory peptides were found to alleviate acute hepatitis significantly. In this study, we purified and identified ACE inhibitory peptide from cashew to evaluate its protective role on alcohol-induced acute hepatitis in mice. RESULTS: The ACE inhibitory peptides were purified by using consecutive chromatographic techniques. One of these peptides (FETISFK) exhibited the highest ACE inhibition rate (91.04 ± 0.31%). In vivo, the results showed that ACE inhibitory peptide decreased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) caused by alcohol exposure. Moreover, it could increase the activities of superoxide dismutase (SOD) and glutathione (GSH), and decrease the level of malondialdehyde (MDA). It was also found to down-regulate markedly the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). It could also decrease the expression of ACE, angiotensin II (AngII) and angiotensin II type 1 receptor (AT1 R). CONCLUSION: These findings support the view that the ACE inhibitory peptide alleviated acute hepatitis by down-regulating the ACE-AngII-AT1 R axis, broadening the research approach to prevent acute hepatitis, and providing experimental data for the development and utilization of cashews. © 2019 Society of Chemical Industry.

Sphingosine kinase 1 knockout alleviates hepatic ischemia/reperfusion injury by attenuating inflammation and oxidative stress in mice.

BACKGROUND: Hepatic ischemia/reperfusion (I/R) injury remains a significant problem in clinical practice. Sphingosine kinase 1 (SphK1) phosphorylates sphingosine to sphingosine-1-phosphate (S1P) which participates in multiple bioactive processes. However, little is known about the role of SphK1 in hepatic I/R injury. This study aimed to investigate the effect of SphK1 knockout on liver I/R injury and to explore underlying mechanisms. METHODS: SphK1 knockout and wild type mice were subjected to 70% partial hepatic I/R. Serum alanine aminotransferase was determined to indicate the degree of liver damage. Hematoxylin-eosin staining and TUNEL assay were used to assess histological changes and hepatocellular apoptosis, respectively. Immunohistochemistry was performed to detect the expression and translocation of phosphorylated p65 and signal transducer and activator of transcription 3 (STAT3). Western blotting was used to determine the expression of S1P receptor 1 (S1PR1), phosphorylated p65 and STAT3. Real-time PCR was used to demonstrate the changes of proinflammatory cytokines. Oxidative stress markers were also determined through biochemical assays. RESULTS: SphK1 knockout significantly ameliorated I/R-induced liver damage, mitigated liver tissue necrosis and apoptosis compared with wild type control. I/R associated inflammation was alleviated in SphK1 knockout mice as demonstrated by attenuated expression of S1PR1 and reduced phosphorylation of nuclear factor kappa B p65 and STAT3. The proinflammatory cytokines interleukin-1ß, interleukin-6 and tumor necrosis factor-α were also inhibited by SphK1 genetic deletion. The oxidative stress markers were lower in SphK1 knockout mice after I/R injury than wild type mice. CONCLUSIONS: Knockout of SphK1 significantly alleviated damage after hepatic I/R injury, possibly through inhibiting inflammation and oxidative stress. SphK1 may be a novel and potent target in clinical practice in I/R-related liver injury.

Beraprost sodium preconditioning prevents inflammation, apoptosis, and autophagy during hepatic ischemia-reperfusion injury in mice via the P38 and JNK pathways.

OBJECTIVE: The goal of this study was to determine the effects of beraprost sodium (BPS) preconditioning on hepatic ischemia-reperfusion (IR) injury and its underlying mechanisms of action. MATERIALS AND METHODS: Mice were randomly divided into sham, IR, IR+BPS (50 µg/kg), and IR+BPS (100 µg/kg) groups. Saline or BPS was given to the mice by daily gavage for 1 week before the hepatic IR model was established. Liver tissues and orbital blood were collected at 2, 8, and 24 hours after reperfusion for the determination of liver enzymes, inflammatory mediators, apoptosis- and autophagy-related proteins, key proteins in P38 and c-Jun N-terminal kinase (JNK) cascades, and evaluation of liver histopathology. RESULTS: BPS preconditioning effectively reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, improved pathological damage, ameliorated production of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), and affected expressions of Bax, Bcl-2, Caspase-3, Caspase-8, and Caspase-9, microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and P62. The protective effects of BPS preconditioning were associated with reduced P38 and JNK phosphorylation. CONCLUSION: BPS preconditioning ameliorated hepatic IR injury by suppressing inflammation, apoptosis, and autophagy, partially via inhibiting activation of the P38 and JNK cascades.

Adipocyte-Specific Deficiency of NADPH Oxidase 4 Delays the Onset of Insulin Resistance and Attenuates Adipose Tissue Inflammation in Obesity.

OBJECTIVE: Obesity is associated with insulin resistance and adipose tissue inflammation. Reactive oxygen species (ROS) increase in adipose tissue during the development of obesity. We previously showed that in response to excess nutrients like glucose and palmitate, adipocytes generated ROS via NADPH oxidase (NOX) 4, the major adipocyte isoform, instead of using mitochondrial oxidation. However, the role of NOX4-derived ROS in the development of whole body insulin resistance, adipocyte inflammation, and recruitment of macrophages to adipose tissue during the development of obesity is unknown. APPROACH AND RESULTS: In this study, control C57BL/6 mice and mice in which NOX4 has been deleted specifically in adipocytes were fed a high-fat, high-sucrose diet. During the development of obesity in control mice, adipocyte NOX4 and pentose phosphate pathway activity were transiently increased. Primary adipocytes differentiated from mice with adipocytes deficient in NOX4 showed resistance against high glucose or palmitate-induced adipocyte inflammation. Mice with adipocytes deficient in NOX4 showed a delayed onset of insulin resistance during the development of obesity, with an initial reduction in adipose tissue inflammation that normalized with prolonged high-fat, high-sucrose feeding. CONCLUSIONS: These findings imply that NOX4-derived ROS may play a role in the onset of insulin resistance and adipose tissue inflammation. As such, therapeutics targeting NOX4-mediated ROS production could be effective in preventing obesity-associated conditions, such as insulin resistance.

Expanding the differential diagnosis for transaminitis in patients with anorexia nervosa.

Aminotransferase elevations have been described in patients with anorexia nervosa. Hypothesized etiologies have included ischemic hepatitis, refeeding-induced transaminitis, and the process of autophagy. Supervised enteral nutrition is the mainstay of treatment for severe anorexia, but an increase in aminotransferase levels after initiation of enteral feeding presents clinicians with a diagnostic dilemma. We present a 31-year-old woman with anorexia nervosa (body mass index [BMI] of 13.5 kg/m2) who experienced a worsening of aminotransferase elevations even after the initiation of enteral feeding. Despite nutritional supplementation, the patient's weight continued to fall for 6 days. Peak aminotransferase concentrations correlated with the patient's lowest weight and improved only after an increase in BMI was eventually achieved. Secondary causes of severe transaminitis were investigated, and after no cause was found, a liver biopsy was performed. Pathology was consistent with liver injury secondary to severe malnutrition rather than from refeeding syndrome. This case highlights malnutrition as an important cause of aminotransferase elevations and underscores the need for judicious early weight restoration in patients with anorexia and abnormal liver chemistry.

Diagnostic value of anti-smooth muscle antibodies and liver enzymes in differentiation of extrahepatic biliary atresia and idiopathic neonatal hepatitis.

BACKGROUND: We aimed to evaluate the diagnostic value of anti-smooth muscle antibodies (ASMA) and two liver markers (gamma-glutamyl transpeptidase [GGT] and alkaline phosphatase [ALP]) for differentiating between patients with extrahepatic biliary atresia (EHBA) and idiopathic neonatal hepatitis (INH). MATERIALS AND METHODS: During April 2010-2011, all infants at 2 weeks of age who were diagnosed with cholestasis and admitted to Children's Hospital of Tabriz were enrolled. Based on the results of physical examination, laboratory, imaging and pathological studies, neonates were divided into two groups (EHBA and INH). Receiver operating characteristics analysis was used to define sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for ASMA, GGT and ALP. RESULTS: Thirty neonates with cholestasis (18 with EHBA and 12 with INH) and mean age of 54.66 ΁ 25.86 days were enrolled. Total and direct bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and ASMA titres were highly not significant (P > 0.05) in patients with INH. GGT (P = 0.008) and ALP (P = 0.01) had statistically significant differences that were higher in patients with EHBA. The sensitivity, specificity, PPV and NPV, accuracy, LR+ and LR- of SMA in differentiating cases with BA were 66.7%, 75%, 80% 60%, 70%, 2.68 and 0.44, respectively. For GGT, the values were 88.9%, 66.7%, 80%, 80%, 79.1%, 3.08 and 0.31, respectively. Finally, for ALP, the values were 77.8%, 75%, 82.4%, 69.2%, 80%, 2.66 and 0.24, respectively. CONCLUSION: Our study showed that ASMA may be a useful biomarker for differentiation of EHBA from INH. Further studies with larger samples are recommended for confirming the results of this study.

Sparstolonin B attenuates early liver inflammation in experimental NASH by modulating TLR4 trafficking in lipid rafts via NADPH oxidase activation.

Although significant research data exist on the pathophysiology of nonalcoholic steatohepatitis (NASH), finding an efficient treatment regimen for it remains elusive. The present study used sparstolonin B (SsnB), a novel TLR4 antagonist derived from the Chinese herb Sparganium stoloniferum, as a possible drug to mitigate early inflammation in NASH. This study used an early steatohepatitic injury model in high-fat-fed mice with CYP2E1-mediated oxidative stress as a second hit. SsnB was administered for 1 wk along with bromodichloromethane (BDCM), an inducer of CYP2E1-mediated oxidative stress. Results showed that SsnB administration attenuated inflammatory morphology and decreased elevation of the liver enzyme alanine aminotransferase (ALT). Mice administered SsnB also showed decreased mRNA expression of proinflammatory cytokines TNF-α, IFN-γ, IL-1ß, and IL-23, while protein levels of both TNF-α and IL-1ß were significantly decreased. SsnB significantly decreased Kupffer cell activation as evidenced by reduction in CD68 and monocyte chemoattractant protein-1 (MCP1) mRNA and protein levels with concomitant inhibition of macrophage infiltration in the injured liver. Mechanistically, SsnB decreased TLR4 trafficking to the lipid rafts, a phenomenon described by the colocalization of TLR4 and lipid raft marker flotillin in tissues and immortalized Kupffer cells. Since we have shown previously that NADPH oxidase drives TLR4 trafficking in NASH, we studied the role of SsnB in modulating this pathway. SsnB prevented NADPH oxidase activation in vivo and in vitro as indicated by decreased peroxynitrite formation. In summary, the present study reports a novel use of the TLR4 antagonist SsnB in mitigating inflammation in NASH and in parallel shows a unique molecular mechanism of decreasing nitrative stress.

Pioglitazone attenuates hepatic inflammation and fibrosis in phosphatidylethanolamine N-methyltransferase-deficient mice.

Phosphatidylethanolamine N-methyltransferase (PEMT) is an important enzyme in hepatic phosphatidylcholine (PC) biosynthesis. Pemt(-/-) mice are protected against high-fat diet (HFD)-induced obesity and insulin resistance; however, these mice develop nonalcoholic fatty liver disease (NAFLD). We hypothesized that peroxisomal proliferator-activated receptor-γ (PPARγ) activation by pioglitazone might stimulate adipocyte proliferation, thereby directing lipids from the liver toward white adipose tissue. Pioglitazone might also act directly on PPARγ in the liver to improve NAFLD. Pemt(+/+) and Pemt(-/-) mice were fed a HFD with or without pioglitazone (20 mg·kg(-1)·day(-1)) for 10 wk. Pemt(-/-) mice were protected from HFD-induced obesity but developed NAFLD. Treatment with pioglitazone caused an increase in body weight gain in Pemt(-/-) mice that was mainly due to increased adiposity. Moreover, pioglitazone improved NAFLD in Pemt(-/-) mice, as indicated by a 35% reduction in liver weight and a 57% decrease in plasma alanine transaminase levels. Livers from HFD-fed Pemt(-/-) mice were steatotic, inflamed, and fibrotic. Hepatic steatosis was still evident in pioglitazone-treated Pemt(-/-) mice; however, treatment with pioglitazone reduced hepatic fibrosis, as evidenced by reduced Sirius red staining and lowered mRNA levels of collagen type Iα1 (Col1a1), tissue inhibitor of metalloproteinases 1 (Timp1), α-smooth muscle actin (Acta2), and transforming growth factor-ß (Tgf-ß). Similarly, oxidative stress and inflammation were reduced in livers from Pemt(-/-) mice upon treatment with pioglitazone. Together, these data show that activation of PPARγ in HFD-fed Pemt(-/-) mice improved liver function, while these mice were still protected against diet-induced obesity and insulin resistance.

Aloe vera attenuated liver injury in mice with acetaminophen-induced hepatitis.

BACKGROUND: An overdose of the acetaminophen causes liver injury. This study aims to examine the anti-oxidative, anti-inflammatory effects of Aloe vera in mice with acetaminophen induced hepatitis. METHODS: Male mice were randomly divided into three groups (n = 8 each). Control group were given orally distilled water (DW). APAP group were given orally N-acetyl-P-aminophenol (APAP) 400 mg/kg suspended in DW. Aloe vera-treated group were given orally APAP and Aloe vera (150 mg/kg) suspended in DW. Twenty-four hours later, the liver was removed to determine hepatic malondialdehyde (MDA), hepatic glutathione (GSH), the number of interleukin (IL)-12 and IL-18 positive stained cells (%) by immunohistochemistry method, and histopathological examination. Then, the serum was collected to determine transaminase (ALT). RESULTS: In APAP group, ALT, hepatic MDA and the number of IL-12 and IL-18 positive stained cells were significantly increased when compared to control group (1210.50 ± 533.86 vs 85.28 ± 28.27 U/L, 3.60 ± 1.50 vs 1.38 ± 0.15 nmol/mg protein, 12.18 ± 1.10 vs 1.84 ± 1.29%, and 13.26 ± 0.90 vs 2.54 ± 1.29%, P = 0.000, respectively), whereas hepatic GSH was significantly decreased when compared to control group (5.98 ± 0.30 vs 11.65 ± 0.43 nmol/mg protein, P = 0.000). The mean level of ALT, hepatic MDA, the number of IL-12 and IL-18 positive stained cells, and hepatic GSH in Aloe vera-treated group were improved as compared with APAP group (606.38 ± 495.45 vs 1210.50 ± 533.86 U/L, P = 0.024; 1.49 ± 0.64 vs 3.60 ± 1.50 nmol/mg protein, P = 0.001; 5.56 ± 1.25 vs 12.18 ± 1.10%, P = 0.000; 6.23 ± 0.94 vs 13.26 ± 0.90%, P = 0.000; and 10.02 ± 0.20 vs 5.98 ± 0.30 nmol/mg protein, P = 0.000, respectively). Moreover, in the APAP group, the liver showed extensive hemorrhagic hepatic necrosis at all zones while in Aloe vera-treated group, the liver architecture was improved histopathology. CONCLUSIONS: APAP overdose can cause liver injury. Our result indicate that Aloe vera attenuate APAP-induced hepatitis through the improvement of liver histopathology by decreased oxidative stress, reduced liver injury, and restored hepatic GSH.

Regulation of heme oxygenase 1 expression by miR-27b with stem cell therapy for liver regeneration in rats.

Adipose-derived mesenchymal stem cells (ASCs) have been considered to be attractive and readily available adult mesenchymal stem cells (MSCs) and are becoming increasingly popular for use in regenerating cell therapy. However, recent evidence attributed a fibrotic potential to MSCs which differentiated into myofibroblasts with highly increased α-smooth muscle actin (α-SMA) expression while transplanted into an injured/regenerating liver in mice. In this study, we studied the role of miR-27b in ASCs and their regenerative potential after partial liver resection in rats. ASCs transfected with control siRNA or miR-27b were intravenously injected into autologous rats undergoing 70% partial hepatectomy (PH). Our data showed that the regenerative capacities of ASCs with overexpressed miR-27b were significantly higher compared with control ASCs. However, the enhanced regeneration, hepatic differentiation, and suppressed liver inflammation, as well as fibrotic activity, were significantly reverted by ZnPP coadministration (heme oxygenase-1 [HO-1] inhibitor) indicating an important role of HO-1 in the regenerating and cytoprotective activities of miR-27b-transfected ASCs. We demonstrated that administration of autologous ASCs overexpressed with miR-27b enhances rapid and early liver regeneration and, importantly, preserves function after PH. The ASCs with miR-27b overexpression might offer a viable therapeutic option to facilitate rapid recovery after liver resection.

Clinical characteristics of primary Epstein Barr virus hepatitis with elevation of alkaline phosphatase and γ-glutamyltransferase in children.

PURPOSE: The aim of the present study was to evaluate the clinical characteristics of the primary Epstein-Barr virus (EBV) hepatitis with elevation of both serum alkaline phosphatase (ALP) and γ-glutamyltransferase (γ-GT) levels in children. MATERIALS AND METHODS: A retrospective study was performed by reviewing of the medical records of 36 patients who were diagnosed with primary EBV hepatitis. The patients were divided into 2 groups: patients with elevated serum ALP and γ-GT levels (group 1) and patients without (group 2). RESULTS: The classic features of infectious mononucleosis (fever, pharyngitis and/or tonsillitis, and cervical lymphadenitis) were seen in 20 (57.1%) of group 1 patients and 18 (50.0%) of group 2 patients. Hepatitis with elevated serum ALP and γ-GT levels were present in 14 (38.9%) of the all patients. Of these patients, Jaundice occurred in only 2 (5.6%). The mean levels of aspartate aminotransferase and alanine aminotransferase (ALT) as well as the number of patients with ALT greater than 400 IU/L were significantly different between the groups (177 IU/L vs. 94 IU/L, 418 IU/L vs. 115 IU/L, and 50.0% vs. 13.6%; p=0.001, p=0.001, p=0.026, respectively). The mean duration of elevated serum ALT levels was 17.5 days in group 1 and 9.0 days in group 2 (p=0.013). All patients recovered fully without any chronic or serious complications. CONCLUSION: Primary EBV hepatitis with predominant biochemical abnormalities of the elevation of ALP and γ-GT is frequent and mostly anicteric. This may represent a benign disease, but a delay in recovery of liver function as well.

Acute cytomegalovirus hepatitis in an immunocompetent host.

A 52-year-old woman presented with a 1-week history of recurrent fevers and joint pains accompanied by abdominal and low back discomfort. She has a history of hypoparathyroidism and is on calcium supplements. Physical examination revealed fever and tachycardia. The rest of the examination was normal. Laboratory tests showed newly increased transaminase activity. Serum bilirubin and prothrombin time were normal. She was admitted for evaluation of acute hepatitis. Serology for hepatitis A, B, C and HIV were negative. Her serum acetaminophen and alcohol were undetected. Abdominal imaging was normal. Cultures were sterile. Additional tests for uncommon viral hepatitis included herpes simplex virus, cytomegalovirus and Epstein-Barr virus. Liver biopsy revealed non-specific inflammation. Subsequently, cytomegalovirus serology showed an IgM positive and negative IgG titre. Cytomegalovirus DNA qualitative PCR was also positive. No antiviral medication was given. She continued to have intermittent daily fever but reported no associated symptoms. She was discharged 9 days after admission in stable condition per her request with the advice to follow-up in the clinic in 1 week. Her serum hepatic profile returned to normal and she reported no more episodes of fever. Repeated titres of cytomegalovirus serology showed seroconversion.

Inhibition of Glutaminyl Cyclases alleviates CCL2-mediated inflammation of non-alcoholic fatty liver disease in mice.

Inflammation is an integral part of non-alcoholic fatty liver disease (NAFLD), the most prevalent form of hepatic pathology found in the general population. In this context, recently we have examined the potential role of Glutaminyl Cyclases (QC and isoQC), and their inhibitors, in the maturation of chemokines, for example, monocyte chemoattractant protein 1 (MCP-1, CCL2), to generate their bioactive conformation. Catalysis by isoQC leads to the formation of an N-terminal pyroglutamate residue protecting CCL2 against degradation by aminopeptidases. This is of importance because truncated forms possess a reduced potential to attract immune cells. Since liver inflammation is characterized by the up-regulation of different chemokine pathways, and within this CCL2 is known to be a prominent example, we hypothesised that application of QC/isoQC inhibitors may alleviate liver inflammation by destabilizing CCL2. Therefore, we investigated the role of QC/isoQC inhibition, in comparison with the angiotensin receptor blocker Telmisartan, during development of pathology in a mouse model of non-alcoholic fatty liver disease. Application of a QC/isoQC inhibitor led to a significant reduction in circulating alanine aminotransferase and NAFLD activity score accompanied by an inhibitory effect on hepatocyte ballooning. Further analysis revealed a specific reduction of inflammation by decreasing the number of F4/80-positive macrophages, which is in agreement with the proposed CCL2-related mechanism of action of QC/isoQC inhibitors. Finally, QC/isoQC inhibitor application attenuated liver fibrosis as characterized by reduced collagen deposition in the liver parenchyma. Thus in conclusion, QC/isoQC inhibitors are a promising novel class of anti-non-alcoholic steatohepatitis drugs which have a comparable disease-modifying effect to that of Telmisartan, which is probably mediated via specific interference with a comparable monocyte/macrophage infiltration that occurs under inflammatory conditions.

Application of capillary electrophoresis coupling with electrochemiluminescence detection to estimate activity of leucine aminopeptidas.

A new method to estimate the leucine aminopeptidase (LAP, EC 3.4.11.1) activity using capillary electrophoresis coupled with electrochemiluminescence (ECL) is described. The liberated proline produced by LAP catalyzing the hydrolysis reaction of leucin-proline was used as an ECL coreagent to enhance Ru(bpy)3 (2+) ECL signals efficiently. The detection limit for proline was 2.88 × 10(-6) m (signal-to-noise ratio 3), which was equal to 9.60 × 10(-8) units of LAP being used to catalyze leucin-proline for 1 min. The Michaelis constant Km (2.07 × 10(-2) mol/L) and the maximum reaction velocity Vmax (1.06 × 10(-5) mol/L/min) of LAP for leucin-proline are reported. The reaction conditions including the concentration of metal ions, incubation temperature and pH were optimized. This method was successfully applied to detect LAP activity in plasma and the results were in good agreement with that obtained by the clinical method.

Role of flavin-containing-monooxygenase-dependent neutrophil activation in thioacetamide-induced hepatic inflammation in rats.

Thioacetamide is widely used in industry and is known to be one of the most potent hepatotoxicants in experimental animals. We investigated the involvement of flavin-containing monooxygenase (FMO)-dependent hepatic-neutrophil activation and the release of proinflammatory mediators in thioacetamide-induced hepatic injury in rats. Thioacetamide (100 mg/kg, intraperitoneally) increased, within 12 h, hepatic serum aspartate transferase and alanine transferase levels, tumor necrosis factor-α production, interleukin-1ß and nitrite levels, and myeloperoxidase activity. Rabbit anti-neutrophil serum markedly inhibited all thioacetamide-altered parameters. In addition, FMO-competitive inhibitor methimazole reduced thioacetamide-induced myeloperoxidase activity, hepatic tumor necrosis factor-α, interleukin-1ß, nitrite, inducible nitric oxide synthase, and hepatic damage in thioacetamide-treated rats. Thus, we conclude that FMO-dependent hepatic neutrophil activation initiates the release of proinflammatory mediators in thioacetamide-treated rats.

Hematopoietic AMPK ß1 reduces mouse adipose tissue macrophage inflammation and insulin resistance in obesity.

Individuals who are obese are frequently insulin resistant, putting them at increased risk of developing type 2 diabetes and its associated adverse health conditions. The accumulation in adipose tissue of macrophages in an inflammatory state is a hallmark of obesity-induced insulin resistance. Here, we reveal a role for AMPK ß1 in protecting macrophages from inflammation under high lipid exposure. Genetic deletion of the AMPK ß1 subunit in mice (referred to herein as ß1(-/-) mice) reduced macrophage AMPK activity, acetyl-CoA carboxylase phosphorylation, and mitochondrial content, resulting in reduced rates of fatty acid oxidation. ß1(-/-) macrophages displayed increased levels of diacylglycerol and markers of inflammation, effects that were reproduced in WT macrophages by inhibiting fatty acid oxidation and, conversely, prevented by pharmacological activation of AMPK ß1-containing complexes. The effect of AMPK ß1 loss in macrophages was tested in vivo by transplantation of bone marrow from WT or ß1(-/-) mice into WT recipients. When challenged with a high-fat diet, mice that received ß1(-/-) bone marrow displayed enhanced adipose tissue macrophage inflammation and liver insulin resistance compared with animals that received WT bone marrow. Thus, activation of AMPK ß1 and increasing fatty acid oxidation in macrophages may represent a new therapeutic approach for the treatment of insulin resistance.

Echinacea alkamides prevent lipopolysaccharide/D-galactosamine-induced acute hepatic injury through JNK pathway-mediated HO-1 expression.

This study aimed to shed light on the anti-inflammatory and hepatoprotective effect of the major alkamides dodeca-2E,4E,8Z,10Z(E)-tetraenoic acid isobutylamides (Alk-8/9), isolated from Echinacea purpurea roots, against acute fulminant hepatitis induced by lipopolysaccharide/D-galactosamine (LPS/D-GalN) in mice. The results show that Alk-8/9 dose-dependently induced heme oxygenase (HO)-1 protein expression in LPS-stimulated murine macrophages that was likely regulated by the JNK-mediated pathway through increasing SAPK/JNK phosphorylation, c-jun protein expression, and phosphorylation, and transcription factor AP-1 binding consensus DNA activity. The HO-1 inhibitor or CO scavenger significantly reversed the inhibitory effect of Alk-8/9 on TNF-α expression, whereas N-acetyl-L-cysteine was observed to reduce Alk-8/9-induced HO-1 expression in LPS-treated macrophages. Furthermore, Alk-8/9 markedly induced c-jun and HO-1 protein expression and suppressed serum aminotransferase activities, TNF-α expression, and hepatocyte damage in liver tissues of LPS/d-GalN-treated mice. This paper suggests a new application of Echinacea, a top-selling herbal supplement, as a hepatoprotective agent.