Prevention Of Liver Injury Research Articles

Safety and Efficacy of the SNAP 12-hour Acetylcysteine Regimen for the Treatment of Paracetamol Overdose

BackgroundAcetylcysteine (NAC) is effective at preventing liver injury after paracetamol overdose. The Scottish and Newcastle Anti-emetic Pre-treatment for Paracetamol Poisoning (SNAP) Study demonstrated that a 12 h NAC regimen was associated with fewer adverse drug reactions compared with the standard 21 h regimen. Here, we describe the clinical effectiveness of the SNAP NAC regimen. MethodsThe SNAP regimen, consisting of intravenous NAC 100 mg/kg over 2 h then 200 mg/kg over 10 h, was introduced to treat all paracetamol overdose patients at the Royal Infirmary of Edinburgh, the Royal Victoria Infirmary, Newcastle and St Thomas' Hospital, London. Patient data were prospectively and systematically collected before and after the change in treatment (total patients N = 3340, 21 h N = 1488, SNAP N = 1852). Health record linkage was used to determine patient outcome after hospital discharge. FindingsThere was no difference in liver injury or liver synthetic dysfunction between regimens. Hepatotoxicity (peak ALT > 1000 U/L) occurred in 64 (4.3%) and 67 (3.6%) patients, respectively, in the 21 h and SNAP groups (absolute difference −0.7%, 95% CI −2.1 to 0.6). Multivariable logistic regression did not identify treatment regimen as an outcome-associated factor. No patients were readmitted to hospital with, or died from, liver failure within 30 days of discharge. Anti-histamine treatment (for NAC anaphylactoid drug reactions) was prescribed for 163 (11.0%) patients with the 21 h regimen and 37 (2.0%) patients with the SNAP regimen (absolute difference 9.0% (95% CI 7.3 to 10.7)). InterpretationIn clinical use the SNAP regimen has similar efficacy as standard therapy for preventing liver injury and produces fewer adverse reactions.

Decreased Macrophage Autophagy Promotes Liver Injury and Inflammation from Alcohol.

One mechanism underlying the development of alcoholic liver disease is overactivation of the innate immune response. Recent investigations indicate that the lysosomal pathway of autophagy down-regulates the inflammatory state of hepatic macrophages, suggesting that macrophage autophagy may regulate innate immunity in alcoholic liver disease. The function of macrophage autophagy in the development of alcoholic liver disease was examined in studies employing mice with a myeloid-specific decrease in autophagy. Littermate control and Atg5Δmye mice lacking Atg5-dependent myeloid autophagy were administered a Lieber-DeCarli control (CD) or ethanol diet (ED) alone or together with lipopolysaccharide (LPS) and examined for the degree of liver injury and inflammation. Knockout mice with decreased macrophage autophagy had equivalent steatosis but increased mortality and liver injury from ED alone. Increased liver injury and hepatocyte death also occurred in Atg5Δmye mice administered ED and LPS in association with systemic inflammation as indicated by elevated serum levels of proinflammatory cytokines. Hepatic macrophage and neutrophil infiltration were unaffected by decreased autophagy, but levels of proinflammatory cytokine gene induction were significantly increased in the livers but not adipose tissue of knockout mice treated with ED and LPS. Inflammasome activation was increased in ED/LPS-treated knockout mice resulting in elevated interleukin (IL)-1β production. Increased IL-1β promoted alcoholic liver disease as liver injury was decreased by the administration of an IL-1 receptor antagonist. Macrophage autophagy functions to prevent liver injury from alcohol. This protection is mediated in part by down-regulation of inflammasome-dependent and inflammasome-independent hepatic inflammation. Therapies to increase autophagy may be effective in this disease through anti-inflammatory effects on macrophages.

SAT-174 Loss of CEACAM1 in Endothelial Cells Causes Hepatic Fibrogenesis

Carcinoembryonic Antigen-related Cell Adhesion Molecule 1 (CEACAM1) has been implicated in physiological processes in the metabolic as well as in the vascular systems, as supported by the cardiometabolic abnormalities associated with insulin resistance that developed in global Ceacam1 null mutants. Given the role of CEACAM1 in maintaining vascular integrity, we aimed at identifying a role for CEACAM1-dependent pathways in endothelial cells in the pathogenesis of hepatic fibrosis. To this end, we generated endothelial cell-specific Ceacam1 knockout mice (VECadCc1-/-) and propagated them on the C57BL/6J genetic background. The mice remain insulin sensitive even at 12-months of age, as determined by hyperinsulinemic-euglycemic clamp analysis at 7 months and by insulin tolerance test. The mice display normoinsulinemia associated with intact insulin clearance and without hepatic steatosis. However, these VECadCc1-/- mutants display inflammatory foci in liver parenchyma, when stained by H&E staining. This was supported by ~2-fold increase in the mRNA levels of genes involved in inflammation (F4/80, CD68, IL-1β IL-6, and TNF­α) and by immunostaining for macrophage pool (F4/80) and their activation (CD68). Sirius Red stain detected a remarkable chicken-­wire deposition of collagen fibers interstitially and in the perivenular region in livers of VECadCc1-/- but not controls. The mRNA levels of profibrogenic markers (Tgfβ, collagen 1A1, collagen 6a3, and α-SMA) are ~2-fold higher than controls. Moreover, TGFβ1 is a basally activated in null mice, as shown by increased Smad2/3 phosphorylation compared to their controls. Several mechanisms could contribute to hepatic fibrosis in VECadCc1-/- mutants. These include: 1) increased endothelial-to-mesenchymal transition, supported by increased expression of mesenchymal markers (Snail, Slug, and [fibroblast-specific protein1 (FSP1)] with a reciprocal decrease in endothelial cell makers (CD31) in mouse liver endothelial cells (MLEC) isolated from VECadCc1-/- mice; 2) increased capillarization, a liver injury event that precedes fibrogenesis, as shown by the ~2-fold increase in the mRNA levels of markers of capillarization (Gli1, Gli2, Gli3, iNOS, and osteopontin) in hepatic primary endothelial cells; 3) elevated levels of plasma endothelin-1 (ET-1) that promotes fibrogenesis. Mechanistically, the rise in plasma ET-1 results from increased coupling of the Ras/MAPKinase pathway to insulin receptor and VEGFR via Shc, a Src homology 2 (SH2)-containing cytoplasmic adaptor protein that upon its binding to phosphorylated CEACAM1 undergoes sequestration. Thus, endothelial cell CEACAM1 plays a key role in preventing liver injury and resulting fibrogenesis.

Rebaudioside A administration prevents experimental liver fibrosis: an in vivo and in vitro study of the mechanisms of action involved.

Rebaudioside A (Reb A) is a diterpenoid isolated from the leaves of Stevia rebaudiana (Bertoni) that has been shown to possess pharmacological activity, including anti-inflammatory and antioxidant properties. However, the ability of Reb A to prevent liver injury has not been evaluated. Therefore, we aimed to study the potential of Reb A (20mg/kg; two times daily intraperitoneally) to prevent liver injury induced by thioacetamide (TAA) administration (200mg/kg; three times per week intraperitoneally). In addition, cocultures were incubated with either lipopolysaccharide or ethanol. Antifibrotic, antioxidant and immunological responses were evaluated. Chronic TAA administration produced considerable liver damage and distorted the liver parenchyma with the presence of prominent thick bands of collagen. In addition, TAA upregulated the expression of α-smooth muscle actin, transforming growth factor-β1, metalloproteinases 9, 2 and 13, and nuclear factor kappaB and downregulated nuclear erythroid factor 2. Reb A administration prevented all of these changes. In cocultured cells, Reb A prevented the upregulation of genes implicated in fibrotic and inflammatory processes when cells were exposed to ethanol and lipopolysaccharide. Altogether, our results suggest that Reb A prevents liver damage by blocking oxidative processes via upregulation of nuclear erythroid factor 2, exerts immunomodulatory effects by downregulating the nuclear factor-κB system and acts as an antifibrotic agent by maintaining collagen content.

Liver Injury Induced by Carbon Tetrachloride in Mice Is Prevented by the Antioxidant Capacity of Anji White Tea Polyphenols.

Anji white tea is a unique variety of green tea that is rich in polyphenols. In this study, the effect of Anji white tea polyphenols (AJWTP) on the prevention of carbon tetrachloride (CCl4)-induced liver injury through its antioxidant properties was studied. Biochemical and molecular biology methods were used to analyze the serum and liver tissue of mice. The antioxidant capacity and liver injury preventive effect of AJWTP were determined, and the mechanism was elaborated. The results showed that AJWTP decreased the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) in mice with liver injury, it increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the serum and liver tissue of mice with liver injury, and it also decreased the amount of malondialdehyde (MDA). Further quantitative polymerase chain reaction (qPCR) results showed that AJWTP upregulated the mRNA expression of Cu/Zn-SOD, Mn-SOD, catalase (CAT), and nuclear factor of kappa light polypeptide gene enhancer in B-cell inhibitor alpha (IκB-α) and downregulated the expression of nuclear factor κ-light-chain-enhancer of activated B-cells (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) in the liver tissue of mice with liver injury. Therefore, AJWTP produces sufficient antioxidant action to prevent liver injury, and the effect increases with the increase in AJWTP concentration. The effect of 200 mg/kg AJWTP was similar to that of the same concentration of the drug (silymarin) used for the treatment of liver injury. This indicates excellent potential for the development and utilization of AJWTP because it is an active substance with excellent antioxidant effects and can prevent liver injury.

Randomised open label exploratory, safety and tolerability study with calmangafodipir in patients treated with the 12-h regimen of N-acetylcysteine for paracetamol overdose\u2014the PP100\u201301 for Overdose of Paracetamol (POP) trial: study protocol for a randomised controlled trial

BackgroundParacetamol (acetaminophen) overdose (POD) is the commonest cause of acute liver failure in Europe and North America. Current treatment involves the use of the antidote N-acetylcysteine (NAC) in patients deemed at risk of liver damage. This regimen was introduced in the 1970s and has remained largely unchanged even though the initial NAC infusion is frequently associated with adverse reactions, in particular nausea, vomiting, and anaphylactoid reactions. NAC has reduced efficacy for preventing liver injury in those patients who present later after overdose. We designed a randomised study investigating the safety and tolerability of a superoxide dismutase (SOD) mimetic, calmangafodipir (PP100–01), co-treatment with a 12-h NAC regimen compared with NAC treatment alone in patients with POD.Methods/designWe have designed an open-label, randomised, exploratory, rising dose design, NAC-controlled, phase 1 safety and tolerability study in patients treated with NAC for POD. A total of 24 patients will be assigned into one of three dosing cohorts of eight patients (n = 6 for PP100–01 and NAC; n = 2 for NAC alone). The doses of PP100–01 are 2, 5, and 10 μmol/kg. The primary outcome is the safety and tolerability of PP100–01 when co-administered with a 12-h NAC regimen compared with NAC treatment alone. Furthermore, the study will explore if PP100–01 has potential efficacy for the treatment of paracetamol-induced liver injury by measurement of conventional clinical and exploratory biomarkers.DiscussionThe aim of the study is to test the safety and tolerability of a SOD mimetic, PP100–01, in combination with a 12-h NAC regimen in patients presenting within 24 h of POD. This study will provide valuable data regarding the incidence of adverse events caused by the 12-h NAC plus PP100–01 regimen and may provide evidence of PP100–01 efficacy in the treatment of paracetamol-induced liver injury.Trial registrationEudraCT, 2017–000246-21; ClinicalTrials.gov, NCT03177395. Registered on 6 June 2017.

Ketoconazole pretreatment ameliorates carbon tetrachloride-induced acute liver injury in rats by suppressing inflammation and oxidative stress.

Several studies have demonstrated the chemopreventive role of ketoconazole in animal models of liver injury. However, the underlying molecular mechanisms of this hepatoprotective effect are poorly understood. The present study assessed the potential of ketoconazole to enhance resistance to carbon tetrachloride-induced hepatotoxicity in vivo in a rat model. Ketoconazole pretreatment adult male rats were intraperitoneally injected with carbon tetrachloride for 24 hr and various hepatic parameters were analyzed. We observed decreased serum transaminases activity, reduced nuclear RelA/p65 expression, and suppressed production of pro-inflammatory cytokines in the liver tissue. Histopathological examination demonstrated ketoconazole pretreatment to extensively prevent liver injury. In addition, it significantly increased nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) protein expression, glutathione (GSH) to oxidized glutathione (GSSG) ratio, and antioxidant enzymes gene expression. These results suggest that ketoconazole pretreatment ameliorates carbon tetrachloride-induced acute liver injury in rats, signifying its anti-inflammatory and antioxidant functions.

Glutathione inhibits expression of the proinflammatory biomarker inducible nitric oxide synthase in hepatocytes

Background: Intracellular glutathione (GSH) plays an important regulatory role in the host response to liver injury. However, there have been few scientific reports on the anti-inflammatory effects of GSH. In the inflamed liver, proinflammatory cytokines stimulate liver cells, followed by expression of inducible nitric oxide synthase (iNOS). Excessive nitric oxide (NO) levels produced by iNOS are one of the factors involved in liver injury. Therefore, inhibiting iNOS induction is important for preventing liver injury. This study aimed to investigate the protective effects of GSH on the liver by examining interleukin (IL)-1β-stimulated hepatocytes.Methods: Primary cultured rat hepatocytes were treated with IL-1β in the presence or absence of GSH. Induction of iNOS and its signaling pathway were analyzed.Results: Addition of GSH decreased IL-1β-induced iNOS protein and mRNA expression levels, which resulted in inhibition of NO production. GSH also decreased tumor necrosis factor (TNF)-α and IL-6 mRNA expression. GSH blocked “type I IL-1 receptor upregulation”, one of the essential signaling pathways for iNOS induction, through inactivation of an upstream kinase, phosphatidylinositol 3-kinase/Akt. In contrast, GSH had no effects on degradation of IκB and activation of NF-ĸB (nuclear translocation and its DNA binding). Transfection experiments revealed that GSH reduced iNOS mRNA levels at the promoter transactivation and mRNA stabilization steps. Delayed administration of GSH after IL-1β addition also inhibited iNOS induction. Conclusions: Our study suggests that GSH affects induction of inflammatory mediators, including iNOS and TNF-α, indicating its therapeutic potential for organ injuries, especially for the liver.Keywords: glutathione, inducible nitric oxide synthase, liver injury, primary cultured hepatocytes, type I interleukin-1 receptor, tumor necrosis factor-α

Protective Effects of Reduced Beta 2 Glycoprotein I on Liver Injury in Streptozotocin (STZ)-Diabetic Rats by Activation of AMP-Activated Protein Kinase.

BackgroundProtective effects of reduced beta 2 glycoprotein I (Rβ2GPI) against vascular injury of diabetes mellitus have been extensively investigated. However, the effects of Rβ2GPI on liver injury in diabetic animals have not been reported.Material/MethodsA diabetic rat model of was produced by systemic injection of streptozotocin (STZ). Rats were divided into a normal control group, a model group, and an Rβ2GPI treatment group (N=6 in each group). After treatments, blood serum and liver tissue were collected to test the protection of Rβ2GPI. AMP-activated protein kinase (AMPK) was detected by immunohistochemistry and Western blotting.ResultsOur results revealed that Rβ2GPI reduced blood glucose, serum creatinine, and urea nitrogen levels, as well as serum inflammation cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-a and C-reactive protein in the diabetic rats. Importantly, Rβ2GPI prevented liver injury in the diabetic rats as confirmed by hematoxylin-eosin (H&E) staining, alanine transaminase, aspartate transaminase, and gamma-glutamyl transferase. Reactive oxygen species (ROS) were promoted by diabetic modeling and were attenuated by Rβ2GPI administration. Moreover, Rβ2GPI significantly reduced liver catalase, malondialdehyde, and superoxide dismutase levels in the diabetic rats. Rβ2GPI reduced liver glycolipid storage in STZ diabetic rats. Both immunohistochemistry and Western blotting demonstrated that Rβ2GPI promoted AMPK phosphorylation in the diabetic rats.ConclusionsOur data proved that Rβ2GPI prevented liver injury in diabetic rats, likely through activating the AMPK signaling pathway.

The innate immune receptor TREM-1 promotes liver injury and fibrosis.

Inflammation occurs in all tissues in response to injury or stress and is the key process underlying hepatic fibrogenesis. Targeting chronic and uncontrolled inflammation is one strategy to prevent liver injury and fibrosis progression. Here, we demonstrate that triggering receptor expressed on myeloid cells 1 (TREM-1), an amplifier of inflammation, promotes liver disease by intensifying hepatic inflammation and fibrosis. In the liver, TREM-1 expression was limited to liver macrophages and monocytes and was highly upregulated on Kupffer cells, circulating monocytes, and monocyte-derived macrophages in a mouse model of chronic liver injury and fibrosis induced by carbon tetrachloride (CCl4) administration. TREM-1 signaling promoted proinflammatory cytokine production and mobilization of inflammatory cells to the site of injury. Deletion of Trem1 reduced liver injury, inflammatory cell infiltration, and fibrogenesis. Reconstitution of Trem1-deficient mice with Trem1-sufficient Kupffer cells restored the recruitment of inflammatory monocytes and the severity of liver injury. Markedly increased infiltration of liver fibrotic areas with TREM-1-positive Kupffer cells and monocytes/macrophages was found in patients with hepatic fibrosis. Our data support a role of TREM-1 in liver injury and hepatic fibrogenesis and suggest that TREM-1 is a master regulator of Kupffer cell activation, which escalates chronic liver inflammatory responses, activates hepatic stellate cells, and reveals a mechanism of promotion of liver fibrosis.

Gomisin N Alleviates Ethanol-Induced Liver Injury through Ameliorating Lipid Metabolism and Oxidative Stress.

Gomisin N (GN), a lignan derived from Schisandra chinensis, has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. In the present study, we investigated the protective effect of GN against ethanol-induced liver injury using in vivo and in vitro experiments. Histopathological examination revealed that GN administration to chronic-binge ethanol exposure mice significantly reduced ethanol-induced hepatic steatosis through reducing lipogenesis gene expression and increasing fatty acid oxidation gene expression, and prevented liver injury by lowering the serum levels of aspartate transaminase and alanine transaminase. Further, it significantly inhibited cytochrome P450 2E1 (CYP2E1) gene expression and enzyme activity, and enhanced antioxidant genes and glutathione level in hepatic tissues, which led to decreased hepatic malondialdehyde levels. It also lowered inflammation gene expression. Finally, GN administration promoted hepatic sirtuin1 (SIRT1)-AMP-activated protein kinase (AMPK) signaling in ethanol-fed mice. Consistent with in vivo data, treatment with GN decreased lipogenesis gene expression and increased fatty acid oxidation gene expression in ethanol-treated HepG2 cells, thereby preventing ethanol-induced triglyceride accumulation. Furthermore, it inhibited reactive oxygen species generation by downregulating CYP2E1 and upregulating antioxidant gene expression, and suppressed inflammatory gene expression. Moreover, GN prevented ethanol-mediated reduction in SIRT1 and phosphorylated AMPK. These findings indicate that GN has therapeutic potential against alcoholic liver disease through inhibiting hepatic steatosis, oxidative stress and inflammation.

Salidroside and Curcumin Formula Prevents Liver Injury in Nonalcoholic Fatty Liver Disease in Rats

Introduction and aim. Salidroside and curcumin (SC) formula could alleviate lipid deposition in high fat diet-induced nonalcoholic fatty liver disease (NAFLD). However, the mechanisms are still unknown, and the magnitude of potential therapeutic benefit remains understudied.Material and methods. The rats were treated with high fat diet for 14 weeks to induce NAFLD. The experiment was divided into control, model (NAFLD), SC formula and rosiglitazone groups (n = 7 in each group). Hematoxylin-eosin (H&E) staining was applied to detect liver morphological changes. Biochemical, metabolic indices and inflammation factors in liver tissue and serum were detected. Additionally, the activities of related enzymes were detected by enzyme-linked immunosorbent assay.Results. In the established rat model, typical lipid deposition and liver steatosis were observed. Liver triglyceride, free fatty acids, sera alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, fasting insulin, fasting blood glucose and homeostasis model assessment of insulin resistance were elevated in model group. Liver malondialdehyde was significantly elevated, while superoxide dismutase was significantly decreased in model group, compared with control. Moreover, tumor necrosis factor-α and Interleukin-1 were significantly prod uced in model group, compared with control. As a mechanism, high fat diet decreased tissue AMP-activated protein kinase (AMPK), phosphorylated AMPK, carnitine palmitoyltransferase 1 and increased inacetyl-CoA carboxylase (ACCase), phosphorylated ACCase. Importantly, these abnormal changes caused by high fat diet were reduced by SC formula administration.Conclusion. SC formula could ameliorate the injury caused by high fat diet. The effect was likely mediated via its influence on insulin resistance, lipid peroxidation injury and AMPK signaling pathway.

Antioxidant Potential, Anti-Inflammatory and Hepatoprotective Effect of Curcumin in a Rat Model of Hepatotoxicity

Curcumin [1,7- bis (4-hydroxy-3-methoxyphenyl)- 1,6- heptadiene- 3,5-dione] was shown to exert potent antioxidant, anti-inflammatory and hepatoprotective properties. This study was done to investigate the protective effects of curcumin in thioacetamide (TAA)-induced hepatic injury in rats. Thirty-six male albino rats were divided into three equal groups. Group I (normal control group). Group II (TAA-intoxicated group): rats received thioacetamide (50 mg/kg b. wt. ip) twice weekly for 6 weeks. Group III (TAA + curcumin co-treated group): rats received thioacetamide (50 mg/kg b. wt.) and simultaneously administered curcumin (200 mg/kg b. wt./daily/orally) for 6 weeks (end of experiment). All animals were sacrificed after 6 weeks. TAA administration induced liver damage manifested by the significant increases in serum levels of ALT, AST, ALP and total bilirubin compared with control group. Oxidative stress in the group II was manifested by a significant rise in L-MDA levels with a marked reduction in the activities of antioxidant enzymes like GST, catalase CAT and depletion of GSH content in liver tissues as compared with the control group. On the other hand, TAA significantly affected the inflammation markers represented by elevation of myeloperoxidase (MPO) activities and upregulation of interleukin-6 (IL-6) gene expression levels in liver tissues. The coadministration of curcumin and thioacetamide (protection modality) prevented liver injury by normalizing the biochemical parameters, lipid peroxidation index and improving the protein oxidation, inflammatory markers and the antioxidant status. These findings suggested that, liver injury could be curtailed by the antioxidant and anti-inflammatory activities of curcumin and the normal status of the liver could be preserved.

DHA attenuates hepatic ischemia reperfusion injury by inhibiting pyroptosis and activating PI3K/Akt pathway

Hepatic ischemia reperfusion (I/R) injury is very common in liver transplantation and major liver surgeries and may cause liver failure or even death. Docosahexaenoic acid (DHA) has displayed activities in reducing oxidative stress and inflammatory reaction in many disorders. In the present study, we investigated the protective effects of DHA against I/R-induced injury and the underlying mechanisms. Here, we show that DHA protected hepatic I/R injury by reducing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and decreasing the oxidative stress in liver tissues. The viability of Buffalo rat liver (BRL) cells was reduced by hypoxia/restoration (H/R) but restored by DHA. DHA significantly downregulated the expression of pyroptosis-related proteins including NLR pyrin domain containing 3 (NLRP3), apoptotic speck-like protein containing CARD (ASC) and cleaved caspase-1 and reduced the secretion of pro-inflammatory cytokines. The above results were supported by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. However, incubation with LY294002, a specific inhibitor of phosphatidylinositol-3-kinase (PI3K), abolished the effects of DHA, since it increased the expression of cleaved caspase-1 and the production of inflammatory cytokines. The present results have demonstrated that DHA ameliorated I/R-induced injury by inhibiting pyroptosis of hepatocytes induced in liver I/R injury in vivo and in vitro through the PI3K/Akt pathway, providing a potential therapeutic option to prevent liver injury by I/R.

Salidroside and Curcumin Formula Prevents Liver Injury in Nonalcoholic Fatty Liver Disease in Rats

Introduction and aim. Salidroside and curcumin (SC) formula could alleviate lipid deposition in high fat diet-induced nonalcoholic fatty liver disease (NAFLD). However, the mechanisms are still unknown, and the magnitude of potential therapeutic benefit remains understudied. Material and methods. The rats were treated with high fat diet for 14 weeks to induce NAFLD. The experiment was divided into control, model (NAFLD), SC formula and rosiglitazone groups (n = 7 in each group). Hematoxylin-eosin (H&E) staining was applied to detect liver morphological changes. Biochemical, metabolic indices and inflammation factors in liver tissue and serum were detected. Additionally, the activities of related enzymes were detected by enzyme-linked immunosorbent assay. Results. In the established rat model, typical lipid deposition and liver steatosis were observed. Liver triglyceride, free fatty acids, sera alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, fasting insulin, fasting blood glucose and homeostasis model assessment of insulin resistance were elevated in model group. Liver malondialdehyde was significantly elevated, while superoxide dismutase was significantly decreased in model group, compared with control. Moreover, tumor necrosis factor-α and Interleukin-1 were significantly produced in model group, compared with control. As a mechanism, high fat diet decreased tissue AMP-activated protein kinase (AMPK), phosphorylated AMPK, carnitine palmitoyltransferase 1 and increased inacetyl-CoA carboxylase (ACCase), phosphorylated ACCase. Importantly, these abnormal changes caused by high fat diet were reduced by SC formula administration. Conclusion. SC formula could ameliorate the injury caused by high fat diet. The effect was likely mediated via its influence on insulin resistance, lipid peroxidation injury and AMPK signaling pathway.

Effects of nutritional status on acetaminophen measurement and exposure

Introduction: Fasting, as well as a high-fat diet, might increase the risk on acetaminophen-induced toxicity after an acute overdose. Therefore, it has been suggested to lower the threshold for acetylcysteine treatment to prevent liver injury in case of fasting. This study aims to investigate the effects of 36 hours of fasting and three days of a hypercaloric high-fat diet on acetaminophen measurement and exposure.Methods: Nine healthy male subjects were enrolled in a randomized crossover intervention study. Subjects received 1000mg oral acetaminophen after an overnight fast following: (1) regular diet,(2) 36h of fasting and (3) three days of a hypercaloric high-fat diet consisting of 500ml of cream (1715 kcal) supplemented to their regular diet. Pharmacokinetic parameters were determined by non-compartmental analysis. Samples were analyzed by an enzymatic colorimetric method used in routine practice and by LC-MS/MS being the gold standard. Agreement between these methods was assessed by the Bland–Altman method.Results: Short-term fasting increased acetaminophen exposure by 20% (ΔAUC0-8 hours, p = .04) in comparison with the control diet. Three days of hypercaloric high-fat diet did not affect acetaminophen exposure (ΔAUC0–8 hours= 9%, p = .67). The intraclass correlation coefficient between the enzymatic assay and LC-MS/MS methods of the fasting samples was 0.46 (0.28–0.61), compared to 0.87 (0.81–0.92) and 0.87 (0.79–0.91) in the control and high-fat samples respectively.Conclusions: Short-term fasting increases acetaminophen exposure in healthy subjects, whereas no effect is observed after a high-fat diet. Furthermore, short-term fasting decreases the accuracy of the enzymatic colorimetric method when measuring relatively low acetaminophen concentrations. This suggests considering nutritional status when assessing the risk of acetaminophen-induced toxicity, although further research at toxic doses is needed.

4-Methylpyrazole protects against acetaminophen hepatotoxicity in mice and in primary human hepatocytes.

Liver injury due to acetaminophen (APAP) overdose is the major cause of acute liver failure in the United States. While treatment with N-acetylcysteine is the current standard of care for APAP overdose, anecdotal evidence suggests that administration of 4-methylpyrazole (4MP) may be beneficial in the clinic. The objective of the current study was to examine the protective effect of 4MP and its mechanism of action. Male C57BL/6J mice were co-treated with 300 mg/kg of APAP and 50 mg/kg of 4MP. The severe liver injury induced by APAP at 6 h as indicated by elevated plasma alanine aminotransferase activities, centrilobular necrosis, and nuclear DNA fragmentation was almost completely eliminated by 4MP. In addition, 4MP largely prevented APAP-induced activation of c-Jun N-terminal kinase (JNK), mitochondrial translocation of phospho-JNK and Bax, and the release of mitochondrial intermembrane proteins. Importantly, 4MP inhibited the generation of APAP protein adducts and formation of APAP-glutathione (GSH) conjugates and attenuated the depletion of the hepatic GSH content. These findings are relevant to humans because 4MP also prevented APAP-induced cell death in primary human hepatocytes. In conclusion, early treatment with 4MP can completely prevent liver injury after APAP overdose by inhibiting cytochrome P450 and preventing generation of the reactive metabolite.

Sphingosine kinase 1 promotes liver fibrosis by preventing miR-19b-3p-mediated inhibition of CCR2.

Chronic liver disease mediated by activation of hepatic stellate cells (HSCs) and Kupffer cells (KCs) leads to liver fibrosis. Here, we aimed to investigate the molecular mechanism and define the cell type involved in mediating the sphingosine kinase (SphK)1‐dependent effect on liver fibrosis. The levels of expression and activity of SphK1 were significantly increased in fibrotic livers compared with the normal livers in human. SphK1 was coexpressed with a range of HSC/KC markers including desmin, α‐smooth muscle actin (α‐SMA) and F4/80 in fibrotic liver. Deficiency of SphK1 (SphK1−/−) resulted in a marked amelioration of hepatic injury, including transaminase activities, histology, collagen deposition, α‐SMA and inflammation, in CCl4 or bile duct ligation (BDL)‐induced mice. Likewise, treatment with a specific inhibitor of SphK1, 5C, also significantly prevented liver injury and fibrosis in mice induced by CCl4 or BDL. In cellular levels, inhibition of SphK1 significantly blocked the activation and migration of HSCs and KCs. Moreover, SphK1 knockout in KCs reduced the secretion of CCL2, and SphK1 knockout in HSCs reduced C‐C motif chemokine receptor 2 ([CCR2] CCL2 receptor) expression in HSCs. CCL2 in SphK1−/− mice was lower whereas microRNA‐19b‐3p in SphK1−/− mice was higher compared with wild‐type (WT) mice. Furthermore, microRNA‐19b‐3p downregulated CCR2 in HSCs. The functional effect of SphK1 in HSCs on liver fibrosis was further strengthened by the results of animal experiments using a bone marrow transplantation (BMT) method. Conclusion: SphK1 has distinct roles in the activation of KCs and HSCs in liver fibrosis. Mechanistically, SphK1 in KCs mediates CCL2 secretion, and SphK1 in HSCs upregulates CCR2 by downregulation of miR‐19b‐3p. (Hepatology 2018).

Inhibition of Glycogen Synthase II with RNAi Prevents Liver Injury in Mouse Models of Glycogen Storage Diseases.

Glycogen storage diseases (GSDs) of the liver are devastating disorders presenting with fasting hypoglycemia as well as hepatic glycogen and lipid accumulation, which could lead to long-term liver damage. Diet control is frequently utilized to manage the potentially dangerous hypoglycemia, but there is currently no effective pharmacological treatment for preventing hepatomegaly and concurrent liver metabolic abnormalities, which could lead to fibrosis, cirrhosis, and hepatocellular adenoma or carcinoma. In this study, we demonstrate that inhibition of glycogen synthesis using an RNAi approach to silence hepatic Gys2 expression effectively prevents glycogen synthesis, glycogen accumulation, hepatomegaly, fibrosis, and nodule development in a mouse model of GSD III. Mechanistically, reduction of accumulated abnormally structured glycogen prevents proliferation of hepatocytes and activation of myofibroblasts as well as infiltration of mononuclear cells. Additionally, we show that silencing Gys2 expression reduces hepatic steatosis in a mouse model of GSD type Ia, where we hypothesize that the reduction of glycogen also reduces the production of excess glucose-6-phosphate and its subsequent diversion to lipid synthesis. Our results support therapeutic silencing of GYS2 expression to prevent glycogen and lipid accumulation, which mediate initial signals that subsequently trigger cascades of long-term liver injury in GSDs.

Theanine supplementation prevents liver injury and heat shock response by normalizing hypothalamic-pituitaryadrenal axis hyperactivity in mice subjected to whole body heat stress

Thermal stress evokes heat shock response and activates hypothalamic-pituitaryadrenal (HPA) axis. Additionally, liver injury is an important adverse effect of thermal stress. Considering the anti-stress effects of theanine, an amino acid found in tea plants, we hypothesized that theanine may protect against heat stress. Mice were administered intragastrically with theanine prior to whole body thermal exposure. Theanine prevented the heat-induced upregulation of heat shock proteins and reduced the heat-induced liver damage and oxidative stress. Theanine significantly prevented the heat-induced effects on inflammatory and acute phase responses as measured by plasma inflammatory cytokine concentrations, hepatic inflammatory cytokine mRNA levels, plasma nitric oxide and C-reactive protein levels. Additionally, theanine supplementation suppressed heat stress-related disorders associated with normalizing HPA axis hyperactivity. These findings suggest that theanine can have beneficial effects against heat stress and may be an attractive dietary application for people who are at high risk of developing heat stress.