Experimental Liver Injury Research Articles

575 - Depletion of Microrna-21 Reduces Infiltration of Macrophages and Neutrophils in the Liver and Attenuates Inflammatory Cytokine Production in Liver Macrophages During Experimental Cholestatic Liver Injury

575 - Depletion of Microrna-21 Reduces Infiltration of Macrophages and Neutrophils in the Liver and Attenuates Inflammatory Cytokine Production in Liver Macrophages During Experimental Cholestatic Liver Injury

Urinary and Serum Metabolomics Analyses Uncover That Total Glucosides of Paeony Protect Liver against Acute Injury Potentially via Reprogramming of Multiple Metabolic Pathways.

Total glucosides of paeony (TGP) have been confirmed to be hepatoprotective. However, the underlying mechanism is largely unclear. In this study, we investigated the metabolic profiles of urine and serum in rats with carbon tetrachloride- (CCl4-) induced experimental liver injury and TGP administration by using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The vehicle or a single dose of TGP was intragastrically administered to Wistar rats once a day for 14 consecutive days. To induce ALI, 50% CCl4 was injected intraperitoneally into these rats 2 hours after the last time administration of saline of TGP at the 14th day. The results indicated that TGP administration could protect rats from CCl4-induced ALI and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevation, as well as hepatocyte apoptosis and inflammation. Furthermore, metabolomics analysis showed that TGP treatment significantly attenuated CCl4-triggered deregulation of multiple metabolites in both urine and serum, including glycine, alanine, proline, and glutamine. Metabolite set enrichment and pathway analyses demonstrated that amino acid cycling and glutathione metabolism were two main pathways involved in CCl4-induced experimental liver injury and TGP administration. Taken together, these findings revealed that regulation of metabolites potentially plays a pivotal role in the protective effect of TGP on ALI.

Erzhi Pill® Repairs Experimental Liver Injury via TSC/mTOR Signaling Pathway Inhibiting Excessive Apoptosis.

The present study aimed to investigate the mechanism of hepatoprotective effect of Erzhi Pill (EZP) on the liver injury via observing TSC/mTOR signaling pathway activation. The experimental liver injury was induced by 2-acetylaminofluorene (2-AAF) treatment combined with partial hepatectomy (PH). EZP treated 2-AAF/PH-induced liver injury by the therapeutic and prophylactic administration. After the administration of EZP, the activities of aspartic transaminase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AKP), and gamma-glutamyl transpeptidase (γ-GT) were decreased, followed by the decreased levels of hepatocyte apoptosis and caspase-3 expression. However, the secretion of albumin, liver weight, and index of liver weight were elevated. Microscopic examination showed that EZP restored pathological liver injury. Meanwhile, Rheb and mammalian target of rapamycin (mTOR) activation were suppressed, and tuberous sclerosis complex (TSC) expression was elevated in liver tissues induced by 2-AAF/PHx and accompanied with lower-expression of Bax, Notch1, p70S6K, and 4E-EIF and upregulated levels of Bcl-2 and Cyclin D. Hepatoprotective effect of EZP was possibly realized via inhibiting TSC/mTOR signaling pathway to suppress excessive apoptosis of hepatocyte.

Antioxidant and Hepatoprotective Effect of Swertiamarin on Carbon Tetrachloride-Induced Hepatotoxicity via the Nrf2/HO-1 Pathway

Background/Aims: Swertiamarin (STM), the main bioactive component in Swertia mussotii Franch (Gentianaceae), has been shown to exert hepatoprotective effects on experimental liver injury. However, the effects and exact mechanisms of STM on carbon tetrachloride (CCl₄) causing hepatotoxicity are still unknown. This study investigated the potential protective effects and mechanisms of STM on CCl₄-induced liver injury in rats. Methods: Adult male Sprague-Dawley (SD) rats were exposed to CCl₄ with or without STM co-administration for consecutive eight weeks. Results: STM significantly ameliorated CCl₄-induced increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels and histopathological changes in the liver. Hepatic oxidative stress was repressed by STM, as evidenced by the decrease in malondialdehyde (MDA), with concomitant increase in antioxidase activity (e.g. superoxide dismutase (SOD); glutathione peroxidase (GPx)), glutathione (GSH) level. STM also obviously attenuated inflammatory response in CCl₄-lesioned livers as evidenced by the decrease in inflammatory cytokines/ chemokines (e.g. inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β)). Additionally, STM significantly induced the expression of CYPs, efflux transporters and PDZK1 as compared with the CCl₄ group. Moreover, co-administration of STM with CCl₄ remarkably up-regulated the expression of Nrf2, HO-1 and NQO1 compared with the CCl₄ group. Conclusions: The present study demonstrates that STM exerts a protective effect against CCl₄-induced liver injury and inflammation with its antioxidant effects and induction of hepatic detoxification enzymes and efflux transporters expression, at least in part, via the Nrf2/HO-1 pathway in rats.

HMGB1 and Extracellular Histones Significantly Contribute to Systemic Inflammation and Multiple Organ Failure in Acute Liver Failure.

Acute liver failure (ALF) is the culmination of severe liver cell injury from a variety of causes. ALF occurs when the extent of hepatocyte death exceeds the hepatic regenerative capacity. ALF has a high mortality that is associated with multiple organ failure (MOF) and sepsis; however, the underlying mechanisms are still not clear. Emerging evidence shows that ALF patients/animals have high concentrations of circulating HMGB1, which can contribute to multiple organ injuries and mediate gut bacterial translocation (BT). BT triggers/induces systemic inflammatory responses syndrome (SIRS), which can lead to MOF in ALF. Blockade of HMGB1 significantly decreases BT and improves hepatocyte regeneration in experimental acute fatal liver injury. Therefore, HMGB1 seems to be an important factor that links BT and systemic inflammation in ALF. ALF patients/animals also have high levels of circulating histones, which might be the major mediators of systemic inflammation in patients with ALF. Extracellular histones kill endothelial cells and elicit immunostimulatory effect to induce multiple organ injuries. Neutralization of histones can attenuate acute liver, lung, and brain injuries. In conclusion, HMGB1 and histones play a significant role in inducing systemic inflammation and MOF in ALF.

The pro-fibrotic role of dipeptidyl peptidase 4 in carbon tetrachloride-induced experimental liver injury.

Liver fibrosis is a progressive pathological process involving inflammation and extracellular matrix deposition. Dipeptidyl peptidase 4 (DPP4), also known as CD26, is a cell surface glycoprotein and serine protease. DPP4 binds to fibronectin, can inactivate specific chemokines, incretin hormone and neuropeptides, and influences cell adhesion and migration. Such properties suggest a pro-fibrotic role for this peptidase but this hypothesis needs in vivo examination. Experimental liver injury was induced with carbon tetrachloride (CCl4) in DPP4 gene knockout (gko) mice. DPP4 gko had less liver fibrosis and inflammation and fewer B cell clusters than wild type mice in the fibrosis model. DPP4 inhibitor-treated mice also developed less liver fibrosis. DNA microarray and PCR showed that many immunoglobulin (Ig) genes and some metabolism-associated transcripts were differentially expressed in the gko strain compared with wild type. CCl4-treated DPP4 gko livers had more IgM+ and IgG+ intrahepatic lymphocytes, and fewer CD4+, IgD+ and CD21+ intrahepatic lymphocytes. These data suggest that DPP4 is pro-fibrotic in CCl4-induced liver fibrosis and that the mechanisms of DPP4 pro-fibrotic action include energy metabolism, B cells, NK cells and CD4+ cells.

Combination of tauroursodeoxycholic acid and N-acetylcysteine exceeds standard treatment for acetaminophen intoxication.

Acetaminophen overdose in mice is characterized by hepatocyte endoplasmic reticulum stress, which activates the unfolded protein response, and centrilobular hepatocyte death. We aimed at investigating the therapeutic potential of tauroursodeoxycholic acid, a hydrophilic bile acid known to have anti-apoptotic and endoplasmic reticulum stress-reducing capacities, in experimental acute liver injury induced by acetaminophen overdose. Mice were injected with 300mg/kg acetaminophen, 2hours prior to receiving tauroursodeoxycholic acid, N-acetylcysteine or a combination therapy, and were euthanized 24hours later. Liver damage was assessed by serum transaminases, liver histology, terminal deoxynucleotidyl transferase dUTP nick end labelling staining, expression profiling of inflammatory, oxidative stress, unfolded protein response, apoptotic and pyroptotic markers. Acetaminophen overdose resulted in a significant increase in serum transaminases, hepatocyte cell death, unfolded protein response activation, oxidative stress, NLRP3 inflammasome activation, caspase 1 and pro-inflammatory cytokine expressions. Standard of care, N-acetylcysteine and, to a lesser extent, tauroursodeoxycholic treatment were associated with significantly lower transaminase levels, hepatocyte death, unfolded protein response activation, oxidative stress markers, caspase 1 expression and NLRP3 levels. Importantly, the combination of N-acetylcysteine and tauroursodeoxycholic acid improved serum transaminase levels, reduced histopathological liver damage, UPR-activated CHOP, oxidative stress, caspase 1 expression, NLRP3 levels, IL-1β levels and the expression of pro-inflammatory cytokines and this to a greater extend than N-acetylcysteine alone. These findings indicate that a combination strategy of N-acetylcysteine and tauroursodeoxycholic acid surpasses the standard of care in acetaminophen-induced liver injury in mice and might represent an attractive therapeutic opportunity for acetaminophen-intoxicated patients.

Paracetamol induced hepatic toxicity and amelioration by cinnamon in rats

The study was designed to evaluate the hepato-protective activity of aqueous extract of cinnamon in acute experimental liver injury induced by paracetamol. Twenty four male albino rats were randomly divided into four groups (six rats in each). Group I rats received distilled water for 15 days and served as a vehicle control. The animals in the group II were given single oral administration of paracetamol (1 g/kg), 1 h after last distilled water administration and acts as paracetamol toxic control group. Groups III and IV received aqueous extract of cinnamon (200 and 400 mg/kg bwt), respectively, once daily for 15 consecutive days followed by a single oral administration of paracetamol (1 g/kg), 1 h after the last cinnamon dose administration. The degree of hepatoprotection was measured using liver enzymes (Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), bilirubin, albumin, and lipid profile levels. Also, histopathological examinations of liver were done. The significantly disturbed liver functions by paracetamol toxicity were restored to nearly normal values by administration of cinnamon. Also, the change in biochemical parameters in groups received paracetamol alone was modified towards the normal values in groups given paracetamol and cinnamon. Histopathological effect of paracetamol on liver was also markedly decreased by co-administration of cinnamon. Our findings concluded that cinnamon aqueous extracts possessed hepato-protective activity against paracetamol induced hepatic toxicity in rats.

NLRP3 inflammasome as a target of berberine in experimental murine liver injury: interference with P2X7 signalling.

Berberine (BRB) is commonly used in herbal medicine, but its mechanisms of action are poorly understood. In the present study, we tested BRB in steatohepatitis induced by a methionine- and choline-deficient (MCD) diet, in acute acetaminophen intoxication and in cultured murine macrophages. BRB markedly improved parameters of liver injury and necroinflammation induced by the MCD diet, although increased mortality was observed by mechanisms independent of bacterial infections or plasma levels of BRB. The MCD diet induced up-regulation of all components of the NLRP3 (NACHT, LRR and PYD domain-containing protein 3) inflammasome, and increased hepatic levels of mature IL-1β (interleukin 1β). All of these parameters were significantly reduced in mice treated with BRB. In mice administered an acetaminophen overdose, a model dependent on inflammasome activation, BRB reduced mortality and ALT (alanine aminotransferase) elevation, and limited the expression of inflammasome components. Invitro, LPS (lipopolysaccharide)-induced activation of NLRP3 inflammasome in RAW264.7 murine macrophages was markedly decreased by pre-incubation with BRB. BRB significantly limited the activation of the purinergic receptor P2X7, involved in the late phases of inflammasome activation. Upon P2X7 knockdown, the ability of BRB to block LPS-induced secretion of IL-1β was lost. These data indicate that administration of BRB ameliorates inflammation and injury in two unrelated murine models of liver damage. We demonstrate for the first time that BRB interferes with activation of the NLRP3 inflammasome pathway invivo and invitro, through a mechanism based on interference with activation of P2X7, a purinergic receptor involved in inflammasome activation.

OECD DART guidelines update: Addition of endocrine disruptor relevant endpoints

Emerging evidence supports a protective effect of platelets in experimental cholestatic liver injury and cholangiofibrosis. Coagulation-mediated platelet activation has been shown to inhibit experimental chronic cholestatic liver necrosis and biliary fibrosis. This occurs through thrombin-mediated activation of protease activated receptor-4 (PAR-4) in mice. However, it is not known whether other pathways of platelet activation, such as adenosine diphosphate (ADP)-mediated receptor P2Y12 activation is also protective. We tested the hypothesis that inhibition of P2Y12-mediated platelet activation exacerbates hepatic injury and cholangiofibrosis, and examined the impact of P2Y12 inhibition in both the presence and absence of PAR-4. Treatment of wild-type mice with the P2Y12 receptor antagonist clopidogrel increased biliary hyperplasia and cholangiofibrosis in wild-type mice exposed to the xenobiotic alpha-naphthylisothiocyanate (ANIT) for 4 weeks compared to vehicle-treated mice exposed to ANIT. Interestingly, this effect of clopidogrel occurred without a corresponding increase in hepatocellular necrosis. Whereas biliary hyperplasia and cholangiofibrosis were increased in PAR-4−/− mice, clopidogrel treatment failed to further increase these pathologies in PAR-4−/− mice. The results indicate that inhibition of receptor P2Y12-mediated platelet activation exacerbates bile duct fibrosis in ANIT-exposed mice, independent of hepatocellular necrosis. Moreover, the lack of an added effect of clopidogrel administration on the exaggerated pathology in ANIT-exposed PAR-4−/− mice reinforces the prevailing importance of coagulation-mediated platelet activation in limiting this unique liver pathology.

Inhibition of PAR-4 and P2Y12 receptor-mediated platelet activation produces distinct hepatic pathologies in experimental xenobiotic-induced cholestatic liver disease.

Emerging evidence supports a protective effect of platelets in experimental cholestatic liver injury and cholangiofibrosis. Coagulation-mediated platelet activation has been shown to inhibit experimental chronic cholestatic liver necrosis and biliary fibrosis. This occurs through thrombin-mediated activation of protease activated receptor-4 (PAR-4) in mice. However, it is not known whether other pathways of platelet activation, such as adenosine diphosphate (ADP)-mediated receptor P2Y12 activation is also protective. We tested the hypothesis that inhibition of P2Y12-mediated platelet activation exacerbates hepatic injury and cholangiofibrosis, and examined the impact of P2Y12 inhibition in both the presence and absence of PAR-4. Treatment of wild-type mice with the P2Y12 receptor antagonist clopidogrel increased biliary hyperplasia and cholangiofibrosis in wild-type mice exposed to the xenobiotic alpha-naphthylisothiocyanate (ANIT) for 4 weeks compared to vehicle-treated mice exposed to ANIT. Interestingly, this effect of clopidogrel occurred without a corresponding increase in hepatocellular necrosis. Whereas biliary hyperplasia and cholangiofibrosis were increased in PAR-4(-/-) mice, clopidogrel treatment failed to further increase these pathologies in PAR-4(-/-) mice. The results indicate that inhibition of receptor P2Y12-mediated platelet activation exacerbates bile duct fibrosis in ANIT-exposed mice, independent of hepatocellular necrosis. Moreover, the lack of an added effect of clopidogrel administration on the exaggerated pathology in ANIT-exposed PAR-4(-/-) mice reinforces the prevailing importance of coagulation-mediated platelet activation in limiting this unique liver pathology.

Therapeutic Potential of Bone Marrow-Derived Mesenchymal Stem Cells on Experimental Liver Injury Induced bySchistosoma mansoni:A Histological Study

Background and ObjectivesBone marrow derived mesenchymal stem cells (BM-MSCs) have been proposed as effective treatment of many diseases owing to their unique ability to differentiate into other cell types in vivo. Schistosoma mansoni (S. mansoni) infection is characterized by hepatic granuloma formation around schistosome eggs at acute stage of infection, followed by hepatic fibrosis at chronic and advanced stages. Whether BM-MSCs have an ameliorative effect on hepatic tissue injury caused by S. mansoni infection or not, was inspected in the current study.Materials and ResultsFemale Swiss Albino mice were divided into a control group and an experimental group. Half of control animals served as donors for bone marrow stem cells, and the other half was used to collect liver samples. Experimental group was injected with circariae of S. mansoni, and then subdivided into three subgroups; Subgroup B1, sacrificed after eight weeks of infection without treatment, subgroup B2, received BM-MSCs at the eighth week and sacrificed four weeks later, and subgroup B3, was untreated till the twelfth week of infection. Histological examination of liver samples showed the formation of granulomas and liver fibrosis which were extensive in subgroup B3. However, treated subgroup illustrated improvement of liver histology, signs of hepatocytes regeneration, and possible contribution of oval cell in the process of hepatic and biliary regeneration.ConclusionBM-MSCs decreased liver fibrosis and contributed to an increase in oval cells, generation of new hepatocytes and/or to the improvement of resident hepatocytes in S. mansoni infected mice.

STAT3, a Key Parameter of Cytokine-Driven Tissue Protection during Sterile Inflammation - the Case of Experimental Acetaminophen (Paracetamol)-Induced Liver Damage.

Acetaminophen (APAP, N-acetyl-p-aminophenol, or paracetamol) overdosing is a prevalent cause of acute liver injury. While clinical disease is initiated by overt parenchymal hepatocyte necrosis in response to the analgetic, course of intoxication is substantially influenced by associated activation of innate immunity. This process is supposed to be set in motion by release of danger-associated molecular patterns (DAMPs) from dying hepatocytes and is accompanied by an inflammatory cytokine response. Murine models of APAP-induced liver injury emphasize the complex role that DAMPs and cytokines play in promoting either hepatic pathogenesis or resolution and recovery from intoxication. Whereas the function of key inflammatory cytokines is controversially discussed, a subclass of specific cytokines capable of efficiently activating the hepatocyte signal transducer and activator of transcription (STAT)-3 pathway stands out as being consistently protective in murine models of APAP intoxication. Those include foremost interleukin (IL)-6, IL-11, IL-13, and IL-22. Above all, activation of STAT3 under the influence of these cytokines has the capability to drive hepatocyte compensatory proliferation, a key principle of the regenerating liver. Herein, the role of these specific cytokines during experimental APAP-induced liver injury is highlighted and discussed in a broader perspective. In hard-to-treat or at-risk patients, standard therapy may fail and APAP intoxication can proceed toward a fatal condition. Focused administration of recombinant STAT3-activating cytokines may evolve as novel therapeutic approach under those ill-fated conditions.

ДИНАМИКА ПАТОМОРФОЛОГИЧЕСКИХ ИЗМЕНЕНИЙ В ИШЕМИЗИРОВАННОМ СПИННОМ МОЗГЕ КРЫС ПОСЛЕ ЛЕЧЕНИЯ РЕКОМБИНАНТНЫМ ЭРИТРОПОЭТИНОМ (ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ)

Aim. To study how experimental autoimmune liver injury in mother influences morphofunctional features of monocyte development in the bone marrow of progeny. Materials and methods. The subjects of study were female Wistar rats with experimental liver injury and their progeny on days 30 and 60 of postnatal development divided into two groups: control and experimental. Chronic autoimmune liver injury was modeled using BCG vaccine via subcutaneous immunization with periodic intraperitoneal administration of liver antigen each three days. Results. The study showed that absolute cell count at all stages of development in the experimental group of animals decreased in comparison with the control group. Besides, the decrease was observed in PAS positive cell number, acid phosphatase activity and level of alpha-glycerophosphate dehydrogenase in monocyte series of the bone marrow and in peripheral blood monocytes of the groups of animals under observation. Conclusion. Mothers with experimental autoimmune hepatobiliary disorder give birth to progeny with disturbance expressed in functional immaturity of monocytes.

Comparison of the hemostatic effects of oxidized cellulose and calcium alginate in an experimental animal model of hepatic parenchymal bleeding.

Background:Despite all recent developments, bleeding is still one of the main causes of increasing morbidity and mortality following both trauma and elective hepatic surgery. The main goal of treatment is stop the bleeding immediately. In this study, the hemostatic and histopathological effects of Ankaferd blood stopper (ABS), oxidized cellulose (OC), and calcium alginate (CA) were compared in an experimental liver injury.Materials and Methods:Forty Wistar albino rats were randomly divided into four groups of ten animals each, receiving 0.9% NaCl, CA, OC, or ABS following liver resection. After 5 days, the samples from the resection site were acquired for histopathological evaluation. The efficacy of the agents was assessed using the hematocrit level and histopathological examination. Statistical analyses were applied.Results:The amount of bleeding was lowest in ABS–treated rats, followed by those treated with OC, CA, and NaCl, respectively. The difference among the groups was statistically significant (P < 0.001). ABS–treated rats also had significantly less necrosis than those receiving OC; other differences in this regard were not significant. Inflammatory status was significantly different between OC- and CA–treated rats (P < 0.05) but not among the other groups (P > 0.05). No significant difference was determined between the groups regarding granulation (P > 0.05).Conclusion:ABS reduced the volume of bleeding in liver surgery and partial liver resection. The hemostatic effect of CA was limited.

An Orally-Bioavailable Glutathione-Based Hepatoprotective Compound in Experimental Acute Liver Injury: More Effective than Silymarin and YHK

Many hepatoprotective non-chemical preparations have been recommended as complementary medicine for the treatment of liver disorders. We have utilized a well-defined model of liver injury to study the efficacy of GLU-9599 (a oral bioavailable glutathione-based compound added with selenium, L-cysteine and vitamin C) designed to support liver detox function. Wistar albino rats were divided into five groups. Group I represented the healthy control group; Groups II-IV were given carbon tetrachloride (CCl4) intragastrically. Rats were exposed to CCl4 after they had been pretreated for five days with either saline, silymarin extract, YHK (am herbal Japanese compound with putative hepatoprotective effects) or GLU-9599. After inducing hepatic damage, Group II served as control CCl4; Group III and IV were given silymarin (reference hepatoprotective) and YHK whereas Groups V was administered GLU-9599. Animals were sacrificed 24 hours after receiving CCl4. Liver enzymes and hepatic histology formed the basis for evaluating the efficacy of the treatments. Samples of livers were observed under microscope and electron microscopy (TEM) for the histopathological changes. Levels of marker enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) significantly increased in CCl4 treated rats (Group II). Groups III, IV and V intoxicated with CCl4 and treated with the above hepatoprotective agents showed a significant decrease of the activities of these two enzymes (p<0.05). However, GLU-9599 provided a significantly stronger effect than YHK (p<0.05) and a trend improvement as compared to sylimarin. This was confirmed at histology and TEM whereas the others hepatoprotective compounds had only limited benefits on morphological abnormalities. In conclusion GLU-9599 could be a promising hepatoprotective compound of safe profile although extensive clinical studies are warranted.

Carbon Tetrachloride-Induced Nephrotoxicity in Mice Is Prevented by Pretreatment with Zinc Sulfate.

Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. In addition, many studies showed that CCl4 can induce kidney damage. In the current study, we evaluated the protective effect of zinc (Zn) against CCl4-induced nephrotoxicity. We hypothesized that this protective effect would result from the ability of Zn to serve as an inducer of metallothionein (MT), a known endogenous scavenger of free radicals. We administered Zn (as ZnSO4) 50 mg/kg subcutaneously once daily for 3 successive days prior to a single intraperitoneal administration of CCl4 4 g/kg in male ddY mice. Our results showed that Zn pretreatment significantly decreased creatinine and blood urea nitrogen levels and reduced renal histopathological damage at 6 h post-CCl4 injection, observations consistent with enhanced antioxidative activity in the kidney. Moreover, kidney MT levels in the Zn+CCl4-treated group decreased by greater than 70% compared with levels in the Zn-alone group, implying that MT was consumed by CCl4-induced radicals. These findings suggest that prophylaxis with Zn protects mice from CCl4-induced acute nephrotoxicity, presumably by induction of MT, which in turn scavenges radicals induced by CCl4 exposure.

Carbon tetrachloride-induced lethality in mouse is prevented by multiple pretreatment with zinc sulfate.

Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. Several compounds have been demonstrated to attenuate the hepatic damage caused by sublethal doses of CCl4. However, rescue from lethal toxicity of CCl4 has not been reported. In the present study, we evaluated the protective effect of metallothionein (MT), an endogenous scavenger of free radicals, on CCl4-induced lethal toxicity of mice. To induce MT production in male ddY mice, we administered Zn (as ZnSO4) at 50 mg/kg as a once-daily subcutaneous injection for 3 days prior to a single intraperitoneal administration of 4 g/kg CCl4. Animals were observed for mortality every 3 hr for 24 hr after CCl4 injection. Liver damage was assessed by determining (in a subset of these mice) blood levels of alanine aminotransferase (ALT; a marker of liver injury) and liver histopathology at 6 hr after CCl4 injection. Our results showed that three times pretreatment with Zn yielded > 40-fold induction of hepatic MT protein levels compared to control group. Zn pretreatment completely abolished the CCl4-induced mortality of mice. We also found that pretreatment of mice with Zn significantly decreased the ALT levels and reduced the histological liver damage as assessed at 6 hr post-CCl4. These findings suggest that prophylaxis with Zn protects mice from CCl4-induced acute hepatic toxicity and mortality, presumably by induction of radical-scavenging MT.

Hepatoprotective effect of aqueous extract of cardamom against gentamicin induced hepatic damage in rats

The study was designed to evaluate the hepatoprotective activity of aqueous extract of cardamom in acute experimental liver injury induced by gentamicin. Twenty four male albino rats were randomly divided into four groups (six rats in each). Animals of the first group served as control and orally (p.o.) received (1 ml/kg saline). The second experimental group was given gentamicin (80 mg/kg i.p.) for 7 days. Third and fourth groups were given aqueous extract of cardamom (100 and 200 mg/kg p.o.) + gentamicin for 7 days, respectively. The degree of hepatoprotection was measured using serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, albumin, and lipid profile levels. In the acute liver damage induced by gentamicin, cardamom aqueous extracts (100 and 200 mg/kg, p.o.) significantly reduced the elevated serum levels of AST, ALT, bilirubin, cholesterol, triglycerides and low density lipoprotein cholesterol (LDL-chol) in gentamicin induced hepatotoxicity. Also cardamom aqueous extracts (100 &amp; 200 mg/kg, p.o.) significantly increased the lowered serum levels of albumin and high density lipoprotein cholesterol (HDL-chol) in gentamicin induced hepatotoxicity rats. Histopathological examination of the liver tissues supported the hepatoprotection. Our findings concluded that cardamom aqueous extracts possessed hepatoprotective activity against gentamicin induced hepatotoxicity in rats.

Acute Liver Injury Is Independent of B Cells or Immunoglobulin M.

Background & AimsAcute liver injury is a clinically important pathology and results in the release of Danger Associated Molecular Patterns, which initiate an immune response. Withdrawal of the injurious agent and curtailing any pathogenic secondary immune response may allow spontaneous resolution of injury. The role B cells and Immunoglobulin M (IgM) play in acute liver injury is largely unknown and it was proposed that B cells and/or IgM would play a significant role in its pathogenesis.MethodsTissue from 3 models of experimental liver injury (ischemia-reperfusion injury, concanavalin A hepatitis and paracetamol-induced liver injury) and patients transplanted following paracetamol overdose were stained for evidence of IgM deposition. Mice deficient in B cells (and IgM) were used to dissect out the role B cells and/or IgM played in the development or resolution of injury. Serum transfer into mice lacking IgM was used to establish the role IgM plays in injury.ResultsSignificant deposition of IgM was seen in the explanted livers of patients transplanted following paracetamol overdose as well as in 3 experimental models of acute liver injury (ischemia-reperfusion injury, concanavalin A hepatitis and paracetamol-induced liver injury). Serum transfer into IgM-deficient mice failed to reconstitute injury (p = 0.66), despite successful engraftment of IgM. Mice deficient in both T and B cells (RAG1-/-) mice (p<0.001), but not B cell deficient (μMT) mice (p = 0.93), were significantly protected from injury. Further interrogation with T cell deficient (CD3εKO) mice confirmed that the T cell component is a key mediator of sterile liver injury. Mice deficient in B cells and IgM mice did not have a significant delay in resolution following acute liver injury.DiscussionIgM deposition appears to be common feature of both human and murine sterile liver injury. However, neither IgM nor B cells, play a significant role in the development of or resolution from acute liver injury. T cells appear to be key mediators of injury. In conclusion, the therapeutic targeting of IgM or B cells (e.g. with Rituximab) would have limited benefit in protecting patients from acute liver injury.