Liver Tissue Injury Research Articles

Natural Killer T Cells in Liver Ischemia-Reperfusion Injury.

Restoration of blood flow to an ischemic organ results in significant tissue injury. In the field of liver transplantation, ischemia–reperfusion injury (IRI) has proven to be a formidable clinical obstacle. In addition to metabolic stress and inflammation, IRI results in profound graft dysfunction and loss. The severity of IRI further limits the ability to expand the donor pool by using partial grafts and marginal organs. As such, the inflammatory response to reperfusion of the liver continues to be an area of intense investigation. Among the various leukocytes involved in IRI, new insights suggest that natural killer T (NKT) cells may be a central driver of hepatocellular injury. Herein, we examine recent experimental observations that provide a mechanistic link between NKT cell recruitment to liver and post-perfusion tissue injury.

CD24 attenuates carbon tetrachloride-induced murine liver fibrosis

Objective To investigate the effects of CD24 on CCl4-induced murine liver fibrosis and to analyze the possible molecular mechanism. Methods Wild type (WT) and CD24 knockout (CD24-/-) C57BL/6 mice were treated with CCl4 through intraperitoneal injection. Levels of ALT in serum samples were detected and liver tissues were stained with hematoxylin and eosin (HE) to assess liver tissue injury. Sirius Red staining was used to observe liver fibrosis. Real-time PCR was performed to detect the expression of α-SMA (α-smooth muscle actin), Col1a1 (Collagen, typeⅠ, alpha 1), TGF-β1 (transforming growth factor-β1) and CD24 at mRNA level in liver tissues. Western blot was performed to analyze the expression of α-SMA and Col1a1 at protein level. Flow cytometry analysis was used to detect the macrophages in liver tissues. ELISA was used to detect the expression of TGF-β1 in the culture supernatants of M1 and M2 macrophages. Results The expression of CD24 at both mRNA and protein levels were up-regulated in mice with CCl4-induced liver fibrosis. HE staining showed that liver inflammation in CD24-/- mice was more severe than that in WT mice after treated with CCl4. Sirius Red staining of paraffin-embadded liver sections revealed that compared with WT mice, CD24-/- mice presented with more severe liver fibrosis. Moreover, α-SMA and Col1a1, indicators of liver fibrosis, in CD24-/- mice were significantly higher than those in WT mice. Flow cytometry analysis showed that murine hepatic macrophages significantly increased in CD24-/- mice than in WT mice following CCl4 treatment. Real-time PCR analysis also confirmed that significantly enhanced expression of TGF-β1 at mRNA level in liver tissues was observed in CD24-/- mice than in WT mice. TGF-β1 secreted in the culture supernatant of M2 macrophages derived from CD24-/- mice group was more than that of the WT mice group. No significant difference in TGF-β1 secretion in culture supernatant of M1 macrophages was observed between the two groups. Conclusion Taken together, these data suggest that CD24 plays an important role in attenuating CCl4-induced chronic inflammation and hepatic fibrosis in mice. The mechanism of CD24 in alleviating liver fibrosis might be through regulating intrahepatic macrophages, inhibiting the secretion of TGF-β1 by M2 macrophages and suppressing the activation of hepatic stellate cells. Key words: CD24; CCl4; Liver fibrosis; Macrophage; TGF-β1

An assessment of the nutraceutical potential of Juglans regia L. leaf powder in diabetic rats

In this study, we evaluated the nutraceutical potential of Juglans regia L. (a dietary supplement and food-additive) by evaluating the in-vitro anti-diabetic potential and by assessing the in-vivo anti-hyperglycaemic, anti-hyperlipidaemic, and organ-protective effects of freshly-dried and powdered leaves of J. regia L. in diabetic rats. In the in-vivo experiments, dry powder of J. regia L. leaf (25, 50 and 100 mg/kg) was administered orally, twice daily (9.00 a.m. and 5 p.m.) to streptozocin-induced diabetic rats over a period of 28 days, during which body weight and blood glucose were monitored weekly. At the end of the experimental period, animals were sacrificed, blood was taken for assessment of lipid profile, antioxidant activity and liver/kidney biochemistry; while samples of the pancreas, liver and kidneys were fixed, processed, sectioned, and stained for general histology. Phytochemical evaluations of three extracts were carried out using HPLC-PDA validated procedures, while enzyme-inhibitory potentials were tested against α-amylase and α-glucosidase. In-vivo assays showed that twice-daily administration of J. regia L. leaf resulted in weight gain, glycaemic control, reversal of dyslipidaemia and biochemical evidences of liver/kidney injury, and protection against pancreas, liver and kidney tissue injury.

Role of stabilin-1 in chronic liver tissue injury and repair

BackgroundOrgan fibrosis is a major cause of global mortality. Few medical therapies are available to treat this condition. We have previously demonstrated increased expression of stabilin-1 at sites of chronic liver disease. Using models of chronic liver injury, we aimed to elucidate the role of stabilin-1 during fibrosis and repair. MethodsWe used full knockout and cell specific knockouts of stabilin-1 in murine models of chronic liver injury including carbon tetrachloride treatment and a methionine and choline deficient diet. A resolution phase after carbon tetrachloride treatment was used to study tissue repair. Tissue was analysed for fibrosis by confocal microscopy, collagen quantification, and immune cell infiltrate analysis. RNA sequencing and cell transfer experiments were done to elucidate underlying mechanisms. Human tissue was also analysed for stabilin-1 expression in chronic liver injury. FindingsWe detected a subset of stabilin-1 macrophages that were induced at sites of cellular injury close to the hepatic scar in mouse models of liver fibrosis and in human liver disease. Stabilin-1 deficiency abrogated malondialdehyde-LDL uptake by hepatic macrophages and was associated with excess collagen III deposition. Mechanistically, the lack of stabilin-1 led to elevated intrahepatic levels of the profibrogenic chemokine CCL3 and an increase in GFAP+ fibrogenic cells. Stabilin-1 knockout macrophages demonstrated a proinflammatory phenotype during liver injury and this led to delayed wound healing. InterpretationWe have demonstrated a pathway in which the evolutionarily conserved receptor stabilin-1 on tissue-infiltrating macrophages promotes the uptake of products of lipid peroxidation and thus prevents excess scarring. We propose that macrophage stabilin-1 is a crucial defence against oxidative tissue damage and thereby maintains tissue homoeostasis. FundingWellcome Trust.

Polydatin alleviates alcohol-induced acute liver injury in mice: Relevance of matrix metalloproteinases (MMPs) and hepatic antioxidants

BackgroundAlcohol, a most commonly consumed beverage, is the foremost cause of liver injury throughout the world. Polydatin, a stilbenoid glucoside, was known to possess antioxidant and anti-inflammatory properties and is being investigated for use in various disorders. PurposeThe present study was intended at investigating the hepatoprotective efficacy of polydatin against acute-alcohol induced liver injury model in mice. Study designC57BL/6 mice were fed with five doses of 50% ethyl alcohol (10ml/kg body weight) to induce acute liver injury. Effect of polydatin against alcohol induced hepatic injury was investigated by giving 50 or 100mg/kg polydatin, orally, for 8 days. MethodsSerum markers of liver injury, morphology, histology and fibrosis of liver tissue, levels of enzymatic and non-enzymatic antioxidants and the mitochondrial respiratory enzyme activities in liver tissue were investigated. The activities and the protein expression of matrix metalloproteinases (MMP-2 and -9), the expression of NF-κB in the liver tissue were also studied. ResultsPolydatin pre-treatment significantly alleviated the alcohol induced hepatic injury by reducing the serum liver injury markers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), attenuating oxidative stress and restoring antioxidant balance in the hepatic tissue. Simultaneously, polydatin pre-treatment also prevented alcohol induced mitochondrial damage and refurbished the matrix metalloproteinases levels of the hepatic tissue. ConclusionThe findings of the present study suggest that polydatin may have a potential benefit in preventing alcohol-induced acute hepatic injury.

Comprehensive CircRNA expression profile and selection of key CircRNAs during priming phase of rat liver regeneration

BackgroundRat liver regeneration (LR) proceeds along a process of highly organized and ordered tissue growth in response to the loss or injury of liver tissue, during which many physiological processes may play important roles. The molecular mechanism of hepatocyte proliferation, energy metabolism and substance metabolism during rat LR had been elucidated. Further, the correlation of circular RNA (circRNA) abundance with proliferation has recently been clarified. However, the regulatory capacity of circRNA in rat LR remains a fascinating topic.ResultsTo investigate the regulatory mechanism of circRNA during priming phase of rat LR, high-throughput RNA sequencing technology was performed to unbiasedly profile the expression of circRNA during priming phase of rat LR. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analysis was conducted to predict the functions of differentially expressed circRNAs and their host linear transcripts. Co-expression networks of circRNA-miRNA were constructed based on the correlation analysis between the differentially expressed LR-related circRNAs and the condition of their miRNA binding sites. To excavate the key circRNAs in the early phase of rat LR, we comprehensively evaluated and integrated the relationship of expression level between the circRNAs and the linear transcripts as well as the distribution of miRNA binding sites in circRNA sequences.ConclusionsThis paper is the first to employ the comprehensive circRNA expression profile and to investigate circRNA-miRNA interactions during priming phase of rat LR. Two thousand four hundred twelve circRNAs were detected, and 159 circRNAs deriving from 116 host linear transcripts differentially expressed (p < 0.05). Six significantly changed circRNAs during priming phase of rat LR were screened as key circle molecules, and then were validated by qRT-PCR. This study will lay the foundation for revealing the functional roles of circRNAs during rat LR and help solve the remaining clinical problems.

Preliminary research on effect of licorice-processed Tripterygium wilfordii on reducing liver toxicity

To explore the effect of the licorice-processed Tripterygium wilfordii on reducing the liver toxicity. In animal experiments, the liver toxicity of T. wilfordii was evaluated both before and after processing, and the differences in liver tissue biopsy, serum biochemical indexes and inflammatory cell factor among blank group, T. wilfordii group and licorice-processed T. wilfordii group were observed. Liver tissue biopsy results showed that liver tissue injury was obvious in T. wilfordii group, and no obvious injury was found in licorice-processed T. wilfordii group. As compared with the blank group, the levels of AST, ALT and CRE were significantly increased (P<0.01), UREA was increased (P<0.05), and ALB level was significantly decreased (P<0.01) in the T. wilfordii group. As compared with T. wilfordii group, the levels of AST, ALT, CRE, and UREA were decreased (P<0.01), while ALB was increased (P<0.01) in the licorice-processed T. wilfordii group. The results of inflammatory factors in rats showed that the levels of IL-1β, IL-6, and TNF-α in T. wilfordii group were significantly higher than those in blank group (P<0.01); the levels of IL-1β, IL-6, and TNF-α in licorice-processed T. wilfordii group were significantly lower than those in T. wilfordii group (P<0.01). Overall, licorice processing of T. wilfordii can effectively reduce the liver toxicity and reduce the liver injury caused by T. wilfordii. The experiment can provide reference for the clinical rational use of the T. wilfordii, and provide data support for the studies on reducing the liver toxicity of T. wilfordii by licorice processing.

Contribution of mitochondria to injury of hepatocytes and liver tissue by hyperthermia

ObjectiveThe aim of this study was to investigate functional changes of liver mitochondria within the experimentally modeled transition zone of radiofrequency ablation and to estimate possible contribution of these changes to the energy status of liver cells and the whole tissue. Materials and methodsExperiments were carried out on mitochondria isolated from the perfused liver and isolated hepatocytes of male Wistar rats. Hyperthermia was induced by changing the temperature of perfusion medium in the range characteristic for the transition zone (38–52°C). After 15-min perfusion, mitochondria were isolated to investigate changes in the respiration rates and the membrane potential. Adenine nucleotides extracted from isolated hepatocytes and perfused liver subjected to hyperthermic treatment were analyzed by HPLC. ResultsHyperthermic liver perfusion at 42–52°C progressively impaired oxidative phosphorylation in isolated mitochondria. Significant inhibition of the respiratory chain components was observed after perfusion at 42°C, irreversible uncoupling became evident after liver perfusion at higher temperatures (46°C and above). After perfusion at 50–52°C energy supplying function of mitochondria was entirely compromised, and mitochondria turned to energy consumers. Hyperthermia-induced changes in mitochondrial function correlated well with changes in the energy status and viability of isolated hepatocytes, but not with the changes in the energy status of the whole liver tissue. ConclusionsIn this study the pattern of the adverse changes in mitochondrial functions that are progressing with increase in liver perfusion temperature was established. Results of experiments on isolated mitochondria and isolated hepatocytes indicate that hyperthermic treatment significantly and irreversibly inhibits energy-supplying function of mitochondria under conditions similar to those existing in the radiofrequency ablation transition zone and these changes can lead to death of hepatocytes. However, it was not possible to estimate contribution of mitochondrial injury to liver tissue energy status by estimating only hyperthermia-induced changes in adenine nucleotide amounts on the whole tissue level.

Protective Effect of Spirulina Against Irradiation Induced Liver Injury in Adult Albino Rat Rats

Background and Objective: Spirulina is a nutritional supplement that has a variety of pharmacologicalproperties, such as antioxidant and anti-inflammatory effects. This study aimed to investigate the protectiveeffect of Spirulina against liver tissue injury induced by gamma irradiation.Materials and Methods: Thirty two adult male albino rats were divided into 4 groups each of whichincluded 8 rats: (1) control group, (2) irradiation group: exposed to gamma irradiation in a dose of 8 Gyfor 15 min, (3) Spirulina low dose treated (SPL) group which received Spirulina 300 mg/kg b.w. by gavageonce/day for 3 weeks prior to irradiation and (4) Spirulina high dose treated (SPH) group which receivedSpirulina 1000 mg/kg b.w. by gavage once/day for 3 weeks before irradiation. Blood samples were collectedto determine levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde(MDA) and plasma total proteins, in addition to liver tissue from all groups to be examined histologicallyby light microscope and transmission electron microscope.Results: The obtained results showed that plasma levels of ALT and AST were significantly reduced in ratstreated with low dose of Spirulina prior to irradiation when compared to irradiation group together withsignificant rise of plasma total proteins and histological improvement of liver tissue, however, Spirulinahigh dose treated group did not show any signs of improvement compared to irradiation group. It could beconcluded that low dose Spirulina treatment has a hepatoprotective effect against irradiation, whereas highdose treatment may have a hepatotoxic effect that needs further investigations.

Role of autophagy in acute liver failure induced by D-galactosamine/lipopolysaccharide in mice

Objective: To investigate the expression and role of autophagy in the progression of acute liver failure (ALF) using the mouse model of ALF induced by D-galactosamine/LPS (D-GalN/LPS). Methods: The C57BL/6 mice were used, and intraperitoneal injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS) was performed to establish the mouse model of ALF. The mice were divided into control group and 2-, 4-, and 6-hour D-GalN/LPS-induced ALF model groups. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess liver function, and the pathological changes in liver tissue were observed to evaluate the status of liver injury. Quantitative real-time PCR was used to measure the expression of autophagy-related genes, Western blot was used to measure the expression of autophagy-related proteins in liver tissue, and a fluorescence microscope was used to observe the expression of autophagosome in the progression of liver failure. A one-way ANOVA was used for comparison of means of multiple samples between any two groups (LSD-t test for data with homogeneity of variance and Games-Howell method for data with heterogeneity of variance).P< 0.05 was considered statistically significant. Results: The ALF model groups showed gradual liver impairment over the time of D-GalN/LPS stimulation. There were significant increases in ALT and AST after 4 hours; the pathological injury of liver tissue gradually aggravated over the time of D-GalN/LPS stimulation and fulfilled the criteria for ALF at 6 hours. The mRNA and protein expression of autophagy-related genes (ATG-7, ATG-5, Beclin-1, Lamp-1, and LC3a) increased in the early and medium stages of ALF (2 and 4 hours) and decreased after ALF progressed to liver failure (6 hours). As was observed via the fluorescence microscope, the 4-hour D-GalN/LPS-induced ALF model group showed the highest expression of autophagosome. Conclusion: The expression of autophagy gradually increases in the early and medium stages of ALF and decreases when ALF progresses to liver failure. Therefore, autophagy plays an important role in the pathogenesis of ALF.

Keratins: Biomarkers and modulators of apoptotic and necrotic cell death in the liver.

Keratins, formerly known as cytokeratins, are the major epithelial-specific subgroup of intermediate filament proteins. Adult hepatocytes express keratin polypeptides 8 and 18 (K8/K18), whereas cholangiocytes express K8/K18 and keratins 7 and 19 (K7/K19). Keratins function primarily to protect hepatocytes from apoptosis and necrosis, which was revealed using several genetic mouse models. This cytoprotective function was further clarified by the identification of natural human keratin variants that are normally silent, but become pathogenic by predisposing their carriers to apoptosis during acute or chronic liver injury mediated by toxins, virus infection, or metabolic stress. During apoptosis, caspases cleave K18 and K19 at conserved aspartates (human K18/K19: (235) Val-Glu-Val-Asp(↓) ) and K18 at a unique aspartate (human K18: (394) Asp-Ala-Leu-Asp(↓) ), with the latter exposed epitope becoming recognized by the M30 antibody in blood and tissues. Additional K18-containing protein backbone epitopes are detected using the M6 and M5 (termed M65) antibodies. Intact K18 and its associated fragments, which are released into blood during apoptosis and necrosis in various diseases, have been analyzed by enzyme-linked immunosorbent assay using the M30/M65 antibodies or their signal ratios. Furthermore, M30/M65 levels have been used as diagnostic and prognostic biomarkers in acute and chronic liver diseases, including nonalcoholic steatohepatitis and acute liver failure. Other keratin biomarkers include K8/K18/K19-related tissue polypeptide antigen, K18-related tissue polypeptide-specific antigen, and K19-related CYFRA-21-1, which have been evaluated mostly in patients with epithelial tumors. Keratins and their fragments are released into blood during liver and other epithelial tissue injury. The epithelial specificity of K18/K19, epitope unmasking upon caspase digestion, keratin abundance, and relative keratin stability render them useful biomarkers for hepatocyte and cholangiocyte apoptosis and necrosis. However, the precise biochemical nature and release mechanism of circulating keratins remain unknown. (Hepatology 2016;64:966-976).

Glial cell line–derived neurotrophic factor–induced mice liver defatting: A novel strategy to enable transplantation of steatotic livers

Moderate macrovesicular steatosis (>30%), which is present in almost 50% of livers considered for transplantation, increases the risk of primary graft dysfunction. Our previously published data showed that glial cell line-derived neurotrophic factor (GDNF) is protective against high-fat diet (HFD)-induced hepatic steatosis in mice. Hence, we hypothesized that perfusion of steatotic livers with GDNF may reduce liver fat content before transplantation. Livers from 8 weeks of regular diet (RD) and of HFD-fed mice were perfused ex vivo for 4 hours with either vehicle, GDNF, or a previously described defatting cocktail. The liver's residual fat was quantified colorimetrically using a triglyceride (TG) assay kit and by Oil Red O (ORO) and Nile red/Hoechst staining. Liver tissue injury was assessed by using a lactate dehydrogenase (LDH) activity assay. In vitro induction of lipolysis in HepG2 cells was assessed by measuring glycerol and free fatty acid release. ORO staining showed significantly more steatosis in livers from HFD-fed mice compared with RD-fed mice (P < 0.001). HFD livers perfused with GDNF had significantly less steatosis than those not perfused (P = 0.001) or perfused with vehicle (P < 0.05). GDNF is equally effective in steatotic liver defatting compared to the defatting cocktail; however, GDNF induces less liver damage than the defatting cocktail. These observations were consistent with data obtained from assessment of liver TG content. Assessment of liver injury revealed significant hepatocyte injury in livers perfused with the control defatting cocktail but no evidence of injury in livers perfused with either GDNF or vehicle. In vitro, GDNF reduced TG accumulation in HepG2 cells and stimulated increased TG lipolysis. In conclusion, GDNF can decrease mice liver fat content to an acceptable range and could be a potential defatting agent before liver transplantation.

Liver transplantation in the mouse: Insights into liver immunobiology, tissue injury, and allograft tolerance.

The surgically demanding mouse orthotopic liver transplant model was first described in 1991. It has proved to be a powerful research tool for the investigation of liver biology, tissue injury, the regulation of alloimmunity and tolerance induction, and the pathogenesis of specific liver diseases. Liver transplantation in mice has unique advantages over transplantation of the liver in larger species, such as the rat or pig, because the mouse genome is well characterized and there is much greater availability of both genetically modified animals and research reagents. Liver transplant experiments using various transgenic or gene knockout mice have provided valuable mechanistic insights into the immunobiology and pathobiology of the liver and the regulation of graft rejection and tolerance over the past 25 years. The molecular pathways identified in the regulation of tissue injury and promotion of liver transplant tolerance provide new potential targets for therapeutic intervention to control adverse inflammatory responses/immune-mediated events in the hepatic environment and systemically. In conclusion, orthotopic liver transplantation in the mouse is a valuable model for gaining improved insights into liver biology, immunopathology, and allograft tolerance that may result in therapeutic innovation in the liver and in the treatment of other diseases.

Preventive activity of banana peel polyphenols on CCl4-induced experimental hepatic injury in Kunming mice.

The aim of the present study was to evaluate the preventive effects of banana peel polyphenols (BPPs) against hepatic injury. Mice were divide into normal, control, 100 mg/kg and 200 mg/kg banana peel polyphenol and silymarin groups. All the mice except normal mice were induced with hepatic damage using CCl4. The serum and tissue levels of mice were determined by a kit and the tissues were further examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. BPPs reduced the serum levels of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase in a CCl4-induced mouse model of hepatic injury. Furthermore, BPPs reduced the levels of malondialdehyde and triglyceride, while increasing glutathione levels in the serum and liver tissues of mice. In addition, the effects of 200 mg/kg treatment were more evident, and these effects were comparable to those of the drug silymarin. Serum levels of the cytokines, interleukin (IL)-6, IL-12, tumor necrosis factor (TNF)-α and interferon-γ, were reduced in the mice treated with BPPs compared with injury control group mice, and these levels were comparable to those of the normal and silymarin-treated groups. Histopathological examination indicated that BPPs were able to reduce the extent of CCl4-induced liver tissue injury and protect the liver cells. Furthermore, the mRNA and protein expression levels of the inflammation-associated factors cyclooxygenase-2, nitric oxide synthase, TNF-α and IL-1β were reduced in mice treated with BPPs compared with the control group mice. Mice that received 200 mg/kg BPP exhibited reduced expression levels of these factors compared with mice that received 100 mg/kg BPP. In conclusion, the results of the present study suggested that BPPs exert a good preventive effect against hepatic injury.

Intestinal ischemic preconditioning reduces liver ischemia reperfusion injury in rats

The aim of the current study was to investigate whether intestinal ischemic preconditioning (IP) reduces damage to the liver during hepatic ischemia reperfusion (IR). Sprague Dawley rats were used to model liver IR injury, and were divided into the sham operation group (SO), IR group and IP group. The results indicated that IR significantly increased Bax, caspase 3 and NF-κBp65 expression levels, with reduced expression of Bcl-2 compared with the IP group. Compared with the IR group, the levels of AST, ALT, MPO, MDA, TNF-α and IL-1 were significantly reduced in the IP group. Immunohistochemistry for Bcl-2 and Bax indicated that Bcl-2 expression in the IP group was significantly increased compared with the IR group. In addition, IP reduced Bax expression compared with the IR group. The average liver injury was worsened in the IR group and improved in the IP group, as indicated by the morphological evaluation of liver tissues. The present study suggested that IP may alleviates apoptosis, reduce the release of pro-inflammatory cytokines, ameloriate reductions in liver function and reduce liver tissue injury. To conclude, IP provided protection against hepatic IR injury.

CLINICAL ASPECTS OF THE POISONING BY THE PESTICIDE ENDOSULFAN

Endosulfan is an organochlorine insecticide, widely used in insect control. Unfortunately, it is also an acute neurotoxic compound to both insects and mammals, including humans, and has been responsible for many severe poisonings and several fatal cases. Endosulfan also imitates or enhances the effect of the female hormone estrogen, having the capability of causing reproductive and developmental damage in both, animals and humans, and its exposure has been linked to liver tissue injury. This persistent lipophilic compound is one of the most abundant organochlorine pesticides in the environment, capable of undergoing long range transport to remote locations such as the Arctic. It is practically water-insoluble, but readily adheres to clay particles and persists in soil and water for several years. Its indiscriminate and injudicious use in the control of insects on a wide range of agricultural products and in the extermination of house-hold pests, has considerably increased the hazard risk for human health. Also, this compound has a high fatality rate in humans when ingested accidentally, from food or water contaminated, or in suicidal cases. The aim of this article is to review and summarize chemical, biochemical, environmental, and toxicological data of endosulfan and draw attention to its toxicological potential risk to human health.

Antioxidant and anti-inflammatory action of melatonin in an experimental model of secondary biliary cirrhosis induced by bile duct ligation.

AIMTo evaluate the effects of melatonin (Mel) on oxidative stress in an experimental model of bile duct ligation (BDL).METHODSMale Wistar rats (n = 32, weight ± 300 g) were allocated across four groups: CO (sham BDL), BDL (BDL surgery), CO + Mel (sham BDL and Mel administration) and BDL + Mel (BDL surgery and Mel administration). Mel was administered intraperitoneally for 2 wk, starting on postoperative day 15, at a dose of 20 mg/kg.RESULTSMel was effective at the different standards, reestablishing normal liver enzyme levels, reducing the hepatosomatic and splenosomatic indices, restoring lipoperoxidation and antioxidant enzyme concentrations, reducing fibrosis and inflammation, and thereby reducing liver tissue injury in the treated animals.CONCLUSIONThe results of this study suggest a protective effect of Mel when administered to rats with secondary biliary cirrhosis induced by BDL.

Combined Activities of JNK1 and JNK2 in Hepatocytes Protect Against Toxic Liver Injury

c-Jun N-terminal kinase (JNK) 1 and JNK2 are expressed in hepatocytes and have overlapping and distinct functions. JNK proteins are activated via phosphorylation in response to acetaminophen- or carbon tetrachloride (CCl4)-induced liver damage; the level of activation correlates with the degree of injury. SP600125, a JNK inhibitor, has been reported to block acetaminophen-induced liver injury. We investigated the role of JNK in drug-induced liver injury (DILI) in liver tissue from patients and in mice with genetic deletion of JNK in hepatocytes. We studied liver sections from patients with DILI (dueto acetaminophen, phenprocoumon, nonsteroidal anti-inflammatory drugs, or autoimmune hepatitis) or patients without acute liver failure (controls) collected from a DILI Biobank in Germany. Levels of total and activated (phosphorylated) JNK were measured by immunohistochemistry and Western blotting. Mice with hepatocyte-specific deletion of Jnk1 (Jnk1(Δhepa)) or combination of Jnk1 and Jnk2 (Jnk(Δhepa)), as well as Jnk1-floxed C57BL/6 (control) mice, were given injections of CCl4 (to induce fibrosis) or acetaminophen (to induce toxic liver injury). We performed gene expression microarray and phosphoproteomic analyses to determine mechanisms of JNK activity in hepatocytes. Liver samples from DILI patients contained more activated JNK, predominantly in nuclei of hepatocytes and in immune cells, than healthy tissue. Administration of acetaminophen to Jnk(Δhepa) mice produced a greater level of liver injury than that observed in Jnk1(Δhepa) or control mice, based on levels of serum markers and microscopic and histologic analysis of liver tissues. Administration of CCl4 also induced stronger hepatic injury in Jnk(Δhepa) mice, based on increased inflammation, cell proliferation, and fibrosis progression, compared with Jnk1(Δhepa) or control mice. Hepatocytes from Jnk(Δhepa) mice given acetaminophen had an increased oxidative stress response, leading to decreased activation of adenosine monophosphate-activated protein kinase, total protein adenosine monophosphate-activated protein kinase levels, and pJunD and subsequent necrosis. Administration of SP600125 before or with acetaminophen protected Jnk(Δhepa) and control mice from liver injury. In hepatocytes, JNK1 and JNK2 appear to have combined effects in protecting mice from CCl4- and acetaminophen-induced liver injury. It is important to study the tissue-specific functions of both proteins, rather than just JNK1, in the onset of toxic liver injury. JNK inhibition with SP600125 shows off-target effects.

Hepatoprotective activity of total iridoid glycosides isolated from Paederia scandens (lour.) Merr. var. tomentosa

Ethnopharmacological relevanceCurrently, human liver is susceptible to injury caused by alcohol and virus infiltration, resulting in hepatitis, cirrhosis, and even hepatocellular carcinoma. Paederia scandens (Lour.) Merr. var. tomentosa (Rubiaceae) has been used as traditional medicine in Asian countries to treat jaundice, dysentery, and abdominal mass. Furthermore, the abundance of iridoid glycosides in Paederia species indicates their notable hepatoprotective potential. Materials and methodsTotal iridoid glycosides (TG) was prepared, and constituents of TG were analyzed by HPLC. TG and silymarin (positive) were orally administered for 15 days. Then, acute liver injury rats was induced by intraperitoneally injection (i.p.) of 10% CCl4 (0.12%, v/v, dissolved in olive oil, 10mL/kg, body weight). Rats were sacrificed at 16h after CCl4 injection. Liver tissues and blood were collected. Serum samples were prepared to determine the activities of alanine transaminase (ALT) and aspartate transaminase (AST), whereas liver tissue sections were prepared for the purpose of examining possible liver histopathological changes. In addition, antioxidant enzyme activities in liver tissues were also evaluated. ResultsOur results demonstrated that TG significantly decreased the levels of AST and ALT, compared with those in control rats. In addition, pre-treatment of the rats with TG clearly alleviated their liver tissue injuries. What’s more, the activities of GSH, GAT and SOD in the groups of TG-treated rats were significantly increased compared with those of rats in the control group, whereas the levels of MDA were decreased. ConclusionsOur present research indicated that TG possessed notable hepatoprotective activity via decreasing oxidative stress level in liver tissues.

Ameliorative effect of riboflavin on hyperglycemia, oxidative stress and DNA damage in type-2 diabetic mice: Mechanistic and therapeutic strategies

Increasing evidence in both experimental and clinical studies suggests that oxidative stress play a major role in the pathogenesis of type-2 diabetes mellitus (T2DM). Abnormally high levels of free radicals and the simultaneous decline of antioxidant defence mechanisms can lead to damage of cellular organelles and enzymes. Riboflavin constitutes an essential nutrient for humans and is also an important food additive for animals. It is a precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) which serves as a coenzyme for several enzymes. The aim of this study was to observe the effects of illuminated and non-illuminated riboflavin in a diabetic mice model. The protocol included treatment of diabetic mice with illuminated RF and a control set without light. To our surprise, group receiving RF without light gave better results in a dose dependent manner. Significant amelioration of oxidative stress was observed with an increased glucose uptake in skeletal muscles and white adipose tissue. Histological studies showed recovery in the liver and kidney tissue injury. Cellular DNA damage was also recovered. Therefore, it is suggested that supplementation with dietary riboflavin might help in the reduction of diabetic complications. A possible mechanism of action is also proposed.