Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Indices of oxidative stress, nitric oxide (NO) metabolism as well as the activity of caspase-3, an important enzyme of apoptotic cell death, were measured during the morphine withdrawal syndrome in liver and thymus of rats. Male Wistar rats were administered with morphine hydrochloride (i.p., at increasing doses from 10 to 100 mg/kg, twice a day, for 6 days). Thirty-six hours after the last administration the withdrawal syndrome was monitored using the specific autonomic and locomotor indices. During this period, weights of body and thymus significantly decreased. Oxidative stress in liver was accompanied by an increase in aspartate aminotransferase and gamma-glutamyl transferase in blood serum. No signs of oxidative stress could be demonstrated in thymus. The activity of the Ca(2+)-dependent isoform of nitric oxide synthase (NOS) in liver increased, while, the activity of the Ca(2+)-independent NOS diminished, the total activity of NOS in liver and thymus remained unchanged. The concentration of nitrates/nitrites in blood was decreased, in thymus increased, and in liver unchanged. Caspase-3 activity changed neither in liver, nor in thymus. The results are discussed from the perspective of possible antioxidant and antiapoptotic role of NO during morphine withdrawal syndrome.
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PMID:[Effects of morphine withdrawal on the indices of free radical homeostasis and nitric oxide system in rat liver and thymus]. 1562 95

1. Minocycline has anti-inflammatory and antiapoptotic effects on cartilage, neurons and periodontal tissues, and both properties are central to the pharmaceutical treatment of liver diseases. We investigated the effects of minocycline on fulminant hepatitis in C57BL/6J mice induced by lethal challenge of the activating anti-Fas antibody, Jo2. 2. Intraperitoneal injection of Jo2 (0.6 microg g(-1)) to mice resulted in fulminant hepatitis, as evidenced by increase of serum alanine/aspartate transaminase activities and histopathological alterations in liver sections, as well as animal death. Nevertheless, mice pretreated with three doses of minocycline (5 mg kg(-1)) resisted this lethal effect significantly. Minocycline treatment improved the survival kinetics, although to a lesser extent, when mice were challenged simultaneously with Jo2 or even treated 30 min after the lethal challenge. 3. Jo2-induced activation of caspase-3 or -9 in liver tissues was inhibited by minocycline pretreatment, and yet the direct addition of minocycline to liver extracts from Jo2-challenged mice failed to block caspase activation in vitro. Moreover, minocycline efficiently suppressed the release of cytochrome c from mitochondria of the liver tissues from Jo2-challenged mice. In contrast, caspase-8 activation and Bid truncation triggered by Jo2 were not diminished by minocycline pretreatment in mouse livers. 4. Our results suggest that easing of Fas-triggered fulminant hepatitis by minocycline may involve a mitochondrial apoptotic pathway, probably through preventing cytochrome c release and thereby blocking downstream caspase activation.
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PMID:Effects of minocycline on Fas-mediated fulminant hepatitis in mice. 1566 64

The effects of 6-formylpterin on tumor necrosis factor (TNF)-alpha-induced apoptotic cell injury were studied in cultured rat hepatocytes. The incubation of the hepatocytes with TNF-alpha and actinomycin D (ActD) induced the apoptotic cell injury. The level of aspartate transaminase (AST) in the culture supernatant increased, and the cell viability, estimated by mitochondrial respiration (MTT assay), decreased. The DNA fragmentation and the caspase 3-like activity, which are characterized to apoptosis, increased. When the hepatocytes were incubated with 100-500 microM 6-formylpterin, the intracellular formation of reactive oxygen species (ROS) was observed, and the ratio of reduced and oxidized glutathione (GSH/GSSG) of whole cell lysate decreased. The co-incubation of the TNF-alpha/ActD-treated hepatocytes with 100-500 microM 6-formylpterin attenuated the TNF-alpha/ActD-induced apoptotic cell injury. The level of AST decreased and the cell viability increased. Both the DNA fragmentation and the caspase 3-like activity decreased. The caspases, executors of apoptosis, are known to require a reduced cystein in their active site to function, and the intact intracellular GSH/GSSG is essential for the caspase activation. Therefore, our findings suggest that intracellular ROS generated by 6-formylpterin decline the intracellular redox state to an oxidant state, which suppresses the caspase activity and prevents the apoptotic cell injury of hepatocytes.
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PMID:Protective effects of intracellular reactive oxygen species generated by 6-formylpterin on tumor necrosis factor-alpha-induced apoptotic cell injury in cultured rat hepatocytes. 1596 7

To examine the role of histamine H1 and H2 receptors in the regulation of lipopolysaccharide (LPS)-induced liver injury, a combination of D-galactosamine and LPS (GalN/LPS) was administered to histamine H1 receptor knockout (H1-R KO) and H2 receptor knockout (H2-R KO) mice. The numbers of necrotic and apoptotic hepatocytes in the liver, as well as the levels of serum aspartate transaminase (AST) and alanine transaminase (ALT), were increased significantly by GalN/LPS treatment compared to the appropriate controls. Pretreatment with histamine ameliorated the GalN/LPS-induced necrotic and apoptotic changes in the hepatocytes and inhibited the elevation of serum AST and ALT levels. Histamine attenuated the GalN/LPS-induced increases in the levels of TNF-alpha, but augmented those of IL-10 both in the liver and serum. Histamine inhibited the GalN/LPS-induced caspase-3 activity in the liver. Furthermore, these effects of histamine were completely or partially attenuated in H2-R KO mice, but not in H1-R KO mice. Peritoneal macrophages from H2-R KO mice exhibited blunted changes in the effects of histamine on LPS-induced TNF-alpha and IL-10 production in vitro compared to the wild-type (WT) controls. In summary, the present findings suggest that the histamine H2-R-TNF-alpha and -IL-10 pathways play protective roles in endotoxin-induced hepatic injury.
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PMID:The role of histamine H1 receptor and H2 receptor in LPS-induced liver injury. 1605 91

Sixteen barrows (Duroc x Landrace x Yorkshire) were randomly divided into two groups, each consisting eight pigs. The groups received the same basal diet supplemented with 0 and 400 mg/kg fluoride, respectively. Histological examinations, including in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), Haematoxylin and Eosin staining (HE) and transmission electron microscopy observation, found apoptotic hepatocytes 50 days after additional 400 mg/kg fluoride treatment. The obvious DNA ladder and the significantly increased both hepatic caspase-9 and caspase-3 activity indicated that fluoride induced caspase-dependent apoptosis in vivo. In addition, serum glutamate pyruvate transaminase (GPT) activity and hepatic lipid peroxides (LPO) concentration was significantly increased. The activity of serum glutamate oxaloacetate transaminase (GOT) showed an increased trend. The results suggest that fluoride induces apoptosis by elevating the oxidative stress-induced lipid peroxidation, causing mitochondrial dysfunction and further activating caspase-9 and caspase-3.
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PMID:Evaluation of caspase-dependent apoptosis during fluoride-induced liver lesion in pigs. 1613 39

We investigated the protective effects of diallyl disulfide (DADS), a potent inhibitor of cytochrome P450 2E1 (CYP2E1), on ethanol-induced toxicity in human hepatocytes. We found a clear dose-dependent response between ethanol and CYP2E1 activity. The ethanol-dependent CYP2E1 enzyme activity and protein expression, lactate dehydrogenase and aspartate transaminase release, malondialdehyde formation and caspase-3 activity decreased dramatically in the presence of DADS. Furthermore, DADS increased the hepatocellular glutathione (GSH) content and prevented the ethanol-dependent cellular GSH depletion. Our data show that DADS reduces ethanol-induced toxicity in human hepatocytes by reducing CYP2E1 activity and/or stabilizing the cellular GSH content, which might be of therapeutic interest.
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PMID:Human hepatocytes are protected from ethanol-induced cytotoxicity by DADS via CYP2E1 inhibition. 1635 68

Recently, erythropoietin was shown to have both hematopoietic as well as tissue-protective properties. Erythropoietin (EPO) had a protective effect in animal models of cerebral ischemia, mechanical trauma of the nervous system, myocardial infarction, and ischemia-reperfusion (I/R) injury of the kidney. It is not known whether EPO protects the liver against I/R injury. Using a rat model of liver I/R injury, we aimed to determine the effect of the administration of human recombinant erythropoietin (rhEPO) on liver injury. Rats were subjected to 30 min of liver ischemia followed by 2 h of reperfusion. When compared with the sham-operated rats, I/R resulted in significant rises in the serum levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, gamma-glutamyl transferase, tissue lipid peroxidation, caspase-3 activity and altered histology. Administration of rhEPO 5 min before ischemia was able to reduce the biochemical evidence of liver injury; however, this protection was not evident when rhEPO was administered 5 min before reperfusion. Mechanistically, early administration of rhEPO was able to reduce the oxidative stress and caspase-3 activation, suggesting the subsequent reduction of apoptosis. This study provides the first evidence that rhEPO causes a substantial reduction of the liver injury induced by I/R in the rat.
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PMID:Recombinant human erythropoietin protects the liver from hepatic ischemia-reperfusion injury in the rat. 1701 28

In the present study, we investigated the hepatoprotective effects of salvianolic acid A, a novel antioxidant, against oxidative stress and acute liver injury induced by carbon tetrachloride (CCl(4)) in rats, and the mechanisms underlying its protective effects. Administration of CCl(4) to rats caused severe hepatic damage, as demonstrated by the significant increase in the levels of serum alanine aminotransferase, aspartate aminotransferase and classic histological changes including hepatocyte necrosis or apoptosis, haemorrhage, fatty degeneration, etc. Co-treatment with salvianolic acid A (20 mg/kg, intraperitoneally), a water-soluble extract from a Chinese traditional drug, Radix Salvia miltiorrhiza, significantly decreased CCl(4)-induced hepatotoxicity. Salvianolic acid A not only decreased serum alanine aminotransferase, aspartate aminotransferas levels and ameliorated histopathological manifestations in CCl(4)-treated rats, but also reduced oxidative stress, as evidenced by decreased reactive oxygen species production and malondialdehyde concentrations in the liver tissues, combined with elevated hepatic superoxide dismutase activity and gluthathione content. In addition, salvianolic acid A treatment remarkably reduced intrahepatic tumour necrosis factor-alpha concentrations and caspase-3 activities as compared with the CCl(4)-treated rats. The results suggested that treatment with salvianolic acid A provides a potent protective effect against acute hepatic damage caused by CCl(4) in rats, which may mainly be related to its antioxidative effect.
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PMID:Effects of salvianolic acid a on oxidative stress and liver injury induced by carbon tetrachloride in rats. 1724 60

The antioxidant and hepatoprotective actions of Terminalia catappa L. collected from Okinawa Island were evaluated in vitro and in vivo using leaves extract and isolated antioxidants. A water extract of the leaves of T. catappa showed a strong radical scavenging action for 1,1-diphenyl-2-picrylhydrazyl and superoxide (O(2)(.-)) anion. Chebulagic acid and corilagin were isolated as the active components from T. catappa. Both antioxidants showed a strong scavenging action for O(2)(.-) and peroxyl radicals and also inhibited reactive oxygen species production from leukocytes stimulated by phorbol-12-myristate acetate. Galactosamine (GalN, 600 mg/kg, s.c.,) and lipopolysaccharide (LPS, 0.5 microg/kg, i.p.)-induced hepatotoxicity of rats as seen by an elevation of serum alanine aminotransferase, aspartate aminotransferase and glutathione S-transferase (GST) activities was significantly reduced when the herb extract or corilagin was given intraperitoneally to rats prior to GalN/LPS treatment. Increase of free radical formation and lipid peroxidation in mitochondria caused by GalN/LPS treatment were also decreased by pretreatment with the herb/corilagin. In addition, apoptotic events such as DNA fragmentation and the increase in caspase-3 activity in the liver observed with GalN/LPS treatment were prevented by the pretreatment with the herb/corilagin. These results show that the extract of T. catappa and its antioxidant, corilagin are protective against GalN/LPS-induced liver injury through suppression of oxidative stress and apoptosis.
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PMID:Antioxidant and hepatoprotective actions of medicinal herb, Terminalia catappa L. from Okinawa Island and its tannin corilagin. 1729 97

Fulminant hepatic failure (FHF) is a dramatic clinical syndrome characterized by massive hepatocyte apoptosis and very high mortality. The c-Jun-N-terminal kinase (JNK) pathway is an important stress-responsive kinase activated by several forms of liver injury. The aim of this study is to assess the role of JNK during D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury, an experimental model of FHF, using SP600125, a small molecule JNK-specific inhibitor. Mice were given an intraperitoneal dose of GalN (800 microg/g body weight)/LPS (100 ng/g body weight) with and without subcutaneous SP600125 (50 mg/kg body weight) treatment (at 6 and 2 h before and 2 h after GalN/LPS administration). GalN/LPS treatment induced sustained JNK activation. Administration of SP600125 diminished JNK activity, suppressed lethality and the elevation of both serum alanine aminotransferase and aspartate aminotransferase, but had no effect on serum tumor necrosis factor-alpha, and reduced hepatocyte apoptosis after GalN/LPS administration. In support of the role of JNK in promoting the mitochondria-mediated apoptosis pathway, SP600125 prevented cytochrome c release, caspase-9 and caspase-3 activity. Moreover, SP600125 downregulated the mRNA and protein expression of Bad in the early periods following GalN/LPS injection and prevented Bid cleavage in the late periods. These results confirm the role of JNK as a critical apoptotic mediator in GalN/LPS-induced FHF. SP600125 has the potential to protect FHF by downregulating Bad and inhibiting Bid cleavage.
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PMID:An inhibitor of c-Jun NH2-terminal kinase, SP600125, protects mice from D-galactosamine/lipopolysaccharide-induced hepatic failure by modulating BH3-only proteins. 1730 Aug 14


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