Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.1 (aspartate aminotransferase)
 21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

In this study, the possible potentiation of cisplatin-induced hepatotoxicity by cytochrome P450 2E1 (CYP2E1) was examined both in vitro and in vivo. Transfected HepG2 cells expressing CYP2E1 (E47 cells) and not expressing CYP2E1 (C34 cells) were used as an in vitro model, and mice drinking 2% acetone for 7 days to induce CYP2E1 were used as an in vivo model. Exposure of E47 cells to cisplatin caused a much greater loss of cell viability, more striking depletion of reduced glutathione (GSH), and higher reactive oxygen species (ROS) production as compared with C34 cells. The prooxidant L-buthionine-[R,S]-sulfoximine (BSO), which depletes GSH, enhanced cisplatin-induced loss of cell viability, whereas the antioxidant glutathione ethyl ester, or the iron chelator deferoxamine mesylate (DFO) protected against the cisplatin-induced loss of E47 cell viability. Diallyl sulfide (DAS), an inhibitor of CYP2E1, also protected against the cisplatin toxicity in the E47 cells. After being injected with cisplatin (ip, 45 mg/kg), mice drinking 2% acetone with increased CYP2E1 levels exhibited elevated levels of serum ALT and AST, liver caspase-3 activity and positive staining of TUNEL increased, and histopathology indicated the presence of necrotic foci in livers of acetone plus cisplatin-treated mice. Lipid peroxidation and protein oxidation as indicated by carbonyl formation, staining of 3-nitrotyrosine (3-NT) and iron were higher in the cisplatin plus acetone group, compared with cisplatin alone group. Both in vitro and in vivo results indicate that elevated CYP2E1 enhances cisplatin-induced hepatotoxicity, and the mechanism may involve increased production of ROS and oxidative stress.
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PMID:Cisplatin-induced hepatotoxicity is enhanced by elevated expression of cytochrome P450 2E1. 1625 82

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

We hypothesized that the hepatotoxicity that develops after the induction of oxidative stress (induced by d-galactosamine [GalN]) can be ameliorated by alpha-tocopherol (ATC) and the soy isoflavone daidzein. To test this, we ranked and assigned male Wistar rats into 6 groups, which involved pretreatment (ATC or daidzein) for 1 hour followed by treatment (GalN) for 23 hours. Histopathologic analysis showed that GalN administration induced marked necrosis (P < .001), steatosis (P < .001), both lobular and portal inflammations (P < .001), overall histopathologic score (P < .001), and activation of caspase-3 in the liver (P < .001). Immunohistochemical staining of malondialdehyde-protein adducts, a measure of oxidative stress, was increased in response to GalN (P < .001). Paradoxically, there were increases in total (P < .05) and cytosolic superoxide dismutase (P < .001) activities after GalN administration, indicative of an up-regulation of antioxidant defenses. The concentration of total protein (P < .001), albumin (P < .01), and globulin fractions (P < .001) in the plasma, as well as the activity of aspartate aminotransferase (P < .001), was significantly perturbed after GalN treatment, reflective of overall acute hepatic injury. Administration of daidzein showed a significant amelioration of the Ga1N-induced increase in malondialdehyde-protein adducts (P < .01) and cytosolic superoxide dismutase activities (P < .01) in the liver. However, all other variables were not significantly altered in response to daidzein. In response to ATC pretreatment, the total histopathologic score (P < .05), degree of necrosis (P < .05), and both lobular (P < .05) and portal (P = .05) inflammations were significantly ameliorated. To conclude, both daidzein and ATC protect the liver against oxidative damage possibly via different pathways.
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PMID:The cytoprotective effect of alpha-tocopherol and daidzein against d-galactosamine-induced oxidative damage in the rat liver. 1757 Feb 44

Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme catabolism, has been shown to be induced during oxidative injury, and its induction acts as an important cellular defense mechanism against such injuries. In this study, we examined the functional roles of HO-1 induction in a rat model of d-galactosamine (GalN) and lipopolysaccharide (LPS)-induced liver injury. We found that GalN/LPS treatment of rats produced severe hepatic injury, whereas upregulation of HO-1 by hemin pretreatment prevented rats from liver damage, as evidenced by decreased serum ALT, AST levels and ameliorated histological signs in the liver. Induction of HO-1 resulted in a significant decrease in hepatic malondialdehyde (MDA) contents, tumor necrosis factor-alpha (TNF-alpha) levels, iNOS/NO production, as well as the levels of caspase-3. In contrast, inhibition of HO activity by zinc protoporphyrin-9 (ZnPP, a specific inhibitor of HO) completely reversed HO-1-induced hepatoprotective effect. These data therefore suggested that HO-1 induction provided critical protection against GalN/LPS-induced liver injury, and the protection seemed to be mediated through the anti-oxidant, anti-inflammatory and anti-apoptotic functions.
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PMID:Upregulation of heme oxygenase-1 with hemin prevents D-galactosamine and lipopolysaccharide-induced acute hepatic injury in rats. 1758 81

The potential protective effect of the natural antioxidant, carnosine was evaluated against ischemia/reperfusion liver injury in rats. Ischemia was induced by clamping the pedicle supplying the left hepatic lobe for 60 min followed by reperfusion for 2 h. Untreated rats exposed to ischemia/reperfusion showed significant elevation of serum aspartate aminotransferase and alanine aminotransferase levels, and malondialdehyde level and caspase-3 activity in liver homogenates associated with significant reduction in hepatic nitrite level, catalase and glutathione peroxidase activities as compared with sham-operated group. Pre-treatment with a single i.p. dose of carnosine (250 mg/kg), 30 min prior to the ischemic episode significantly attenuated the deterioration in the measured biochemical parameters observed with ischemia/reperfusion-induced liver injury. Also, light and electron microscopic examinations in ischemia/reperfusion untreated group revealed severe hepatic damage, such as cytoplasmic vacuolation, necrotic and apoptotic cell death, which was markedly ameliorated by pre-ischemic treatment with carnosine. These results strongly emphasize that carnosine can be useful as a prophylactic treatment to protect the liver against hypoxia-reoxygenation damage.
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PMID:The hepatoprotective effect of carnosine against ischemia/reperfusion liver injury in rats. 1761 Aug 73


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