Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Scutellarin is a natural compound from a Chinese herb. The purpose of this paper was to study the protective effect of scutellarin on concanavalin A (Con A)-induced immunological liver injury and its effect on liver nuclear factor kappaB (NF-kappaB), tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and inducible nitric oxide synthase (iNOS) expression in mice. Mouse liver injury was produced by injection of Con A 25 mg kg-1 via the tail vein. Scutellarin 50 or 100 mg kg-1 was peritoneally administered to mice 9 or 1 h before injection of Con A. The levels of serum alanine aminotransferase (ALT) and asparatate aminotransferase (AST), NO2-/NO3- and TNF-alpha were determined with biochemical kits, and ELISA using Quantikine Mouse TNF-alpha kit according the manufacturer's instructions. Liver lesions were examined by light microscope. The expression of TNF-alpha, IFN-gamma, iNOS and Fas mRNA in the livers was detected by RT-PCR; and the expression of c-Fos, c-Jun, iNOS and IkappaB proteins was measured by Western Blotting. As a result, pretreatment with scutellarin 100 mg kg-1 significantly decreased the serum ALT, AST, NO2-/NO3- and TNF-alpha levels, and also reduced liver lesions induced by Con A. Scutellarin 100 mg kg-1 down-regulated expression of TNF-alpha and iNOS mRNA, and c-Fos, c-Jun and iNOS protein, while scutellarin enhanced the degradation of IkappaB in the livers of mice injected with Con A. The results suggest that scutellarin has a protective action against Con A-induced liver injury in mice, and its active mechanism may be related to the inhibition of the NF-kappaB-TNF-alpha-iNOS transduction pathway.
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PMID:The protective action of scutellarin against immunological liver injury induced by concanavalin A and its effect on pro-inflammatory cytokines in mice. 1722 28

Lead (Pb) increases lipopolysaccharide (LPS)-induced tumor necrosis factor alpha, which causes liver damage. In this study, we investigated the effect of sesame oil on Pb-plus-LPS (Pb + LPS)-induced acute liver damage in mice. Mice were given sesame oil (8 mL/kg orally) just after Pb acetate (10 mmol/kg i.p.) plus LPS (5 mg/kg i.p.). Aspartate aminotransferase, alanine aminotransferase, tumor necrosis factor-alpha, interleukin-1beta, nitric oxide, and inducible nitric oxide synthase levels were examined. Sesame oil significantly decreased serum aspartate aminotransferase and alanine aminotransferase levels in Pb + LPS-stimulated mice. Sesame oil reduced Pb + LPS-induced tumor necrosis factor-alpha, interleukin-1beta, and nitric oxide production in serum and liver tissue. Furthermore, sesame oil decreased inducible nitric oxide synthase expression in leukocytes and liver tissue in Pb + LPS-treated mice. We hypothesize that the inhibition of proinflammatory cytokines and nitric oxide might be involved in sesame oil-associated protection against Pb + LPS-induced acute hepatic injury in mice.
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PMID:Sesame oil protects against lead-plus-lipopolysaccharide-induced acute hepatic injury. 1730 16

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

Carbon monoxide (CO), a product of heme degradation by heme oxygenases (HO), has been shown to provide cytoprotection in various tissue injury models. This study examined the efficacy and molecular mechanisms of exogenously delivered inhaled CO in protecting liver grafts from cold ischemia/reperfusion (I/R) injury associated with liver transplantation. Orthotopic syngenic liver transplantation (OLT) was performed in Lewis rats with 18-h cold preservation in University of Wisconsin solution. Recipients were exposed to air or different concentrations of CO (20-250 ppm) for 1 h before and 24 h after OLT and killed 1-48 h posttransplant. CO inhalation significantly decreased serum alanine transaminase (ALT) levels and suppressed hepatic necrosis and neutrophil accumulation at 24-48 h after OLT in a dose-dependent manner. Reduced hepatic injury with inhaled CO is associated with marked downregulation of early mRNA expression for TNF-alpha and IL-6. Expression in liver grafts of mRNA and protein of the stress-responding enzyme inducible nitric oxide synthase was significantly reduced by CO, while HO-1 was only marginally suppressed. Cold hepatic I/R injury was associated with prompt MAPK phosphorylation in liver grafts at 1 h after OLT, and CO significantly inhibited phosphorylation of ERK1/2 MAPK and its upstream MEK1/2 and downstream transcriptional factor c-Myc. CO also significantly inhibited I/R injury-induced STAT1 and STAT3 activation. In contrast, CO did not inhibit p38 or JNK MAPK pathways during hepatic I/R injury. Results demonstrate that exogenous CO suppresses early proinflammatory and stress-response gene expression and efficiently ameliorates hepatic I/R injury. The possible mechanism may include the downregulation of MEK/ERK1/2 signaling pathway with CO.
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PMID:Protection of transplant-induced hepatic ischemia/reperfusion injury with carbon monoxide via MEK/ERK1/2 pathway downregulation. 1800 5

1,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylic acid methyl 6-(5-phenyl-3-pyrazolyloxy)hexyl ester (CV159) exhibits selective blocking of Ca(2+)/calmodulin and inhibits Ca(2+) overloading in living organisms. The effects of this antagonist in mice with hepatic ischemia-reperfusion injury were investigated using electron paramagnetic resonance imaging (EPRI) and ex vivo EPR (x-band EPR) techniques. The EPRI determined that the 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl half-life in CV159-treated mice was significantly shorter than that in untreated mice and was almost equal to that in the sham group. Both the cytosolic and the mitochondrial superoxide scavenging activities in CV-treated mice were significantly higher than that in untreated mice. Faint staining of the anti-superoxide dismutase antibody and strong staining of anti-inducible nitric oxide synthase antibody were observed in the liver of control group. In contrast to these findings, immunostaining of these antibodies in the liver of CV159-treated mice were reversed compared to control group. Western blotting showed that CV159 contributed to the high superoxide dismutase expression and low expression of inducible nitric oxide synthase. The alanine aminotransferase level in CV159-treated mice significantly decreased in comparison to that observed in the untreated mice. We conclude that CV159 retains its organ-reducing activity against radicals in hepatic reperfusion injury, which is mediated by the inhibition of Ca(2+) overloading.
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PMID:Effect of CV159-Ca(2+)/calmodulin blockade on redox status hepatic ischemia-reperfusion injury in mice evaluated by a newly developed in vivo EPR imaging technique. 1806 26

The production of reactive oxygen species during hepatic ischemia/reperfusion (I/R) can help create disturbances in microcirculation. This study examined the effect of melatonin, a pineal secretory product and a potent antioxidant, on the expression of vascular stress genes during hepatic I/R. Rats were subjected to 60 min of hepatic warm ischemia followed by 5 h reperfusion. Melatonin (10 mg/kg) was administered intraperitoneally 15 min before ischemia and immediately before reperfusion. The serum alanine aminotransferase and hepatic malondialdehyde levels increased markedly after I/R. These increases were significantly inhibited by melatonin. The levels of endothelin-1 (ET-1) and its receptor, ET(B) mRNA, were elevated by I/R but attenuated by melatonin. The mRNA levels of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and heme oxygenase-1 were significantly higher after I/ R. Melatonin augmented the increase in the eNOS mRNA level, whereas it reduced the increase in the iNOS mRNA level. The expression of tumor necrosis factor-alpha was increased markedly by I/R. This increase was also attenuated by melatonin. These results suggest that melatonin ameliorates the imbalanced expression of the vascular stress genes during hepatic I/R through its antioxidant property.
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PMID:Effect of melatonin on altered expression of vasoregulatory genes during hepatic ischemia/reperfusion. 1825 50

Recent evidence indicates that inhibition of the Na+/H+ exchanger improves heart and brain injuries induced by I/R. Studies were performed to investigate whether FR183998, a Na/H exchanger inhibitor, has protective effects on hepatic I/R injury in rats. Male Sprague-Dawley rats were subjected to 70% hepatic ischemia by occluding the hepatic artery, portal vein, and bile duct associated with the left and median liver lobes with a microvascular clip for 2 h. FR183998 (1 mg/kg) was administered i.v. 10 min before the hepatic ischemia. Hepatic I/R increased the serum levels of aspartate transaminase, alanine transaminase, and lactate dehydrogenase, which peaked at 9 h after reperfusion. FR183998 reduced these injury markers and recovered liver functions. Histopathologic analysis revealed that FR183998 prevented the incidences of hepatic necrosis, apoptosis, and neutrophil infiltration at 6 and 9 h (P < 0.05). FR183998 reduced the increases in proinflammatory cytokines such as TNF-alpha (1-6 h), IL-6 (1-12 h), interferon-gamma (6-12 h), IL-1beta (1-3 h), and cytokine-induced neutrophil chemoattractant 1 (1-3 h), but enhanced the anti-inflammatory cytokine IL-10 (1 h). FR183998 inhibited the hepatic I/R-induced activation of the transcription factor nuclear factor-kappaB at 1 to 6 h and reduced the induction of iNOS at 6 to 12 h, followed by inhibition of nitric oxide production. Furthermore, FR183998 decreased the expression of the iNOS gene antisense transcript, which is involved in the stability of iNOS messenger RNA, at 9 to 12 h in the liver of hepatic I/R rats. These results demonstrate that FR183998 reduces the induction of proinflammatory cytokines and iNOS at least in part through inhibition of nuclear factor-kappaB activation and iNOS antisense transcript expression, thereby preventing hepatic I/R injury.
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PMID:Protective effect of FR183998, a Na+/H+ exchanger inhibitor, and its inhibition of iNOS induction in hepatic ischemia-reperfusion injury in rats. 1827 53

Previous experiments showed that treatment of mice and rats with thioacetamide (TAA) induced liver cell damage, fibrosis and/or cirrhosis, associated with increased oxidative stress and activation of hepatic stellate cells. Some experiments suggest that CYP2E1 may be involved in the metabolic activation of TAA. However, there is no direct evidence on the role of CYP2E1 in TAA-mediated hepatotoxicity. To clarify this, TAA-induced hepatotoxicity was investigated using Cyp2e1-null mice. Male wild-type and Cyp2e1-null mice were treated with TAA (200 mg/kg of body weight, single, i.p.) at 6 weeks of age, and hepatotoxicity examined 24 and 48 h after TAA treatment. Relative liver weights of Cyp2e1-null mice were significantly different at 24 h compared to wild-type mice (p<0.01). Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in Cyp2e1-null mice were significantly different at both time points compared to wild-type mice (p<0.01). Histopathological examination showed Cyp2e1-null mice represented no hepatototoxic lesions, in clear contrast to severe centriobular necrosis, inflammation and hemorrhage at both time points in wild-type mice. Marked lipid peroxidation was also only limited to wild-type mice (p<0.01). Similarly, TNF-alpha, IL-6 and glutathione peroxidase mRNA expression in Cyp2e1-null mice did not significantly differ from the control levels, contrasting with the marked alteration in wild-type mice (p<0.01). Western blot analysis further revealed no increase in iNOS expression in Cyp2e1-null mice. These results reveal that CYP2E1 mediates TAA-induced hepatotoxicity in wild-type mice as a result of increased oxidative stress.
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PMID:Role of CYP2E1 in thioacetamide-induced mouse hepatotoxicity. 1837 80

Kidney stones are known to haunt humanity for centuries and increase in oxalate is a predominant risk factor for stone formation. The present study was initiated with a notion to study the oxidative and nitrosative stress on erythrocytes under oxalate stress and the putative role of sulphated polysaccharides. Hyperoxaluria was induced in two groups by the administration of 0.75% ethylene glycol in drinking water for 28 days and one of them was treated with sulphated polysaccharides from Fucus vesiculosus from the 8th day to the end of the experimental period of 28 days at a dose of 5 mg/kg body weight subcutaneously. Control and drug control (sulphated polysaccharides alone) were also included in the study. Glycolic and glyoxylic acid levels of urine were analyzed as an index of hyperoxaluria. The plasma enzymic markers of cellular integrity, redox status of red blood cells, osmotic fragility, and (14)C-oxalate binding were investigated. Urine and plasma nitric oxide metabolites, expression of inducible nitric oxide synthase protein, and mRNA were assessed in kidney to evaluate the nitrosative stress. Increased levels of glycolic and glyoxylic acid in urine indicated the prevalence of hyperoxaluria in ethylene glycol-administered groups. Plasma aspartate and alanine transaminase were not altered, but alkaline phosphatase and lactate dehydrogenase of hyperoxaluric group were increased indicating tissue damage. Activities of antioxidant enzymes were decreased, whereas erythrocyte membrane lipid peroxidation was increased in hyperoxaluric rats. Moreover, an altered fragility with an increase in oxalate binding activity was observed in hyperoxaluric group. Increase in nitric oxide metabolites levels in urine and plasma along with an increase in expression of inducible nitric oxide synthase protein and mRNA in kidney were observed in hyperoxaluric rats. Administration of sulphated polysaccharides to hyperoxaluric rats averted the abnormal increase in urinary glycolic and glyoxylic acid levels and enzyme activities, decreased lipid peroxidation, and increased the activities of antioxidant enzymes. Furthermore, increased nitrosative stress accompanying hyperoxaluria was also normalized on sulphated polysaccharides treatment. To conclude, sulphated polysaccharide administration was able to maintain the integrity of erythrocyte membrane and decrease the damage to erythrocytes in hyperoxaluria.
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PMID:Effect of sulphated polysaccharides on erythrocyte changes due to oxidative and nitrosative stress in experimental hyperoxaluria. 1837 35

The modulation influence of Misgurnus anguillicaudatus polysaccharide on the expression of nitric oxide synthase (NOS), B cell lymphoma/leukemia-2 (Bcl-2, hepatocyte apoptosis inhibitor) and Bcl-2 associated X protein (Bax, hepatocyte apoptosis promoter) in mice's liver with immunological hepatic injury was studied. Immunological hepatic injury was induced by lipopolysaccharide (LPS ip, 0.2 mg kg(-1)) in bacillus calmette-guerin (BCG ip, 0.15 g kg(-1), once, before 7 days) primed mice. The mice were treated with M. anguillicaudatus polysaccharides (MAP) at doses of 30 mg kg(-1), 60 mg kg(-1), respectively, ig, once a day, and sacrificed on the 8th day after ip LPS for 4 h. In comparison to the normal mice, the nitric oxide production, serum alanine aminotransferase (sALT) and serum glutathione s-transferase (sGST) levels were increased significantly, iNOS and Bax expression were up-regulated by 16.5 times (P<0.001 vs. normal animal group) and 0.43 times (P<0.05, vs. normal animal group) respectively, cNOS expression was not apparently changed, and no Bcl-2 expression was found in immunological hepatic injury mice. The M. anguillicaudatus polysaccharide (30 mg kg(-1)) could reduce sALT, sGST and nitric oxide production levels (vs. BCG-LPS model control group) by 25.1%, 42.6% and 17.8% respectively, and the expression of iNOS and Bax was decreased (vs. BCG-LPS model control group) by 80.3% and 38.4%, while the expression of cNOS and Bcl-2 increased (vs. BCG-LPS model control group) by 58.7% and 352%, respectively.
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PMID:Protective effect of Misgurnus anguillicaudatus polysaccharide on immunological liver injury in mice. 1838 2


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