Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many idiosyncratic non-steroidal anti-inflammatory drugs (NSAIDs) cause GI, liver and bone marrow toxicity in some patients which results in GI bleeding/ulceration/fulminant hepatic failure/hepatitis or agranulocytosis/aplastic anemia. The toxic mechanisms proposed have been reviewed. Evidence is presented showing that idiosyncratic NSAID drugs form prooxidant radicals when metabolised by peroxidases known to be present in these tissues. Thus GSH, NADH and/or ascorbate were cooxidised by catalytic amounts of NSAIDs and hydrogen peroxide in the presence of peroxidase. During GSH and NADH cooxidation, oxygen uptake and activation occurred. Furthermore the formation of NSAID oxidation products was prevented during the cooxidation indicating that the cooxidation involved redox cycling of the first formed NSAID radical product. The order of prooxidant catalytic effectiveness of fenamate and arylacetic acid NSAIDs was mefenamic acid>tolfenamic acid>flufenamic acid, meclofenamic acid or diclofenac. Diphenylamine, a common moiety to all of these NSAIDs was a more active prooxidant for NADH and ascorbate cooxidation than these NSAIDs which suggests that oxidation of the NSAID diphenylamine moiety to a cation and/or nitroxide radical was responsible for the NSAID prooxidant activity. The order of catalytic effectiveness found for sulfonamide derivatives was sulfaphenazole>sulfisoxazolez.Gt;dapsone>sulfanilic acid>procainamide>sulfamethoxazole>sulfadiazine>sulfadimethoxine whereas sulfanilamide, sulfapyridine or nimesulide had no prooxidant activity. Although indomethacin had little prooxidant activity, its major in vivo metabolite, N-deschlorobenzoyl indomethacin had significant prooxidant activity. Aminoantipyrine the major in vivo metabolite of aminopyrine or dipyrone was also more prooxidant than the parent drugs. It is hypothesized that the NSAID radicals and/or the resulting oxidative stress initiates the cytotoxic processes leading to idiosyncratic toxicity.
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PMID:Idiosyncratic NSAID drug induced oxidative stress. 1239 53

OBJECTIVE: To study signal transduction pathways in cultured rat hepatocytes in the high nitric oxide (NO) environment of hepatitis. METHODS: NO levels were assessed by measurement of its stable oxidative products nitrite (NO2(-)) and nitrate (NO3(-)) using the Griess method with or without thiols (GSH or L-Cys). Rat hepatocytes were incubated with Sodium Nitroprusside (SNP) to produce a high NO environment and the intracellular cGMP and s-nitrosoglutathione (GSNO) in the culture media were measured using radioimmunoassay or with the MTT assay absorbed at 334nm respectively. RESULTS: After incubation of 1.543 mmol/L SNP for 30 minutes 0.63+/-0.06 mmol/L and at 25 minutes 0.98+/-0.11 mmol/L of NO was released in containing 25 mmol/L GSH and L-Cys condition. The levels of both cGMP and GSNO were significantly increased (compared with control P<0.05) in a dose related manner. CONCLUSION: Signal transduction of cultured rat hepatocytes in a high NO environment could be a cGMP-dependent as well as a non-cGMP-dependent pathway.
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PMID:[Signal transduction pathways induced by nitric oxide in rat hepatocytes] 1260 57

Copper is an essential trace element with various biological functions. Excess copper, however, is extremely toxic, leading to many pathological conditions that are consistent with oxidative damage to membranes and molecules. Exposure to high levels of copper results in various changes in the tissues. In liver, hypertrophy of hepatocytes, hepatitis, hepatocellular necrosis, and hepatocellular death are the results. Lipid peroxidation causes dysfunction in the cell membrane, decreased fluidity, inactivation of receptors and enzymes, and changes ion permeability. In this study, we aimed to determine the effect of copper on oxidative and antioxidative substances in plasma and liver tissue in a rat model. Sixteen male Sprague-Dawley rats were divided into two groups: Group 1 rats included control rats given tap water. Group 2 rats were given water containing copper in a dose of 100 microg/mL. All rats were sacrificed at 4 wk under ether anesthesia. Plasma and liver superoxide dismutase (SOD) activities, plasma and liver MDA (malondialdehyde) levels, and liver glutathione (GSH) levels were studied. Plasma and liver SOD activities were found to be higher in group 2 than those in group 1. Although plasma MDA levels were higher in group 2, MDA levels in liver tissues were comparable. Liver tissue glutathione levels were lower in group 2. It was concluded that although copper is needed in trace amounts, an excess amount is toxic for the organism. It increases lipid peroxidation and depletes GSH reserves, which makes the organism more vulnerable to other oxidative challenges.
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PMID:Copper-mediated oxidative stress in rat liver. 1471

Wilson's disease (WD) is an inherited disorder, characterized by selective copper deposition in liver and brain, chronic hepatitis and extra-pyramidal signs. In this study, we investigated changes of biochemical markers of oxidative stress and apoptosis in liver, striatum and cerebral cortex homogenates from Long-Evans Cinnamon (LEC) rats, a mutant strain isolated from Long Evans (LE) rats, in whom spontaneous hepatitis develops shortly after birth. LEC and control (LE) rats at 11 and 14 weeks of age were used. We determined tissue levels of glutathione (GSH/GSSG ratio), lipid peroxides, protein-thiols (P-SH), nitric oxide metabolites, activities of caspase-3 and total superoxide-dismutase (SOD), striatal levels of monoamines and serum levels of hepatic amino-transferases. We observed a decrease of protein-thiols, GSH/GSSG ratio and nitrogen species associated to increased lipid peroxidation in the liver and striatum - but not in the cerebral cortex - of LEC rats, accompanied by dramatic increase in serum amino-transferases and decrease of striatal catecholamines. Conversely, SOD and caspase-3 activity increased consistently only in the cortex of LEC rats. Hence, we assume that enhanced oxidative stress may play a central role in the cell degeneration in WD, at the main sites of copper deposition, with discrete pro-apoptotic conditions developing in distal areas.
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PMID:Oxidative stress and pro-apoptotic conditions in a rodent model of Wilson's disease. 1608 Dec 51

The present study was aimed to examine the protective effects of Sargassum polycystum (Phaeophyceae) alcoholic extract on changes in liver mitochondrial enzymes against acetaminophen induced toxic hepatitis in experimental rats. The levels of protein, lipid peroxide, glutathione (GSH) in mitochondrial fraction, superoxide dismutase (SOD) and catalase (CAT) were also determined. The activities of tricarboxylic acid enzymes such as isocitrate dehydrogenase (ICD), alpha-ketoglutarate dehydrogenase (alpha-KGD), succinate dehydrogenase (SD), malate dehydrogenase (MD), NADH dehydrogenase, and cytochrome-c-oxidase were determined in mitochondrial fraction. The rats intoxicated with acetaminophen showed significant elevation in the levels of lipid peroxides with decreased levels of protein, GSH, SOD, CAT and impaired tricarboxylic acid cycle enzyme activities. The prior oral administration of S. polycystum alcoholic extract showed significant diminution in the severity of toxic hepatitis in acetaminophen-induced rats by maintaining the activities of tricarboxylic acid enzymes with concomitant improvement in the hepatic mitochondrial antiperoxidative status when compared with intoxicated animals. The results obtained in the present study indicate that the protective effects of S. polycystum extract may be due to the presence of some active compounds that are inhibitory against the free radicals generated during lipid peroxidation in acetaminophen induced toxic hepatitis.
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PMID:Antioxidant effect of Sargassum polycystum (Phaeophyceae) against acetaminophen induced changes in hepatic mitochondrial enzymes during toxic hepatitis. 1616 51

Drug-induced autoimmune hepatitis is among the most severe hepatic idiosyncratic adverse drug reactions. Considered multifactorial, the disease combines immunological and metabolic aspects, the latter being to date much better known. As for many other model drugs, studies on tienilic acid (TA)-induced hepatitis have evidenced the existence of bioactivation during the hepatic oxidation of the drug, allowing the identification of the neoantigen of anti-LKM2 autoantibodies and the pathway responsible for its formation. However, most of these results are based on the use of microsomal fractions whose relevance to the liver in vivo still needs to be established. In the more complex intact cell environment, several endogenous processes may play a significant role on triggering the reaction and should therefore be considered. In this work we have characterised the kinetics of TA biotransformation in metabolically competent hepatocytes, the influence of TA bioactivation on physiological GSH levels, and the qualitative and quantitative profile of drug-protein conjugates generated in situ, as a function of exposure time. Results confirm that intact hepatocytes reproduce in vitro the metabolic sequence that leads to the functional generation of drug-protein adducts, in conditions that simulate clinical human exposure to TA. Metabolically competent cultured hepatocytes appear as a very promising approach to investigate the early preimmunological events of drug-induced autoimmune hepatitis, adequate to identify the conditions that may modulate the formation and specificity of drug-protein adducts in vivo, to study the hepatic disposition of the TA-protein targets, and to define the specific role of the hepatocyte in the origin of this adverse reaction.
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PMID:Kinetics of tienilic acid bioactivation and functional generation of drug-protein adducts in intact rat hepatocytes. 1625 91

Bicyclol, a second generation of synthetic hepatoprotectant being used in China for anti-hepatitis therapy, shows chemosensitizing effect on reverting multiple drug resistance (MDR) of cytostatic agents in two established MDR carcinoma cell lines, vincristine resistant human stomatic epidermoid carcinoma VinRKB and adriamycin resistant human breast carcinoma AdrRMCF-7. The reversal rate of drug resistance was calculated from the changes of the IC50 of cell growth inhibition. Bicyclol at the concentration of 25, 50, 100 microM induced 2.8 7.3 and 20.7 fold, respectively, reversal of vincristine resistance in VinRKB cell. Bicyclol also reversed the cross-resistance of VinRKB cell to taxol and AdrRMCF-7 cell resistance to adriamycin at the similar range of potency. Further, Bicyclol recovered the reduced accumulation of adriamycin in AdrRMCF-7 cell partially to the level in drug-sensitive MCF-7 cell, indicate the inhibition of MDR related membrane efflux pump system. Overexpression of membrane p-glycoprotein coded by Mdr-1 genes, the most common efflux pump correlated to MDR, was found in both VinRKB and AdrRMCF-7 cells by Western blot and immunocytochemistry as compared with drug-sensitive cells. The p-glycoprotein was decreased to the levels in drug-sensitive cells when VinRKB and AdrRMCF-7 cells were treated with Bicyclol for 12-72 hours. Both VinRKB and AdrRMCF-7 cells showed increased GSH contents, and AdrRMCF-7 cell showed increased GST activity and the overexpression of Bcl-2 protein, by which molecules are tightly related to the MDR formation besides Mdr-1 p-glycoprotein. Bicyclol reduced the GSH contents, GST activities and Bcl-2 expression. All these data demonstrate that, by modifying the expressions of Mdr-1, GSH/GST and Bcl-2, Bicyclol increases the intracellular drug concentration and sensitizes the resistant cells to the anti-carcinoma agents.
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PMID:Chemosensitizing multiple drug resistance of human carcinoma by Bicyclol involves attenuated p-glycoprotein, GST-P and Bcl-2. 1662 75

Inherited defects of copper metabolism resulting in hepatic copper accumulation and oxidative-stress might cause breed-associated forms of hepatitis. Biliary excretion is the major elimination route of copper, therefore increased hepatic copper concentrations could also be caused by cholestasis. The aim of this study was to find criteria to determine whether copper-accumulation is primary or occurs secondary to hepatitis. Liver samples of Bedlington Terriers with copper toxicosis (CT), breeds with non-copper-associated chronic extrahepatic cholestasis (EC) or chronic hepatitis (CH), and healthy dogs were used. Copper metabolism was analyzed by means of histochemical staining (copper concentration) and quantitative reverse transcriptase polymerase chain reaction (Q-PCR) on copper excretion/storage (ATOX1, COX17, ATP7A, ATP7B, CP, MT1A, MURR1, XIAP). Oxidative stress was measured by determining GSH/GSSG ratios and gene-expression (SOD1, CAT, GSHS, GPX1, CCS, p27KIP, Bcl-2). Results revealed 5+ copper in CT, but no or 1-2+ copper in EC and CH. Most gene products for copper metabolism remained at concentrations similar to healthy dogs. Three clear exceptions were observed in CT: 3-fold mRNA increase of ATP7A and XIAP and complete absence of MURRI. The only quantitative differences between the diseased and the control groups were in oxidative stress, evidenced by reductions in all GSH/GSSG ratios. We conclude that 3+ or higher histochemical detection of copper indicates a primary copper storage disease. The expression profile of copper-associated genes can be used as a reference for future studies on copper-associated diseases. All 3 diseases have reduced protection against oxidative stress, opening a rationale to use antioxidants as possible therapy.
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PMID:Copper metabolism and oxidative stress in chronic inflammatory and cholestatic liver diseases in dogs. 1706

Experimental toxic hepatitis is accompanied by a decrease of 6-phosphogluconate dehydrogenase (6PGD, 1.1.1.44) activity in rat liver. Enzyme preparations of 6PGD, obtained from livers of control group rats and animals with toxic exhibit the same molecular mass of 114.2 +/- 5.8 kDa. However G6PD isolated from liver of animals with toxic hepatitis exhibited altered Km and pH-optimum values. Reduced glutathione inhibited 6PGD-activity from the liver of control group rats and did not affect the enzyme from liver of animals with toxic hepatitis. Inhibition effect of oxidized glutathione is stronger in the pathological state. Malate, citrate, 2-oxoglutarate and isocitrate activated the enzyme from control animals, but did not the enzyme isolated from animals with hepatitis. Regulation of 6PGD-activity from liver of control and experimental animals by some nucleotides (NAD, ADP, AMP) and ribose-5-phosphate was also different.
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PMID:[Catalytic properties of 6-phosphogluconate dehydrogenase from rat liver in normal state and during toxic hepatitis]. 1718 Sep 22

Hydro-ethanolic extract (70%) of Calotropis procera flowers was prepared and tested for its hepatoprotective effect against paracetamol-induced hepatitis in rats. Alteration in the levels of biochemical markers of hepatic damage like SGPT, SGOT, ALP, bilirubin, cholesterol, HDL and tissue GSH were tested in both treated and untreated groups. Paracetamol (2 g/kg) has enhanced the SGPT, SGOT, ALP, bilirubin and cholesterol levels and reduced the serum levels of HDL and tissue level of GSH. Treatment with hydro-ethanolic extract of C. procera flowers (200 mg/kg and 400 mg/kg) has brought back the altered levels of biochemical markers to the near normal levels in the dose dependent manner.
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PMID:Hepatoprotective activity of Calotropis procera flowers against paracetamol-induced hepatic injury in rats. 1760 Jun 35


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