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)

Obstructive sleep apnoea (OSA) leads to chronic intermittent hypoxia (CIH) during sleep. Obstructive sleep apnoea has been associated with liver injury. Acetaminophen (APAP; known as paracetamol outside the USA) is one of the most commonly used drugs which has known hepatotoxicity. The goal of the present study was to examine whether CIH increases liver injury, hepatic oxidative stress and inflammation induced by chronic APAP treatment. Adult C57BL/6J mice were exposed to CIH or intermittent air (IA) for 4 weeks. Mice in both groups were treated with intraperitoneal injections of either APAP (200 mg kg(-1)) or normal saline daily. A combination of CIH and APAP caused liver injury, with marked increases in serum alanine aminotransferase, aspartate aminotransferase (AST), gamma-glutamyl transferase and total bilirubin levels, whereas CIH alone induced only elevation in serum AST levels. Acetaminophen alone did not affect serum levels of liver enzymes. Histopathology revealed hepatic necrosis and increased apoptosis in mice exposed to CIH and APAP, whereas the liver remained intact in all other groups. Mice exposed to CIH and APAP exhibited decreased hepatic glutathione in conjunction with a fivefold increase in nitrotyrosine levels, suggesting formation of toxic peroxynitrite in hepatocytes. Acetaminophen or CIH alone had no effect on either glutathione or nitrotyrosine. A combination of CIH and APAP caused marked increases in pro-inflammatory chemokines, monocyte chemoattractant protein-1 and macrophage inflammatory protein-2, which were not observed in mice exposed to CIH or APAP alone. We conclude that CIH and chronic APAP treatment lead to synergistic liver injury, which may have clinical implications for patients with OSA.
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PMID:Chronic intermittent hypoxia and acetaminophen induce synergistic liver injury in mice. 1914 48

The single cell gel electrophoresis (comet) assay is a simple and effective method for detecting DNA damage in cells with or without the capability of cell division. Methyl methanesulfonate (MMS), as a genotoxic compound that reacts with DNA directly, was confirmed for its DNA damage potential by in vivo comet assay in multiple organs such as liver, kidneys and bone marrow in mice and acetaminophen (APAP), a widely used analgesic drug, was evaluated for whether it possesses DNA damage potential or not. Furthermore, cytotoxicity was verified by hematology and /or blood chemistry simultaneously. Male Crj:CD1(ICR) mice were intraperitoneally once treated with MMS at 50, 100, and 150 mg/kg, and APAP at 12, 60, and 300 mg/kg. These organs were collected at 4 and 24 hr after treatment, and the comet assay was performed concomitantly with hematology and/or blood chemistry. The results showed that MMS induced a significant concentration-dependent increase in the frequency of tailed nuclei (DNA damage), tail moment, % DNA in the tail, and tail length in the liver, kidneys and bone marrow at both time points. With regard to hematology and blood chemistry results, nephrotoxic markers were not changed, but aspartate aminotransferase (AST) and alanine aminotransferase (ALT) increased in the 150 mg/kg-treated group, and bone marrow counts (BMC) decreased in all of the treatment groups 24 hr after treatment. These results suggested that DNA damage observed in the kidneys was due to genotoxicity, not nephrotoxicity. The DNA damage was more severe at 4 hr than 24 hr after treatment. This might indicate that the decrease in DNA damage was due to detoxification, repair of the lesions induced by the treatment, or cell turnover, all of which would reduce cellular damage. On the other hand, APAP induced increases in plasma AST and ALT levels in the highest dose group only, and the DNA damage in the liver increased at the same dose. These results suggest that the in vivo comet assay might be used to detect the DNA damage induced by MMS and the subsequent DNA repair in mouse liver, kidneys and bone marrow. APAP at the highest dose induces DNA damage in liver. Blood chemical results may indicate that the DNA damage by APAP treatment was attributable to hepato-cytotoxicity, because DNA damage and hepato-cytotoxicity were detected at the same doses.
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PMID:An in vivo comet assay of multiple organs (liver, kidney and bone marrow) in mice treated with methyl methanesulfonate and acetaminophen accompanied by hematology and/or blood chemistry. 1904 73

Acute liver failure (ALF), an often fatal condition characterized by massive hepatocyte necrosis, is frequently caused by drug poisoning, particularly with acetaminophen (N-acetyl-p-aminophenol/APAP). Hepatocyte necrosis is consecutive to glutathione (GSH) depletion and mitochondrial damage caused by reactive oxygen species (ROS) overproduction. Magnolol, one major phenolic constituent of Magnolia officinalis, have been known to exhibit potent antioxidative activity. In this study, the anti-hepatotoxic activity of magnolol on APAP-induced toxicity in the Sprague-Dawley rat liver was examined. After evaluating the changes of several biochemical parameters in serum, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) were elevated by APAP (500 mg/kg) intraperitoneal administration (8 and 24 h) and reduced by treatment with magnolol (0.5 h after APAP administration; 0.01, 0.1, and 1 mug/kg). Histological changes around the hepatic central vein, lipid peroxidation (thiobarbituric acid-reactive substance/TBARS), and GSH depletion in liver tissue induced by APAP were also recovered by magnolol treatment. The data show that oxidative stress followed by lipid peroxidation may play a very important role in the pathogenesis of APAP-induced hepatic injury; treatment with lipid-soluble antioxidant, magnolol, exerts anti-hepatotoxic activity. Our study points out the potential interest of magnolol in the treatment of toxic ALF.
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PMID:Antioxidative and hepatoprotective effects of magnolol on acetaminophen-induced liver damage in rats. 1928 Jan 52

The present study was undertaken to examine the protective effects of an anthocyanin fraction (AF) obtained from purple-fleshed sweet potato on acetaminophen (paraceptamol [APAP])-induced hepatotoxicity in mice and to determine the mechanism involved. Mice pretreated with AF prior to APAP administration showed significantly lower increases in serum alanine aminotransferase and aspartate aminotransferase activities and hepatic malondialdehyde formation than APAP-treated animals without AF. In addition, AF prevented hepatic glutathione (GSH) depletion by APAP, and hepatic GSH levels and GSH S-transferase activities were up-regulated by AF. APAP-induced hepatotoxicity was also prevented by AF, as indicated by liver histopathology findings. In addition, the effects of AF were examined on cytochrome P450 (CYP) 2E1, the major isozyme involved in APAP bioactivation. Treatment of mice with AF significantly and dose-dependently reduced CYP2E1-dependent aniline hydroxylation and CYP2E1 protein levels. Furthermore, AF had an antioxidant effect on FeCl(2)/ascorbate-induced lipid peroxidation in mouse liver homogenates and had superoxide radical scavenging activity. These results suggest that AF protects against APAP-induced hepatotoxicity by blocking CYP2E1-mediated APAP bioactivation, by up-regulating hepatic GSH levels, and by acting as a free radical scavenger.
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PMID:Hepatoprotective effects of an anthocyanin fraction from purple-fleshed sweet potato against acetaminophen-induced liver damage in mice. 1945 32

Acetaminophen (APAP) is safe at therapeutic levels but causes hepatotoxicity via N-acetyl-p-benzoquinone imine-induced oxidative stress upon overdose. To determine the effect of human (h) pregnane X receptor (PXR) activation and CYP3A4 induction on APAP-induced hepatotoxicity, mice humanized for PXR and CYP3A4 (TgCYP3A4/hPXR) were treated with APAP and rifampicin. Human PXR activation and CYP3A4 induction enhanced APAP-induced hepatotoxicity as revealed by hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities elevated in serum, and hepatic necrosis after coadministration of rifampicin and APAP, compared with APAP administration alone. In contrast, hPXR mice, wild-type mice, and Pxr-null mice exhibited significantly lower ALT/AST levels compared with TgCYP3A4/hPXR mice after APAP administration. Toxicity was coincident with depletion of hepatic glutathione and increased production of hydrogen peroxide, suggesting increased oxidative stress upon hPXR activation. Moreover, mRNA analysis demonstrated that CYP3A4 and other PXR target genes were significantly induced by rifampicin treatment. Urinary metabolomic analysis indicated that cysteine-APAP and its metabolite S-(5-acetylamino-2-hydroxyphenyl)mercaptopyruvic acid were the major contributors to the toxic phenotype. Quantification of plasma APAP metabolites indicated that the APAP dimer formed coincident with increased oxidative stress. In addition, serum metabolomics revealed reduction of lysophosphatidylcholine in the APAP-treated groups. These findings demonstrated that human PXR is involved in regulation of APAP-induced toxicity through CYP3A4-mediated hepatic metabolism of APAP in the presence of PXR ligands.
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PMID:Rifampicin-activated human pregnane X receptor and CYP3A4 induction enhance acetaminophen-induced toxicity. 1946 Sep 45

We have used a murine model of Acetaminophen induced hepatoxicity to determine if S-adenosyl methionine 1,4 butanedisulfonate (SD4) in liposomes can prevent liver injury when administered immediately prior to acetaminophen, as judged by serum aspartate aminotransferase and alanine aminotransferase levels, and histological evidence of liver necrosis. No protection was observed when mice received 1 g/kg unencapsulated SD4. Partial protection was observed with 5 or 0.5 mg/kg SD4 in unextruded distearoylphosphatidylglycerol (DSPG) liposomes. Protection comparable to that seen in mice receiving encapsulated SD4 is achieved when mice received lipid alone in equivalent amounts, suggesting that the contribution of encapsulated SD4 to the efficacy of the liposomes may be minimal. Unextruded distearoylphosphatidylcholine (DSPC) liposomes show only slight effects even at 50 mg/kg SD4. This is likely caused by the size of unextruded DSPC lipsomes, because extruded DSPC liposomes, whose size is smaller, are of comparable efficacy to unextruded DSPG liposomes.
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PMID:Evaluation of phospholipid and liposomal S-adenosyl methionine for the treatment of liver injury in a murine model. 1978 Jan 35

This study was designed to investigate the protective effects of the active part of Artemisia sacrorum Ledeb. Extract (ASE) against acetaminophen (APAP)-induced hepatotoxicity in mice. As a result, pretreated with ASE prior to the administration of APAP significantly prevented the increases of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor-alpha (TNF-alpha) levels in serum, and glutathione (GSH) depletion, malondialdehyde (MDA) accumulation in liver tissue. In addition, ASE prevented APAP-induced apoptosis and necrosis, as indicated by a liver histopathological analysis and DNA laddering. Furthermore, according to the results from Western blot analysis, ASE markedly decreased APAP-induced caspase-3 and -8 protein expressions in mouse livers. All these results suggest that the protective effects of ASE against APAP-induced liver injury may involve mechanisms associated with its inhibitive effects of lipid peroxidation and the down-regulation of TNF-alpha mediated apoptosis.
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PMID:Protective Effects of the Supernatant of Ethanol Eluate from Artemisia sacrorum Ledeb. against Acetaminophen-Induced Liver Injury in Mice [corrected]. 1980 28

Our previous studies showed that administration of a subtoxic dose of acetaminophen (APAP) to female rats increased generation of carbon monoxide from dichloromethane, a metabolic reaction catalyzed mainly by cytochrome P450 (CYP) 2E1. In this study we examined the changes in metabolism and toxicity of APAP upon repeated administration. An intraperitoneal dose of APAP (500 mg/kg) alone did not increase aspartate aminotransferase, alanine aminotransferase, or sorbitol dehydrogenase activity in serum, but was significantly hepatotoxic when the rats had been pretreated with an identical dose of APAP 18 h earlier. The concentrations and disappearance of APAP and its metabolites in plasma were monitored for 8 h after the treatment. APAP pretreatment reduced the elevation of APAP-sulfate, but increased APAP-cysteine concentrations in plasma. APAP or APAP-glucuronide concentrations were not altered. Administration of a single dose of APAP 18 h before sacrifice increased microsomal CYP activities measured with p-nitrophenol, p-nitroanisole, and aminopyrine as probes. Expression of CYP2E1, CYP3A, and CYP1A proteins in the liver was also elevated significantly. The results suggest that administration of APAP at a subtoxic dose may result in an induction of hepatic CYP enzymes, thereby altering metabolism and toxicological consequences of various chemical substances that are substrates for the same enzyme system.
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PMID:Alteration in metabolism and toxicity of acetaminophen upon repeated administration in rats. 1983 87

Acetaminophen is one of the most popular analgesic and antipyretic drugs and its overdose, which can cause severe damage to liver and kidneys, is one of the most common reasons of emergency admissions. In this study we investigated the effects of curcumin, derived from plant Curcuma longa, on acetaminophen toxicity, and the possibility of combining therapy of curcumin and N-acetyl cysteine (NAC) to treat this toxicity. The experiments were conducted on 72 male Sprague-Dawley rats randomly divided into 12 groups. Control group was left without treatment, and the other groups were treated with different combinations of acetaminophen, curcumin and NAC. 15min after intraperitoneal injection, the blood level of curcumin was measured using HPLC. Blood levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase), blood urea nitrogen and creatinine were determined 18 and 42h after acetaminophen injection. One week later, the left kidney and the caudate lobe of the liver were harvested to assay glutathione peroxidase, catalase and malondialdehyde. The right kidney and the remaining lobes of the liver were used for histopathology. Analysis of organ function and oxidation parameters showed that curcumin significantly reduced toxic effects of acetaminophen on the liver and kidneys in a dose-dependent manner and significantly potentiated the protective effects of NAC. These findings were confirmed by histopathology. It is concluded that curcumin can protect the liver and kidney from the damage caused by acetaminophen overdose. Moreover, curcumin has the potential to be used in a combination therapy with NAC, significantly decreasing the therapeutic dose of NAC and therefore its side-effects.
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PMID:Curcumin protects rats against acetaminophen-induced hepatorenal damages and shows synergistic activity with N-acetyl cysteine. 1991 35

Cats most commonly receive toxic amounts of acetaminophen (APAP) because owners medicate them without consulting a veterinarian. The aim of this study was to compare the hepatoprotective action of silymarin and N-acetylcysteine (NAC) against APAP poisoning. Twenty healthy cats were randomly allotted to five equal groups. Animals in group A were given APAP (single dose 150 mg/kg, p.o.); groups B and C consisted of cats that received NAC (100 mg/kg, p.o.) or silymarin (30 mg/kg, p.o.) concurrent with APAP administration respectively; groups D and E were treated like groups B and C, respectively, but 4 h after APAP administration. The serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), methemoglobin, and total and direct bilirubin were measured before APAP administration and 4, 24, and 72 h later. A single oral administration of APAP significantly elevated serum concentrations of ALT, AST, ALP, LDH, methemoglobin, and total and direct bilirubin. In both the groups receiving APAP plus NAC or silymarin, levels of serum enzyme activities, methemoglobin, and total and direct bilirubin remained within the normal values. It was concluded that silymarin as well as NAC can protect liver tissue against oxidative stress in cats with an APAP intoxication.
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PMID:Evaluation of prophylactic and therapeutic effects of silymarin and N-acetylcysteine in acetaminophen-induced hepatotoxicity in cats. 2044 31


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