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)

The tannoid principles of the fruits of the plant Emblica officinalis Gaertn comprising of emblicanin A. emblicanin B, punigluconin and pedunculagin, have been reported to exhibit antioxidant activity in vitro and in vivo. In the present study, an emblicanin A (37%) and B (33%) enriched fraction of fresh juice of Emblica fruits (EOT), administered prophylactically (10, 20 and 50 mg/kg, p.o.) for 10 consecutive day, was found to inhibit acute iron overload (30 mg/kg, i.p.) hepatic lipid peroxidation and the increase of serum levels of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, used as markers of the induced hepatic dysfunction. A similar effect was produced by silymarin (20 mg/kg, p.o.), an antioxidant hepatoprotective agent. The results support the use of Emblica fruits for hepatoprotection in Ayurveda.
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PMID:Effect of bioactive tannoid principles of Emblica officinalis on iron-induced hepatic toxicity in rats. 1083 22

Glycowithanolides, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, isolated from the roots of Withania somnifera Dunal, have been reported to have an antioxidant effect in the rat brain frontal cortex and striatum. In the present study, the effect of 10 days of oral administration of these active principles, in graded doses (10, 20 and 50 mg/kg), was noted on iron overload (FeSo(4), 30 mg/kg, i.p.) induced hepatotoxicity in rats. Apart from hepatic lipid peroxidation (LPO), the serum enzymes, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, were assessed as indices of hepatotoxicity. Silymarin (20 mg/kg, p.o.) was used for comparison. Iron overload induced marked increase in hepatic LPO and serum levels of the enzymes, which was attenuated by WSG in a dose-related manner, and by silymarin. The results indicate that the reported use of WS in Ayurveda for hepatoprotection against heavy metals and other environmental toxins, may be due the antioxidant action of WSG.
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PMID:Effect of Withania somnifera glycowithanolides on iron-induced hepatotoxicity in rats. 1105 55

The effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the liver of C57BL/6J mice is a model for clinical sporadic porphyria cutanea tarda (PCT). There is massive uroporphyria, inhibition of uroporphyrinogen decarboxylase (UROD) activity, and hepatocellular damage. A variety of evidence implicates the CYP1A2 enzyme as necessary for mouse uroporphyria. Here we report that, 5 weeks after a single oral dose of TCDD (75 microg/kg), Cyp1a2(+/+) wild-type mice showed severe uroporphyria and greater than 90% decreases in UROD activity; in contrast, despite exposure to this potent agent Cyp1a2(-/-) knockout mice displayed absolutely no increases in hepatic porphyrin levels, even after prior iron overload, and no detectable inhibition of UROD activity. Plasma levels of alanine-aminotransferase (ALT) and aspartate aminotransferase (AST)-although elevated in both genotypes after TCDD exposure-were significantly less in Cyp1a2(-/-) than in Cyp1a2(+/+) mice, suggesting that the absence of CYP1A2 also affords partial protection against TCDD-induced liver toxicity. Histological examination confirmed a decrease in hepatocellular damage in TCDD-treated Cyp1a2(-/-) mice; in particular, there was no bile duct damage or proliferation that in the Cyp1a2(+/+) mice might be caused by uroporphyrin. We conclude that CYP1A2 is both necessary and essential for the potent uroporphyrinogenic effects of TCDD in mice, and that CYP1A2 also plays a role in contributing to TCDD-induced hepatocellular injury. This study has implications for both the toxicity assessment of TCDD and the hepatic injury seen in PCT patients.
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PMID:Protection of the Cyp1a2(-/-) null mouse against uroporphyria and hepatic injury following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin. 1138 10

The role of iron overload as cause of liver dysfunction has never been studied in detail in patients without concomitant hepatotropic infections who receive multiple transfusions. We therefore investigated the relationship between the extent of hepatocellular injury as reflected by serum levels of aminotransferases (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) and several iron status indices in 39 anti-hepatitis C virus-negative (HCV(-)) nonthalassemic patients with transfusional iron overload owing to acquired anemias. In 12 patients, we monitored aminotransferase levels and indices of iron status during iron chelation treatment. Before treatment, elevated aminotransferase activity was seen only at liver iron concentrations more than 300 microM/g. During treatment all aminotransferase values were normal if the liver iron concentration returned below 350 microM/g. At the start of treatment, ALT (R(2) = 0.64, P =.006) and AST activity (R(2) = 0.57, P =.01) were closely related to urinary iron excretion, reflecting the size of the chelatable or the labile iron pool. During treatment, a comparable pattern was seen and the urinary iron excretion was also directly related to the liver iron concentration at concentrations above approximately 400 microM/g. All elevated ALT values were associated with a urinary iron excretion more than 15 mg/24 h. In conclusion, our data suggest the existence of a critical liver iron concentration range, above which hepatocellular injury is seen. The extent of the injury seems to be determined mainly by the size of the chelatable or labile iron pool, supporting the concept of the labile iron pool as the compartment directly involved in iron toxicity. Our findings may be helpful in establishing criteria for safety from complications of transfusional iron overload.
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PMID:Relationship between hepatocellular injury and transfusional iron overload prior to and during iron chelation with desferrioxamine: a study in adult patients with acquired anemias. 1239 28

The clinical use of doxorubicin (DOX), an anthracycline chemotherapeutic agent, is limited by cardiotoxicity. The possible involvement of iron in DOX-induced cardiotoxicity became evident from studies in which iron chelators were shown to be cardioprotective. Iron overload is found in hereditary hemochromatosis, a genetic disorder prevalent in individuals of European descent. We hypothesized that Hfe deficiency may increase susceptibility to DOX-induced toxicity. Acute cardiotoxicity and iron changes were studied after treatment with DOX in Hfe knock-out (Hfe-/-) mice and wild-type mice. DOX-induced iron metabolism changes were intensified in Hfe-/- mice, which accumulated significantly more iron in the heart, liver, and pancreas, but less in the spleen compared with wild-type mice. In addition, Hfe-deficient mice exhibited significantly greater sensitivity to DOX-induced elevations in serum creatine kinase and aspartate aminotransferase. Increased mortality after chronic DOX treatment was observed in Hfe-/- mice and Hfe+/-mice compared with wild-type mice. DOX-treated Hfe-/- mice had a higher degree of mitochondrial damage and iron deposits in the heart than did wild-type mice. These data demonstrate that Hfe deficiency in mice increases susceptibility to DOX-induced cardiotoxicity and suggest that genetic mutations related to defects in iron metabolism may contribute to its cardiotoxicity in humans.
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PMID:Hfe deficiency increases susceptibility to cardiotoxicity and exacerbates changes in iron metabolism induced by doxorubicin. 1280 55

Chronic liver disease is a major cause of morbidity and mortality in the United States. Although often used to detect liver disease, the prevalence and etiology of elevated aminotransferases are unknown. We analyzed data on adults ages 17 yr and older (N = 15,676) from the Third National Health and Nutrition Examination Survey (1988-1994). Participants were classified as having elevated aminotransferase levels if either aspartate aminotransferase or alanine aminotransferase was elevated above normal. Aminotransferase elevation was classified as "explained" if there was laboratory evidence of hepatitis B or C infection, iron overload, or if there was a history of alcohol consumption. Analyses were weighted to provide national estimates. The prevalence of aminotransferase elevation in the United States was 7.9%. Aminotransferase elevation was more common in men compared to women (9.3% vs 6.6%, p = 0.002), in Mexican Americans (14.9%) and non-Hispanic blacks (8.1%) compared to non-Hispanic whites (7.1%, p < 0.001). High alcohol consumption, hepatitis B or C infection and high transferrin saturation were found in only 31.0% of cases. Aminotransferase elevation was unexplained in the majority (69.0%). In both men and women, unexplained aminotransferase elevation was significantly associated with higher body mass index, waist circumference, triglycerides, fasting insulin, and lower HDL; and with type 2 diabetes and hypertension in women (all p < 0.05). Aminotransferase elevation was common in the United States, and the majority could not be unexplained by alcohol consumption, viral hepatitis or hemochromatosis. Unexplained aminotransferase elevation was strongly associated with adiposity and other features of the metabolic syndrome, and thus may represent nonalcoholic fatty liver disease.
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PMID:The prevalence and etiology of elevated aminotransferase levels in the United States. 1280 14

Hereditary hemochromatosis is a common inherited disorder characterized by iron overload. A single mutation (C282Y) in the HFE gene is present in 80-95% of cases in populations of northern European extraction. The disorder presents a large phenotypic heterogeneity, and its expression can be influenced by environmental factors. This 1977-2002 study aimed to identify the influence of alcohol consumption on expression of the disease. The authors retrospectively registered 378 C282Y-homozygous patients treated in a blood center of western Brittany, France. In this cohort, 33 patients reported excessive alcohol consumption (8.7%). Those subjects presented significantly increased iron parameters (serum ferritin: 1745.2 vs. 968.7 microg/liter, p< 0.0001; serum iron: 39.9 vs. 36.0 micromol/liter, p = 0.0040; transferrin saturation: 87.1 vs. 80.1%, p = 0.0071) and elevated liver enzymes (alanine aminotransferase: 66.3 vs. 41.1 IU/liter, p = 0.0003; aspartate aminotransferase: 56.2 vs. 34.9 IU/liter, p = 0.0002). Their risk of skin pigmentation was also higher (odds ratio = 3.4, p = 0.0006). Results remained unchanged after adjustment. This study provides precise quantitative data about the impact of alcohol on expression of hereditary hemochromatosis in C282Y-homozygous patients. Excessive alcohol consumption accentuates disease expression and therefore the risk of cirrhosis and cancer. Consequently, these patients should be encouraged to consume very moderate quantities of alcohol.
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PMID:Hereditary hemochromatosis: effect of excessive alcohol consumption on disease expression in patients homozygous for the C282Y mutation. 1285 Dec 25

Hepatitis C virus (HCV) infection is a common cause of liver disease in thalassemia major patients in Western, especially Mediterranean, countries. Its significance in thalassemic patients from Southeast Asia has not been critically evaluated. In this report, we describe our study of the prevalence of HCV infection among Thai patients with thalassemia. The relationships of the infection to blood transfusion and the infection's effects on liver function have also been determined. Of the 104 patients studied, 21 (20.2%) tested positively by enzyme immunoassay for anti-HCV antibody, whereas only 2 patients (2%) had the hepatitis B surface antigen. There was no significant relationship between the presence of anti-HCV antibodies and the number and frequency of blood transfusions. In fact, 2 patients (10%) who tested positive for anti-HCV antibodies had never received transfusions. Patients with anti-HCV antibodies had significantly abnormal liver functions, such as higher levels of serum aspartate aminotransferase (SGOT) and alanine aminotransferase (SGPT) and lower levels of serum albumin, compared with patients without anti-HCV antibodies (P = .021, .017, and .004, respectively). However, there were also significant correlations between iron status as indicated by transferrin saturation or serum ferritin levels and SGOT, SGPT, and gamma-glutamyltransferase (GGT) levels. Moreover, abnormal liver function as represented by elevated levels of SGOT, SGPT, GGT, and serum alkaline phosphatase was observed more frequently in patients with iron overload than in patients with a lower degree of iron burden. The presence of HCV did not alter the effects of iron overload on liver function. The findings suggest that both HCV and iron overload are the main causes of abnormal liver function in Thai patients with thalassemia. The treatment of both problems, if coexisting in patients with thalassemia, is required to prevent progression to chronic liver disease.
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PMID:Prevalence and clinical significance of hepatitis C virus infection in Thai patients with thalassemia. 1468 98

Deferiprone at a dose of 75 mg/kg/day is not sufficiently effective to maintain iron stores at a level which has been considered safe in all patients with iron overload. Our main aim was to determine the safety of long-term therapy with high-dose (100 mg/kg/day) deferiprone. A secondary aim was to determine the efficacy of this high dose. Twelve thalassemia major patients received deferiprone at a dose of 100 mg/kg/day over 2 years. Transient aspartate aminotransferase increase (8 patients), gastrointestinal discomfort (3 patients) and arthralgia (2 patients) were the most commonly reported side effects. None of the patients discontinued therapy. The mean serum ferritin level fell from 3,901 +/- 3,618 to 1,790 +/- 2,205 microg/l after 2 years (p < 0.05). Five of the 12 patients continued to receive deferiprone for an additional 3 years. No new side effects were encountered. The mean serum ferritin level in this subgroup was initially 2,510 +/- 332 microg/l and dropped to 1,511 +/- 664 microg/l after 5 years (p < 0.05). Liver iron levels at the end of the 2-year study ranged from 1.0 to 30.9 mg/g dry weight, 3 of the patients having levels above 15 mg/g.
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PMID:Safety and effectiveness of 100 mg/kg/day deferiprone in patients with thalassemia major: a two-year study. 1622 77

To assess the effects of liver iron overload and fibrosis after treatment with a chelating agent in hepatitis C virus (HCV)-infected thalassemia, from April 1999 to July 2004, 45 patients with thalassemia major (age range 9-33 years, mean 19.3) received daily deferiprone (L1) for 23-60 months (75 mg/kg). The patients were divided into two groups on the basis of their hepatitis status (27 with, 18 without). Their serum was analyzed for alanine aminotransferase (GPT), aspartate aminotransferase (GOT), bilirubin (total/direct), r-glutamyl transpeptidase (r-GT), alkaline phosphatase (Alk-P), and ferritin. Liver iron overload and fibrosis were defined by a senior pathologist. No significant differences were demonstrated in serum levels of GPT, GOT, bilirubin, r-GT, Alk-P or ferritin; comparison was made for each group before and after L1 treatment. Iron scores were 2.3 +/- 0.9 and 2.8 +/- 0.9 for the hepatitis C negative and positive groups, respectively (p = 0.07), with liver fibrosis scores of 1.0 +/- 0.5 and 0.4 +/- 0.52 (p = 0.56). The two scores were not higher for the positive group. There was no evidence of: 1) greater iron overload and fibrosis in the HCV-infected thalassemic patients; 2) L1 inducing progressive hepatic fibrosis or worsening iron overload in HCV-infected thalassemic patients after long-term therapy; 3) further damage to liver cells associated with L1 treatment.
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PMID:Effect of deferiprone on liver iron overload and fibrosis in hepatitis-C-virus-infected thalassemia. 1679 45


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