Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatic damage associated with chronic hepatitis B (CHB) relies on measurement of serum transaminases and asssessment of hepatic histology. We determined if serum hepatic function tests, including alpha-glutathione-S-transferase ((GST), were of value in monitoring or predicting the effect of lamivudine therapy for CHB. Thirty-nine patients received orally 100 mg of lamivudine daily for 48 weeks. Blood samples were obtained at baseline and at 24 and 48 weeks. At the end of the treatment period the patients were then divided into four groups according to the pattern of HBs and HBe antigens. At baseline and at 24 weeks ALT, AST, and (GST had lower values in the complete response compared to the complete failure groups. Using ROC analysis, only ALT at 24 weeks (area under the curve = 0.803) had significant diagnostic ability in detecting responders. These results reaffirm the value of measuring serum ALT as an indicator of treatment response and provide information on the potential use of (GST as an additional prognostic biomarker in this patient group.
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PMID:Evaluation of alpha-glutathione-S-transferase as a biomarker of lamivudine therapy for chronic hepatitis B. 1698 2

Hepatitis C Virus (HCV) infection is a disease characterized by a silent evolution, a wide fluctuation of transaminase activities, and the potential presence of significant histological lesions in patients with normal concentrations of transaminases. Alpha-Glutathione S-transferase (alpha-GST) is a class of enzymes responsible for cellular detoxifying processes. Its wide hepatic distribution, high cytosolic concentration, and short in vivo plasma half-life of this enzyme are properties, which may make monitoring this enzyme more clinically useful than conventional biochemical liver function tests as a marker of hepatocellular damage. This work was designed to study whether determining alpha-GST compared to other biochemical parameters might improve the assessment of patients with HCV infection, and to determine whether the increase in alpha-GST concentrations could reflect HCV viraemia. A total of 68 HCV infected patients along with 20 anti-HCV negative healthy subjects were enrolled in this study. HCV infected patients were tested for the presence of HCV RNA in their sera by polymerase chain reaction and evaluated with conventional liver biochemistry (ALT, AST and gamma-GT). Alpha-GST concentrations were determined in all cases and control subjects included in the study using an enzyme immunoassay. HCV viraemia was found in 36/68( 52.9%) seropositive patients. Alpha-GST levels were markedly elevated in HCV infected subjects compared to healthy controls (P < 0.001). Alpha-GST values were significantly higher than the cut off value in the 36 HCV viraemic patients compared to 81.3% of the HCV RNA-negative subjects (P < 0.05). The estimated alpha-GST concentrations were significantly above the cut off value in 91.2% of HCV infected subjects compared to 4.4% for ALT, 17.6% for AST and 41.2 % for gamma-GT (P < 0.001). In conclusion, measurement of alpha-GST levels in HCV infected patients could reflect liver injury more than biochemical markers. Therefore, it is possible that in combination with the other traditionally used liver markers; alpha-GST determination could provide another parameter, which may play a complimentary role in the assessment of hepatocellular damage caused by HCV.
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PMID:Diagnostic value of alpha-glutathione S-transferase as a sensitive marker of increased risk for hepatocellular damage in hepatitis C virus (HCV) infection: relation to HCV viraemia. 1726 14

Our aim was to study the protective effect of quercitin on liver cirrhosis induced by carbon tetrachloride (CCl(4)) in rats and its relationship with liver morphology. Thirty male Wistar rats weighing 200-250 g were randomly divided into three groups: control, CCl(4), and CCl(4)+ quercetin. Rats in the experimental groups were given CCl(4) (0.5 ml/kg i.p.), diluted 1:6 in vegetable oil (5 mmol/kg body wt), at 10:00 p.m. every 4 days for 17 weeks. Quercetin (500 microl/kg i.p.; 150 micromol/kg body wt) or vehicle was administered at 6:00 p.m. for the last 3 weeks of the study. Control group rats were given only olive oil for the same period. At the end of the 17 weeks, all rats were sacrificed. Blood samples were taken for determination of serum indicators (ALT, AST, total bilirubin, conjugated bilirubin, factor V) and the livers were dissected out and divided into two parts: one was homogenized and the supernatant was used for measurement of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities, as well as lipid peroxidation. The other part was used for the histopathological study. CCl(4) caused a marked rise in serum levels of ALT, AST, total bilirubin, and conjugated bilirubin, as well as a decrease in factor V (P<0.05). Lipid peroxidation levels were significantly increased, whereas GSH, SOD, catalase, GPx, and GST levels were decreased in the liver of CCl(4)-treated rats. Quercetin (50 mg/kg/day) successfully attenuated these effects of CCl(4). We conclude that quercetin has beneficial effects on liver fibrosis in rats by enhancing antioxidant enzyme activity and decreasing the pro-oxidant effect.
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PMID:Quercetin prevents oxidative stress in cirrhotic rats. 1743 69

In our previous study, we demonstrated that the initial hepatic injury caused by bromobenzene (BB) was no longer detected in rats despite subsequent dosing, indicating that the liver acquired resistance to BB-induced hepatotoxicity. In this experiment, microarray analysis was conducted to characterize this resistance. The liver samples for the analysis utilized were obtained from previous experiments where F344 rats were treated intraperitoneally with BB (150 mg/kg). At 24 hr post-dose, hepatic injury was confirmed by monitoring the AST values and then the rats were maintained at the same dosing regimen for an additional 8 days. The gene expression profiles of the BB-treated rat livers were compared with a vehicle-treated group by Affymetrix RG_U34A arrays. As results, a decreased expression level of CYP3A9 and an increased expression level of GST Yc2 and glutathione peroxidase (GPX) were detected. These changes indicated suppression of the phase I reaction and induction of the phase II reaction (glutathione conjugation). Increased expression levels of epoxide hydrolase (EH) and NAD(P)H:quinone oxidoreductase (NQO1) also suggested the involvement of EH- and NQO1-mediated hydrolysis other than glutathione conjugation with resistance in the phase II reaction. Moreover, an increased expression level of abcc3 (multidrug resistance protein 3; Mrp3) was significantly noted. Based on the present findings, it was suggested that Mrp3 in the phase III reaction (drug elimination) contributed to the resistance to BB hepatotoxicity in addition to the suppression of the phase I reaction (metabolic activation) and the induction of the phase II reaction (detoxification). Among them, the factors which contributed most were considered to be the increased GST Yc2 and Mrp3, based on the degree of the gene expression changes.
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PMID:Characterization of resistance to bromobenzene-induced hepatotoxicity by microarray. 1753 37

Wild Panax ginseng C.A. Meyer (WG) is a well-known medicinal herb. In this study, the protective effects of a water extract from the root of WG on benzo[alpha]pyrene (BP)-induced hepatotoxicity and the mechanism of these effects were investigated for the first time. The effects of WG on liver toxicities induced by BP were assessed by blood biochemical and histopathological analyses. BP caused severe liver injury in rats, as indicated by elevated plasma ALT, AST and LPO levels. Pretreatment with WG for 4 weeks completely abrogated increases in the ALT, AST and LPO levels when challenged with BP. Reductions in GSH content and GST activity by BP were reversed by WG. These protective effects of WG against BP-induced toxicity were consistent with the results of histopathological examinations. We next examined the effects of WG on the gene expression of the enzymes that metabolize BP in H4IIE cells. CYP1A1 mRNA and protein expression were increased by BP. WG moderately inhibited BP-induced CYP1A1 gene expression. Moreover, GSTA2, GSTA3 and GSTM2 gene expressions were significantly increased by WG through the Nrf2/antioxidant responsive element pathway for enzyme induction. In summary, WG is efficacious in protecting against BP-induced hepatotoxicity as results of metabolic regulations through both the inhibition of metabolic enzyme activation and the enhancement of electrophilic detoxification, implying that WG should be considered a potential chemopreventive agent.
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PMID:The potent protective effect of wild ginseng (Panax ginseng C.A. Meyer) against benzo[alpha]pyrene-induced toxicity through metabolic regulation of CYP1A1 and GSTs. 1759 Feb 95

Penicillin and other antibiotics are routinely incorporated in insect culture media. Although culturing insects in the presence of antibiotics is a decades-old practice, antibiotics can exert deleterious influences on insects. In this article, we test the hypothesis that one of the effects of dietary penicillin is to increase oxidative stress on insects. The effects of penicillin on midgut concentrations of the oxidative stress indicator malondialdehyde (MDA) and on midgut antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], glutathione S-transferase [GST], and glutathione peroxidase [GPx]) and transaminases (alanine aminotransferase and aspartate aminotransferase) activities in greater wax moth, Galleria mellonella (L.), were investigated. The insects were reared from first instars on artificial diets containing 0.001, 0.01, 0.1, or 1.0 g penicillin per 100 g of diets. MDA content was significantly increased in the midgut tissues of each larval instar reared in the presence of high penicillin concentrations. Activities of antioxidant and transaminase enzymes did not show a consistent pattern with respect to penicillin concentrations in diet or age of larvae. Despite the increased penicillin-induced oxidative stress in gut tissue, antioxidant and transaminase enzymes did not correlate with oxidative stress level or between each other in larvae of other age stages except for the seventh instar. We found a significant negative correlation of MDA content with SOD and GST activities in seventh instars. SOD activity was also negatively correlated with CAT activity in seventh instars. These results suggest that exposure to dietary penicillin resulted in impaired enzymatic antioxidant defense capacity and metabolic functions in wax moth larval midgut tissues and that the resulting oxidative stress impacts midgut digestive physiology.
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PMID:Penicillin-induced oxidative stress: effects on antioxidative response of midgut tissues in instars of Galleria mellonella. 1797 30

Alcoholic liver disease is a major medical complication of drinking alcohol. Oxidative stress plays an important role in the development of alcohol liver disease. The present study was carried to evaluate the effect of grape leaf extract (GLEt) on antioxidant and lipid peroxidation states in liver and kidney alcohol induced toxicity. In vitro studies with DPPH* and ABTS*(+) (cation radical) showed that GLEt possesses antioxidant activity. In vivo administration of ethanol (7.9 g/kg bw/day) for 45 days resulted an activity of liver marker enzymes (AST, ALT, ALP and GGT), lipid peroxidation markers (TBARS, lipid hydroperoxides) in liver and kidney with significantly lower activity of SOD, CAT, GPx, GST and non-enzymatic antioxidants (vitamin E, vitamin C and GSH) in liver and kidney as compared with control rats. Administration of ethanol along with GLEt significantly decreased the activities of liver markers enzyme in serum towards near normal level. GLEt at a dose of 100 mg/kg was highly effective than 25 and 50 mg/kg body weight. In addition GLEt also significantly reduced the levels of lipid peroxidation and addition, significantly restored the enzymic and non-enzymatic antioxidants level in liver and kidney of alcohol administration rats. This observation was supplemented by histopathological examination in liver and kidney. Our data suggest that GLEt exerts its protective effect by decreased the lipid peroxidation and improving antioxidants status, thus proving itself as an effective antioxidant in alcohol induced oxidative damage in rats.
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PMID:Effect of grape (Vitis vinifera L.) leaf extract on alcohol induced oxidative stress in rats. 1828 59

Although acetaminophen overdose is a leading cause of fulminant hepatic failure, it is controversial whether therapeutic doses of acetaminophen can cause hepatotoxicity in alcoholics, especially those rendered most vulnerable by recent abstinence. We performed a randomized, triple-blind, parallel-group trial comparing sustained-release acetaminophen, 1300 mg orally q8h for 11 doses, against placebo. We enrolled chronic alcohol abusers (defined as >or= 6 drinks daily for >or= 6 weeks) who had discontinued alcohol consumption 12 to 72 hours prior to enrollment. Individuals with self-reported viral hepatitis, HIV or intravenous drug use, baseline AST or ALT >120 IU/L, or INR >1.5 were excluded. Hepatic function tests were drawn daily for 5 days. The primary outcome was change in serum alpha-GST, a sensitive experimental biomarker of hepatocellular injury; secondary outcomes were changes in serum AST, ALT, INR, and study withdrawal for a doubling of aminotransferases to >120 IU/L. Of 52 subjects randomized, 40 completed at least four days of intervention. Subjects receiving acetaminophen had 32% [95% CI 7%, 50%] and 29% [6%, 46%] lower serum alpha-GST concentrations on days 2 and 3, respectively, compared to placebo, but these differences disappeared by day 4. No subjects were withdrawn for safety reasons. In conclusion, therapeutic doses of sustained-release acetaminophen cause a measurable decrease in serum alpha-GST during the first days of abstinence from chronic alcohol use. While the mechanism is unclear, these observations do provide some reassurance that short courses of acetaminophen are unlikely to cause subclinical hepatocellular injury in recently abstinent alcoholics.
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PMID:Are recommended doses of acetaminophen hepatotoxic for recently abstinent alcoholics? A randomized trial. 1834 7

Thirteen-week inhalation toxicity of 1,4-dioxane was examined by repeated inhalation exposure of male and female F344 rats to 0 (control), 100, 200, 400, 800, 1600, 3200, or 6400 ppm (v/v) 1,4-dioxane vapor for 6 h/day and 5 days/wk. All the 6400-ppm-exposed males and females died during the first week. Terminal body weight decreased, and relative weights of liver, kidney, and lung increased. AST increased in the 200 ppm-and 3200-ppm-exposed females, and ALT increased in the 3200-ppm-exposed males and females. Nuclear enlargement of nasal respiratory epithelial cells occurring in the 100-ppm-exposed males and females was the most sensitive, followed by the enlarged nuclei in the olfactory, tracheal, and bronchial epithelia. 1,4-Dioxane-induced liver lesions occurred at higher exposure concentrations than the nasal lesions did, and were characterized by single-cell necrosis and centrilobular swelling of hepatocytes in males and females. Glutathione S-transferase placental form (GST-P) positive liver foci were observed in the 1600-ppm-exposed females and 3200-ppm-exposed males and females, which are known as a preneoplastic lesion in rat hepatocarcinogenesis. Plasma levels of 1,4-dioxane increased linearly with an increase in the concentrations of exposure to 400 ppm and above. The enlarged nuclei in the nasal epithelia and the GST-P-positive liver foci were discussed in light of the possible development of nasal and hepatic tumors by long-term inhalation exposure to 1,4-dioxane. A lowest-observed-adverse-effect level (LOAEL) was determined at 100 ppm for the nasal endpoint in both male and female rats.
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PMID:Thirteen-week inhalation toxicity of 1,4-dioxane in rats. 1866 11

The present study evaluated alpha-Glutathione-S-transferase as a biochemical marker for hepatocellular damage in schistosomiasis mansoni patients, with or without chronic hepatitis C (HCV) patients as compared to controls. Alpha GST, ALT and AST were assayed in sera of GI: 20 schistosomiasis mansoni patients with HCV, GII: 16 schistosomiasis mansoni patients without HCV, GIII: 19 pure HCV patients and GIV: 20 normal controls. The results showed that alpha-Glutathione-S-transferase was less sensitive and less specific but more accurate than ALT & AST as a liver affection marker in HCV patients.
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PMID:Alpha-Glutathione S-transferase and serum aminotransferases in schistosomiasis mansoni patients with or without hepatitis C virus. 1885 28


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