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:2.5.1.18 (glutathione S-transferase)
22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

2-(Allylthio)pyrazine (2-AP), synthesized for its possible use as a hepatoprotective agent, has been found to selectively inhibit rat hepatic cytochrome P450 2E1 (Kim et al., Biochem. Pharmacol., 53, 261-269, 1997), while it enhances the activities of phase II detoxification enzymes such as glutathione S-transferase and epoxide hydrolase. As part of a program in evaluating the chemopreventive potential of 2-AP, we have determined its effects on hepatotoxicity, mutagenicity and tumorigenicity of vinyl carbamate (VC), a prototypic hepatocarcinogen preferentially activated by P450 2E1 to the ultimate carcinogenic metabolite vinyl carbamate epoxide (VCO), which undergoes detoxification by glutathione conjugation and oxirane hydrolysis. Administration of 2-AP (100 mg/kg body wt) to male Sprague-Dawley rats by gavage, 2 days, 1 day and 4 h prior to VC or VCO, markedly ameliorated the hepatotoxicity of these compounds as determined by decreased serum aspartate aminotransferase and alanine aminotransferase activities. Furthermore, 2-AP pre-treatment significantly suppressed the VC-induced hepatocarcinogenesis in infant male B6C3F1 mice. In a separate experiment, the multiplicities of skin tumors formed in female ICR mice treated with 5.8 micromol of VC or VCO were inhibited 58 and 70%, respectively, by pre-treatment with 2-AP by oral administration. The mutational spectrum of ras-oncogene in papillomas was not altered by 2-AP pre-treatment. 2-AP also inhibited the mutagenicity of VC in the Salmonella-microsome assay. Taken together, these findings suggest that 2-AP is a potential chemopreventive agent.
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PMID:Chemopreventive effects of 2-(allylthio)pyrazine on hepatic lesion, mutagenesis and tumorigenesis induced by vinyl carbamate or vinyl carbamate epoxide. 968 87

The systemic and neurobehavioral effects of benzo[b]thiophene (routinely referred to as benzothiophene) were studied in rats following 13-wk oral exposure. Male (170 +/- 16 g) and female (146 +/- 12 g) Sprague-Dawley rats (10 animals per group) were fed diet containing 0.5, 5, 50, or 500 ppm benzothiophene for 13 wk. Control animals were given rat feed plus vehicle (corn oil) only. No clinical signs of toxicity and neurobehavioral effects were observed using screening tests that included cage-side observations, righting reflex, open field activities, and forelimb and hindlimb grip strength. Elevated serum aspartate aminotransferase activity and bilirubin level were observed in highest dose females. Except for a statistically significant decrease in hematocrit in the highest dose males, benzothiophene exerted no marked effects on hematological parameters. Benzothiophene exposure did not result in alterations in hepatic alkaline phosphatase activity, or the typical hepatic phase I (aniline hydroxylase, ethoxyresorufin O-deethylase, pentoxyresorufin O-dealkylase, aminopyrine N-demethylase) and phase II (UDP-glucuronosyltransferase, glutathione S-transferase) drug-metabolizing enzyme activities. No significant elevation in urinary ascorbic acid, protein, and N-acetylglucosaminidase activity was detected in the treated animals. Peribiliary fibrosis was the most significant histological change and occurred in the liver of females in the 50 and 500 ppm groups. Mild epithelial hyperplasia in the renal pelvis was detected in the majority of 5 and 50 ppm females, with epithelial hyperplasia in the urinary bladder observed in the 50 ppm females. In males, increased incidence and severity of mild binucleation of hepatocytes and mild thickening of the basement membrane in kidney cortex were observed at 500 ppm. Benzothiophene was not detected in the urine of high-dose animals at the termination of the experiment. Based on the kidney, hepatic, and hematocrit changes, the no-observed-adverse-effect level (NOAEL) in the diet was determined to be 0.5 ppm (0.04 mg/kg/d) for females and 50 ppm (3.51 mg/kg/d) for males.
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PMID:Subchronic toxicity of benzothiophene on rats following dietary exposure. 976 Nov 33

Antioxidant and hepatoprotective actions of the mold Monascus anka (also called Beni-Koji in Japan) against acetaminophen (AAP)-induced liver toxicity were investigated. Serum aspartate aminotransferase and glutathione S-transferase (GST) activities increased by AAP (180 mg/kg, i.p.) treatment were depressed when the Beni-Koji preparation (4 ml/kg, i.p.) was given 15 and 1 hr before AAP administration. The decrease in liver cytosolic GST activity by AAP, reflecting the release of the enzyme into serum, was also blocked by the mold. Cytochrome P450 activity was inhibited by the Beni-Koji preparation. These results suggest that M. anka prevents AAP-induced liver toxicity by both antioxidant action and the inhibition of AAP metabolism.
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PMID:Protective effect of the mold Monascus anka against acetaminophen-induced liver toxicity in rats. 980 66

Antioxidant action of various molds, which are traditionally used for the production of foods or alcoholic beverages in Japan, was studied in vitro and in vivo. Antioxidant action was evaluated by scavenging stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation of rat liver microsomes. Among 40 molds, 16 species showed the DPPH scavenging action, and the molds that can scavenge the DPPH radical inhibited lipid peroxidation. The mold with the strongest action, Monascus anka, was chosen for the investigation of a protective action against liver injury of rats. When galactosamine (GalN, 400 mg/kg) or GalN plus lipopolysaccharide (LPS, 0.5 microg/kg) was given intraperitoneally to rats (Sprague-Dawley), aspartate aminotransferase (AST) and glutathione (GSH) S-transferase (GST) activities in serum were significantly increased. However, such hepatotoxicities seen in the increase in serum enzyme levels were depressed when the extract prepared from M. anka was given 1 and 15 h before the toxic insultant. Liver microsomal GST activity, which is known to be activated by oxidative stress, was increased by GalN or GaIN plus LPS treatment and the increase was also inhibited by pretreatment with the extract. Pathomorphological changes in the liver caused by GalN treatment also were prevented by the mold extract. These results indicate that the extract of M. anka has radical scavenging action and ameliorates chemically induced hepatotoxicity.
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PMID:Screening of antioxidant action of various molds and protection of Monascus anka against experimentally induced liver injuries of rats. 1018 24

There are few reports regarding the effects of benzene and ethanol being administered simultaneously. In our experiments with 4 groups (controls, ethanol, benzene and ethanol plus benzene) Wistar male rats were treated with ethanol (20%) for 5 weeks, and then exposed to benzene (0.26 g/kg) for 5 days per week for 3 weeks. We also investigated the effects of benzene on the body weight, organ weight, peripheral hematology and hepatic drug metabolizing enzymes in the ethanol administrated rats. The liver weight increased significantly, but spleen weight decreased significantly in the benzene exposed group. Hematological examination showed a decrease of leukocyte in the two groups of benzene and ethanol plus benzene in comparison with the controls, but an effect promoted by ethanol was not found. Serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) values were not significantly different in the exposure groups when compared with the controls. The contents of microsomal cytochrome P450 in all the exposed groups showed a tendency to increase, but they were not significantly different in comparison with the controls. On the other hand, hepatic glutathione S-transferase activity in the exposed groups increased significantly.
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PMID:[Effect of benzene exposure on hematology and hepatic drug metabolic enzymes in ethanol administrated rats]. 1020 90

Recent data suggest that levels of glutathione S-transferase Alpha 1-1 in umbilical cord plasma may be a good indicator of neonatal hepatocellular integrity. In order to fully understand the significance of this new marker we compared the values of glutathione S-transferase Alpha 1-1 (GSTA1-1) with that of the well known liver function markers alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in arterial and corresponding venous umbilical cord blood of 93 patients. In addition, in 49 of these patients maternal venous blood was also studied. Both arterial and venous umbilical cord GSTA1-1 and AST levels were significantly higher than corresponding maternal venous levels, whereas ALT levels were not. Arterial umbilical cord GSTA1-1 correlated significantly with the corresponding AST and ALT levels (R = 0.46, P < 0.0001 and R = 0.41, P < 0.0001, respectively). Arterial umbilical cord AST correlated significantly with corresponding ALT levels (R = 0.58, P < 0.0001). Arterial umbilical cord plasma GSTA1-1 levels were significantly lower in the cesarean delivery group as compared to the vaginal birth group, whereas no difference was noted for AST or ALT. Arterial umbilical cord AST and GSTA1-1 levels correlated significantly with base deficit (R = 0.29, P = 0.005; R = 0.29, P = 0.005, respectively), whereas ALT did not (R = 0.06, P = 0.54). Arterial umbilical cord AST, ALT, and GSTA1-1 levels correlated significantly with birthweight. In conclusion, GSTA1-1 levels as assessed in neonatal umbilical cord blood, being unrelated to maternal levels, seem to be a more sensitive marker for early neonatal hepatocellular integrity as compared to ALT or AST and even might detect impaired hepatocellular integrity due to the vaginal birth process. Umbilical cord GSTA1-1 may provide a valuable indicator of neonatal condition immediately after birth, the clinical relevance of which needs to be further established.
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PMID:Glutathione S-transferase Alpha 1-1 and aminotransferases in umbilical cord blood. 1021 91

In this experiment, we studied the different changes in activities and protein levels of each subform of hepatic cytochrome P450 and glutathione S-transferase (GST), in chemical-induced liver injury in rats. Rats were administered 1,1-dichloroethylene (DCE), allyl alcohol (AA), bromobenzene (BB) and N,N-dimethylformamide (DMF) p.o. once every two days for 7 times, and decapitated 18 hr after the last administration. DCE and AA showed stronger hepatic toxicity than BB and DMF, as serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were higher in DCE and AA treated rats than in BB and DMF groups. Anti-cytochrome P450 inhibitable activity of toluene metabolism and/or immunoblot analysis showed that CYP2E1 and CYP2B1/2 were induced by BB and DMF, but not by the other two chemicals; CYP2C11 was greatly decreased by all of the four toxicants; and CYP1A1/2 was slightly reduced by the four treatments. These changes were reflected in testosterone metabolism. Formation of 6 beta- and 7 alpha-hydroxytestosterone from testosterone was enhanced only in DMF-treated rats, whereas that of 2 alpha- and 16 alpha-hydroxytestosterone was reduced by all of the four chemicals. Serum GST activity was increased only in BB and DMF treated rats, but liver cytosolic GST activity was enhanced by all of the four hepatotoxicants, with higher values in BB and DMF groups than in DCE and AA groups. Immunoblot analysis demonstrated that GST Yp was induced by BB and DMF treatments, and Ya and Yc were increased only by BB. GST Yk and Yb1 were not affected by the treatments. The different change patterns of enzymes by a specific toxin and the similar modifying effect on a specific enzyme by different toxins were discussed in relation to the liver damage and to the heterogeneous distribution of enzymes in liver.
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PMID:Different change patterns of the isozymes of cytochrome P450 and glutathione S-transferases in chemically induced liver damage in rat. 1054 60

We previously reported that the mold Monascus anka, traditionally used for fermentation of food, showed antioxidant and hepatoprotective actions against chemically induced liver injuries. In the present study, the antioxidant component of M. anka was isolated and identified. The antioxidant was elucidated to be dimerumic acid. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical was significantly scavenged by the antioxidant whereas hydroxyl radical and superoxide anion were moderately scavenged. When the antioxidant (12 mg/kg) was given to mice prior to carbon tetrachloride (CCl(4), 20 microl/kg, ip) treatment, the CCl(4)-induced liver toxicity in mice seen in an elevation of serum aspartate aminotransferase and alanine aminotransferase activities was depressed, suggesting the hepatoprotective action of the antioxidant. The liver microsomal glutathione S-transferase activity, which is known to be activated by oxidative stress or active metabolites, was increased by CCl(4) treatment and the increase was also depressed by pretreatment with the mold antioxidant. Thus these data confirmed that the dimerumic acid isolated from M. anka is the potential antioxidant and protective against CCl(4)-induced liver injury.
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PMID:Dimerumic acid as an antioxidant of the mold, Monascus anka. 1080 32

Serum concentrations of alpha-glutathione S-transferase (alphaGST) were determined before and after hepatectomy to examine the clinical usefulness of alphaGST as a marker of hepatocellular damage compared with the conventional liver function tests. Prior to hepatectomy, serum alphaGST concentrations correlated significantly with serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). In patients who had a good postoperative course, serum alphaGST concentrations rose significantly to a peak immediately after surgery, followed by a rapid fall to the normal range within 1 week, yielding a monophasic pattern. Serum alphaGST concentrations reached a peak earlier than other parameters of liver function, and peak serum alphaGST concentrations correlated with peak serum concentrations of AST and ALT. The mean decrease rate of serum alphaGST concentration from peak values was significantly more rapid than that of serum AST and ALT, indicating an early return of alphaGST concentrations to the normal range. These findings suggest that serum alphaGST may be a more sensitive marker of hepatocellular damage than transaminases and may therefore be useful for rapid monitoring of the extent and persistence of liver injury after hepatectomy.
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PMID:Serum alpha-glutathione S-transferase: a new marker of hepatocellular damage associated with hepatectomy. 1083 32

The hepatoprotective effects of bergenin, a major constituent of Mallotus japonicus, were evaluated against carbon tetrachloride (CCl(4))-induced liver damage in rats. Bergenin at a dose of 50, 100 or 200 mg/kg was administered orally once daily for successive 7 days and then a mixture of 0.5 ml/kg (ip) of CCl(4) in olive oil (1:1) was injected two times each at 12 and 36 h after the final administration of bergenin. The substantially elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and gamma-glutamyltransferase due to CCl(4) treatment were dose dependently restored towards normalization. Meanwhile, the decreased activities of glutathione S-transferase and glutathione reductase were restored towards normalization. In addition, bergenin also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content in the liver of CCl(4)-intoxicated rats in a dose dependent fashion. The results of this study clearly indicate that bergenin has a potent hepatoprotective action against CCl(4)-induced hepatic damage in rats.
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PMID:Hepatoprotective effects of bergenin, a major constituent of Mallotus japonicus, on carbon tetrachloride-intoxicated rats. 1099 88


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