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

---

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

In order to explore the effect of Panax vietnamensis on carbon tetrachloride-induced hepatotoxicity, mice were pretreated for 7 days with either crude extract or total saponins. Crude extract and total saponins dramatically decreased carbon tetrachloride-induced increase of serum GST alpha level (-50.0%, -49.5% respectively). Serum AST level was significantly decreased only with total saponins (-52.2%) and ALT level was slightly modified. In vitro experiments shown that both preparations at high concentrations (> 2000 micrograms/ml) are able to inhibit CYP2E1 enzymatic activity in mouse and human microsomes. However, we did not observe any modification of Cyp2e1 gene expression (enzymatic activity, protein and mRNA levels) in mice treated with either crude extract or total saponins. Taken together, these data demonstrated that Panax vietnamensis could be used as an hepatoprotectant. However, the mechanism of action is not associated with CYP2E1 expression, as previously suggested in vitro in rat for total saponins from Panax ginseng.
...
PMID:Panax vietnamensis protects mice against carbon tetrachloride-induced hepatotoxicity without any modification of CYP2E1 gene expression. 1119 27

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride (CCl4)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against CCl4-induced liver damage in rats by means of serum and liver biochemical indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ml/kg mixture of CCl4 in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and gamma-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in CCl4-intoxicated rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin has potent hepatoprotective activity against CCl4-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 mg/kg showed almost the same levels of hepatoprotective activity as 100 mg/kg of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of CCl4 than those of the much less lipophilic bergenin.
...
PMID:Protective effects of acetylbergenin against carbon tetrachloride-induced hepatotoxicity in rats. 1133 30

The regulator of immunoglobulin expression Oct-2 and the related widely expressed transcription factor Oct-1 have been shown to interact with DNA sequences containing an "octamer" motif, ATGC(A/T)AAT. To better understand Oct-2 function we have used random oligonucleotide selection and competition assays to define the optimal recognition site for this protein. The selected site contains an extended sequence that is remarkably similar to octamer-heptamer sequences found in immunoglobulin heavy-chain regulatory sequences, and the affinity of Oct-2 for this site is at least 50-fold greater than for sites containing the octamer motif alone. Fusion to glutathione S-transferase, a widely used model for protein-DNA and protein-protein interaction, does not alter the optimal Oct-2 recognition site, but inhibits Oct-2 POU-domain dimerization, slows the dissociation rate of the GST-Oct-2/DNA complex, and increases the relative importance of the heptamer domain for Oct-2 binding. These data advance our ability to identify in vivo targets of POU-factor regulation and also suggest that GST-fusion proteins should be used with caution in DNA-binding studies.
...
PMID:Optimal Oct-2 affinity for an extended DNA site and the effect of GST fusion on site preference. 1136 23

The virus genome-linked protein (VPg) coding region from rabbit hemorrhagic disease virus (RHDV) (isolate AST/89) was expressed in Escherichia coli by using a glutathione S-transferase-based vector. The recombinant polypeptide could be purified in good yields and was uridylylated in vitro from [alpha-32P]UTP in a reaction catalyzed by the recombinant RNA-dependent RNA polymerase from RHDV in the absence of added template RNA. The use of deletion and point mutants allowed the identification of Tyr-21 as the residue involved in uridylylation and consequently in the linkage between VPg and the viral genome. These data constitute the first report on the identity of the amino acid residue involved in VPg uridylylation in a member of the Caliciviridae family.
...
PMID:Identification of the amino acid residue involved in rabbit hemorrhagic disease virus VPg uridylylation. 1136 64

This study examined the effects of 1 degrees C hypo- or hyperthermia on in vivo liver ischemia and reperfusion (I/R) injury in 15 fasted male Wistar rats. Rats were ventilated, and rectal temperature was maintained at 36, 37 (normothermic), or 38 degrees C. In all rats, 70% liver ischemia was induced by clamping the afferent vessels to the median and left lateral lobes for 60 min, and reperfusion was allowed for 90 min. Changes in plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alpha-glutathione S-transferase (alpha-GST) levels were measured, hemodynamics and bile secretion were monitored, and arterial blood-gas analysis was performed. All ventilated rats showed a normal pH, arterial PCO(2), and arterial PO(2). AST, ALT, and alpha-GST levels were significantly higher in the 38 degrees C group when compared with the 36 and 37 degrees C groups after ischemia. No differences in bile secretion were found between all groups. Histopathological alterations were in agreement with AST, ALT, and alpha-GST levels in plasma. We conclude that a decrease of only 1 degrees C in body temperature significantly attenuates liver I/R injury, whereas an increase of 1 degrees C significantly increases liver I/R injury.
...
PMID:Pronounced effect of minor changes in body temperature on ischemia and reperfusion injury in rat liver. 1140 39

Extract of Salvia Miltiorrhiza (SM) has been widely used in traditional Chinese medicine for treating liver diseases. Recent experimental evidence indicates that it has anti-tumor potential. In this study, the effect of SM on alfatoxin B1 (AFB1)-induced hepatocarcinogenesis was investigated in male Fischer 344 rats. AFB1 (40 microg/100 g body wt, by gavage) was administered once a week for 24 weeks. In SM treatment group, rats were given SM (0.25g/100g body wt, 5 days/week by gavage) for a total of 28 weeks, including 4 weeks before and 24 weeks during AFB1 exposure. Results showed that the elevation of serum alanine aminotransferase and aspartate aminotransferase activities due to AFB1 dosing was almost completely abolished by the treatment of SM, indicating that SM could prevent AFB1-induced liver cell injury. It was further observed that SM substantially reduced glutathione S-transferase placenta form (GST-P) positive foci formation and GST-P mRNA expression caused by AFB1, which clearly suggests that SM is effective in preventing AFB1-induced hepatocarcinogenesis. Furthermore, the inhibition on AFB1 hepatocarcinigenesis was associated with a corresponding decrease in AFB1-DNA adducts formation as well as AFB1-induced oxidative DNA damage (8-hydroxydeoxyguanosine) in rat liver. Our results also indicate that the protective effect of SM might be mediated through dual mechanisms: (i) the enhancement of AFB1 detoxification pathway, especially the induction of GST-Yc2 mRNA expression, and (ii) the antioxidant property of SM.
...
PMID:Protection of salvia miltiorrhiza against aflatoxin-B1-induced hepatocarcinogenesis in Fischer 344 rats dual mechanisms involved. 1144 22

The hepatoprotective effects of bergenin, a major constituent of Mallotus japonicus, were evaluated against D-galactosamine (GalN)-induced liver damage in rats. Bergenin (50, 100 and 200 mg/kg) was given orally once daily for 7 successive days and then GalN 400 mg/kg was injected intraperitoneally to rats at 24 and 96 h after the final administration of bergenin. Pretreatment with bergenin reduced the increased enzyme activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase, gamma-glutamyltransferase and the elevated level of malondialdehyde induced by GalN. Bergenin restored the decreased hepatic contents of glutathione as well as the decreased activities of glutathione S-transferase and glutathione reductase by GalN towards normalization, suggesting that the hepatoprotective effects of bergenin may consist in maintaining adequate levels of hepatic glutathione for the removal of xenobiotics. The present results indicate that bergenin has hepatoprotective effects against GalN-induced hepatotoxicity in rats.
...
PMID:Effects of bergenin, the major constituent of Mallotus japonicus against D-galactosamine-induced hepatotoxicity in rats. 1149 Jan 98

Recent studies have reported on the toxicity and related oxidative stress of selenium and mercury. The present study compares the effects of Se as sodium selenite (Na2SeO3) and Hg as mercuric chloride (HgCl2) separately and in combination. Rats received repeated oral doses of Se (0.5 micromol/ml), Hg (0.5 micromol/ml), or Se in combination with Hg (0.5 micromol/ml of each) for 5 consecutive days. Rat serum, brain and liver samples were collected for biochemical assays. The following biochemical alterations occurred in response to Hg treatment: protein content (brain and liver), acetylcholinesterase (AChE) (brain and serum), acid and alkaline (AcP and AlP) phosphatases (plasma and liver) and glutathione S-transferase (GST) (plasma and liver) activities were significantly (P<0.05) decreased, while lactate dehydrogenase (LDH) (plasma, brain and liver), aspartate and alanine aminotransferase (AST, ALT) (serum and liver) activities were significantly increased. Thiobarbituric acid reactive substances (TBARS) was significantly increased in brain and liver. Effect of Se alone included decreased AcP, AlP and GST (serum and liver) activities. However, LDH (serum, brain and liver) and AST (liver) and TBARS (brain and liver) increased. Selenium in combination with Hg partially or totally alleviated the toxic effects of Hg on different studied enzymes. It is concluded that Se could be able to antagonize the toxic effects of mercury.
...
PMID:Effects of selenium and mercury on the enzymatic activities and lipid peroxidation in brain, liver, and blood of rats. 1149 25

Laparoscopic surgery causes a reduction in hepatic blood flow due to a number of factors, including raised intra-abdominal pressure, the neurohumoral response to surgical stress and the effect of patient position. The clinical significance of the phenomenon is not fully understood. Plasma concentrations of alcohol dehydrogenase (AD) and glutathione S-transferase (GST), which are concentrated in the centrilobular acinus of the liver, sensitively reflect hepatic hypoperfusion, and can be used to monitor reductions in hepatic blood flow. We compared perioperative AD, GST, aspartate aminotransferase (AST, normal range 14-32 IU litre(-1)) and alanine aminotransferase (ALT, normal range 8-41 U litre(-1)) concentrations in patients undergoing laparoscopic cholecystectomy or laparoscopic colectomy to study how patient position and surgical manipulation of the liver affect hepatocellular integrity during laparoscopy. There were significant postoperative increases in AD and GST in the cholecystectomy group [mean (SD) peak concentration 10.8 (4.7) U litre(-1) and 113 (55) microg litre(-1) respectively]. Although the duration of pneumoperitoneum was longer in the colectomy group, there were no comparable perioperative increases in AD and GST in this group [peak concentration 4.0 (4.0) U litre(-1) and 33 (35) microg litre(-1) respectively]. AST and ALT on the first postoperative day were significantly higher in the laparoscopic cholecystectomy group (41 and 34 U litre(-1) respectively) than in the laparoscopic colectomy group (24 and 18 U litre(-1); P<0.05 for each). These results indicate that patient position and the effects of surgical manipulation of the liver affect perioperative hepatic perfusion significantly.
...
PMID:Subclinical hepatic dysfunction in laparoscopic cholecystectomy and laparoscopic colectomy. 1187 31

The protective effects of a Platycodi radix (Changkil: CK), the root of Platycodon grandiflorum A. DC (Campanulaceae) on carbon tetrachloride (CC14)-induced hepatotoxicity and the possible mechanisms involved in this protection were investigated in mice. Pretreatment with CK prior to the administration of CC14 significantly prevented the increased serum enzymatic activities of alanine and aspartate aminotransferase in a dose-dependent manner. In addition, pretreatment with CK also significantly prevented the elevation of hepatic malondialdehyde formation and the depletion of reduced glutathione content in the liver of CC14-intoxicated mice. However, hepatic reduced glutathione levels and glutathione S-transferase activities were not affected by treatment with CK alone. CC14-induced hepatotoxicity was also essentially prevented, as indicated by a liver histopathologic study. The effects of CK on the cytochrome P450 (P450) 2E1, the major isozyme involved in CC14 bioactivation were also investigated. Treatment of mice with CK resulted in a significant decrease of P450 2E1-dependent p-nitrophenol and aniline hydroxylation in a dose-dependent manner. CK showed antioxidant effects in FeCl2-ascorbate-induced lipid peroxidation in mice liver homogenate and in superoxide radical scavenging activity. Our results suggest that the protective effects of CK against CC14-induced hepatotoxicity possibly involve mechanisms related to its ability to block P450-mediated CC14 bioactivation and free radical scavenging effects.
...
PMID:Protective effect of Platycodi radix on carbon tetrachloride-induced hepatotoxicity. 1189 10


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---