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)

Mercury(II) is a highly toxic metal which induces oxidative stress in the body. In this study we aimed to investigate the possible protective effect of Ginkgo biloba (EGb), an antioxidant agent, against experimental mercury toxicity in rat model. Following a single dose of 5mg/kg mercuric chloride (HgCl(2); Hg group) either saline or EGb (150mg/kg) was administered for 5days. After decapitation of the rats trunk blood was obtained and the tissue samples from the brain, lung, liver, and kidney were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Formation of reactive oxygen species in the tissue samples was monitored by chemiluminescence (CL) technique. BUN, creatinin, ALT, and AST levels and tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) activity were assayed in serum samples. The results revealed that HgCl(2) induced oxidative damage caused significant decrease in GSH level, significant increase in MDA level, MPO activity and collagen content of the tissues. Treatment of rats with EGb significantly increased the GSH level and decreased the MDA level, MPO activity, and collagen contents. Similarly, serum ALT, AST and BUN levels, as well as LDH and TNF-alpha, were elevated in the Hg group as compared to control group. On the other hand, EGb treatment reversed all these biochemical indices. Our results implicate that mercury-induced oxidative damage in brain, lung, liver, and kidney tissues protected by G. biloba extract, with its antioxidant effects.
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PMID:Ginkgo biloba extract protects against mercury(II)-induced oxidative tissue damage in rats. 1726 89

Ischemia-reperfusion injury (IRI) contributes to early and late dysfunction of liver transplants. We have shown that sentinel Toll-like receptor-4 (TLR4) plays a key role in the activation of T cell immune responses during hepatic IRI. We have also documented that overexpression of heme oxygenase-1 (HO-1) exerts potent cytoprotective effects. This study analyzes how adenovirus (Ad)-based viral interleukin-10 (vIL-10) gene transfer affects TLR4 and HO-1 signaling in host innate and adaptive immunity during liver IRI. Using a partial lobar warm IRI model, groups of wild-type and HO-1(+/-) knockout (KO) mice were assessed for severity of hepatocellular damage after 90 min of warm ischemia followed by 6 hr of reperfusion. Both wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 have shown improved hepatic function (serum glutamic-oxaloacetic transaminase levels), ameliorated histological signs of IRI (Suzuki's score), decreased neutrophil accumulation (myeloperoxidase activity), and depressed tumor necrosis factor-alpha/IL-1beta, IL-2/interferon-gamma, E-selectin, and macrophage inflammatory protein-2 expression. These effects were IL-10 dependent as treatment with neutralizing antibody re-created liver IRI. In contrast, untreated wild-type and HO-1 (+/-) KO mice, as well as wild-type and HO-1 (+/-) KO mice treated with Ad-beta-Gal, showed severe hepatocellular damage due to IRI. Unlike in controls, wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 revealed markedly depressed TLR4 and NF-kappaB expression, along with increased HO-1 and Bcl-2/Bcl-x(L) expression, as compared with respective controls. Thus, vIL-10 gene transfer prevents hepatic IRI in association with depressed expression of innate TLR4, and adaptive Th1 cytokine/chemokine programs. The induction of antioxidant HO-1 and anti-apoptotic Bcl-2/Bcl-x(L) by vIL-10 exerts synergistic cytoprotective function against antigen-independent hepatic inflammatory response triggered by IRI.
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PMID:Viral interleukin-10 gene transfer prevents liver ischemia-reperfusion injury: Toll-like receptor-4 and heme oxygenase-1 signaling in innate and adaptive immunity. 1743 57

This study was designed to investigate the protective effect of oleanolic acid (OA) against isoproterenol-induced myocardial ischemia in rat myocardium. Wistar strain rats were pretreated with OA (20, 40, and 60 mg/kg, s.c) for 7 days and then intoxicated with isoproterenol (ISO, 85 mg/kg, sc for 2 consecutive days). Heart were excised from the experimental animals and assessed for the activities of marker enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatine phosphokinase (CPK)], the levels of lipid peroxide products [thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (HP) and conjugated dienes (CD)], myeloperoxidase (MPO), lipid profiles [total cholesterol (TC), free cholesterol, ester cholesterol, triglycerides (TG), free fatty acids (FFA) and phospholipids (PL)], and membrane-bound ATPase enzymes (total ATPase, Na(+)K(+) ATPase, Ca(2 +) ATPase, and Mg(2 +) ATPase). Troponin T and I were estimated in plasma. Leakage of cardiac markers, elevated lipid peroxidation with increased lipid profiles and decreased activities of membrane-bound ATPase enzymes were confirmed the severe myocardial damage occurring as a consequence of isoproterenol-induced ischemia, and they also showed the significant improvement effected by oleanolic acid pretreatment. These findings provided evidence that oleanolic acid was found to be protecting rat myocardium against ischemic insult and the protective effect could attribute to its anti-oxidative, anti-hyperlipedemic, and anti-arrhythmic properties as well as its membrane-stabilizing action.
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PMID:Cardioprotective effect of oleanolic acid on isoproterenol-induced myocardial ischemia in rats. 1745 91

Severe burn induces the activation of an inflammatory cascade that contributes to the development of subsequent immunosuppression, increased susceptibility to sepsis, as well as generation of reactive oxygen radicals and lipid peroxidation, leading to multiple organ failure. In the present study, we investigated whether rosiglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand is protective against burn-induced remote organ injury. Under brief ether anaesthesia, shaved dorsum of the rats were exposed to 90 degrees C (burn group) or 25 degrees C (control group) water bath for 10s. Rosiglitazone (4 mg/kg) or saline was administered intraperitoneally immediately after and at the 12th hour of the burn. Rats were decapitated 24h after injury and the tissue samples from lung, liver, and kidney were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, and creatinine, blood urea concentrations (BUN) were determined to assess liver and kidney function, respectively. Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and lactate dehydrogenase (LDH) were also assayed. Severe skin scald injury (30% of total body surface area) caused a significant decrease in GSH level, and significant increases in MDA level, MPO activity and collagen content of tissues. Similarly, serum ALT, AST and BUN levels, as well as LDH, IL-1 beta and TNF-alpha were elevated in the burn group as compared to the control group. Rosiglitazone treatment reversed all these biochemical indices. According to the findings of the present study, rosiglitazone possesses a anti-inflammatory effect that prevents burn-induced damage in remote organs and protects against organ damage.
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PMID:Rosiglitazone, a PPAR-gamma ligand, protects against burn-induced oxidative injury of remote organs. 1746 12

We examined how oxidative stress and cell damage develop in the liver of rats subjected to water-immersion stress (WIRS). In rats subjected to WIRS for 1.5, 3 or 6 h, serum alanine aminotransferase and aspartate aminotransferase activities increased time-dependently. In the liver tissue, vacuolization and apoptosis occurred at 1.5 h of WIRS and vacuolization further developed without further appearance of apoptosis at 3 h or 6 h. Serum lipid peroxide (LPO) and NOx (nitrite/nitrate) concentrations increased at 3 h of WIRS and these increases were enhanced at 6 h. In liver tissue, increases in LPO and NOx concentrations and myeloperoxidase activity and decreases in ascorbic acid and reduced glutathione concentrations and superoxide dismutase activity occurred at 3 h of WIRS and these changes were enhanced at 6 h, although vitamin E concentration and xanthine oxidase activity were unchanged. These results indicate that oxidative stress in the liver of rats with WIRS develops after the appearance of cell damage in the tissue, and suggests that oxidative stress is caused through disruption of the antioxidant defense system and increases in NO generation and neutrophil infiltration in the liver, which may contribute to the progression of cell damage in the tissue.
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PMID:Development of oxidative stress and cell damage in the liver of rats with water-immersion restraint stress. 1762 21

Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (CIH) during sleep. OSA is associated with nonalcoholic steatohepatitis (NASH) in obese individuals and may contribute to progression of nonalcoholic fatty liver disease from steatosis to NASH. The purpose of this study was to examine whether CIH induces inflammatory changes in the liver in mice with diet-induced hepatic steatosis. C57BL/6J mice (n = 8) on a high-fat, high-cholesterol diet were exposed to CIH for 6 mo and were compared with mice on the same diet exposed to intermittent air (control; n = 8). CIH caused liver injury with an increase in serum ALT (461 +/- 58 U/l vs. 103 +/- 16 U/l in the control group; P < 0.01) and AST (637 +/- 37 U/l vs. 175 +/- 13 U/l in the control group; P < 0.001), whereas alkaline phosphatase and total bilirubin levels were unchanged. Histology revealed hepatic steatosis in both groups, with mild accentuation of fat staining in the zone 3 hepatocytes in mice exposed to CIH. Animals exposed to CIH exhibited lobular inflammation and fibrosis in the liver, which were not evident in control mice. CIH caused significant increases in lipid peroxidation in serum and liver tissue; significant increases in hepatic levels of myeloperoxidase and proinflammatory cytokines IL-1beta, IL-6, and CXC chemokine MIP-2; a trend toward an increase in TNF-alpha; and an increase in alpha1(I)-collagen mRNA. We conclude that CIH induces lipid peroxidation and inflammation in the livers of mice on a high-fat, high-cholesterol diet.
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PMID:Chronic intermittent hypoxia causes hepatitis in a mouse model of diet-induced fatty liver. 1800 63

Punica granatum L. (pomegranate) is a widely used plant that has high nutritional value. The aim of this study was to assess the effect of chronic administration of pomegranate peel extract (PPE) on liver fibrosis induced by bile duct ligation (BDL) in rats. PPE (50 mg kg(-1)) or saline was administered orally for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver function and tissue damage. Proinflammatory cytokines (tumor necrosis factor-alpha and interleukin 1 beta) in the serum and antioxidant capacity (AOC) were measured in plasma samples. Samples of liver tissue were taken for measurement of hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence assay. Serum AST, ALT, LDH and cytokines were elevated in the BDL group compared with the control group; this increase was significantly decreased by PPE treatment. Plasma AOC and hepatic GSH levels were significantly depressed by BDL but were increased back to control levels in the PPE-treated BDL group. Increases in tissue MDA levels and MPO activity due to BDL were reduced back to control levels by PPE treatment. Similarly, increased hepatic collagen content in the BDL rats was reduced to the level of the control group with PPE treatment. Thus, chronic PPE administration alleviated the BDL-induced oxidative injury of the liver and improved the hepatic structure and function. It therefore seems likely that PPE, with its antioxidant and antifibrotic properties, may be of potential therapeutic value in protecting the liver from fibrosis and oxidative injury due to biliary obstruction.
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PMID:Pomegranate peel extract prevents liver fibrosis in biliary-obstructed rats. 1793 10

The aim of this study was to evaluate and compare the effectiveness of N-acetylcysteine (NAC) and liposomally-encapsulated NAC (L-NAC) in ameliorating the hepatotoxic effects of lipopolysaccharide (LPS). LPS, a major cell wall molecule of Gram-negative bacteria and the principal initiator of septic shock, causes liver injury in vivo that is dependent on neutrophils, platelets, and several inflammatory mediators, including tumour necrosis factor-alpha (TNF-alpha). Male Sprague-Dawley rats were pretreated intravenously with saline, plain liposomes (dipalmitoylphosphatidylcholine [DPPC]), NAC (25 mg/kg body weight), or L-NAC (25 mg/kg NAC body weight) and 4 h later were challenged intravenously with LPS (Escherichia coli O111:B4, 1.0 mg/kg body weight); animals were killed 20 h post-LPS challenge. Hepatic cell injury was evaluated by measuring the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in plasma. LPS-induced activation of the inflammatory response was evaluated by measuring the levels of myeloperoxidase activity and chloramine concentration in liver homogenates as well as TNF-alpha levels in plasma. The hepatic levels of lipid peroxidation products and non-protein thiols (NPSH) were used to assess the extent of involvement of oxidative stress mechanisms. In general, challenge of animals with LPS resulted in hepatic injuries, activation of the inflammatory response, decreases in NPSH levels and increases in the levels of lipid peroxidation products (malondialdehyde and 4-hydroxyalkenals). Pretreatment of animals with NAC or empty liposomes did not have any significant protective effect against LPS-induced hepatotoxicity. On the other hand, pretreatment of animals with an equivalent dose of L-NAC conferred protection against the liver injuries induced following LPS challenge. These data suggest that NAC when delivered as a liposomal formulation is a potentially more effective prophylactic pharmacological agent in alleviating LPS-induced liver injuries.
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PMID:Prophylactic effect of liposomal N-acetylcysteine against LPS-induced liver injuries. 1798 88

Massive hepatectomy associated with infection induces liver dysfunction, or even multiple organ failure and death. Glycyrrhizin has been shown to exhibit anti-oxidant and anti-inflammatory activities. The aim of the present study was to investigate whether glycyrrhizin could attenuate endotoxin-induced acute liver injury after partial hepatectomy. Male Wistar rats (6 to 8 weeks old, weighing 200-250 g) were randomly assigned to three groups of 24 rats each: sham, saline and glycyrrhizin. Rats were injected intravenously with lipopolysaccharide (LPS) 24 h after 70% hepatectomy. Glycyrrhizin, pre-administered three times with 24 h intervals 48 h before hepatectomy, prolonged the survival of rats submitted to partial hepatectomy and LPS injection, compared with saline controls. Glycyrrhizin was shown to attenuate histological hepatic changes and significantly reduced serum levels of aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase, at all the indicated times (6 rats from each were sacrificed 1, 3, 6, and 9 h after LPS injection), compared with saline controls. Glycyrrhizin also significantly inhibited hepatocyte apoptosis by down-regulating the expression of caspase-3 and inhibiting the release of cytochrome C from mitochondria into the cytoplasm. The anti-inflammatory activity of glycyrrhizin may rely on the inhibition of release of tumor necrosis factor-a, myeloperoxidase activity, and translocation of nuclear factor-kappa B into the nuclei. Glycyrrhizin also up-regulated the expression of proliferating cell nuclear antigen, implying that it might be able to promote regeneration of livers harmed by LPS. In summary, glycyrrhizin may represent a potent drug protecting the liver against endotoxin-induced injury, especially after massive hepatectomy.
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PMID:Glycyrrhizin attenuates endotoxin- induced acute liver injury after partial hepatectomy in rats. 1799 67

Endotoxemia is a life-threatening, inflammatory condition that involves multiple organ injury and dysfunction. Preprotachykinin-A (PPT-A) gene products, substance P (SP), and neurokinin-A have been shown to play an important role in neurogenic inflammation. To investigate the role of PPT-A gene products on multiple organ injury in LPS-induced endotoxemia, endotoxemia was induced by LPS administration (10 mg/kg, i.p.) in PPT-A gene-deficient mice (PPTA(-/-)) and the wild-type (WT) control mice (PPT-A+/+). I.p. administration of LPS to WT mice caused a significant increase in circulating levels of SP as well as in liver, lung, and kidney. PPT-A gene deletion significantly protected against liver, pulmonary, and renal injury following LPS-induced endotoxemia, as evidenced by tissue myeloperoxidase activities, plasma alanine aminotransferase, aspartate aminotransferase levels, and histological examination. Furthermore, PPT-A(-/-) mice had significantly attenuated chemokines, proinflammatory cytokines, and adhesion molecule levels in the liver, lung, and kidney. These results show that PPT-A gene products are critical proinflammatory mediators in endotoxemia and the associated multiple organ injury. In addition, the data suggest that deletion of the PPT-A gene protected mice against organ damage in endotoxemia by disruption in neutrophil recruitment.
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PMID:Role of preprotachykinin-A gene products on multiple organ injury in LPS-induced endotoxemia. 1799 2


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