Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.109 (AST)
 6,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatic ischemia reperfusion (HIR) not only results in liver injury, but also leads to endotoxemia, which aggravates HIR-induced liver injury and dysfunction, or even causes liver failure. Taurine has been shown to protect organs from ischemia reperfusion or endotoxin by its anti-oxidant and anti-inflammatory activities. The aim of this study was to investigate whether taurine could attenuate endotoxin-induced acute liver injury after HIR. Wistar rats subjected to 30 min of hepatic ischemia followed by reperfusion and lipopolysaccharide (LPS) (0.5 mg/kg) administration, exhibited liver dysfunction (elevated serum levels of ALT, AST and LDH) and hepatic histopathological alteration. The serum levels of TNF-alpha and production of myeloperoxidase (MPO) and malondialdehyde (MDA) in liver tissues and apoptosis of hepatocytes were also increased after the combination of HIR and LPS. However, pre-administration of taurine protected livers from injury induced by the combination of HIR + LPS as the histological score, apoptotic index, MPO activity and production of MDA in liver tissues, and serum levels of AST, ALT, LDH and TNF-alpha, were significantly reduced. The expression of caspase-3, Fas and Fas ligand was upregulated in homogenates of livers from rats subjected to HIR and LPS, and this elevated expression could be inhibited by taurine. In summary, the results further emphasize the potential utilization of taurine in protecting livers against endotoxin-induced injury especially after HIR, by its anti-inflammatory, anti-oxidative and anti-apoptotic activities.
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PMID:Protective effects of taurine against endotoxin-induced acute liver injury after hepatic ischemia reperfusion. 1926 95

Alcohol consumption is implicated in the genesis of a spectrum of liver abnormalities, which are associated with a number of factors. In the present study, time-dependent effects of ethanol on cytokines (TNF-alpha, IL-2, IL-4, IL-10, IFN-gamma, VEGF-A and TGF-beta1) in serum, and blood oxidative stress parameters such as reduced glutathione content, TBARS level and activities of GPx, GR, GST, catalase and SOD in 8-10 weeks-old male BALB/c mice have been investigated. Ethanol administered @ 1.6 g/kg body wt/day significantly increased the activities of liver marker enzymes AST, ALT and ALP. Serum nitrite levels and haemolysate TBARS level also increased, while total antioxidant status in serum and GSH content in whole blood hemolysate decreased from 4th week onwards of exposure. In spite of the increased serum nitrite level and GST activity in the haemolysate, albumin level in serum, GPx and GR activities in haemolysate decreased after 12 weeks of exposure. Chronic ethanol treatment did not show any effect on IL-2, but IL-4 level was reduced and other cytokines such as IL-10, TNF-alpha, IFN-gamma, TGF-beta1 and VEGF-A levels were increased significantly after 12 weeks. The study indicates a relationship between free radical generation and immune response, and suggests that ethanol-induced liver damage is associated with oxidative stress and immunological alterations in a time-dependent manner.
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PMID:Time-dependent effects of ethanol on blood oxidative stress parameters and cytokines. 1937 64

It is well known that some intestinal bacteria, such as Escherichia coli, can produce a remarkable amount of molecular hydrogen (H(2)). Although the antioxidant effects of H(2) are well documented, the present study examined whether H(2) released from intestinally colonized bacteria could affect Concanavalin A (ConA)-induced mouse hepatitis. Systemic antibiotics significantly decreased the level of H(2) in both liver and intestines along with suppression of intestinal bacteria. As determined by the levels of AST, ALT, TNF-alpha and IFN-gamma in serum, suppression of intestinal bacterial flora by antibiotics increased the severity of ConA-induced hepatitis, while reconstitution of intestinal flora with H(2)-producing E. coli, but not H(2)-deficient mutant E. coli, down-regulated the ConA-induced liver inflammation. Furthermore, in vitro production of both TNF-alpha and IFN-gamma by ConA-stimulated spleen lymphocytes was significantly inhibited by the introduction of H(2). These results indicate that H(2) released from intestinal bacteria can suppress inflammation induced in liver by ConA.
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PMID:Hydrogen from intestinal bacteria is protective for Concanavalin A-induced hepatitis. 1952 50

IL-12 is an excellent candidate for the treatment of cancer due to its ability to drive strong antitumor responses. Recombinant IL-12 protein is currently used in cancer patients; however, systemic expression of rIL-12 presents disadvantages including cost and dose limitation due to its toxicity. In this study, we used hydrodynamic shear of cDNA as a tool to achieve systemic expression of IL-12. We found that sustained but toxic levels of serum IL-12 could be generated in 6- to 7-wk-old B6 mice after a single injection of the cDNA. Unexpectedly, we observed that when IL-12 cDNA is coinjected with IL-18 cDNA, IL-12 antitumor activity was maintained, but there was a significant attenuation of IL-12 toxicity, as evidenced by a greater survival index and a diminution of liver enzymes (ALT and AST). Interestingly, after IL-12 plus IL-18 cDNA administration, more rapid and higher IL-10 levels were observed than after IL-12 cDNA treatment alone. To understand the mechanism of protection, we coinjected IL-12 plus IL-10 cDNAs and observed an increase in survival that correlated with diminished serum levels of the inflammatory cytokines TNF-alpha and IFN-gamma. Confirming the protective role of early IL-10 expression, we observed a significant decrease in survival in IL-10 knockout mice or IL-10R-blocked B6 mice after IL-12 plus IL-18 treatment. Thus, our data demonstrate that the high and early IL-10 expression induced after IL-12 plus IL-18 cDNA treatment is critical to rapidly attenuate IL-12 toxicity without affecting its antitumor capacity. These data could highly contribute to the design of more efficient/less toxic protocols for the treatment of cancer.
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PMID:Coexpression of IL-18 strongly attenuates IL-12-induced systemic toxicity through a rapid induction of IL-10 without affecting its antitumor capacity. 1953 28

Reperfusion injury remains one of the major problems in transplantation. Free radicals and disturbance of microcirculation are the supposed main contributors. Recent evidence shows that Danshen, a traditional Chinese drug used in vascular diseases, can scavenge radicals and improve microcirculation. This study investigates its effect on liver transplantation (LTx). Before organ recovery, female Sprague-Dawley rats (210-240 g) received intravenous Danshen or the same volume of Ringer solution as control. LTx was performed after 1 h of cold storage. Microperfusion, leukocyte-endothelium interaction and latex-bead phagocytosis were evaluated with in vivo microscopy. Survival, transaminases and histology were assessed. Immunohistology was used for TNF-alpha levels. anova and Fisher's exact test were employed for statistical analyses as appropriate. Survival increased from 60% in controls to 100% (P < 0.05). AST and LDH decreased from 3969 +/- 1255 U/l and 15444 +/- 5148 U/l in controls to 1236 +/- 410 U/l and 5039 +/- 1594 U/l, respectively (P < 0.05). In vivo microscopy revealed decreased leukocyte-adherence and increased blood flow velocity in sinusoidal zones after administration of Danshen (P < 0.05), while latex-bead phagocytosis was found in 60% of controls (P < 0.05). The TNF-alpha index decreased from 2.08 +/- 0.09 in controls to 1.09 +/- 0.09 (P < 0.05). This study clearly demonstrates hepatoprotective effects after experimental LTx, which can be explained via anti-oxidative effects, improved microcirculation and decreased Kupffer cell activation.
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PMID:Danshen protects liver grafts from ischemia/reperfusion injury in experimental liver transplantation in rats. 1966 39

Although magnolol is cytoprotective against warm ischemia/reperfusion injury, its effect on cold preservation has not been fully investigated. This study aimed at examining whether magnolol maintains the liver graft integrity after cold preservation and elucidating the underlying mechanisms in terms of apoptotic signaling under both normothermic and hypothermic conditions. After being preserved in Ringer's lactate (RL) at 4 degrees C for 6h ex vivo, the magnolol-treated grafts demonstrated significantly higher AST, ALT, and LDH levels in perfusates than those from negative controls. TUNEL staining showed no difference in the number of apoptotic nuclei in both groups, whereas a more intense apoptotic signal in magnolol-treated grafts was shown as compared with the controls. In vitro data showed no significant difference in viability of RL-preserved clone-9 hepatocytes between the magnolol-treated and control groups, while magnolol pretreatment at 30min before cold preservation prominently induced hepatocyte cell death. RT-PCR and Western blotting analyses revealed a suppression in Bcl-2, but an up-regulation in Bax expression in clone-9 cells after magnolol treatment. Magnolol suppressed the ratios of NF-kappaB to I-kappaBalpha protein contents and I-kappaBalpha phosphorylation induced by TNF-alpha, and potentiated mitochondrial cytochrome c release and subsequent caspase-3 cleavage. Conversely, caspase-3 inhibitor attenuated magnolol-induced hepatotoxicity. We concluded that magnolol could not protect liver grafts from cold ischemia/reperfusion injury. High concentration of magnolol under serum-reduced conditions attenuates NF-kappaB-mediated signaling and induces intrinsic apoptotic pathway, thereby inducing in vitro hepatotoxicity.
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PMID:High concentration of magnolol induces hepatotoxicity under serum-reduced conditions. 1968 8

Enhanced oxidative stress is associated with hepatic fibrosis. Salvianolic acids A (Sal A) and B (Sal B) have been reported to be strong polyphenolic antioxidants and free radical scavengers. The present study is to investigate if Sal A and B could attenuate oxidative stress and liver fibrosis in rats. A cell line of rat hepatic stellate cells (HSCs) was stimulated with platelet-derived growth factor (PDGF, 10 ng/ml). The inhibitory effects of Sal A and B on intracellular hydrogen peroxide levels were measured with dichlorofluorescein diacetate (DCF-DA) dye assay. alpha-Smooth muscle actin (alpha-SMA), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits were measured by Western blotting. Liver fibrosis was induced by intraperitoneal injections of thioacetamide (TAA, 200 mg/kg) twice per week for 6 weeks. Sal A (10 mg/kg), Sal B (50 mg/kg) or S-adenosylmethionine (SAMe, 10 mg/kg), was given by gavage twice per day consecutively for 4 weeks starting 2 weeks after TAA injection. In vitro, PDGF increased the accumulation of hydrogen peroxide in HSCs, which was attenuated by Sal A (10 muM) and Sal B (200 muM). Sal A and B attenuated the PDGF-stimulated expressions of alpha-SMA and NADPH oxidase subunits gp91(phox) and p47(phox) in membrane fractions. In vivo studies showed that the hepatic levels of collagen, malondialdehyde, TNF-alpha, IL-6, and IL-1beta, fibrosis scores and protein expressions of alpha-SMA, heme-oxygenase-1, iNOS, and gp91(phox), and serum levels of ALT, AST, IL-6, and IL-1beta were increased in TAA-intoxicated rats, all of which were attenuated by 4-week treatment of Sal A or Sal B. Our results showed that Sal A and B attenuated PDGF-induced ROS formation in HSCs, possibly through inhibition of NADPH oxidase. Sal A and B treatments were also effective against hepatic fibrosis in TAA-intoxicated rats.
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PMID:Effects of salvianolic acids on oxidative stress and hepatic fibrosis in rats. 1982 64

Endothelium has long been considered both a source and a target of systemic inflammation. However, to what extent endothelial activation contributes to systemic inflammation remains unclear. This study addresses the relative contribution of endothelial activation to systemic inflammation and multiple organ dysfunction and injury (MOD/I) in an E. coli peritonitis model of sepsis. We prevented endothelial activation using transgenic (TG) mice that conditionally overexpress a mutant I-kappaBalpha, a NF-kappaB inhibitor, selectively on endothelium. TG mice and their transgene negative littermates (WT) were injected with saline or E. coli (10(8) CFU per mouse). At 7 h after E. coli infection, markers of systemic inflammation, endothelial activation, and MOD/I were assessed. WT-E. coli mice showed significantly increased serum levels of TNF-alpha, IL-1beta, IFN-gamma, IL-6, KC, and MCP-1; tissue levels of TNF-alpha, IL-6, KC, MCP-1, ICAM-1, and VCAM-1; endothelial leakage index in heart, lungs, liver, and kidney; significantly increased serum levels of AST, ALT, BUN, and creatinine; and increased mortality. Blockade of NF-kappaB-mediated endothelial activation in TG mice had no effects on serum levels of TNF-alpha, IL-1beta, IFN-gamma, IL-6, KC, and MCP-1 (markers of systemic inflammation), and tissue levels of TNF-alpha, IL-6, KC, and MCP-1, but significantly reduced tissue levels of ICAM-1 and VCAM-1 (markers of endothelial inflammation and activation) in those four organs. TG-E. coli mice displayed reversed endothelial leakage index; reduced serum levels of AST, ALT, BUN, and creatinine; and improved survival. Our data demonstrate that endothelial NF-kappaB-driven inflammatory response contributes minimally to systemic inflammation, but plays a pivotal role in septic MOD/I, suggesting that endothelium is mainly a target rather than a source of systemic inflammation.
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PMID:Selective blockade of endothelial NF-kappaB pathway differentially affects systemic inflammation and multiple organ dysfunction and injury in septic mice. 2002 May 11

Aflatoxins (AF), a group of closely related, extremely toxic mycotoxins, produced by Aspergillus flavus and A. parasiticus can occur as natural contaminants of foods and feeds. Aflatoxins have been shown to be hepatotoxic, carcinogenic, mutagenic, and teratogenic to different animal species. Zizyphus spina-christi L. extract was investigated for its antifungal and antimicrobial activities. The aim of the present work was to evaluate the antioxidant activity of the methanol extract of Z. spina-christi L. leaves against the oxidative stress of aflatoxin in rats. Fourty male Sprague-Dawley male rats were divided into four groups including the control group, the group fed aflatoxin-contaminated diet (3 mg/kg diet) and the groups treated with Zizyphus extract (5 mg/kg b.w) alone or in combination with AF for 15 days. Biochemical analysis revealed that treatment with AF resulted in a significant increase in ALT, AST, cholesterol, triglycerides, uric acid, TNFa, LPO, NO and CEA, whereas it decrease significantly GPX and SOD. The histopathological examination of the liver, kidney and testis showed sever histological changes typical to those reported for aflatoxicosis. Animals treated with Zizyphus extract alone or plus AF showed a significant improvement in all biochemical parameters and histological picture of liver, kidney and testis. It could be concluded that Zizyphus extract have a power protective role against aflatoxicosis.
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PMID:Zizyphus spina-christi extract protects against aflatoxin B1-initiated hepatic carcinogenicity. 2016 85

Quercetin, a natural compound of multiple origins, has broad biopharmacological effects, such as antioxidant, directly scavenging free radical, and hepatoprotectivity effects. This study is designed to investigate the interveneous effect of quercetin on liver injury induced by ethanol in rats. The rats that were orally treated with 50% ethanol for continuous ten days, which resulted in cell necrosis, fibrosis and inflammatory infiltration, were included in this study. Higher contents of AST, ALT ADH, gamma-GT, TG in plasma and MDA in liver tissue, and lower content of GSH in liver tissue were highlighted in ethanol-treated rats when compared with healthy ones. The levels of cytokines such as IL-1beta, IL-1, IL-6, IL-8, and TNF-alpha in rats plasma were also significantly enhanced, and level of IL-10 was obviously lowered through ethanol treatment. By preventive and synchronism treatment with quercetin for fourteen days, the contents of AST, ALT ADH, gamma-GT, TG and MDA, and levels of IL-1beta, IL-1, IL-6, IL-8, and TNF-alpha were significantly reduced, whereas GSH and level of IL-10 were obviously increased. It may be deduced that quercetin, by multiple mechanisms interplay, demonstrated somewhat protective effect on liver injury induced by ethanol in rats.
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PMID:Protective effects of quercetin on liver injury induced by ethanol. 2066 81


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