Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0008370 (cholestasis)
 9,378 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxidative stress is involved in the pathogenesis and progression of different liver diseases, such as alcoholic liver disease and biliary cirrhosis. The increased mitochondrial production of O2(-) at complexes I and III, and consequently of H2O2 and other reactive oxygen species (ROS), triggered by NADH overproduction seems the major cause of mitochondrial and cellular oxidative stress and damage in chronic alcoholism. The mitochondrial oxidative stress renders hepatocytes susceptible to ethanol- or acetaldehyde-induced mitochondrial membrane permeability transition (MMPT) and apoptosis. Nitrosative stress contributes to cell death by peroxynitrite formation. The expression of the death receptor ligand CD95 is also up-regulated by acetaldehyde metabolism. Consequently, a dual mechanism, NADH-driven MMPT and CD95-mediated apoptosis, involving in both cases acetaldehyde metabolism and ROS production, operates in ethanol-induced apoptosis. In the biliary cirrhosis induced by chronic cholestasis, liver mitochondria show increased H2O2 production and GSH depletion and oxidation. Dysfunctional hepatocytes, with a loss in mitochondrial cardiolipin and decreased mitochondrial membrane potential evolve during cholestasis to apoptosis. Ursodeoxycholic acid prevents enlargement of this population as well as mitochondrial oxidative stress. Mitochondrial oxidative stress precedes the initiation and execution of hepatocyte apoptosis in chronic alcoholism and biliary cirrhosis. We suggest that overproduction of mitochondrial NADH is the primary cause for the development of alcoholic and non-alcoholic liver disease by a situation of chronic mitochondrial oxidative stress, which should be considered the second hit that renders hepatocytes susceptible to cell injury and apoptosis.
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PMID:Mitochondrial function in liver disease. 1712 73

Curcumin, an anti-inflammatory and antioxidant compound, was evaluated for its ability to suppress acute carbon tetrachloride-induced liver damage. Acute hepatotoxicity was induced by oral administration of CCl4 (4 g/kg, p.o.). Curcumin treatment (200 mg/kg, p.o.) was given before and 2 h after CCl4 administration. Indicators of necrosis (alanine aminotransferase) and cholestasis (gamma-glutamyl transpeptidase and bilirubins) resulted in significant increases after CCl4 intoxication, but these effects were prevented by curcumin treatment. As an indicator of oxidative stress, GSH was oxidized and the GSH/GSSG ratio decreased significantly by CCl4, but was preserved within normal values by curcumin. In addition to its antioxidants properties, curcumin is capable of preventing NF-kappaB activation and therefore to prevent the secretion of proinflammatory cytokines. Therefore, in this study we determined the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) mRNA, and NF-kappaB activation. CCl4-administered rats depicted significant increases in TNF-alpha, IL-1beta, and IL-6 production, while curcumin remarkably suppressed these mediators of inflammation in liver damage. These results were confirmed by measuring TNF-alpha, and IL-1beta protein production using Western Blot analysis. Accordingly, these proteins were increased by CCl4 and this effect was abolished by curcumin. Administration of CCl4 induced the translocation of NF-kappaB to the nucleus; CCl4 induced NF-kappaB DNA binding activity was blocked by curcumin treatment. These findings suggest that curcumin prevents acute liver damage by at least two mechanisms: acting as an antioxidant and by inhibiting NF-kappaB activation and thus production of proinflammatory cytokines.
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PMID:Curcumin protects against acute liver damage in the rat by inhibiting NF-kappaB, proinflammatory cytokines production and oxidative stress. 1738 25

Maternal cholestasis is usually a benign condition for the mother but induces profound placental damage and may be lethal for the fetus. The aim of this study was to investigate the protective effects in rat maternal and fetal livers as also the placenta of melatonin or silymarin against the oxidative stress and apoptosis induced by maternal obstructive cholestasis during the last third of pregnancy (OCP). Melatonin or silymarin administration (i.e. 5 mg/100 g bw/day after ligation of the maternal common bile duct on day 14 of pregnancy) reduced OCP-induced lipid peroxidation, and prevented decreases in total glutathione levels. However, the protective effect on OCP-induced impairment in the GSH/GSSG ratio was mild in the placenta and fetal liver, while absent in maternal liver. Melatonin or silymarin also reduced OCP-induced signs of apoptosis (increased caspase-3 activity and Bax-alpha upregulation) in all the organs assayed. Moreover, melatonin (but not silymarin) upregulated several proteins involved in the cellular protection against the oxidative stress in rats with OCP. These included, biliverdin-IX alpha reductase and the sodium-dependent vitamin C transport proteins SVCT1 and SVCT2, whose expression levels were enhanced in maternal and fetal liver by melatonin treatment. In contrast, in placenta only biliverdin-IX alpha reductase and SVCT2 were upregulated. These results indicate that whereas the treatment of cholestatic pregnant rats with melatonin or silymarin affords a direct protective antioxidant activity, only melatonin has dual beneficial effects against OCP-induced oxidative challenge in that it stimulates the expression of some components of the endogenous cellular antioxidant defense.
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PMID:Multiple protective effects of melatonin against maternal cholestasis-induced oxidative stress and apoptosis in the rat fetal liver-placenta-maternal liver trio. 1764 91

The aim of the study was to analyze the impact of melatonin on brain oxidative stress in experimental biliary obstruction. Cholestasis was done by a double ligature and section of the extrahepatic biliary duct. Melatonin was injected intraperitoneally (500 microg/kg/day). Malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) contents were determined in the brain tissue. Biliary obstruction raised MDA and reduced GSH contents in the cortex, cerebellum, and hypothalamus areas. Moreover, the scavenger enzyme activity significantly dropped in all areas of the brain. Melatonin drastically reduced MDA concentration and enhanced GSH concentration, as well as all antioxidant enzyme activity in all brain areas obtained from the bile duct-ligated animals. In conclusion, the treatment with melatonin decreased lipid peroxidation and recovered the antioxidant status in the brain from cholestatic animals.
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PMID:Melatonin prevents brain oxidative stress induced by obstructive jaundice in rats. 1767 89

The aim of this study was to evaluate the role of antioxidant enzyme activity and nitric oxide levels induced by 28 day biliary obstruction in the rat. A total of 21 young Swiss albino rats were divided in to 3 groups. Bile duct ligations, bile duct ligations plus resveratrol, sham operated. Bile duct ligations plus resveratrol group received 10 mg/kg dose of resveratrol intraperitonealy once daily throughout for 28 days. Liver damage and cholestasis were determined by biochemical examination. SOD, CAT and GSH-PX activity decreased in BDL group compared with shame opareted groups (p < 0.001). NO levels increased in BDL groups compared with shame opareted groups (p < 0.001). SOD, CAT and GSH-PX activity was found higher in BDL+resveratrol treated groups than BDL groups (p < 0.001). In addition this NO levels decreased in BDL+resveratrol treated groups than BDL groups (p < 0.001). In conclusion, it is thought that resveratrol may be used as a protective agent in biliary obstructions; however, further clinical and experimental studies are needed to verify its antioxidative and hepatoprotective effects.
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PMID:Changing of antioxidant enzyme activity on the biliary obstructed rats treated with resveratrol. 1792 75

The differences and similarities of the pathogenesis of alcoholic (ASH) and non-alcoholic steatohepatitis (NASH) were examined. Mice (six/group) received one of four Lieber-Decarli liquid diets for 6 weeks: (1) paired-fed control diet; (2) control diet with ethanol (ethanol); (3) paired-fed methionine/choline deficient (MCD) diet; and (4) MCD plus ethanol (combination). Hepatotoxicity, histology, and gene expression changes were examined. Both MCD and ethanol induced macrovesicular steatosis. However, the combination diet produced massive steatosis with minor necrosis and inflammation. MCD and combination diets, but not ethanol, induced serum ALT levels by 1.6- and 10-fold, respectively. MCD diet, but not ethanol, also induced serum alkaline phosphatase levels suggesting bile duct injury. Ethanol increased liver fatty acid binding protein (L-FABP) mRNA and protein levels. In contrast, the combination diet decreased L-FABP mRNA and protein levels and increased hepatic free fatty acid and lipid peroxide levels. Ethanol, but not MCD, reduced hepatic S-adenosylmethionine (SAM) and GSH levels. Hepatic TNFalpha protein levels were increased in all treatment groups, however, IL-6, a hepatoprotective cytokine which promotes liver regeneration was increased in ethanol-fed mice (2-fold), but decreased in the combination diet-treated mice. In addition, the combination diet reduced phosphorylated STAT3 and Bcl-2 levels. While MCD diet might cause bile duct injury and cholestasis, ethanol preferentially interferes with the SAM-GSH oxidative stress pathway. The exacerbated liver injury induced by the combination diet might be explained by reduced L-FABP, increased free fatty acids, oxidative stress, and decreased IL-6 protein levels. The combination diet is an efficient model of steatohepatitis.
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PMID:The pathogenesis of ethanol versus methionine and choline deficient diet-induced liver injury. 1803 73

L-methionine (Met) has been implicated in parenteral nutrition-associated cholestasis in infants and, at high levels, it causes liver toxicity by mechanisms that are not clear. In this study, Met toxicity was characterized in freshly isolated male and female mouse hepatocytes incubated with 5 to 30 mM Met for 0 to 5 h. In male hepatocytes, 20 mM Met was cytotoxic at 4 h as indicated by trypan blue exclusion and lactate dehydrogenase leakage assays. Cytotoxicity was preceded by reduced glutathione (GSH) depletion at 3 h without glutathione disulfide formation. Exposure to 30 mM Met resulted in increased cytotoxicity and GSH depletion. It is interesting to note that female hepatocytes were resistant to Met-induced cytotoxicity at these concentrations and showed increased cellular GSH levels compared with hepatocytes exposed to medium alone. The effects of amino-oxyacetic acid (AOAA), an inhibitor of Met transamination, and 3-deazaadenosine (3-DA), an inhibitor of the Met transmethylation pathway enzyme S-adenosylhomocysteine hydrolase, on Met toxicity in male hepatocytes were then examined. Addition of 0.2 mM AOAA partially blocked Met-induced GSH depletion and cytotoxicity, whereas 0.1 mM 3-DA potentiated Met-induced toxicity. Exposure of male hepatocytes to 0.3 mM 3-methylthiopropionic acid (3-MTP), a known Met transamination metabolite, resulted in cytotoxicity and cellular GSH depletion similar to that observed with 30 mM Met, whereas incubations with D-methionine resulted in no toxicity. Female hepatocytes were less sensitive to 3-MTP toxicity than males, which may partially explain their resistance to Met toxicity. Taken together, these results suggest that Met transamination and not transmethylation plays a major role in Met toxicity in male mouse hepatocytes.
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PMID:L-methionine toxicity in freshly isolated mouse hepatocytes is gender-dependent and mediated in part by transamination. 1855 30

Bile duct ligation (BDL) induces primary biliary cirrhosis characterized by cholestasis, impaired liver function, and cognition. Young male Sprague-Dawley rats were used: rats underwent laparotomy without BDL [sham-control (SC) group]; rats had restricted diets supply [diet-control (DC) group]; rats underwent BDL for 2 wk (BDL group); BDL rats with melatonin (500 microg/kg/d) intraperitoneally for 2 wk [melatonin (500 microg/kg/d) (M500) group]; and BDL rats with melatonin (1000 microg/kg/d/intraperitoneally) for 2 wk [melatonin (1000 microg/kg/d) (M1000) group]. All the surviving rats were assessed for spatial memory and blood was tested for biochemical study. Liver, brain cortex, and hippocampus were collected for determination of malondialdehyde (MDA) and glutathione (GSH)/oxidized glutathione (GSSG) ratios. BDL group rats had significantly higher plasma direct/total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), MDA values and higher liver MDA values and lower GSH/GSSG ratios when compared with SC group. In addition, BDL group rats had impaired spatial performance. After melatonin treatment, cholestatic rats' plasma MDA levels, liver MDA levels, and liver GSH/GSSG ratios approached to the values of SC group. Only high dose of melatonin improved spatial performance. Results of this study indicate cholestasis in the developing rats increase oxidative stress and cause spatial memory deficits, which are prevented by melatonin treatment.
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PMID:Melatonin ameliorates bile duct ligation-induced systemic oxidative stress and spatial memory deficits in developing rats. 1904 58

The accumulation of hydrophobic bile acids plays a role in the induction of apoptosis and necrosis of hepatocytes during cholestasis. Glycochenodeoxycholate acid (GCDC) triggers a rapid oxidative stress response as an event of glutathione (GSH) depletion and nuclear factor kappa B (NF-kappaB) activation. We therefore investigated whether the bioactivity of the antioxidant capillarisin (Cap) prevents GCDC-induced hepatocyte damage. Isolated rat hepatocytes were co-incubated with 100 muM GCDC and 0.5 mg/ml Cap for 4 h. GSH depletion and thiobarbituric acid-reactive substances (TBARS, measure of lipid peroxidation) increased after GCDC exposure, but were markedly suppressed by Cap treatment. Cap protected hepatocytes from a GCDC-induced increase in reactive oxygen species (ROS) generation and mitochondrial membrane potential induction, as measured by flow cytometry analysis. In addition, Cap was shown to inhibit GCDC-mediated NF-kappaB activation by using electrophoretic mobility shift assays (EMSA). In contrast to GCDC, Cap not only significantly decreased cytochrome c release and caspase-3 enzyme activity, but also suppressed heme oxygenase-1 protein and mRNA expression in hepatocytes. These results demonstrate that Cap function as an antioxidant reduced hepatocyte injury caused by hydrophobic bile acids, perhaps by preventing generation of ROS and release of cytochrome c, thereby minimizing hepatocytes apoptosis.
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PMID:The effect of capillarisin on glycochenodeoxycholic acid-induced apoptosis and heme oxygenase-1 in rat primary hepatocytes. 1913 99

Surgery and infection are prominent risk factors for the development of obstructive cholestasis which in turn is associated with failure of the liver barrier. We studied the effects of oral Lactobacillus plantarum (LP) supplementation on endotoxemia, oxidative stress, apoptosis, and tight junctions of hepatocytes in an experimental model of obstructive jaundice. Fifty male Wistar rats were randomly divided into five groups of 10 each: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BLD followed by oral LP treatment; group IV, BDL followed by internal biliary drainage (IBD); group V, BDL followed by IBD and oral LP treatment. Hepatocyte apoptosis, plasma reduced glutathione (GSH) and oxidized glutathione (GSSG) levels, and portal blood endotoxin levels were measured and changes in tight junction-associated proteins occludin, claudin-1, claudin-4, and ZO-1 were observed. Compared to the sham-operated group I, significant increases in endotoxemia, apoptosis, and GSSG were observed in group II and significant decreases were observed in group V. Tight junctions were destroyed in group II animals but were not in animals treated with oral LP (groups III and V). An increase in occludin, claudin-1, claudin-4, and ZO-1 mRNA and protein levels were detected in livers in LP-treated animals (group V) compared with group II levels. Oral LP treatment of rats with obstructive jaundice assisted in the return of active hepatic barrier function. These results may lead to treatments to prevent the deleterious effects of obstructive jaundice.
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PMID:Effects of oral Lactobacillus plantarum on hepatocyte tight junction structure and function in rats with obstructive jaundice. 1981 88


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