8-epi-prostaglandin-f2alpha and Fatty-Liver

The aim was to examine the role of cyclooxygenase (COX)-2-mediated inflammation in the development of obese linked insulin resistance and fatty liver. The rats were fed separately regular diet (CONT), high-fat diet (HFD) ad libitum, or energy restrictedly for 12 weeks. Rats fed HFD ad libitum were further divided into three subgroups co-treated with vehicle (HFa), or a selective COX-2 inhibitor celecoxib (HFa-Cel) or mesulid (HFa-Mes). Euglycemic hyperinsulinemic clamp (EHC) experiment was performed at the end of study. Another set of rats with similar grouping was further divided into those with a 4, 8, or 12-week intervention period for hepatic sampling. Body weight was increased significantly and similarly in HFa, HFa-Cel, and HFa-Mes. Time-dependent increases in plasma insulin, glucose, 8-isoprostanes, leptin levels, homeostasis model assessment of insulin resistance (HOMA-IR) and hepatic triglyceride contents shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. During EHC period, the reduction in stimulation of whole body glucose uptake, suppression of hepatic glucose production and metabolic clearance rate of insulin shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. The enhanced COX-2 and tumor necrosis factor-alpha (TNF-alpha) but attenuated PPAR-gamma and C/EBP-alpha mRNA expressions in epididymal fat shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. The increases in average cell size of adipocytes and CD68 positive cells shown in HFa were also significantly reversed in HFa-Cel and HFa-Mes. Our findings suggest that COX-2 activation in fat inflammation is important in the development of insulin resistance and fatty liver in high fat induced obese rats.

Topics: Adipocytes; Adipogenesis; Adipose Tissue; Animals; Blood Glucose; Body Weight; Celecoxib; Cell Size; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dinoprost; Disease Models, Animal; Fatty Liver; Insulin; Insulin Resistance; Leptin; Liver; Macrophages; Male; Membrane Proteins; Obesity; Panniculitis; Pyrazoles; Rats; Rats, Sprague-Dawley; Sulfonamides; Time Factors; Triglycerides; Tumor Necrosis Factor-alpha

Squalene is an intermediate of cholesterol biosynthesis which can be obtained from the diet where it is abundant, for example, in olive oil. The effect of this isoprenoid on the development of atherosclerosis was investigated on apoE-knockout mice.. Two groups of animals, separated according to sex, were fed on standard chow diet: the control group receiving only vehicle and the second group an aqueous solution of squalene to provide a dose of 1g/kg/day in male and female mice. This treatment was maintained for 10 weeks. At the end of this period, plasma lipid parameters, oxidative stress markers and hepatic fat were measured as well as cross-sectional lesion area of aortic root in both groups. Data showed that in males squalene feeding reduced atherosclerotic lesion area independently of plasma lipids and activation of circulating monocytes. In contrast, squalene intake did not decrease lesion area in females, despite reducing plasma cholesterol and triglycerides, isoprostane and percentage of Mac-1 expressing white cells. In males, atherosclerotic lesion area was positively and significantly associated with hepatic fat content and the plasma triglycerides were also strongly associated with liver weight.. These results indicate that administration of squalene modulates lesion development in a gender specific manner, and that accumulation of hepatic fat by liver is highly correlated with lesion progression in males. Hence, squalene administration could be used as a safe alternative to correct hepatic steatosis and atherosclerosis particularly in males.

Topics: Animals; Apolipoprotein A-I; Apolipoprotein A-V; Apolipoproteins; Apolipoproteins E; Aryldialkylphosphatase; Atherosclerosis; Body Weight; CD11b Antigen; Cholesterol; Dinoprost; DNA-Binding Proteins; Fatty Liver; Female; Liver; Liver X Receptors; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Orphan Nuclear Receptors; Receptors, Cytoplasmic and Nuclear; Receptors, LDL; RNA, Messenger; Scavenger Receptors, Class B; Sex Characteristics; Squalene; Triglycerides

Oxidative stress plays a major role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Mitochondrial abnormality may be associated with the onset and progression of NASH via excessive formation of mitochondrial reactive oxygen species. This study aimed to investigate the role of mitochondrial abnormality in NASH in relation to oxidative stress.. Twenty-six patients with NASH, 11 with simple steatosis, and 10 healthy volunteers underwent clinico-pathological analysis. The liver/spleen ratio, an index of the hepatic fat content, was evaluated with computed tomography. Plasma glutathione levels were measured as an antioxidative marker, and the urinary 8-isoprostane levels and 3-nitrotyrosine staining in the liver as an oxidative stress marker. Mitochondrial abnormality was estimated by serum levels of mitochondria aspartate transaminase (mAST) and the mitochondrial staining in the liver.. Urinary 8-isoprostane levels were higher in NASH than in the healthy volunteers, whereas plasma glutathione levels were similar in the 2 groups. In NASH, urinary 8-isoprostane levels positively correlated with alanine transaminase levels and negatively with the liver/spleen ratio. The 3-nitrotyrosine staining was more advanced in simple steatosis and NASH than in the normal liver, but was similar in simple steatosis and NASH. In contrast to the normal mAST levels in the healthy volunteers and simple steatosis, serum mAST levels were elevated in one-fourth of the NASH patients and positively correlated with urinary 8-isoprostane levels in NASH. Most cases of NASH showed diffuse or focal but intense mitochondrial staining in the liver in contrast to scattered staining in simple steatosis.. Our present study demonstrated that in NASH, the enhanced oxidative stress may be associated with hepatic inflammation and the degree of fat infiltration in the liver. However, simple steatosis and NASH were both exposed to oxidative stress, while NASH alone was associated with mitochondrial abnormality. These findings indicate that mitochondrial abnormality may play a role in the onset and progression of NASH in correlation with oxidative stress.

Topics: Adult; Aspartate Aminotransferases; Biopsy; Dinoprost; Fatty Liver; Female; Glutathione; Humans; Liver; Male; Middle Aged; Mitochondria, Liver; Oxidative Stress; Reference Values; Spleen; Statistics as Topic; Tomography, X-Ray Computed; Tyrosine

The relevance of oxidative stress in mice fed a choline-deficient diet (CDD) was investigated in relation to the oxidative stress marker, hydroxyoctadecadienoic acid (HODE) in comparison with F2-isoprostanes. Further, the protective effects of antioxidants against oxidative damage were assessed by using HODE.. We recently proposed total HODE as a biomarker for oxidative stress in vivo. Biological samples such as plasma, urine, and tissues were first reduced and then saponified to convert various oxidation products of linoleates to HODE. In the present study, this method was applied to measure oxidative damage in mice induced by CDD for 1 mo.. CDD, when compared with choline-controlled diet (CCD), increased liver weight and fatty acid accumulation but the increase in body weight was less significant. Remarkable increases in HODE and 8-iso-prostaglandin F(2alpha) in liver and plasma were observed when mice were fed with the CDD for 1 mo compared with the CCD. The HODE level was about two to three orders higher than the F2-isoprostane level. This increase was decreased to the level of the CCD when alpha-tocopherol or 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran, a potent synthetic antioxidant, was mixed with the CDD. The stereoisomer ratio of HODE (9-and-13 (Z,E)-HODE/9-and-13 (E,E)-HODE) was decreased by CDD compared with CCD, which was spared by the addition of alpha-tocopherol and 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran. However, the increase in plasma glutamic-pyruvic transaminase and fatty acids in liver induced by the CDD was not recovered by any antioxidant.. This study clearly demonstrated that oxidative stress was involved in fatty liver formation induced by the CDD and that HODE was a good biomarker for an oxidative stress in vivo.

Topics: Animals; Antioxidants; Benzofurans; Biomarkers; Choline; Choline Deficiency; Chromatography, High Pressure Liquid; Dinoprost; Fatty Acids, Unsaturated; Fatty Liver; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Organ Size; Oxidation-Reduction; Oxidative Stress; Random Allocation; Specific Pathogen-Free Organisms

Oxidative stress plays an important role in the pathogenesis of chronic liver diseases. The plasma level of 8-isoprostane, a product of lipid peroxidation, is a marker of oxidative stress in vivo. The aim of the present study was to clarify whether the degree of lipid peroxidation, as measured by the plasma level of 8-isoprostane, influences the progression of chronic liver diseases and hepatocarcinogenesis.. Plasma 8-isoprostane levels were investigated in 14 patients with non-alcoholic fatty liver disease (NAFLD), 75 with chronic hepatitis C (CH-C), 14 with cured CH-C, 14 with HCV-positive hepatocellular carcinoma (HCC-C) and 38 healthy volunteers. 8-Isoprostane was measured by enzyme immunoassay after affinity column purification.. Plasma 8-isoprostane was significantly elevated in NAFLD (11.9 [3.8-56.8] pg/mL), CH-C (10.1 [4.2-134.5] pg/mL) as compared to controls (6.3 [3.6-11.1] pg/mL). Plasma 8-isoprostane values were positively correlated with body mass index in NAFLD (P < 0.05) and with total cholesterol in cured CH-C (P < 0.01). 8-Isoprostane levels were not significantly related to sex, age, biochemical data or iron metabolism markers in all liver diseases. In addition, after the administration of peg-interferon, the values of 8-isoprostane improved in almost all patients, reaching values of healthy subjects.. 8-Isoprostane values are elevated in patients with NAFLD and CH-C as compared to healthy controls. Oxidative stress caused by increased lipid peroxidation is involved in the pathogenesis of NAFLD and CH-C.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antiviral Agents; Biomarkers; Dinoprost; Disease Progression; Drug Carriers; Fatty Liver; Female; Hepatitis C, Chronic; Humans; Immunoenzyme Techniques; Interferon alpha-2; Interferon-alpha; Lipid Peroxidation; Male; Middle Aged; Polyethylene Glycols; Prognosis; Recombinant Proteins

A single dose of valproic acid (VPA), which is a widely used antiepileptic drug, is associated with oxidative stress in rats, as recently demonstrated by elevated levels of 15-F(2t)-isoprostane (15-F(2t)-IsoP). To determine whether there was a temporal relationship between VPA-associated oxidative stress and hepatotoxicity, adult male Sprague-Dawley rats were treated ip with VPA (500 mg/kg) or 0.9% saline (vehicle) once daily for 2, 4, 7, 10, or 14 days. Oxidative stress was assessed by determining plasma and liver levels of 15-F(2t)-IsoP, lipid hydroperoxides (LPO), and thiobarbituric acid reactive substances (TBARs). Plasma and liver 15-F(2t)-IsoP were elevated and reached a plateau after day 2 of VPA treatment compared to control. Liver LPO levels were not elevated until day 7 of treatment (1.8-fold versus control, p < 0.05). Liver and plasma TBARs were not increased until 14 days (2-fold vs. control, p < 0.05). Liver toxicity was evaluated based on serum levels of alpha-glutathione S-transferase (alpha-GST) and by histology. Serum alpha-GST levels were significantly elevated by day 4, which corresponded to hepatotoxicity as shown by the increasing incidence of inflammation of the liver capsule, necrosis, and steatosis throughout the study. The liver levels of beta-oxidation metabolites of VPA were decreased by day 14, while the levels of 4-ene-VPA and (E)-2,4-diene-VPA were not elevated throughout the study. Overall, these findings indicate that VPA treatment results in oxidative stress, as measured by levels of 15-F(2t)-IsoP, which precedes the onset of necrosis, steatosis, and elevated levels of serum alpha-GST.

Topics: Animals; Anticonvulsants; Biomarkers; Dinoprost; Fatty Liver; Glutathione Transferase; Lipid Peroxidation; Liver; Necrosis; Oxidative Stress; Rats; Thiobarbituric Acid Reactive Substances; Valproic Acid