4-hydroxy-2-nonenal and Hepatitis--Alcoholic

Liver damage is a serious and sometimes fatal consequence of long-term alcohol intake, which progresses from early-stage fatty liver (steatosis) to later-stage steatohepatitis with inflammation and fibrosis/necrosis. However, very little is known about earlier stages of liver disruption that may occur in problem drinkers, those who drink excessively but are not dependent on alcohol.. We examined how repeated binge-like alcohol drinking in C57BL/6 mice altered liver function, as compared with a single binge-intake session and with repeated moderate alcohol consumption. We measured a number of markers associated with early- and later-stage liver disruption, including liver steatosis, measures of liver cytochrome P4502E1 (CYP2E1) and alcohol dehydrogenase (ADH), alcohol metabolism, expression of cytokine mRNA, accumulation of 4-hydroxynonenal (4-HNE) as an indicator of oxidative stress, and alanine transaminase/aspartate transaminase as a measure of hepatocyte injury.. Importantly, repeated binge-like alcohol drinking increased triglyceride levels in the liver and plasma, and increased lipid droplets in the liver, indicators of steatosis. In contrast, a single binge-intake session or repeated moderate alcohol consumption did not alter triglyceride levels. In addition, alcohol exposure can increase rates of alcohol metabolism through CYP2E1 and ADH, which can potentially increase oxidative stress and liver dysfunction. Intermittent, excessive alcohol intake increased liver CYP2E1 mRNA, protein, and activity, as well as ADH mRNA and activity. Furthermore, repeated, binge-like drinking, but not a single binge or moderate drinking, increased alcohol metabolism. Finally, repeated, excessive intake transiently elevated mRNA for the proinflammatory cytokine IL-1B and 4-HNE levels, but did not alter markers of later-stage liver hepatocyte injury.. Together, we provide data suggesting that even relatively limited binge-like alcohol drinking can lead to disruptions in liver function, which might facilitate the transition to more severe forms of liver damage.

Topics: Alanine Transaminase; Alcohol Dehydrogenase; Alcohol Drinking; Aldehydes; Animals; Aspartate Aminotransferases; Binge Drinking; Central Nervous System Depressants; Cytochrome P-450 CYP2E1; Ethanol; Hepatitis, Alcoholic; Interleukin-1; Liver Function Tests; Male; Mice; Mice, Inbred C57BL

Oxidants have been shown to be involved in alcohol-induced liver injury. Moreover, 2-phenyl-1,2-benzisoselenazole-3(2H)-one (ebselen), an organoselenium compound and glutathione peroxidase mimic, decreases oxidative stress and protects against stroke clinically. This study was designed to test the hypothesis that ebselen protects against early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-16 g/kg/d) continuously for up to 4 weeks using the intragastric enteral feeding protocol developed by Tsukamoto and French. Ebselen (50 mg/kg twice daily, intragastrically) or vehicle (1% tylose) was administered throughout the experiment. Mean urine ethanol concentrations were not significantly different between treatment groups, and ebselen did not affect body weight gains or cyclic patterns of ethanol concentrations in urine. After 4 weeks, serum ALT levels were increased significantly about 4-fold over control values (37 +/- 5 IU/l) by enteral ethanol (112 +/- 7 IU/l); ebselen blunted this increase significantly (61 +/- 8 IU/l). Enteral ethanol also caused severe fatty accumulation, mild inflammation, and necrosis in the liver (pathology score: 4.3 +/- 0.3). In contrast, these pathological changes were blunted significantly by ebselen (pathology score: 2.5 +/- 0.4). While there were no significant effects of either ethanol or ebselen on glutathione peroxidase activity in serum or liver tissue, ebselen blocked the increase in serum nitrate/nitrite caused by ethanol. Furthermore, ethanol increased the activity of NF-kappaB over 5-fold, the number of infiltrating neutrophils 4-fold, and the accumulation of 4-hydroxynonenal over 5-fold. Ebselen blunted all of these effects significantly. These results indicate that ebselen prevents early alcohol-induced liver injury, most likely by preventing oxidative stress, which decreases inflammation.

Topics: Alanine Transaminase; Aldehydes; Animals; Antioxidants; Azoles; Body Weight; Enteral Nutrition; Ethanol; Glutathione Peroxidase; Hepatitis, Alcoholic; Inflammation; Isoindoles; Liver; Male; NF-kappa B; Organoselenium Compounds; Oxidative Stress; Oxidoreductases; Rats; Rats, Wistar

F2-isoprostanes (F2-IP) and 4-hydroxynonenal (4-HNE), peroxidation products of polyunsaturated fatty acids (PUFA), are considered the most reliable indicators of endogenous lipid peroxidation in vivo. To determine to what extent these are also altered in patients with alcoholic liver disease, plasma free and esterified F2-IP as well as 4-HNE were measured by GC/MS in 49 fasting subjects who underwent diagnostic percutaneous needle biopsies of the liver. Compared to patients with mild steatosis and no fibrosis, free F2-IP and 4-HNE were strikingly increased in individuals with alcoholic hepatitis. There was also a significant but lesser rise of 4-HNE in patients with perivenular fibrosis. An increase of F2-IP was also found in subjects with transition to, or complete, alcoholic cirrhosis, with a comparable trend for 4-HNE. By contrast, in patients who were drinking heavily up to 48 hr before admission, F2-IP were not abnormal, but they increased later (p < 0.005). Contrasting with plasma free F2-IP, esterified F2-IP were not significantly changed with fibrosis. Thus, whereas circulating esterified F2-IP were unchanged in patients with alcoholic liver disease, there was an increase in free F2-IP as well as 4-HNE during recovery from intoxication. The increase was not a result of accompanying hepatitis C but a function of the stage of alcoholic liver injury, possibly reflecting enhanced lipid peroxidation as well as interference with biliary excretion and/or hepatic esterification.

Topics: Aldehydes; Cysteine Proteinase Inhibitors; Dinoprost; F2-Isoprostanes; Gas Chromatography-Mass Spectrometry; Hepatitis, Alcoholic; Humans; Lipid Peroxidation; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases, Alcoholic; Male; Predictive Value of Tests