The combination of blueberry juice and probiotics reduces apoptosis of alcoholic fatty liver of mice by affecting SIRT1 pathway.

PURPOSE: To explore the effects of the combination of blueberry juice and probiotics on the apoptosis of alcoholic fatty liver disease (AFLD). METHODS: Healthy C57BL/6J mice were used in the control group (CG). AFLD mice models were established with Lieber-DeCarli ethanol diet and evenly assigned to six groups with different treatments: MG (model), SI (SIRT1 [sirtuin type 1] small interfering RNA [siRNA]), BJ (blueberry juice), BJSI (blueberry juice and SIRT1 siRNA), BJP (blueberry juice and probiotics), and BJPSI (blueberry juice, probiotics, and SIRT1 siRNA). Hepatic tissue was observed using hematoxylin and eosin (HE) and Oil Red O (ORO) staining. Biochemical indexes of the blood serum were analyzed. The levels of SIRT1, caspase-3, forkhead box protein O1 (FOXO1), FasL (tumor necrosis factor ligand superfamily member 6), BAX, and Bcl-2 were measured by reverse transcription-polymerase chain reaction and Western blotting. RESULTS: HE and ORO staining showed that the hepatocytes were heavily destroyed with large lipid droplets in MG and SI groups, while the severity was reduced in the CG, BJ, and BJP groups (P<0.05). The levels of superoxide dismutase (SOD), reduced glutathione (GSH), and high-density lipoprotein-cholesterol (HDL-C) were increased in BJ and BJP groups when compared with the model group (P<0.05). In contrast, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total triglycerides (TGs), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and malondialdehyde (MDA) were lower in BJ and BJP groups than in the model group (P<0.05). The level of SIRT1 was increased, while the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 were decreased in CG, BJ, and BJP groups (P<0.05). Meanwhile, SIRT1 silence resulted in increase of the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2. CONCLUSION: The combination of blueberry juice and probiotics reduces apoptosis in AFLD by suppressing FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 via the upregulation of SIRT1.

Nicotinic acid supplementation in the context of alcoholic liver injury: friend or foe?

Li and colleagues (2014) in this issue report that dietary nicotinic acid (NA) supplementation ameliorates ethanol-induced hepatic steatosis, but a deficiency does not worsen injury induced by alcohol alone. The authors further present some mechanistic insights into the protective role of NA supplementation. Results of this and other previous studies in the context of alcoholic liver injury raise one important question as to what should be an adequate dose of NA that will provide the maximum benefit to hepatic and extrahepatic tissues and with minimum adverse effects.

Dietary nicotinic acid supplementation ameliorates chronic alcohol-induced fatty liver in rats.

BACKGROUND: Alcohol abuse frequently causes niacin deficiency in association with the development of alcoholic liver disease. The objective of the present study was to determine whether dietary nicotinic acid (NA) deficiency exaggerates and whether dietary NA supplementation alleviates alcohol-induced fatty liver. METHODS: Male Sprague-Dawley rats were pair-fed with 4 isocaloric liquid diets: control, ethanol (EtOH), EtOH with dietary NA deficiency, and EtOH with dietary NA supplementation, respectively, for 8 weeks. The control and EtOH diets contained normal levels of NA (7.5 mg/l). Dietary NA deficiency (0 mg NA/l) was achieved by removing NA from the vitamin mix, while NA was added to the liquid diet at 750 mg/l for dietary NA supplementation. RESULTS: Chronic EtOH feeding induced significant lipid accumulation in the liver, which was not worsened by dietary NA deficiency, but was ameliorated by dietary NA supplementation. Liver total NAD, NAD(+) , and NADH levels were remarkably higher in the NA supplemented group than the NA deficient or EtOH alone groups. Dietary NA supplementation to EtOH-fed rats increased the protein levels of hepatic cytochrome P450 4A1 (CYP4A1) and acyl-coenzyme A oxidase 1 without affecting their mRNA levels. Interestingly, we found dietary NA supplementation reduced the ubiquitination level of CYP4A1. In addition, hepatic fatty acid synthase expression was reduced, while the serum ß-hydroxybutyrate and adiponectin concentrations were significantly elevated by dietary NA supplementation. Moreover, dietary NA supplementation modulated EtOH-perturbed liver and serum metabolite profiles. CONCLUSIONS: These results demonstrate that alcoholic fatty liver was not exaggerated by dietary NA deficiency, but was ameliorated by dietary NA supplementation. Increased hepatic fatty acid oxidation and decreased hepatic de novo lipogenesis contribute to the effects of dietary NA supplementation.

Biochemical and molecular study of the influence of Amaranthus hypochondriacus flour on serum and liver lipids in rats treated with ethanol.

Hyperlipidemia and hepatic steatosis are frequent alterations due to alcohol abuse. Amaranth is a pseudocereal with hypolipidemic potential among other nutraceutical actions. Here we study the effect of Amaranthus hypochondriacus (Ah) seeds on serum and liver lipids, and the expression of genes associated to lipid metabolism and liver histology in male Wistar rats intoxicated with ethanol. The animals were divided into four groups; two groups were fed the American Institute of Nutrition 1993 for maintenance diet (AIN-93M), and the other two with AIN-93M containing Ah as protein source. One of each protein group received 20% ethanol in the drinking water, thus obtaining: CC (control casein), EC (ethanol casein), CAh (control Ah) and EAh (ethanol Ah). When comparing EAh vs . EC, we found a positive effect of Ah on lipids, preventing the increment of serum cholesterol (p <0.001), through the higher expression of the LDL receptor (p <0.001); and it also decreased free (p < 0.05) and esterified cholesterol (p <0.01) in liver, probably via the reduction of the 3-hydroxy-3-methylglutaryl coenzyme A reductase expression (p <0.001). We also observed that amaranth contributed to the decrease of fat deposits in liver, probably through the decrease in acetyl-CoA carboxylase alpha (p <0.01), glycerol-3-phosphate acyltransferase 1 (p <0.01) and diacylglycerol O-acyltransferase 2 (p <0.05) expression. The histological study showed a decrease in the fat deposits in the amaranth group when compared to casein; this is consistent with the biochemical and molecular parameters studied in this work. In conclusion, amaranth could be recommended to avoid the alterations in the lipid metabolism induced by alcohol and other harmful agents.

Preservation of hepatocyte nuclear factor-4α contributes to the beneficial effect of dietary medium chain triglyceride on alcohol-induced hepatic lipid dyshomeostasis in rats.

BACKGROUND: Alcohol consumption is a major cause of fatty liver, and dietary saturated fats have been shown to protect against alcoholic fatty liver. This study investigated the mechanisms of how dietary saturated fat may modulate alcohol-induced hepatic lipid dyshomeostasis. METHODS: Male Sprague Dawley rats were pair-fed with 3 isocaloric liquid diets, control, alcohol, and medium chain triglyceride (MCT)/alcohol, respectively, for 8 weeks. The control and alcohol diets were based on the Lieber-DeCarli liquid diet formula with 30% total calories derived from corn oil (rich in unsaturated long chain fatty acids). The corn oil was replaced by MCT, which consists of exclusive saturated fatty acids, in the MCT/alcohol diet. HepG2 cell culture was conducted to test the effects of unsaturated fatty acids on hepatocyte nuclear factor-4α (HNF4α) and the role of HNF4α in regulating hepatocyte lipid homeostasis. RESULTS: Alcohol feeding caused significant lipid accumulation, which was attenuated by dietary MCT. The major effect of alcohol on hepatic gene expression is the up-regulation of CYP4A1, CD36, and GPAT3, and down-regulation of apolipoprotein B (ApoB). Dietary MCT further up-regulated CYP4A1 gene, normalized ApoB gene, and up-regulated MTTP and SCD1 genes. The protein level of HNF4α, a master transcription factor of the liver, was reduced by alcohol feeding, which was normalized by dietary MCT. Fatty acid profiling demonstrated that alcohol feeding dramatically increased hepatic unsaturated long chain fatty acyl species, particularly linoleic acid and oleic acid, which was attenuated by dietary MCT. Dietary MCT attenuated alcohol-reduced serum triglyceride level and modulated the fatty acid composition of the serum triglycerides. Cell culture study demonstrated polyunsaturated linoleic acid rather than monounsaturated oleic acid inactivated HNF4α in HepG2 cells. Knockdown of HNF4α caused lipid accumulation in HepG2 cells due to dysregulation of very low density lipoprotein secretion. CONCLUSIONS: Results suggest that dietary MCT prevents alcohol-induced hepatic lipid accumulation, at least partially, through reducing hepatic polyunsaturated long chain fatty acids and preserving HNF4α.

Prevention of alcoholic fatty liver and mitochondrial dysfunction in the rat by long-chain polyunsaturated fatty acids.

BACKGROUND/AIMS: We reported that reduced dietary intake of polyunsaturated fatty acids (PUFA) such as arachidonic (AA,20:4n6,omega-6) and docosahexaenoic (DHA,22:6n3,omega-3) acids led to alcohol-induced fatty liver and fibrosis. This study was aimed at studying the mechanisms by which a DHA/AA-supplemented diet prevents alcohol-induced fatty liver. METHODS: Male Long-Evans rats were fed an ethanol or control liquid-diet with or without DHA/AA for 9 weeks. Plasma transaminase levels, liver histology, oxidative/nitrosative stress markers, and activities of oxidatively-modified mitochondrial proteins were evaluated. RESULTS: Chronic alcohol administration increased the degree of fatty liver but fatty liver decreased significantly in rats fed the alcohol-DHA/AA-supplemented diet. Alcohol exposure increased oxidative/nitrosative stress with elevated levels of ethanol-inducible CYP2E1, nitric oxide synthase, nitrite and mitochondrial hydrogen peroxide. However, these increments were normalized in rats fed the alcohol-DHA/AA-supplemented diet. The number of oxidatively-modified mitochondrial proteins was markedly increased following alcohol exposure but significantly reduced in rats fed the alcohol-DHA/AA-supplemented diet. The suppressed activities of mitochondrial aldehyde dehydrogenase, ATP synthase, and 3-ketoacyl-CoA thiolase in ethanol-exposed rats were also recovered in animals fed the ethanol-DHA/AA-supplemented diet. CONCLUSIONS: Addition of DHA/AA prevents alcohol-induced fatty liver and mitochondrial dysfunction in an animal model by protecting various mitochondrial enzymes most likely through reducing oxidative/nitrosative stress.

Unsaturated fat and low energy intake induce whereas an increment in energy intake ameliorates fatty liver during prolonged alcohol consumption by rats.

Two groups of rats were fed liquid diets containing 35% of energy as fat and either 36 or 26% of energy as alcohol to examine the effect of fat and energy intake on alcoholic fatty liver production. After 4 wk, five rats in each group were killed for analysis of liver triglyceride concentration, and then the alcohol diets fed to remaining rats were switched. All remaining rats were killed for hepatic triglyceride determination after another 4 wk. Rats initially fed the 36% alcohol diet or those switched to this diet ingested less energy, exhibited alcoholemia and slow growth, and developed fatty livers. Rats initially fed the 26% alcohol diet or those switched to this diet ingested significantly more energy, high amounts of alcohol and fat, exhibited low alcoholemia and faster growth than when they were fed the 36% alcohol diet. Fatty liver was absent in rats fed the 26% alcohol diet but was induced when they were fed the 36% alcohol diet. Fatty liver in rats initially fed the 36% alcohol diet regressed completely when the rats were switched to the 26% alcohol diet. Additional studies employing 36% alcohol diets containing 35% of energy as fat, derived from either corn oil or olive oil, revealed that unsaturated fat and not specifically linoleate plays a role in the induction of fatty liver. Thus, nutritional factors regulate the induction or regression of fatty liver and alcoholemia in alcoholic rats.