allopurinol and Non-alcoholic-Fatty-Liver-Disease

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease in Western countries with potential progression to nonalcoholic steatohepatitis (NASH) and cirrhosis, is associated with cardiovascular disease (CVD) mortality. Several studies have reported a relationship between uric acid and NAFLD/NASH and it seems that serum uric acid (SUA) is a significant independent factor for the development of NAFLD. Potential mediating mechanisms include insulin resistance, endothelial dysfunction, and activation of inflammasome, especially NLRP3. Moreover, emerging evidence indicates a strong association between elevated SUA, metabolic syndrome (MetS), NAFLD, and CVD. The emphasis of the present review is whether common therapy of elevated SUA levels and NAFLD can improve compliance. There are several drugs with "off target" properties that show some separate benefit on SUA reduction (e.g. losartan) or NAFLD/NASH (pioglitazone); however, there is no randomized controlled trial (RCT) of a single drug with beneficial outcome for both diseases. Allopurinol reduces SUA levels and ameliorates NAFLD/NASH; however, no RCTs have been performed up to now to explore potential survival benefits. Atorvastatin, which has proven safe in NAFLD/NASH, reduces SUA levels, ameliorates NAFLD/NASH, prevents liver fibrosis, and above all substantially reduces CVD morbidity and mortality in comparison with those on statins but without NAFLD/NASH. This drug could be a solution to improve compliance in both diseases, which are prevalent and becoming even more common with the obesity, MetS, and type 2 diabetes mellitus epidemic.

Topics: Allopurinol; Atorvastatin; Biomarkers; Gout Suppressants; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperuricemia; Non-alcoholic Fatty Liver Disease; Prevalence; Risk Factors; Treatment Outcome; Uric Acid

Uric acid (UA) is the end product of purine metabolism and can reportedly act as an antioxidant. However, recently, numerous clinical and basic research approaches have revealed close associations of hyperuricemia with several disorders, particularly those comprising the metabolic syndrome. In this review, we first outline the two molecular mechanisms underlying inflammation occurrence in relation to UA metabolism; one is inflammasome activation by UA crystallization and the other involves superoxide free radicals generated by xanthine oxidase (XO). Importantly, recent studies have demonstrated the therapeutic or preventive effects of XO inhibitors against atherosclerosis and nonalcoholic steatohepatitis, which were not previously considered to be related, at least not directly, to hyperuricemia. Such beneficial effects of XO inhibitors have been reported for other organs including the kidneys and the heart. Thus, a major portion of this review focuses on the relationships between UA metabolism and the development of atherosclerosis, nonalcoholic steatohepatitis, and related disorders. Although further studies are necessary, XO inhibitors are a potentially novel strategy for reducing the risk of many forms of organ failure characteristic of the metabolic syndrome.

Topics: Animals; Atherosclerosis; Disease Progression; Free Radicals; Heart Failure; Humans; Inflammasomes; Inflammation; Metabolic Syndrome; Mice; Non-alcoholic Fatty Liver Disease; Superoxides; Uric Acid; Xanthine Oxidase

Xanthine oxidase (XO) generates reactive oxygen species during uric acid production. Therefore, XO inhibitors, which suppress oxidative stress, may effectively treat non-alcoholic steatohepatitis (NASH) and atherosclerosis via uric acid reduction. In this study, we examined the antioxidant effect of the XO inhibitor febuxostat on NASH and atherosclerosis in stroke-prone spontaneously hypertensive 5 (SHRSP5/Dmcr) rats.. SHRSP5/Dmcr rats were divided into three groups: SHRSP5/Dmcr + high-fat and high-cholesterol (HFC) diet [control group, n = 5], SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) [fructose group, n = 5], and SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) + febuxostat (1.0 mg/kg/day) [febuxostat group, n = 5]. Glucose and insulin resistance, blood biochemistry, histopathological staining, endothelial function, and oxidative stress markers were evaluated.. Febuxostat reduced the plasma uric acid levels. Oxidative stress-related genes were downregulated, whereas antioxidant factor-related genes were upregulated in the febuxostat group compared with those in the fructose group. Febuxostat also ameliorated inflammation, fibrosis, and lipid accumulation in the liver. Mesenteric lipid deposition decreased in the arteries, and aortic endothelial function improved in the febuxostat group.. Overall, the XO inhibitor febuxostat exerted protective effects against NASH and atherosclerosis in SHRSP5/Dmcr rats.

Topics: Animals; Antioxidants; Atherosclerosis; Diet, High-Fat; Enzyme Inhibitors; Febuxostat; Lipids; Non-alcoholic Fatty Liver Disease; Rats; Rats, Inbred SHR; Uric Acid; Xanthine Oxidase

High-fructose intake (HF) represents an inducible risk factor for non-alcoholic fatty liver disease (NAFLD). Present study aimed to illustrate the effect of HF diet (HFD) on the induction of NAFLD, hyperuricemia and role of ellagic acid as modulator.. Twenty-four adult male albino rats were randomly divided into four groups (6/each). The first group received normal chow diet only while the others received 60 % HFD for 4 weeks and subdivided later into 3 groups. The first and second groups received allopurinol and ellagic acid, respectively while the third group received HFD only for extra 4 weeks.. Rats fed on HFD for 8 weeks displayed body weight gain, insulin resistance (IR), hyperglycemia, dyslipidemia, hyperuricemia with increased oxidative stress and hepatic lipogenic enzymes such as ATP citrate lyase (ACL), aldolase B, and fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SERBP-1c). C1q /tumor necrosis factor-related protein -3 (CTRP3), and phosphorylated AMP-activated protein kinase (p-AMPK) however showed significant decreases. Ellagic acid or allopurinol administration significantly decreased serum lipids, uric acid, glucose, insulin levels and hepatic contents of enzymes. Malondialdehyde (MDA), FAS, aldolase B, SERBP-1c, and xanthine oxidase (XO) hepatic contents showed significant decreases along with glutathione (GSH) increase as compared to fructose group where ellagic acid was more remarkable compared with allopurinol.. Our findings indicated that ellagic acid had alleviated HFD-induced hyperuricemia, its associated NAFLD pattern as mediated through activation of CTRP3 and inhibition of ACL activities in a pattern more remarkable than allopurinol.

Topics: Allopurinol; Animals; ATP Citrate (pro-S)-Lyase; Carrier Proteins; Complement C1q; Diet, High-Fat; Ellagic Acid; Fructose; Fructose-Bisphosphate Aldolase; Hyperuricemia; Liver; Male; Non-alcoholic Fatty Liver Disease; Rats; Rats, Wistar; Tumor Necrosis Factors

Although highly active antiretroviral therapy (HAART) is effective in the management of HIV, it has been reported to induce hepatic injury and non-alcoholic fatty liver (NAFLD). However, there is a lack of data on the roles of the adenosine deaminase (ADA)/xanthine oxidase (XO)/uric acid (UA) pathway and caspase 3 signaling in HAART-induced NAFLD. Also, whether or not zinc confers protection against HAART-induced NAFLD is not known.. This study evaluated the involvement of the ADA/XO/UA pathway and caspase 3 signaling in HAART-induced hepatic lipid accumulation. It also evaluated the possible protective effect of zinc in HAART-induced hepatic lipid accumulation and injury.. Thirty two male Wistar rats (n = 8/group) were assigned into four groups namely; vehicle-treated (p.o), zinc-treated (3 mg/kg/day of elemental zinc; p.o), HAART-treated (a cocktail of 52.9 mg/kg of Efavirenz, 26.48 mg/kg of Lamivudine, and 26.48 mg/kg of Tenofovir; p.o), and HAART + zinc-treated groups. The treatment lasted for 8 weeks.. HAART administration led to increased body weight and hepatic weight, but unaltered hepatic organo-somatic index. HAART exposure also resulted in impaired glucose homeostasis, evidenced by increased fasting blood glucose, hyperinsulinemia, and insulin resistance (IR), increased plasma and hepatic cholesterol and triglycerides, and impaired hepatic function as depicted by elevated hepatic injury markers and reduced glycogen synthase activity and glycogen content. These findings were accompanied by increased plasma and hepatic ADA and XO activities, UA and malondialdehyde levels, inflammatory markers, and caspase 3 activities. However, HAART suppressed plasma and hepatic antioxidant defenses. Furthermore, HAART distorted hepatic histoarchitecture and reduced hepatic sinusoidal diameter. Co-administration of zinc with HAART normalized HAART-induced alterations.. These findings showed that downregulation of the ADA/XO/UA pathway and caspase 3 signalings may rescue the liver from HAART-induced lipid accumulation and injury.

Topics: Adenosine Deaminase; Animals; Antiretroviral Therapy, Highly Active; Caspase 3; Liver; Male; Non-alcoholic Fatty Liver Disease; Rats; Rats, Wistar; Triglycerides; Uric Acid; Xanthine Oxidase; Zinc

Topics: Animals; Aorta; Atherosclerosis; Benzodioxoles; Cholesterol, Dietary; Diet, High-Fat; Dietary Carbohydrates; Dietary Supplements; Eating; Endoplasmic Reticulum Stress; Lipid Metabolism; Liver; Male; Membrane Proteins; NLR Family, Pyrin Domain-Containing 3 Protein; Non-alcoholic Fatty Liver Disease; Phenols; Protein Serine-Threonine Kinases; Rats; Rats, Sprague-Dawley; Signal Transduction; Uric Acid; Weight Gain; Xanthine Oxidase

Excess fructose consumption contributes to development obesity, metabolic syndrome, and nonalcoholic fatty liver disease (NAFLD). Uric acid (UA), a metabolite of fructose metabolism, may have a direct role in development of NAFLD, with unclear mechanism. This study aimed to evaluate role of fructose and UA in NAFLD and explore mechanisms of allopurinol (Allo, a UA lowering medication) on NAFLD in Otsuka Long-Evans Tokushima Fatty (OLETF) rats fed a high fructose diet (HFrD), with Long-Evans Tokushima Otsuka (LETO) rats used as a control. There were six groups: LETO, LETO-Allo, OLETF, OLETF-Allo, OLETF-HFrD, and OLETF-HFrD-Allo. HFrD significantly increased body weight, epididymal fat weight, and serum concentrations of UA, cholesterol, triglyceride, HbA1c, hepatic enzymes, HOMA-IR, fasting insulin, and two hour-glucose after intraperitoneal glucose tolerance tests, as well as NAFLD activity score of liver, compared to the OLETF group. Allopurinol treatment significantly reduced hepatic steatosis, epididymal fat, serum UA, HOMA-IR, hepatic enzyme levels, and cholesterol in the OLETF-HFrD-Allo group. Additionally, allopurinol significantly downregulated expression of lipogenic genes, upregulated lipid oxidation genes, downregulated hepatic pro-inflammatory cytokine genes, and decreased ER-stress induced protein expression, in comparison with the OLETF-HFrD group. In conclusion, allopurinol ameliorates HFrD-induced hepatic steatosis through modulation of hepatic lipid metabolism, inflammation, and ER stress pathway. UA may have a direct role in development of fructose-induced hepatic steatosis, and allopurinol could be a candidate for prevention or treatment of NAFLD.

Topics: Allopurinol; Animals; Blood Glucose; Diabetes Mellitus, Type 2; Disease Models, Animal; Endoplasmic Reticulum Stress; Fructose; Glucose Tolerance Test; Humans; Inflammation; Lipid Metabolism; Liver; Male; Non-alcoholic Fatty Liver Disease; Rats; Rats, Inbred OLETF; Uric Acid; Xanthine Oxidase

Hyperuricemia is a major risk for non-alcoholic fatty liver disease. However, the mechanisms for this phenomenon are not fully understood. This study aimed to investigate whether microRNAs mediated the pathogenic effects of uric acid on non-alcoholic fatty liver disease.. Microarray was used to determine the hepatic miRNA expression profiles of male C57BL/6 mice fed on standard chow diet, high fat diet (HFD), and HFD combined with uric acid-lowering therapy by allopurinol. We validated the expression of the most significant differentially expressed microRNAs and explored its role and downstream target in uric acid-induced hepatocytes lipid accumulation.. Microarray analysis and subsequent validation showed that miR-149-5p was significantly up-regulated in the livers of HFD-fed mice, while the expression was down-regulated by allopurinol therapy. MiR-149-5p expression was also significantly up-regulated in uric acid-stimulated hepatocytes. Over-expression of miR-149-5p significantly aggregated uric acid-induced triglyceride accumulation in hepatocytes, while inhibiting miR-149-5p ameliorated the triglyceride accumulation. Luciferase report assay confirmed that FGF21 is a target gene of miR-149-5p. Silencing FGF21 abolished the ameliorative effects of miR-149-5p inhibitor on uric acid-induced hepatocytes lipid accumulation, while overexpression of FGF21 prevented the lipid accumulation induced by miR-149-5p mimics.. Uric acid significantly up-regulated the expression of miR-149-5p in hepatocytes and induced hepatocytes lipid accumulation via regulation of miR-149-5p/FGF21 axis.

Topics: Allopurinol; Animals; Antimetabolites; Diet, High-Fat; Enzyme Inhibitors; Fibroblast Growth Factors; Hepatocytes; Hyperuricemia; Male; Mice; Mice, Inbred C57BL; MicroRNAs; Non-alcoholic Fatty Liver Disease; Triglycerides; Up-Regulation; Uric Acid; Xanthine Oxidase

We investigated whether short term high fructose intake may induce early hepatic dysfunction in rats and to test whether allopurinol treatment may have beneficial effects. Twenty male Sprague-Dawley rats received 20% fructose in drinking water (10 treated with allopurinol and 10 received vehicle) and 10 control rats received tap water. After 14 days, the hepatic response to an acute fructose load was evaluated, and in fasted animals, respirometry studies in freshly isolated mitochondria were performed. In fasting rats, we did not find differences in systemic or hepatic uric acid and triglyceride concentrations among the groups, but mitochondrial respiratory control rate was significantly decreased by high fructose feeding and correlated with a reduced expression of Complex I, as well as decreased aconitase-2 activity. On the other hand, in fructose fed rats, an acute fructose load increased systemic and hepatic uric acid, triglycerides and oxidative stress. Fructose feeding was also associated with fructokinase and xanthine oxidase overexpression and increased liver de novo lipogenesis program (fatty acid synthase (FAS) and cell death-inducing DFFA-like effector C (CIDEC) overexpression, ATP citrate lyase (ACL) and acetyl coA carboxylase (ACC) overactivity and decreased AMP-activated protein kinase (AMPk) and endothelial nitric oxide synthase (eNOS) activation). Allopurinol treatment prevented hepatic and systemic alterations. These data suggest that early treatment with xanthine oxidase inhibitors might provide a therapeutic advantage by delaying or even halting the progression of non-alcoholic fatty liver disease (NAFLD).

Topics: Administration, Oral; Allopurinol; Animals; Apoptosis; Enzyme Inhibitors; Fructose; Lipogenesis; Male; Non-alcoholic Fatty Liver Disease; Rats; Rats, Sprague-Dawley

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease. Swertia bimaculata (Sieb. et Zucc.) Hook. Thoms.ex Clarke, a glabrous or procumbent perennial herb, is a traditional herb medicine. Swertiamarin, a secoiridoid glycoside, is a representative ingredient in this medical plant crude extract and shows antidiabetic and antihyperlipidaemic activities and protective effect against hepatic injury.. The present study aimed to determine whether swertiamarin can attenuate NAFLD in fructose-fed mice.. Healthy male mice freely drank water containing 10% fructose for 12 consecutive weeks, whereas animals in those swertiamarin tested groups received different doses of swertiamarin (25, 50 and 100 mg/kg) by intragastric administration once a day from the ninth week to the twelfth week.. At the end of the experiment, fructose-fed mice administrated with swertiamarin showed low levels of serum glucose, triglycerides, uric acid, alanine aminotransferase and aspartate transaminase. Histological examinations suggested the alleviation of hepatic ballooning degeneration and steatosis by swertiamarin treatment. Moreover, swertiamarin administration mitigated hepatic oxidative stress along with decreases of hepatic pro-inflammation cytokines, which was associated with decrease of hepatic xanthine oxidase (XO) activity and enhancements of anti-oxidant defense system enzymes, as well as activation of nuclear factor E2-related factor 2 (Nrf2) in fructose-fed mice. In addition, swertiamarin down-regulated expression of sterol-regulatory element-binding protein-1 (SREBP-1), fatty acid synthase (FAS) and acetyl-CoA carboxylase 1 (ACC1) in liver of fructose-fed mice.. The present study demonstrates that swertiamarin alleviates NAFLD and metabolic alterations in fructose-fed mice.

Topics: Acetyl-CoA Carboxylase; Alanine Transaminase; Animals; Cytokines; Fatty Acid Synthases; Fructose; Iridoid Glucosides; Liver; Male; Mice; NF-E2-Related Factor 2; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Pyrones; Sterol Regulatory Element Binding Protein 1; Triglycerides; Xanthine Oxidase

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver-related morbidity and mortality disease in the world. However, no effective pharmacological treatment for NAFLD has been found. In this study, we used a high fat diet (HFD)-induced NAFLD model to investigate hepatoprotective effect of apigenin (API) against NAFLD and further explored its potential mechanism. Our results demonstrated that gavage administration of API could mitigate HFD-induced liver injury, enhance insulin sensitivity and markedly reduce lipid accumulation in HFD-fed mice livers. In addition, histological analysis showed that hepatic steatosis and macrophages recruitment in the API treatment group were recovered compared with mice fed with HFD alone. Importantly, API could reverse the HFD-induced activation of the NLRP3 inflammasome, further reduced inflammatory cytokines IL-1β and IL-18 release, accompanied with the inhibition of xanthine oxidase (XO) activity and the reduction of uric acid and reactive oxygen species (ROS) production. The pharmacological role of API was further confirmed using free fatty acid (FFA) induced cell NAFLD model. Taking together, our results demonstrated that API could protect against HFD-induced NAFLD by ameliorating hepatic lipid accumulation and inflammation. These protective effects may be partially attributed to the regulation of XO by API, which further modulated NLRP3 inflammasome activation and inflammatory cytokines IL-1β and IL-18 release. Therefore API is a potential therapeutic agent for the prevention of NAFLD.

Topics: Animals; Apigenin; Diet, High-Fat; Gene Expression Regulation; Glucose; Hepatitis; Inflammasomes; Lipid Metabolism; Liver; Macrophages; Male; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Non-alcoholic Fatty Liver Disease; Weight Gain; Xanthine Oxidase

Xanthine oxidase (XOD) and paraoxonase 1 (PON1) are important enzymes in redox reactions in vivo, and are predominantly synthesized by the liver. The aim of the present study was to investigate the redox state in nonalcoholic fatty liver disease, and determine the association between the activities of XOD and PON1 and the severity of NAFLD. Sprague‑Dawley rats were randomly divided into control, model and α‑lipoic acid (high and low dose) groups. The rats in the NAFLD model were induced by feeding a high fat diet for 12 weeks and the in vitro cell model of hepatocyte steatosis was induced by treating L‑02 cells with oleic acid for 24 h. The body weight, liver function, lipid and oxidative stress indices, and histological features of the liver were examined in the rats. Compared with the control group, the rats in the NAFLD model group showed impaired liver function, lipid disorders and damage from oxidative stress. The serum activity of XOD increased significantly from the 4th week and was markedly higher, compared with that in the control group, reaching a peak in the 12th week. The activity of PON1 was negatively correlated with that of XOD. Compared with the control cells, the activity of XOD and levels of free‑fatty acids were significantly higher, and the activity of PON1 was significantly lower in the NAFLD L‑02 cell model. All the above indicators were significantly improved by treatment with the antioxidant, α‑lipoic acid. The activities of XOD and PON1 may be promising as markers in a noninvasive approach for detecting the severity of NAFLD clinically. α‑lipoic acid had protective effects on the NAFLD rats, and the potential mechanism may be associated with the inhibition of oxidative stress and lipid peroxidation.

Topics: Animals; Aryldialkylphosphatase; Cell Line; Lipid Metabolism; Lipids; Liver; Male; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Rats, Sprague-Dawley; Xanthine Oxidase

Increased fructose consumption predisposes the liver to nonalcoholic fatty liver disease (NAFLD), but the mechanisms are elusive. Thioredoxin-interacting protein (TXNIP) links oxidative stress to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation and this signaling axis may be involved in fructose-induced NAFLD. Here, we explore the role of reactive oxygen species (ROS)-induced TXNIP overexpression in fructose-mediated hepatic NLRP3 inflammasome activation, inflammation, and lipid accumulation.. Rats were fed a 10% fructose diet for 8 weeks and treated with allopurinol and quercetin during the last 4 weeks. Five millimolars of fructose-exposed hepatocytes (primary rat hepatocytes, rat hepatic parenchymal cells [RHPCs], HLO2, HepG2) were co-incubated with antioxidants or caspase-1 inhibitor or subjected to TXNIP or NLRP3 siRNA interference. Fructose induced NLRP3 inflammasome activation and pro-inflammatory cytokine secretion, janus-activated kinase 2/signal transducers and activators of transcription 3-mediated inflammatory signaling, and expression alteration of lipid metabolism-related genes in cultured hepatocytes and rat livers. NLRP3 silencing and caspase-1 suppression blocked these effects in primary rat hepatocytes and RHPCs, confirming that inflammasome activation alters hepatocyte lipid metabolism. Hepatocellular ROS and TXNIP were increased in animal and cell models. TXNIP silencing blocked NLRP3 inflammasome activation, inflammation, and lipid metabolism perturbations but not ROS induction in fructose-exposed hepatocytes, whereas antioxidants addition abrogated TXNIP induction and diminished the detrimental effects in fructose-exposed hepatocytes and rat livers.. This study provides a novel mechanism for fructose-induced NAFLD pathogenesis by which the ROS-TXNIP pathway mediates hepatocellular NLRP3 inflammasome activation, inflammation and lipid accumulation. Antioxidant-based interventions can inhibit the ROS-TXNIP pathway.

Topics: Allopurinol; Animals; Antioxidants; Carrier Proteins; Cell Cycle Proteins; Cell Line; Cytokines; Enzyme Inhibitors; Fructose; Hepatocytes; Inflammasomes; Inflammation; Lipid Metabolism; Liver; Male; NLR Family, Pyrin Domain-Containing 3 Protein; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Quercetin; Rats, Sprague-Dawley; Reactive Oxygen Species

Hyperuricemia is a common feature of patients with non-alcoholic fatty liver disease (NAFLD). This study aimed to explore the causal relationship and underlying mechanisms between NAFLD and hyperuricemia.. We evaluated the impact of NAFLD on the development of hyperuricemia in a cohort of 5541 baseline hyperuricemia-free individuals. We further analyzed xanthine oxidase (XO), a rate-limiting enzyme that catalyzes uric acid production, as a candidate to link NAFLD and hyperuricemia.. In the first study, a 7-year prospective analysis found that NAFLD was strongly associated with subsequent development of hyperuricemia. Cox proportional hazards regression analyses showed that age, gender, and body mass index adjusted hazard ratio (95% confidence interval) for incident hyperuricemia was 1.609 (1.129-2.294) in individuals with NAFLD, as compared with those without NAFLD at baseline. In the second study, we observed that expression and activity of XO were significantly increased in cellular and mouse models of NAFLD. Knocking down XO expression or inhibiting XO activity significantly decreases uric acid production and attenuates free fatty acids-induced fat accumulation in HepG2 cells. Inhibiting XO activity also significantly prevents the development of and ameliorates established hepatic steatosis induced by a high-fat diet in mice. Further experiments indicated that XO regulates activation of the NLRP3 inflammasome, which may be essential for the regulatory effect of XO on NAFLD.. NAFLD significantly increases the risk of incident hyperuricemia. XO is a mediator of the relationship between NAFLD and hyperuricemia, and may serve as a novel therapeutic target for the two linked diseases.

Topics: Adult; Animals; Carrier Proteins; Cohort Studies; Disease Models, Animal; Female; Gene Knockdown Techniques; Hep G2 Cells; Humans; Hyperuricemia; Inflammasomes; Lipid Metabolism; Male; Mice; Middle Aged; NLR Family, Pyrin Domain-Containing 3 Protein; Non-alcoholic Fatty Liver Disease; Prospective Studies; Risk Factors; Uric Acid; Xanthine Oxidase

Xanthine oxidase (XO) is an enzyme involved in the production of uric acid (UA) from purine nucleotides. Numerous recent studies have revealed the likelihood of metabolic syndrome including nonalcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH) to be related to hyperuricemia. However, it remains unclear whether elevated serum UA during the development of NAFLD or NASH is a cause or a consequence of these diseases. In this study, the XO inhibitor febuxostat was administered to two types of NASH model mice. Febuxostat exerted a strong protective effect against NASH development induced by a high-fat diet containing trans fatty acid (HFDT). In contrast, methionine choline-deficient-diet-induced NASH development not accompanied by hyperuricemia showed no UA normalization, suggesting that the ameliorating effect of febuxostat occurs via the normalization of hyperuricemia itself and/or accompanying molecular mechanism(s) such as oxidative stress. In the HFDT-fed mice, hyperuricemia, elevated alanine aminotransferase, and increased Tunnel-positive cells in the liver were normalized by febuxostat administration. In addition, upregulation of fatty acid oxidation-related genes, fibrotic change, and increases in collagen deposition, inflammatory cytokine expressions, and lipid peroxidation in the HFDT-fed mice were also normalized by febuxostat administration. Taken together, these observations indicate that administration of febuxostat has a protective effect against HFDT-induced NASH development, suggesting the importance of XO in its pathogenesis. Thus XO inhibitors are potentially potent therapies for patients with NASH, particularly that associated with hyperuricemia.

Topics: Animals; Apoptosis; Choline Deficiency; Cytoprotection; Diet, High-Fat; Enzyme Inhibitors; Febuxostat; Gout Suppressants; Hyperuricemia; Liver; Liver Cirrhosis, Experimental; Methionine; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Thiazoles; Uric Acid; Xanthine Oxidase

Basis on study through integrated comparative assessment of clinical, biochemical survey data revealed that in patients with impaired metabolism of uric acid in a greater percentage of common biliary sludge, a violation of the rheological properties of bile, a violation of cholate-cholesterol ratio index, which indicates an increased risk of bile stones. The study found that despite the high levels of uric acid there is a violation of the spectrum of bile acids, cholic and deoxycholic growth acid reduction taurocholic acid. Thus, application of ursodeoxycholic acid, rosuvastatin and allopurinol in these study patients with NAFLD dosages in combination with hyperuricemia improves the clinical symptoms and normalization of biochemical parameters and normalizes the spectrum of biliary acids.

Topics: Adult; Allopurinol; Bile; Cholagogues and Choleretics; Cholestasis, Intrahepatic; Cholesterol; Cholic Acid; Deoxycholic Acid; Drug Therapy, Combination; Duodenoscopy; Female; Fluorobenzenes; Humans; Hyperuricemia; Liver; Male; Middle Aged; Non-alcoholic Fatty Liver Disease; Pyrimidines; Rosuvastatin Calcium; Sulfonamides; Taurocholic Acid; Uric Acid; Ursodeoxycholic Acid

Thioredoxin-interacting protein (TXNIP), a regulator of cellular oxidative stress, has been associated with activation of NOD-like receptor 3 (NLRP3) inflammasome, inflammation and lipid metabolism, suggesting it has a role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) in diabetes. In this study we investigated whether TXNIP is involved in type 1 diabetes-associated NAFLD and whether antioxidants, quercetin and allopurinol, alleviate NAFLD by targeting TXNIP.. Diabetes was induced in male Sprague-Dawley rats by a single i.p. injection of 55 mg · kg⁻¹ streptozotocin. Quercetin and allopurinol were given p.o. to diabetic rats for 7 weeks. Hepatic function, oxidative stress, inflammation and lipid levels were determined. Rat BRL-3A and human HepG2 cells were exposed to high glucose (30 mM) in the presence and absence of antioxidants, TXNIP siRNA transfection or caspase-1 inhibitor, Ac-YVAD-CMK.. Quercetin and allopurinol significantly inhibited the TXNIP overexpression, activation of NLRP3 inflammasome, down-regulation of PPARα and up-regulation of sterol regulatory element binding protein-1c (SREBP-1c), SREBP-2, fatty acid synthase and liver X receptor α, as well as elevation of ROS and IL-1β in diabetic rat liver. These effects were confirmed in hepatocytes in vitro and it was further shown that TXNIP down-regulation contributed to the suppression of NLRP3 inflammasome activation, inflammation and changes in PPARα and SREBPs.. Inhibition of hepatic TXNIP by quercetin and allopurinol contributes to the reduction in liver inflammation and lipid accumulation under hyperglycaemic conditions. The targeting of hepatic TXNIP by quercetin and allopurinol may have therapeutic implications for prevention of type 1 diabetes-associated NAFLD.

Topics: Allopurinol; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Carrier Proteins; Cell Cycle Proteins; Cell Line; Diabetes Mellitus, Type 1; Dietary Supplements; Fatty Liver; Gene Silencing; Humans; Inflammasomes; Lipid Metabolism; Liver; Male; Molecular Targeted Therapy; Non-alcoholic Fatty Liver Disease; Oxidative Stress; Quercetin; Random Allocation; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species