Microvesicular Fatty Change Research Articles

A 13-week subchronic toxicity study of linalool oxide in Crl:CD(SD) rats.

Linalool oxide is frequently used as a flavoring agent, however, data on its toxicity is limited. In this study, we performed a 13-week subchronic toxicity study of linalool oxide (furanoid) in male and female Crl:CD(SD) rats. Doses of 0, 80, 250, and 800 mg/kg body weight (bw) per day were orally administered by gavage, using corn oil as the vehicle. Abnormal gait in both sexes and decreased locomotor activity in males were observed in the 800 mg/kg group. Reduced body weight gain was noted in both sexes at 800 mg/kg and at 250 mg/kg in males. In the 800 mg/kg group, serum biochemistry showed increased γ-glutamyl transpeptidase and decreased glucose in both sexes, increased total protein in males, and increased total cholesterol and phospholipids in females, suggesting that linalool oxide may have adverse effects on the liver. Increased relative and/or absolute liver weights, centrilobular hepatocellular hypertrophy in both sexes, and periportal microvesicular fatty changes in females were observed in the 800 mg/kg group. Increased relative liver weights and decreased serum glucose levels were observed in the 250 mg/kg male and female groups, respectively. Increased serum magnesium levels and relative kidney weights were observed in both sexes in the 800 mg/kg group, suggesting possible adverse effects of linalool oxide. Although histopathology showed accumulation of hyaline droplets in the male kidneys, immunohistochemistry revealed α2u-globulin nephropathy, which was not considered toxicologically significant. These results indicate that the no-observed-adverse-effect level of linalool oxide was 80 mg/kg bw/day for both sexes.

Reye Syndrome: Dangers of Aspirin Use in Children

Reye syndrome is a rare and potentially fatal illness that affects the pediatric age group between 6 months – 18 years of age. It is characterized by encephalopathy and fatty degeneration of the liver. The cause is unknown but the disease is usually preceded by a viral illness or aspirin use.Aspirin use historically appears to be an important etiology in the development of Reye syndrome. We found and reviewed 7 published case reports of Reye syndrome after the use of Aspirin, of which six patients were male while one was female and the mean age of patients was 5.5 years(SD=4.25). Reye syndrome has different manifestations ranging from lethargy, irritability, confusion, seizures and death. Diagnosis of this syndrome can be made based on clinical signs and laboratory testing. There’s no test specifically for Reye syndrome, however, liver function test shows elevated levels of liver enzymes (AST and ALT) with increased levels of ammonia. Liver biopsy is also useful in making a diagnosis, showing microvesicular fatty changes. The outcome of Reye Syndrome depends on the level of cerebral dysfunction, with about a third of patients suffering long term neurological deficits.However,when diagnosed and treated early,prognosis for survivors is good and recurrence is rare.

Chronic exposure of industrial grade calcium carbide and ethylene glycol alter histological architecture of systemic organs by disrupting redox balance in rat.

The threat to human health or the surroundings by the use of artificial fruit ripening agents has become a global concern. Calcium carbide (CaC2) and ethylene glycol (EG) are the two widely using ripening agents. The present study evaluates the toxic effect of chronic exposures of CaC2 and EG in rats. CaC2 and EG were administered to the rats for 180days orally. The alterations in oxido-reduction status, haematological, biochemical and histopathological parameters were analysed. Arsenic content in CaC2 and animal samples were detected by atomic absorption spectrometer and phosphorus by molybdate-UV method. At chronic doses, there were no significant alterations in haematological and biochemical parameters except in creatinine level especially by EG. However, histological details revealed microvesicular fatty change in liver, corpuscles degeneration in kidney and lymphocytes infiltration in various tissues. In intestine, the mucosal lesion scoring was found high (p<0.01). SOD and CAT activities and GSH level was reduced significantly by CaC2 administration (p<0.01). Arsenic and phosphorus detected is above the toxic level: 7.222 and 13.91mg/dL in CaC2, 1.634 and 6.22mg/dL in blood and 0.563 and 6.99mg/dL in liver, respectively. The study suggests that the industrial grade CaC2 and EG induce systemic toxicity to rats and the liver is the most susceptible organ. The CaC2 and EG toxicity is mediated through the upset of redox balance and subsequent inflammatory responses. This could be due to the presence of arsenic and phosphorus contents that detected above the normal level in the industrial grade CaC2.

Macrophage migration inhibitory factor deficiency aggravates effects of fructose-enriched diet on lipid metabolism in the mouse liver.

Dietary fructose can disturb hepatic lipid metabolism in a way that leads to lipid accumulation and steatosis, which is often accompanied with low-grade inflammation. The macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with important role not only in the regulation of inflammation, but also in the modulation of energy metabolism in the liver. Thus, the aim of this study was to investigate the role of Mif deficiency in fructose-induced disturbances of hepatic lipid metabolism and ectopic lipid accumulation. Wild type (WT) and Mif deficient (MIF-/- ) C57Bl/6J mice were used to analyze the effects of 9-week 20% fructose-enriched diet on hepatic lipid metabolism (both lipogenesis and β-oxidation) and histology, inflammatory status and glucocorticoid receptor (GR) signaling. The results showed fructose-induced elevation of lipogenic genes (fatty acid synthase (Fas) and stearoyl-CoA desaturase-1 (Scd1) and transcriptional lipogenic regulators (liver X receptor (LXR), sterol regulatory element binding protein 1c (SREBP1c), and carbohydrate response element-binding protein (ChREBP)). However, microvesicular fatty changes, accompanied with enhanced inflammation, were observable only in fructose-fed Mif deficient animals, and were most likely result of GR activation and facilitated uptake and decreased β-oxidation of FFA, as evidenced by elevated protein level of fatty acid translocase (FAT/CD36) and decreased carnitine palmitoyl transferase 1 (CPT1) level. In conclusion, the results show that Mif deficiency aggravates the effects of energy-rich fructose diet on hepatic lipid accumulation, most likely through enhanced inflammation and activation of GR signaling pathway.

Latent, sex-specific metabolic health effects in CD-1 mouse offspring exposed to PFOA or HFPO-DA (GenX) during gestation

BackgroundPerfluorooctanoic acid (PFOA) is an environmental contaminant associated with adverse metabolic outcomes in developmentally exposed human populations and mouse models. Hexafluoropropylene oxide-dimer acid (HFPO-DA, commonly called GenX) has replaced PFOA in many industrial applications in the U.S. and Europe and has been measured in global water systems from <1 to 9350 ng/L HFPO-DA. Health effects data for GenX are lacking. ObjectiveDetermine the effects of gestational exposure to GenX on offspring weight gain trajectory, adult metabolic health, liver pathology and key adipose gene pathways in male and female CD-1 mice. MethodsDaily oral doses of GenX (0.2, 1.0, 2.0 mg/kg), PFOA (0.1, 1.0 mg/kg), or vehicle control were administered to pregnant mice (gestation days 1.5–17.5). Offspring were fed a high- or low-fat diet (HFD or LFD) at weaning until necropsy at 6 or 18 weeks, and metabolic endpoints were measured over time. PFOA and GenX serum and urine concentrations, weight gain, serum lipid parameters, body mass composition, glucose tolerance, white adipose tissue gene expression, and liver histopathology were evaluated. ResultsPrenatal exposure to GenX led to its accumulation in the serum and urine of 5-day old pups (P = 0.007, P < 0.001), which was undetectable by weaning. By 18 weeks of age, male mice fed LFD in the 2.0 mg/kg GenX group displayed increased weight gain (P < 0.05), fat mass (P = 0.016), hepatocellular microvesicular fatty change (P = 0.015), and insulin sensitivity (P = 0.014) in comparison to control males fed LFD. Female mice fed HFD had a significant increase in hepatocyte single cell necrosis in 1.0 mg/kg GenX group (P = 0.022) and 1.0 mg/kg PFOA group (P = 0.003) compared to control HFD females. Both sexes were affected by gestational GenX exposure; however, the observed phenotype varied between sex with males displaying more characteristics of metabolic disease and females exhibiting liver damage in response to the gestational exposure. ConclusionsPrenatal exposure to 1 mg/kg GenX and 1 mg/kg PFOA induces adverse metabolic outcomes in adult mice that are diet- and sex-dependent. GenX also accumulated in pup serum, suggesting that placental and potentially lactational transfer are important exposure routes for GenX.

Effects of several atypical antipsychotics closapine, sertindole or ziprasidone on hepatic antioxidant enzymes: Possible role in drug-induced liver dysfunction

ABSTRACT Chronic use of atypical antipsychotics may produce hepatic damage. Atypical antipsychotics, including clozapine, sertindole, and ziprasidone, are extensively metabolized by the liver and this process generates toxic-free radical metabolic intermediates which may contribute to liver damage. The aim of this study was to investigate whether clozapine, sertindole, or ziprasidone affected hepatic antioxidant defense enzymes which consequently led to disturbed redox homeostasis. The expression and activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), and glutathione-S-transferases (GST) were measured in rat livers at doses corresponding to human antipsychotic therapy. Clozapine increased activity of SOD types 1 and 2, GR and GST, but reduced CAT activity. Sertindole elevated activities of both SODs. In ziprasidone-treated rats only decreased CAT activity was found. All three antipsychotics produced mild-to-moderate hepatic histopathological changes categorized as regenerative alterations. No apparent signs of immune cell infiltration, microvesicular or macrovesicular fatty change, or hepatocytes in mitosis were observed. In conclusion, a 4-week long daily treatment with clozapine, sertindole, or ziprasidone altered hepatic antioxidant enzyme activities and induced histopathological changes in liver. The most severe alterations were noted in clozapine-treated rats. Data indicate that redox disturbances may contribute to liver dysfunction after long-term atypical antipsychotic drug treatment.

Nitrosative Stress and Lipid Homeostasis as a Mechanism for Zileuton Hepatotoxicity and Resistance in Genetically Sensitive Mice.

Zileuton is an orally active inhibitor of leukotriene synthesis for maintenance treatment of asthma, for which clinical usage has been associated with idiosyncratic liver injury. Mechanistic understanding of zileuton toxicity is hampered by the rarity of the cases and lack of an animal model. A promising model for mechanistic study of rare liver injury is the Diversity Outbred (J:DO) mouse population, with genetic variation similar to that found in humans. In this study, female DO mice were administered zileuton or vehicle daily for 7 days (i.g.). Serum liver enzymes were elevated in the zileuton group, with marked interindividual variability in response. Zileuton exposure-induced findings in susceptible DO mice included microvesicular fatty change, hepatocellular mitosis, and hepatocellular necrosis. Inducible nitric oxide synthase and nitrotyrosine abundance were increased in livers of animals with necrosis and those with fatty change, implicating nitrosative stress as a possible injury mechanism. Conversely, DO mice lacking adverse liver pathology following zileuton exposure experienced decreased hepatic concentrations of resistin and increased concentrations of insulin and leptin, providing potential clues into mechanisms of toxicity resistance. Transcriptome pathway analysis highlighted mitochondrial dysfunction and altered fatty acid oxidation as key molecular perturbations associated with zileuton exposure, and suggested that interindividual differences in cytochrome P450 metabolism, glutathione-mediated detoxification, and farnesoid X receptor signaling may contribute to zileuton-induced liver injury (ZILI). Taken together, DO mice provided a platform for investigating mechanisms of toxicity and resistance in context of ZILI which may lead to targeted therapeutic interventions.

Early Lymphocyte Loss and Increased Granulocyte/Lymphocyte Ratio Predict Systemic Spread of Streptococcus pyogenes in a Mouse Model of Acute Skin Infection.

Background: Group A streptococci may induce lymphopenia, but the value of lymphocyte loss as early biomarkers for systemic spread and severe infection has not been examined systematically.Methods: We evaluated peripheral blood cell indices as biomarkers for severity and spread of infection in a mouse model of Streptococcus pyogenes skin infection, using two isolates of greatly differing virulence. Internal organs were examined histologically.Results: After subcutaneous inoculation, strain AP1 disseminated rapidly to peripheral blood and internal organs, causing frank sepsis. In contrast, seeding of internal organs by 5448 was mild, this strain could not be isolated from blood, and infection remained mostly localized to skin. Histopathologic examination of liver revealed microvesicular fatty change (steatosis) in AP1 infection, and examination of spleen showed elevated apoptosis and blurring of the white pulp/red pulp border late (40 h post infection) in AP1 infection. Both strains caused profound lymphopenia, but lymphocyte loss was more rapid early in AP1 infection, and lymphocyte count at 6 h post infection was the most accurate early marker for AP1 infection (area under the receiver operator curve [AUC] = 0.93), followed by the granulocyte/lymphocyte ratio (AUC = 0.89).Conclusions: The results suggest that virulence of S. pyogenes correlates with the degree of early lymphopenia and underscore the value of peripheral blood indices to predict severity of bacterial infections in mice. Early lymphopenia and elevated granulocyte/lymphocyte ratio merit further investigation as biomarkers for systemic spread of S. pyogenes skin infections in humans and, possibly, related pyogenic streptococci in humans and animals.

Subchronic methionine load induces oxidative stress and provokes biochemical and histological changes in the rat liver tissue.

The aim of this study was to assess the effects of L-cysteine (Cys) (7mg/kg) and N-acetyl-L-cysteine (NAC) (50mg/kg) in the rat liver caused by subchronic i.p. application of methionine (Met) (0.8mmol/kg) during 21days. Malondialdehyde (MDA) concentration, glutathione content (GSH), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and acetylcholinesterase (AchE) activities were determined in the liver tissue and activities of liver enzymes (AST, ALT, ALP, and GGT) and concentrations of total proteins and albumin were determinated in plasma/serum. Catalase, superoxide dismutase, and acetylcholinesterase activities were increased by Cys and NAC. Met caused periportal mononuclear infiltration and rare focal necrosis of hepatocytes. In Cys- and NAC-supplemented groups, intracellular edema and microvesicular fatty changes without necrosis were noticed. We observed decrease of AST, ALT, and ALP activity in the methionine-treated group. Our results indicate that Cys and NAC application can increase activity of antioxidative enzymes and prevent intensive histological changes in liver in condition of subchronic methionine exposure.

Interobserver Agreement on Pathologic Features of Liver Biopsy Tissue in Patients with Nonalcoholic Fatty Liver Disease.

Background:The histomorphologic criteria for the pathological features of liver tissue from patients with non-alcoholic fatty liver disease (NAFLD) remain subjective, causing confusion among pathologists and clinicians. In this report, we studied interobserver agreement of NAFLD pathologic features and analyzed causes of disagreement. Methods:Thirty-one cases of clinicopathologically diagnosed NAFLD from 10 hospitals were selected. One hematoxylin and eosin and one Masson’s trichrome-stained virtual slide from each case were blindly reviewed with regard to 12 histological parameters by 13 pathologists in a gastrointestinal study group of the Korean Society of Pathologists. After the first review, we analyzed the causes of disagreement and defined detailed morphological criteria. The glass slides from each case were reviewed a second time after a consensus meeting. The degree of interobserver agreement was determined by multi-rater kappa statistics. Results:Kappa values of the first review ranged from 0.0091–0.7618. Acidophilic bodies (k = 0.7618) and portal inflammation (k = 0.5914) showed high levels of agreement, whereas microgranuloma (k = 0.0984) and microvesicular fatty change (k = 0.0091) showed low levels of agreement. After the second review, the kappa values of the four major pathological features increased from 0.3830 to 0.5638 for steatosis grade, from 0.1398 to 0.2815 for lobular inflammation, from 0.1923 to 0.3362 for ballooning degeneration, and from 0.3303 to 0.4664 for fibrosis.Conclusions:More detailed histomorphological criteria must be defined for correct diagnosis and high interobserver agreement of NAFLD.

Oral delivery of ivermectin using a fast dissolving oral film: Implications for repurposing ivermectin as a pharmacotherapy for alcohol use disorder

Individuals suffering from an alcohol-use disorder (AUD) constitute a major health concern. Preclinical studies in our laboratory show that acute and chronic intraperitoneal (i.p.) administration of ivermectin (IVM) reduces alcohol intake and preference in mice. To enable clinical investigation to use IVM for the treatment of an AUD, development of an oral formulation that can be used in animals as well as long-term preclinical toxicology studies are required. The present work explores the use of a promising alternative dosage form of IVM, fast-dissolving oral films (Cure Pharmaceutical®), to test the efficacy and safety of oral IVM in conjunction with alcohol exposure. We tested the effect of IVM (0.21 mg) using a fast-dissolving oral film delivery method on reducing 10% v/v alcohol (10E) intake in female C57BL/6 mice using a 24-h access two-bottle choice paradigm for 6 weeks (5 days per week). Differences in ethanol intake, preference for ethanol, water intake, fluid intake, food intake, changes in mouse and organ weights, as well as histological changes to kidney, liver, and brain were analyzed. The IVM group drank significantly less ethanol over the 30-day period compared to the placebo (blank strip) and the no-treatment groups. Organ weights did not differ between the groups. Histological evaluation showed no differences in the brain and kidney between groups. In the liver, there was a slight increase in the incidence of microvesicular fatty and degenerative changes of the animals receiving the thin strips. No overt hepatocellular necrosis or perivascular inflammation was noted. Overall, these data support the use of this novel method of oral drug delivery for longer-term studies and should facilitate FDA required preclinical testing that is necessary to repurpose IVM for treatment of an AUD.

Death due to acute fatty liver in pregnancy

Introduction: Acute fatty liver of pregnancy (AFLP) results due to disordered metabolism of fatty acids by mitochondria in the mother, caused by deficiency ofdehydrogenase enzyme. This is a rare instance of a foetus causing metabolic disease in the mother. The ‘working diagnosis’ of the clinicians was HELLP syndrome. The exact cause of death was made clear only after the postmortem examination. Case report : 24 year old primi with 34 weeks of gestation admitted for blood pressure monitoring. She developed jaundice, high blood pressure with proteinurea, marginally elevated liver enzymes, low platelets which warranted termination of pregnancy. Despite the termination of pregnancy, she developed renal failure and hepatic encephalopathy and died on the eleventh day after delivery. Post mortem histopathology of liver revealed that the architecture was not altered and micro-vesicular fat infiltrations in centrilobular and mid zones. Hepatocytes were swollen but inflammation was not evident. Other tissues did not show any fat infiltration. HELLP syndrome was excluded due to absence of macro-vesicular fat infiltration in modest quantities throughout the liver lobules. There were no lobular disarray with hepatocyte dropout, reticulin collapse and portal tract inflammation to suggest viral hepatitis. There were no evidence of drug induced, toxic or viral induced micro-vesicular steatosis. Reye’s syndrome is characterized by uniform micro-vesicular fatty change in the liver and other tissues such as skeletal muscles, kidney and heart. Conclusion: Having excluded all other possibilities, the cause of death was ascertained as AFLP and this emphasizes the value of correct histopathological diagnosis . Medico-Legal Journal of Sri Lanka 2013; 1(2) : 42-45

Protective effects of different dietary proportion of fish oil on hepatic injury in chronic ethanol‐fed rats

Excess consumption of alcohol is known to cause liver damage. The present study was to investigate the effects of different proportions of fish oil on hepatic aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and oxidative stress in ethanol‐fed rats. Male Wistar rats were divided into six groups (n=5/group) and fed with either the control diet or the alcohol diet, in which the fat composition of both diets was adjusted with 25% or 45% fish oil substitution for olive oil. The groups were C (control), 25%CF (control with 25% fish oil), 45%CF (control with 45% fish oil), E (ethanol), 25%EF (ethanol with 25% fish oil), and 45%EF (ethanol with 45% fish oil). Rats were sacrificed after 8 weeks of the treatments. Results showed that plasma levels of AST, ALT activities, 8‐isoprostaglandinF2α, triglyceride and total cholesterol were significantly decreased and hepatic GSH/GSSG ratio was significantly increased in the 25%EF and 45%EF groups than those in the E group (p&lt;0.05). In addition, the pathologic scores for microvesicular fatty change, degeneration and necrosis were significantly decreased in 25% EF and 45% EF groups as compared with that in the E group (p&lt;0.05). The results suggested that fish oil substitution could prevent ethanol‐induced liver damage. Supported by NSC100–2320‐B‐038–023‐MY3.

Effects of Cigarette Smoke and Ethanol Intake on Mouse Oesophageal Mucosa Changes Induced by Dietary Zinc Deficiency and Deoxycholic Acid Supplementation

The noxious effects of dietary zinc deficiency (ZD) and deoxycholic bile acid (DCA) supplementation in the oesophagus were investigated. The additional influence of cigarette smoke and ethanol intake on the changes in the oesophageal mucosa induced by dietary ZD plus DCA was also assessed. Male C57BL/6 mice were allocated into four groups: Group 1 was fed control diet and groups 2-4 were fed ZD plus DCA diet. After 5 weeks, groups 3 and 4 were exposed to 10% ethanol intake or cigarette smoke for 15 weeks, respectively. All animals were euthanized at the end of week 20, and the oesophagus, lung, liver and colon were collected and analysed by conventional morphology. Cell proliferation was assessed in the oesophageal mucosa by Ki-67 immunohistochemistry and cyclooxygenase 2 (COX-2) protein by Western blotting. Dietary ZD plus DCA treatment induced mild hyperkeratosis and hyperplasia, increased cell proliferation index and COX-2 protein expression in the oesophagus, and intranuclear inclusion, karyocytomegaly and microvesicular fatty change in the liver. Cigarette smoke increased COX-2 protein expression in oesophageal mucosa and irregular enlargement of alveolus and alveolar ductal air spaces, while ethanol enhanced liver damage induced by ZD plus DCA diet. These findings indicate that dietary ZD plus DCA treatment during 20 weeks induces a pattern of chemical oesophageal injury but not Barrett's-like lesions.

Perinatal Transmission of Yellow Fever, Brazil

Perinatal Transmission of Yellow Fever, Brazil

Central nervous system pathology in fatal swine-origin influenza A H1N1 virus infection in patients with and without neurological symptoms: an autopsy study of 15 cases

The first influenza pandemic of the twenty-first century was caused by a swine-origin, influenza A (H1N1) virus that contained genes from human, swine, and avian influenza A viruses [4]. It has long been recognized that a small subset of influenza patients develops neurologic complications [1]. Central nervous system (CNS) pathology in influenza virus infection is thought to be indirect and multifactorial [15] and whether H1N1 infects the brain or cerebrospinal fluid (CSF) remains controversial [2]. The current model is that H1N1 triggers a cytokine storm that disrupts the blood–brain barrier and activates glial cells. Subsequent disseminated intravascular coagulation (DIC) and liver and renal dysfunction triggered by hypercytokinemia may also contribute to CNS damage [15]. A number of clinical syndromes affecting the CNS have been described in the context of influenza infection. Although these syndromes have overlapping features and can be caused by other viruses and toxic agents, they have specific clinical, radiological, and laboratory criteria for their diagnosis and the pathogenesis and predisposing factors differ. Classical Reye’s syndrome is a non-inflammatory encephalopathy with associated hepatic microvesicular fatty change and hyperammonemia, and is usually precipitated by the use of salicylates [5]. Reye’slike syndrome occurs at a younger age and does not have the microvesicular fatty change and mitochondrial abnormality of classical Reye’s syndrome [13] and it is not associated with salicylate use. Hemorrhagic shock and encephalopathy syndrome (HSES) occurs in infants, and there is associated fever, shock, DIC, hepatic and renal dysfunction, and the brain shows edema with occasional intracranial hemorrhage [3]. Acute necrotizing encephalopathy (ANE) was first described in Japan in 1995 [8], and then subsequently in other countries [7, 16]. MRI and autopsy studies show bilateral symmetrical infarcts in the thalamus, basal ganglia, cerebellar and cerebral white matter, and brainstem tegmentum. CSF protein is typically elevated and the mortality rate is high. Some infants have complex febrile seizures at the onset, followed by delayed involvement of bilateral frontal lobes or the entire cerebral hemisphere [12]. Recently, familial and recurrent ANE has been described and is associated with mutation in the Ranbinding protein gene (RANBP2) [10]. Like earlier influenza pandemics, the recent pandemic of novel influenza A (H1N1) infection has resulted in a number of cases with neurological complications [2, 7, 16]. The purpose of the present study was to document the changes present in the brains of fatal H1N1 virus patients to determine if cases without documented neurologic A. Mukherjee and J.E.G. Peterson contributed equally to this work.

Macaca radiata (bonnet monkey): a spontaneous model of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a well-recognized condition that includes a spectrum of clinicopathology conditions ranging from steatotosis to cirrhosis and liver failure. Available animal models are not ideal as they show only a partial resemblance to characteristic human NAFLD. This study was aimed at identifying a nonhuman primate model of NAFLD resembling features of human NAFLD, which will be useful in understanding the mechanism of the onset of this disease and for developing novel therapeutic modalities. The histological status of the liver and serum levels of triglycerides (TG), cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) of aged bonnet monkeys were compared with that of the aged rhesus and adult bonnet monkeys. Histopathology and immunostaining of liver sections and oil red 'O' confirmed NAFLD in aged bonnet monkeys. Aged bonnet monkeys showed a significant (P<0.01) increase in serum TG, AST and ALT compared with aged rhesus and adult bonnet monkeys. Histopathology of the liver of aged bonnet macaques showed diffused microvesicular and macrovesicular fatty changes, perivenular and portal and perisinusoidal fibrosis with fatty degeneration of hepatocytes, and immunostaining of liver sections was suggestive of NAFLD. The spontaneous occurrence of NAFLD in normal animals is rare, but aged bonnet monkeys may serve as a unique animal model for studies related to NAFLD because they mimic pathophysiological features of human NAFLD.

Cholesterol-fed rabbit as a unique model of nonalcoholic, nonobese, non-insulin-resistant fatty liver disease with characteristic fibrosis

The number of patients suffering from metabolic syndrome is increasing rapidly. Metabolic syndrome causes severe pathological changes in various organs, including the liver, and its main phenotype is nonalcoholic fatty liver disease (NAFLD). NAFLD has a broad spectrum ranging from simple fatty change to severe steatohepatitis with marked fibrosis. Recently, several experimental animal models for NAFLD have been proposed. However, most were established by rather artificial conditions such as genetic alteration. In the present study, we tried to establish a unique animal model mimicking some of the physiopathological features of NAFLD using high-cholesterol-fed rabbits. Male rabbits fed with standard rabbit food containing 1% cholesterol for 8 weeks and 12 weeks were compared to controls (six rabbits/group). The weight of food was strictly restricted to 100 g/rabbit per day. Body weights and fasting plasma insulin levels showed no significant differences among the groups. In contrast, characteristic fine fibrosis was extended from perivenular to pericellular areas, and microvesicular fatty change with ballooning degeneration was observed in perivenular areas in livers of the cholesterol-fed rabbits. Increase of serum cholesterol level, activation of hepatic stellate cells, and exposure to oxidative stress were also recognized. Cholesterol-fed rabbits share several physiopathological features of NAFLD. Because this model did not show insulin resistance or obesity, it may be useful for elucidating the mechanism of NAFLD related mainly to hyperlipidemia.

Oral administration of S-nitroso-N-acetylcysteine prevents the onset of non alcoholic fatty liver disease in rats

To evaluate the potential of S-nitroso-N-acetylcysteine (SNAC) in inhibition of lipid peroxidation and the effect of oral SNAC administration in the prevention of nonalcoholic fatty liver disease (NAFLD) in an animal model. NAFLD was induced in Wistar male rats by choline-deficient diet for 4 wk. SNAC-treated animals (n=6) (1.4 mg/kg per day of SNAC, orally) were compared to 2 control groups: one (n=6) received PBS solution and the other (n=6) received NAC solution (7 mg/kg per day). Histological variables were semiquantitated with respect to macro and microvacuolar fat changes, its zonal distribution, foci of necrosis, portal and perivenular fibrosis, and inflammatory infiltrate with zonal distribution. LOOHs from samples of liver homogenates were quantified by HPLC. Nitrate levels in plasma of portal vein were assessed by chemiluminescence. Aqueous low-density lipoprotein (LDL) suspensions (200 microg protein/mL) were incubated with CuCl(2) (300 micromol/L) in the absence and presence of SNAC (300 micromol/L) for 15 h at 37 degree Celsius. Extent of LDL oxidation was assessed by fluorimetry. Linoleic acid (LA) (18.8 micromol/L) oxidation was induced by soybean lipoxygenase (SLO) (0.056 micromol/L) at 37 degree Celsius in the presence and absence of N-acetylcysteine (NAC) and SNAC (56 and 560 micromol/L) and monitored at 234 nm. Animals in the control group developed moderate macro and microvesicular fatty changes in periportal area. SNAC-treated animals displayed only discrete histological alterations with absence of fatty changes and did not develop liver steatosis. The absence of NAFLD in the SNAC-treated group was positively correlated with a decrease in the concentration of LOOH in liver homogenate, compared to the control group (0.7+/-0.2 nmol/mg vs 3.2+/-0.4 nmol/mg protein, respectively, P<0.05), while serum levels of aminotransferases were unaltered. The ability of SNAC in preventing lipid peroxidation was confirmed in in vitro experiments using LA and LDL as model substrates. Oral administration of SNAC prevents the onset of NAFLD in Wistar rats fed with choline-deficient diet. This effect is correlated with the ability of SNAC to block the propagation of lipid peroxidation in vitro and in vitro.

Comparative Effects of Curcumin and an Analogue of Curcumin in Carbon Tetrachloride‐Induced Hepatotoxicity in Rats

We have evaluated the comparative effect of curcumin (diferuloyl methane) and its analogue [bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione] (BDMC-A) on carbon tetrachloride-induced hepatotoxicity in rats. Administration of carbon tetrachloride (3 ml/kg/week) for three months significantly (P<0.05) increased the levels of marker enzymes such as aspartate transaminase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT). The levels of plasma thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides were also significantly (P<0.05) increased. We have observed a significant (P<0.05) decrease in the levels of plasma reduced glutathione (GSH), vitamin C and vitamin E. There was a significant (P<0.05) increase in the levels of TBARS and hydroperoxides in liver and kidney and a significant (P<0.05) decrease in the activities of enzymic antioxidants- superoxide dismutase (SOD), catalase and GSH peroxidase along with GSH in CCl(4)-treated rats. Oral administration of curcumin and BDMC-A to CCl(4)-induced rats for a period of three months significantly (P<0.05) decreased the levels of marker enzymes, plasma TBARS and hydroperoxides and increased the levels of plasma and tissue antioxidants. Histopathological studies of liver also showed protective effect of curcumin and BDMC-A. We have observed thickening of blood vessels and microvesicular fatty changes around the portal triad in CCl(4)-treated rat liver. Treatment with curcumin showed only mild sinusoidal dilatation while with BDMC-A there was only mild portal inflammation. The effect exerted by BDMC-A was found to be more promising than curcumin.