Administration Of High-fat Diet Research Articles

Dimeric Histidine as a Novel Free Radical Scavenger Alleviates Non-Alcoholic Liver Injury.

Non-alcoholic liver injury (NLI) is a common disease worldwide. Since free radical damage in the liver is a crucial initiator leading to diseases, scavenging excess free radicals has become an essential therapeutic strategy. To enhance the antioxidant capacity of histidine, we synthesized a protonated dimeric histidine, H-bihistidine, and investigated its anti-free radical potential in several free-radical-induced NLI. Results showed that H-bihistidine could strongly scavenge free radicals caused by H2O2, fatty acid, and CCl4, respectively, and recover cell viability in cultured hepatocytes. In the animal model of nonalcoholic fatty liver injury caused by high-fat diet, H-bihistidine reduced the contents of transaminases and lipids in serum, eliminated the liver’s fat accumulation, and decreased the oxidative damage. Moreover, H-bihistidine could rescue CCl4-induced liver injury and recover energy supply through scavenging free radicals. Moreover, liver fibrosis prepared by high-fat diet and CCl4 administration was significantly alleviated after H-bihistidine treatment. This study suggests a novel nonenzymatic free radical scavenger against NLI and, potentially, other free-radical-induced diseases.

The Protective Effects of Live and Pasteurized Akkermansia muciniphila and Its Extracellular Vesicles against HFD/CCl4-Induced Liver Injury.

ABSTRACTAkkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The response of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs was examined in quiescent, lipopolysaccharide (LPS)-activated LX-2 cells. Liver fibrosis was induced in 8-week-old C57BL/6 mice, using a high-fat diet (HFD) and carbon tetrachloride (CCl4) administration for 4 weeks. The mice were concomitantly treated via oral gavage with three forms of bacteria. The relative expression of different fibrosis and inflammatory markers was assessed in the tissues. Histological markers, serum biochemical parameters, and cytokine production were also analyzed, and their correlations with the relative abundance of targeted fecal bacteria were examined. All A. muciniphila preparations exhibited protective effects against HSC activation; however, EVs showed the greatest activity in HSC regression. Oral gavage with A. muciniphila ameliorated the serum biochemical and inflammatory cytokines and improved liver and colon histopathological damages. The relative expression of fibrosis and inflammatory biomarkers was substantially attenuated in the tissues of all treated mice. The composition of targeted stool bacteria in the live A. muciniphila group was clearly different from that in the fibrosis group. This study indicated that A. muciniphila and its derivatives could successfully protect against HFD/CCl4-induced liver injury. However, further studies are needed to prove the beneficial effects of A. muciniphila on the liver.IMPORTANCE Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The results of the present study indicated that oral administration of live and pasteurized A. muciniphila and its EVs could normalize the fecal targeted bacteria composition, improve the intestinal permeability, modulate inflammatory responses, and subsequently prevent liver injury in HFD/CCl4-administered mice. Following the improvement of intestinal and liver histopathology, HFD/CCl4-induced kidney damage and adipose tissue inflammation were also ameliorated by different A. muciniphila treatments.

Sitagliptin attenuates endothelial dysfunction independent of its blood glucose controlling effect

Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrovascular endothelium in diabetes and explore the role of autophagy in this process. Diabetic rats were induced through administration of high-fat diet and intraperitoneal injection of streptozotocin. Then diabetic rats were treated with or without sitagliptin for 12 weeks. Endothelial damage and autophagy were measured. Human umbilical vein endothelial cells were cultured either in normal glucose or in high glucose medium and intervened with different concentrations of sitagliptin. Rapamycin was used to induce autophagy. Cell viability, apoptosis and autophagy were detected. The expressions of proteins in c-Jun N-terminal kinase (JNK)-Bcl-2-Beclin-1 pathway were measured. Sitagliptin attenuated injuries of endothelium in vivo and in vitro. The expression of microtubuleassociated protein 1 light chain 3 II (LC3II) and beclin-1 were increased in aortas of diabetic rats and cells cultured with high-glucose, while sitagliptin inhibited the over-expression of LC3II and beclin-1. In vitro pre-treatment with sitagliptin decreased rapamycin-induced autophagy. However, after pretreatment with rapamycin, the protective effect of sitagliptin on endothelial cells was abolished. Further studies revealed sitagliptin increased the expression of Bcl-2, while inhibited the expression of JNK in vivo. Sitagliptin attenuates injuries of vascular endothelial cells caused by high glucose through inhibiting over-activated autophagy. JNK-Bcl-2-Beclin-1 pathway may be involved in this process.

The antihyperlipidaemic and hepatoprotective effect of Ipomoea batatas L. leaves extract in high-fat diet rats

The administration of high-fat diets can increase the body's lipid level and damage the organs. Purple sweet potato leaf (Ipomoea batatas L.) was reported as an antioxidant against free radicals. This study aimed to observe the sweet potato leaf extract's activity on decreasing lipid profile and hepatoprotective effect in high-fat diet fed rats. The treatment animals were divided into five groups, namely normal control, high-fat diet (HFD) control, the treatment group of purple sweet potato leaf extract (SPLE) doses 100 mg/kg BW, 200 mg/kg BW and 400 mg/kg BW which fed with high-fat diet for 14 days and SPLE for 28 days. After treatment was completed, the blood was collected for the detection of cholesterol, triglyceride, serum glutamic oxaloacetic transaminase (SGOT), and serum glutamic pyruvate transaminase (SGPT). After that, the animals were sacrificed, and a liver histopathology observation was conducted using Haematoxylien and Eosin staining. The result showed a significant decrease in cholesterol and triglyceride levels (p≤0.05) compared to the negative group in all treated groups. The SGOT and SGPT enzymes in all of treatment groups were also found to decrease compared with HFD control. The result was confirmed by the histopathological observations. The finding suggested the potency of SPLE for antihyperlipidaemic and hepatoprotective agent.

Comparison of glucose lowering ability of Pioglitazone and Glimepiride in Steptozotocin induced type 2 diabetes mellitus male mice model

Introduction: Diabetes mellitus type 2 is a global health problem expanding at an alarming rate and putting individuals at high risk of microvascular and macrovascular complications. Life style modification and drugs intervention can help achieve normal glucose levels. Aim &Objective: To compare the hypoglycemic activity of glimepiride and pioglitazone in a type 2 diabetes mellitus induced male mice model. Place & Duration of study: This study was carried out in the animal house of National Institute of Health (NIH), Islamabad from 7th November 2013 till 21st January 2014. Materials & Methods: Forty albino Balb/C male mice were divided randomly into groups I-IV (n=10). Group I served as normal control group. In rest of mice from group II-IV, type 2 diabetes mellitus was induced by administration of high fat diet (HFD) for two weeks followed by low dose (40 mg/kg) intra-peritoneal streptozotocin (STZ) injections for four consecutive days. Group II served as the disease control group. Group III received Glimepiride in a dose of 2mg/kg body wt. while group IV was administered Pioglitazone in a dose of 30mg/kg body wt. Both the drugs were given orally once a day. Samples were taken at the end of ten weeks. Results: The blood samples estimated for fasting blood glucose (FBG) & glycosylated hemoglobin (HbA1c %) levels showed that both glimepiride and pioglitazone equally lowered the FBG and HbA1c% levels. However, pioglitazone lowered the FBG and HbA1c levels slightly more than Glimepride. Conclusion: Glimepiride and pioglitazone lowered the FBG and HbA1c levels in type 2 diabetes induced male mice with the later having slightly more reduction than Glimepride. Key words: Glimepiride, Pioglitazone, Streptozotocin, type 2 Diabetes Mellitus.

Effects of Hamo NK hard capsule on experimental atherosclerosis model

This study evaluated the effects of Hamo NK hard capsule on athresclerosis using experimental atherosclerosis model. NewZealand White rabbits were fed a high-fat diet (HFD) containing cholesterol and peanut oil. The animals received oral administration of HFD and Hamo NK hard capsule at two doses of 0.126 and 0.378 g/kg bw/day for 8 consecutive weeks. Blood samples were collected for analyis of biochemical parameters at before treatment, week 4 and week 8. Histopathology assessments of the aortic artery and liver were carried out at the end of the experiment. Hamo NK was effective in reducing serum triglyceride level after 8 weeks of the experiment. In addition, Hamo NK at two doses of 0.126 g/kg b.w and 0.378 g/kg b.w for 8 consecutive weeks did not affect the cholesterol, LDL-C and HDL-C concentrations induced by a HFD. Hamo NK at the dose of 0.126 g/kg bw/day was not only able to decrease significant aortic surface lesions but also capable of managing atherosclerosis plaques formation in aorta; whereas theses activities were not notiaceable at the dose of 0.378 g/kg b.w.

Emodin palliates high-fat diet-induced nonalcoholic fatty liver disease in mice via activating the farnesoid X receptor pathway

BackgroundCassia mimosoides Linn (CMD) is a traditional Chinese herb that clears liver heat and dampness. It has been widely administered in clinical practice to treat jaundice associated with damp-heat pathogen and obesity. Emodin (EMO) is a major bioactive constituent of CMD that has apparent therapeutic efficacy against obesity and fatty liver. Here, we investigated the protective effects and underlying mechanisms of EMO against high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD). ObjectiveWe aimed to investigate whether EMO activates farnesoid X receptor (FXR) signaling to alleviate HFD-induced NAFLD. Materials and methodsIn vivo assays included serum biochemical indices tests, histopathology, western blotting, and qRT-PCR to evaluate the effects of EMO on glucose and lipid metabolism disorders in wild type (WT) and FXR knockout mice maintained on an HFD. In vitro experiments included intracellular triglyceride (TG) level measurement and Oil Red O staining to assess the capacity of EMO to remove lipids induced by oleic acid and palmitic acid in WT and FXR knockout mouse primary hepatocytes (MPHs). We also detected mRNA expression of FXR signaling genes in MPHs. ResultsAfter HFD administration, body weight and serum lipid and inflammation levels were dramatically increased in the WT mice. The animals also presented with impaired glucose tolerance, insulin resistance, and antioxidant capacity, liver tissue attenuation, and pathological injury. EMO remarkably reversed the foregoing changes in HFD-induced mice. EMO improved HFD-induced lipid accumulation, insulin resistance, inflammation, and oxidative stress in a dose-dependent manner in WT mice by inhibiting FXR expression. EMO also significantly repressed TG hyperaccumulation by upregulating FXR expression in MPHs. However, it did not improve lipid accumulation, insulin sensitivity, or glucose tolerance in HFD-fed FXR knockout mice. ConclusionsThe present study demonstrated that EMO alleviates HFD-induced NAFLD by activating FXR signaling which improves lipid accumulation, insulin resistance, inflammation, and oxidative stress.

Transcriptomic coordination at hepatic steatosis indicates robust immune cell engagement prior to inflammation

BackgroundDeregulation in lipid metabolism leads to the onset of hepatic steatosis while at subsequent stages of disease development, the induction of inflammation, marks the transition of steatosis to non-alcoholic steatohepatitis. While differential gene expression unveils individual genes that are deregulated at different stages of disease development, how the whole transcriptome is deregulated in steatosis remains unclear.MethodsUsing outbred deer mice fed with high fat as a model, we assessed the correlation of each transcript with every other transcript in the transcriptome. The onset of steatosis in the liver was also evaluated histologically.ResultsOur results indicate that transcriptional reprogramming directing immune cell engagement proceeds robustly, even in the absence of histologically detectable steatosis, following administration of high fat diet. In the liver transcriptomes of animals with steatosis, a preference for the engagement of regulators of T cell activation and myeloid leukocyte differentiation was also recorded as opposed to the steatosis-free livers at which non-specific lymphocytic activation was seen. As compared to controls, in the animals with steatosis, transcriptome was subjected to more widespread reorganization while in the animals without steatosis, reorganization was less extensive. Comparison of the steatosis and non-steatosis livers showed high retention of coordination suggesting that diet supersedes pathology in shaping the transcriptome’s profile.ConclusionsThis highly versatile strategy suggests that the molecular changes inducing inflammation proceed robustly even before any evidence of steatohepatitis is recorded, either histologically or by differential expression analysis.

ASSESSING THE EFFECTS OF ORLISTAT AS AN ANTI-OBESITY DRUG IN HIGH FAT DIET INDUCED OBESITY IN MALE RATS

The present work was designed to evaluate the effectiveness of the orlistat drug on some hormones and biochemical parameters in male rats received a high fat diet (HFD). Twenty-four rats were divided into four groups: 1st group administered normal diet, 2nd group administered HFD, the 3rd group administered HFD plus 9.5 mg/kg b.w./day orlistat, and the 4th group administered HFD diet plus 19 mg/kg b.w./day orlistat. The experimental period was for four weeks. At the end of the experiment, blood samples were obtained for biochemical and hormonal assays. The administration of HFD for four weeks increased significantly the weight gain, serum total cholesterol (TC), triglycerides (TAG), low density lipoprotein (LDL-c), glucose, insulin, triiodothyronine (T3), thyroxine (T4), leptin, with the significant decrease in high density lipoprotein (HDL-c), ghrelin, thyrotropin (TSH) and testosterone hormones in the serum as compared with the control group. The treatment with orlistat neutralized the levels of the measured parameters as compared with HFD fed rats and the results were correlated with the dose of orlistat. In conclusion, an improvement was observed in the biochemical and hormonal results by the treatment with orlistat drug.

Verbascoside inhibits the progression of atherosclerosis in high fat diet induced atherosclerosis rat model.

Atherosclerosis is thickening of arterial wall, which causes several complications. This study evaluated the protective effect of verbascoside against atherosclerosis and the potential molecular mechanism involved. Atherosclerosis was induced by administering a high-fat diet to rats for 3 months and vitamin D3 for 4 days. Verbascoside (2 mg/kg p.o.) was administered for 6 weeks after the end of high-fat diet administration. The serum levels of inflammatory mediators and the lipid profile were determined, and atherosclerotic lesions were observed via Sudan IV staining. Moreover, immunohistochemical analysis, Western blot assay and qRT-PCR were performed to determine the effect of verbascoside on the AMPK/mTOR pathway in atherosclerosis. The results reveal that verbascoside ameliorated the altered serum levels of inflammatory mediators and the lipid profile as well as the organ coefficients in the atherosclerotic rats. A significant decrease in atherosclerotic lesions was detected in the verbascoside-treated group than the atherosclerosis group. AMPK and mTOR mRNA expression decreased in aortic tissues of the verbascoside-treated group compared to the atherosclerosis group. These data suggest that verbascoside ameliorates atherosclerosis by decreasing hyperlipidaemia in atherosclerosis induced by a high-fat diet.

Iron biodistribution profile changes in the rat spleen after administration of high-fat diet or iron supplementation and the role of curcumin.

Curcumin as active metal chelating and antioxidant agent has a potential role in metal reduction and free radicals' neutralization in tissues. Of note, long-term administration of high fat diet (HFD) is considered as a main factor of blood serum iron deficiency. This study aimed to investigate the biodistribution profiles of iron in the spleen after long-term administration of HFD along with iron supplementation. Furthermore, the ameliorative role of curcumin to reduce iron accumulation level and improve the histological abnormalities produced by iron in spleen will be evaluated in the rats. Treated albino rats of this experiment were divided into six groups. Group I was a control group where group II was treated with HFD. Group III and group IV were treated with combination of HFD and curcumin or HFD and iron supplement respectively. Additionally, group V and group VI were treated with combination of HFD, iron supplement and curcumin or curcumin only respectively. Mainly histological analysis was used to investigate iron biodistribution and induced abnormalities in spleen under light microscope. The histochemical specific staining of iron in the spleen showed different biodistribution profiles of iron in the spleen. Administration of the HFD or HFD and iron supplementation increased the iron accumulation in the spleen. Where, curcumin administration with HFD (Group III) or with HFD and iron supplementation (Group V) significantly reduced the iron levels in the spleen. The splenic tissue inflammation, cellular apoptosis and fibrosis produced by higher iron accumulation was ameliorated after administration of curcumin supplementation as shown in the animals treated with HFD/curcumin (Group III) or HFD/iron supplement/curcumin (Group V). This study recommended that, it is preferable to use iron supplementation along with curcumin supplement for less than 4months to avoid additional iron accumulation in the healthy organs.

A Novel Mouse Model of Cardiometabolic Heart Failure with Preserved Ejection Fraction

Background Heart failure with preserved ejection fraction (HFpEF) is considered one of the greatest unmet clinical needs in cardiology that currently affects approximately 13 million people. With a lack of FDA-approved therapies, translational animal modeling is essential to identify beneficial HFpEF therapies with potential clinical impact. One recently reported murine HFpEF model involves C57/BL6N mice treated with high-fat diet (HFD) plus the eNOS inhibitor, L-NAME, on a continuous basis. The chronic administration of L-NAME fails to mimic human HFpEF and limits the study of therapies that modulate eNOS function and nitric oxide modulation. In the present study, we explored the combination of a Western high-fat (HFD) and the eNOS inhibitor, L-NAME administered continuously vs. HFD administration followed by withdrawal of L-NAME. Methods C57/BL6N mice at 10-12 weeks old (n = 4-8 per study group) were placed on a Western HFD (60% kCal from fat) and 0.5 g/L/d L-NAME via drinking water. At 20-22 weeks of age, 10 weeks into the protocol, L-NAME was withdrawn (WD) in one group while the HFD was maintained throughout the experimental protocol. We continued to assess the HFpEF phenotype in both study groups (HFD + L-NAME vs. HFD + L-NAME WD) as compared to age-matched control for an additional 5 weeks. Results Following L-NAME withdrawal (n=8) we observed that the cardiometabolic HFpEF phenotype was maintained in the C57/BL6N mice. (A). Diastolic functional measure E/E’ ratio remained pathologically elevated compared to untreated control animals (n=7) (B). Preservation of left ventricular ejection fraction (LVEF) was observed in the absence of L-NAME removal demonstrating continued preservation of ejection fraction. Conclusion These data clearly demonstrate that the severe cardiometabolic HFpEF phenotype is maintained in C57/BL6N mice following 10 weeks of exposure to Western diet and L-NAME despite withdrawal of the NO inhibitor. These data indicate that the deleterious effects of L-NAME induced during the initial 10 weeks of the protocol results in sustained cardiovascular dysfunction. This novel HFpEF model more faithfully reproduces HFpEF observed in patients and allows for the investigation of eNOS enzymatic function and nitric oxide modulation in this pre-clinical animal model.

High‐Fat High‐Sucrose Diet Increases ACE2 Receptor Expression in Lung and Pancreatic Islets in SIV‐Infected Rhesus Macaques: Implications for Increased Risk for SARS‐CoV‐2 Infection

People with pre‐existing conditions including obesity, diabetes, and kidney disease are at greater risk for complications of COVID‐19, the disease caused by SARS‐CoV‐2 infection. Predisposing risk factors could include poor dietary quality and at‐risk alcohol use. Increased survival and aging of people living with HIV (PLWH) on antiretroviral therapy (ART) is complicated by comorbidities including at‐risk alcohol use, metabolic dysregulation, diabetes, and chronic renal disease, with obesity and metabolic syndrome highest in southern states. We hypothesize that poor dietary quality in combination with at‐risk alcohol use may increase risk factors for SARS‐CoV‐2 infection in PLWH. To test this hypothesis, biospecimen obtained from a longitudinal study in female rhesus macaques (macaca mulatta) were used to determine whether high‐fat high‐sucrose diet (HFD; protein/fat/carbohydrates 16/42/42% of total kcal and 27% sucrose by weight) and chronic binge alcohol administration (CBA) increased expression of the machinery required for SARS‐CoV‐2 cell entry. Female macaques (n=10) were assigned to HFD or standard chow diet (SD; protein/fat/carbohydrates 29/14/57% of total kcal) and CBA (50‐60 mM peak blood alcohol, 5 days/week) or isovolumetric water (VEH) beginning 3 months before SIVmac251 infection. ART was initiated at 2.5 months of SIV infection. Tissue samples including lung, pancreas, and kidney were collected at study endpoint (~12 months post‐SIV infection). Immunohistochemistry was performed on formalin‐fixed, paraffin embedded samples to determine protein expression of angiotensin converting enzyme 2 (ACE2) receptor and transmembrane serine protease 2 (TMPRSS2). Images were obtained at 20x magnification and fluorescence intensity was used for quantification. RNA was extracted from frozen samples and mRNA expression of ACE2 and TMPRSS2 was measured by qPCR and quantified relative to ribosomal protein S13. Normality of data was verified and outliers identified using Grubbs test. Data were then analyzed using a 2 (alcohol) × 2 (diet) ANOVA. Protein expression of ACE2 in the lung (p<0.01, η2=0.59), whole pancreas (p<0.05, η2=0.64), and pancreatic islets (p<0.05, η2=0.44) was greater in HFD‐ than SD‐fed macaques and was not significantly altered by CBA. No alcohol‐ or diet‐mediated differences in ACE2 protein expression were observed for whole kidney or proximal tubules. No alcohol‐ or diet‐mediated differences in protein expression of TMPRSS2 or relative mRNA expression of ACE2 or TMPRSS2 were observed. Results indicate that a high‐fat, high‐sucrose diet increases expression of the ACE2 receptor in SIV‐infected female macaques. Because the ACE2 receptor is required for SARS‐CoV‐2 cell entry, this diet‐mediated increase in expression may increase risk for greater vulnerability to COVID‐19 disease and associated complications. These data provide direct evidence for a link between dietary quality and risk for SARS‐CoV‐2 infection in the context of SIV/HIV infection, urging diet counseling and increased access to higher‐quality foods in this population.

E2F1 and E2F2-Mediated Repression of CPT2 Establishes a Lipid-Rich Tumor-Promoting Environment.

Lipid metabolism rearrangements in nonalcoholic fatty liver disease (NAFLD) contribute to disease progression. NAFLD has emerged as a major risk for hepatocellular carcinoma (HCC), where metabolic reprogramming is a hallmark. Identification of metabolic drivers might reveal therapeutic targets to improve HCC treatment. Here, we investigated the contribution of transcription factors E2F1 and E2F2 to NAFLD-related HCC and their involvement in metabolic rewiring during disease progression. In mice receiving a high-fat diet (HFD) and diethylnitrosamine (DEN) administration, E2f1 and E2f2 expressions were increased in NAFLD-related HCC. In human NAFLD, E2F1 and E2F2 levels were also increased and positively correlated. E2f1 -/- and E2f2 -/- mice were resistant to DEN-HFD-induced hepatocarcinogenesis and associated lipid accumulation. Administration of DEN-HFD in E2f1 -/- and E2f2 -/- mice enhanced fatty acid oxidation (FAO) and increased expression of Cpt2, an enzyme essential for FAO, whose downregulation is linked to NAFLD-related hepatocarcinogenesis. These results were recapitulated following E2f2 knockdown in liver, and overexpression of E2f2 elicited opposing effects. E2F2 binding to the Cpt2 promoter was enhanced in DEN-HFD-administered mouse livers compared with controls, implying a direct role for E2F2 in transcriptional repression. In human HCC, E2F1 and E2F2 expressions inversely correlated with CPT2 expression. Collectively, these results indicate that activation of the E2F1-E2F2-CPT2 axis provides a lipid-rich environment required for hepatocarcinogenesis. SIGNIFICANCE: These findings identify E2F1 and E2F2 transcription factors as metabolic drivers of hepatocellular carcinoma, where deletion of just one is sufficient to prevent disease. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/11/2874/F1.large.jpg.

Cache Domain Containing 1 Is a Novel Marker of Non-Alcoholic Steatohepatitis-Associated Hepatocarcinogenesis.

Simple SummaryThe aim of the present study was to discover novel early molecular biomarkers of liver neoplasms which arise in non-alcoholic steatohepatitis (NASH) Stelic Animal Model (STAM) mice. Significant increase of lipid deposits, hepatocyte ballooning, fibrosis, and incidences and multiplicities of hepatocellular adenomas and carcinomas were detected in the livers of 18-week-old STAM mice. From the results of proteome analysis of STAM mice hepatocellular carcinomas, significant elevation of a novel protein, cache domain-containing 1 (CACHD1) was found. Furthermore, we observed CACHD1-positive foci in STAM mice livers, which number, area, and cell proliferation index within the foci were significantly elevated. Results of immunohistochemical and in vitro functional analysis indicated that CACHD1 may become a useful early biomarker and potential molecular target in NASH-associated hepatocarcinogenesis, which is involved in control of cell proliferation, autophagy and apoptosis.In the present study, potential molecular biomarkers of NASH hepatocarcinogenesis were investigated using the STAM mice NASH model, characterized by impaired insulin secretion and development of insulin resistance. In this model, 2-days-old C57BL/6N mice were subjected to a single subcutaneous (s.c.) injection of 200 μg streptozotocin (STZ) to induce diabetes mellitus (DM). Four weeks later, mice were administered high-fat diet (HFD) HFD-60 for 14 weeks (STAM group), or fed control diet (STZ group). Eighteen-week-old mice were euthanized to allow macroscopic, microscopic, histopathological, immunohistochemical and proteome analyses. The administration of HFD to STZ-treated mice induced significant fat accumulation and fibrosis development in the liver, which progressed to NASH, and rise of hepatocellular adenomas (HCAs) and carcinomas (HCCs). In 18-week-old animals, a significant increase in the incidence and multiplicity of HCAs and HCCs was found. On the basis of results of proteome analysis of STAM mice HCCs, a novel highly elevated protein in HCCs, cache domain-containing 1 (CACHD1), was chosen as a potential NASH-HCC biomarker candidate. Immunohistochemical assessment demonstrated that STAM mice liver basophilic, eosinophilic and mixed-type altered foci, HCAs and HCCs were strongly positive for CACHD1. The number and area of CACHD1-positive foci, and cell proliferation index in the area of foci in mice of the STAM group were significantly increased compared to that of STZ group. In vitro siRNA knockdown of CACHD1 in human Huh7 and HepG2 liver cancer cell lines resulted in significant inhibition of cell survival and proliferation. Analysis of the proteome of knockdown cells indicated that apoptosis and autophagy processes could be activated. From these results, CACHD1 is an early NASH-associated biomarker of liver preneoplastic and neoplastic lesions, and a potential target protein in DM/NASH-associated hepatocarcinogenesis.

Chronic Mild Unpredictable Stress and High-Fat Diet Given during Adolescence Impact Both Cognitive and Noncognitive Behaviors in Young Adult Mice.

Stress and diet are intricately linked, and they often interact in a negative fashion. Increases in stress can lead to poor food choices; adolescence is a period that is often accompanied by increased levels of stress. Stress and poor dietary choices can affect learning and memory; it is important to understand their combined effects when occurring during crucial developmental periods. Here, we present evidence that chronic mild unpredictable stress (CMUS) and high-fat diet (HFD) impact both cognitive and noncognitive behaviors when assessed after four weeks of manipulation in four-week old mice. CMUS mice had increased anxiety in the open field test (OFT) (p = 0.01) and spent more time in the open arms of the elevated zero maze (EZM) (p < 0.01). HFD administration was shown to interact with CMUS to impair spatial memory in the Morris Water Maze (MWM) (p < 0.05). Stress and diet also led to disturbances in non-cognitive behaviors: CMUS led to significantly more burrowing (p < 0.05) and HFD administration led to the poorer nest construction (p < 0.05). These findings allow for researchers to assess how modifying lifestyle factors (including diet and stress) during adolescence can serve as a potential strategy to improve cognition in young adulthood.

High-fat Feeding Causes Inflammation and Insulin Resistance in the Ventral Tegmental Area in Mice

The reward system plays an important role in the pathogenesis of not only drug addiction, but also diet-induced obesity. Recent studies have shown that insulin and leptin receptor signaling in the ventral tegmental area (VTA) regulate energy homeostasis and that their dysregulation is responsible for obesity and altered food preferences. Although a high-fat diet (HFD) induces inflammation that leads to insulin and leptin resistance in the brain, it remains unclear whether HFD induces inflammation in the VTA. In the present study, we placed male mice on a chow diet or HFD for 3, 7, and 28 days and evaluated the mRNA expression of inflammatory cytokines and microglial activation markers in the VTA. The HFD group showed significantly elevated mRNA expressions of IL1β at 3 days; tumor necrosis factor-alpha (TNFα), IL1β, IL6, Iba1, and CD11b at 7 days; and TNFα, IL1β, Iba1, and CD11b at 28 days. The changes in TNFα were also confirmed in immunohistochemical analysis. Next, after administration of chow or HFD for 7 days, we selected mice with equal weights in both groups. In experiments using these mice, Akt phosphorylation in the VTA was significantly decreased after intracerebroventricular injection of insulin, whereas no change in STAT3 phosphorylation was found with leptin. Taken together, these results suggest that HFD induces inflammation at least partly associated with microglial activation in the VTA leading to insulin resistance, independently of the energy balance. Our data provide new insight into the pathophysiology of obesity caused by a dysfunctional reward system under HFD conditions.

Vitexin, a fenugreek glycoside, ameliorated obesity-induced diabetic nephropathy via modulation of NF-κB/IkBα and AMPK/ACC pathways in mice

Obesity is one of the most critical risk factors for diabetes mellitus and plays a significant role in diabetic nephropathy (DN). The present investigation aimed to evaluate the possible mechanism of action of vitexin on obesity-induced DN in a high-fat diet (HFD)-fed experimental C57BL/6 mice model. Obesity was induced in male C57BL/6 mice by chronic administration of HFD, and mice were concomitantly treated with vitexin (15, 30, and 60 mg/kg, p.o.). HFD-induced increased renal oxido-nitrosative stress and proinflammatory cytokine levels were significantly inhibited by vitexin. The Western blot analysis suggested that alteration in renal NF-κB, IκBα, nephrin, AMPK, and ACC phosphorylation levels was effectively restored by vitexin treatment. Histological aberration induced in renal tissue after chronic administration of HFD was also reduced by vitexin. In conclusion, vitexin suppressed the progression of obesity-induced DN via modulation of NF-κB/IkBα and AMPK/ACC pathways in an experimental model of HFD-induced DN in C57BL/6J mice.

Chronic High Fat Diet Induced Weight Gain, Hyperglycaemia and Cognitive Impairment in Albino Mice

With the global rise in consumption of western diet, obesity is becoming a pandemic. High fat and high calorie diet (though more palatable) have been associated with a range of metabolic disorders. Oxidative stress and insulin resistance have a link to the dietary etiology of diabetes and obesity; on the other hand, neuroinflammation and abnormal brain insulin signaling is said to cause cognitive decline when high fat diet (HFD) is consumed. In this study, mice were fed a home-made HFD with a total energy content of 5340kcal/kg. The overall energy contribution of saturated and unsaturated fat was about 70%. Animals were divided into Group I and II of 5 mice each. Group I (control group) were fed normal chow and water ad libidum. Group II (test group) were fed HFD and water ad libidum. HFD significantly (p&lt;0.05) increased the body weight of the test group (40 ±7.7) as compared to control (30 ± 2.9). Blood glucose levels in the test group was also significantly higher (111.6 ± 5.2) compared to the control (77.6 ± 8.7). Morris water maze escape latency in the test group was not significantly different (68 ± 26.3) compared to the control (72 ± 20.9). Similarly, the time spent in target quadrant in the test group was not significantly different (20.8 ± 10.9) compared to the control (15.8 ± 5.6). In the Y-maze the control group had a significantly higher (29.6 ± 3.5) percentage alternations compared to the test group (21 ± 13.1). It is obvious that the chronic administration of HFD in mice altered the body's metabolic processes as evident in the significant weight gain, hyperglycemia and cognitive deficit. These can be attributed to the oxidative damage, insulin dysregulation and pro-inflammatory potentials of HFD.

Assessing the effects of orlistat as an anti-obesity drug in high fat diet induced obesity in male rats

The present work was designed to evaluate the effectiveness of the orlistat drug on some hormones and biochemical parameters in male rats received a high fat diet (HFD). Twenty-four rats were divided into four groups: 1st group administered normal diet, 2nd group administered HFD, the 3rd group administered HFD plus 9.5 mg/kg b.w./day orlistat, and the 4th group administered HFD diet plus 19 mg/kg b.w./day orlistat. The experimental period was for four weeks. At the end of the experiment, blood samples were obtained for biochemical and hormonal assays. The administration of HFD for four weeks increased significantly the weight gain, serum total cholesterol (TC), triglycerides (TAG), low density lipoprotein (LDL−c), glucose, insulin, triiodothyronine (T3), thyroxine (T4), leptin, with the significant decrease in high density lipoprotein (HDL−c), ghrelin, thyrotropin (TSH) and testosterone hormones in the serum as compared with the control group. The treatment with orlistat neutralized the levels of the measured parameters as compared with HFD fed rats and the results were correlated with the dose of orlistat. In conclusion, an improvement was observed in the biochemical and hormonal results by the treatment with orlistat drug.