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Abstract: Background: Information is scarce regarding the effect of dietary protein type, with specific focus on the lysine-to-arginine (Lys:Arg) ratio, on cardiovascular risk factors and vascular reactivity in humans. Objective: Determine the effect of dietary Lys:Arg ratio on cardiovascular risk factors and vascular reactivity in moderately hypercholesterolemic adults. Design: Randomized cross-over design of two 35-day diet phases; thirty adults (21 females and 9 males, ≥50 years, LDL cholesterol ≥120mg/dL). Diets had 20% energy (E) protein, 30%E fat, 50%E carbohydrate and were designed to have low (0.7) or high (1.4) Lys:Arg ratio. Measures included fasting and postprandial lipid, lipoprotein, apolipoprotein concentrations; fasting high sensitivity C-reactive protein (hsCRP), small dense LDL (sdLDL) cholesterol, remnant lipoprotein cholesterol (RemLC), glycated albumin, adiponectin and immunoreactive insulin concentrations, endogenous cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyl transferase (LCAT) activities; cholesterol fractional synthesis rate (FSR); and flow mediated dilation (FMD) and peripheral artery tonometry (PAT). Results: No differences were observed in fasting and/or postprandial total, LDL, HDL and sdLDL cholesterol, RemLC, Lp(a) or apo B concentrations, LCAT and CETP activities, FSR, glycated albumin, immunoreactive insulin, FMD or PAT. The low, relative to the high, Lys:Arg ratio diet resulted in lower postprandial VLDL cholesterol (−24%, P =0.001) and triglycerides (−23%, P =0.001), and small but significant differences in fasting (−3%, P =0.003) and postprandial (−3%, P =0.018) apo AI, and fasting adiponectin concentrations (+7%, P =0.035). Fasting and postprandial hsCRP concentrations were 23% lower after the low Lys:Arg ratio diet (P =0.020 for both). Conclusions: Diets differing in Lys:Arg ratios had no or small effects on cardiovascular risk factors and vascular reactivity. [Copyright &y& Elsevier]

Abstract: Objective: Compared to vegetable oils in their unmodified state, partially-hydrogenated fat is associated with less favorable effects on cardiovascular disease (CVD) risk factors. Acceptable alternatives must be adjudicated. Our objective was to assess the effect of a recent commercial fat substitution, corn oil for partially-hydrogenated soybean oil. Methods: Using a double-blind cross-over design, 30 postmenopausal women ≥50 years with LDL-cholesterol concentrations ≥120mg/dL were randomly assigned to each of two 35-day phases; all food and beverage was provided to maintain body weight. Corn or partially-hydrogenated soybean oil was incorporated throughout the diet and contributed two-thirds of fat. Primary outcomes included fasting and non-fasting lipid, lipoprotein, apolipoprotein, and fasting high sensitivity C-reactive protein (hsCRP) concentrations; secondary outcomes included fasting small dense LDL (sdLDL)-cholesterol, remnant lipoprotein cholesterol (RemLC), glycated albumin, adiponectin and immunoreactive insulin concentrations, and endogenous cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyl transferase (LCAT) activities. Results: Relative to the partially-hydrogenated soybean oil enriched diet, the corn oil enriched diet resulted in lower fasting total cholesterol (7%; P <0.0001), LDL-cholesterol (10%; P <0.0001), VLDL-cholesterol (7%; P =0.052), apo B (9%; P <0.0001), lipoprotein (a) [Lp(a)] (5%; P =0.024), sdLDL-cholesterol (17%; P =0.001), and RemLC (20%; P =0.007) concentrations, and no significant effect on the other outcomes. Changes in postprandial (4-h post-meal) lipid, lipoprotein and apolipoprotein concentrations were similar to the fasting state. Conclusion: The replacement of partially-hydrogenated soybean oil with corn oil favorably affects a range of CVD risk factors and is an appropriate option to decrease cardiovascular disease risk factors in moderately hypercholesterolemic individuals. [Copyright &y& Elsevier]

Background: β-Cryptoxanthin (BCX), a provitamin A carotenoid shown to protect against nonalcoholic fatty liver disease (NAFLD), can be cleaved by β-carotene-15,15'-oxygenase (BCO1) to generate vitamin A, and by β-carotene-9',10'-oxygenase (BCO2) to produce bioactive apo-carotenoids. BCO1/BCO2 polymorphisms have been associated with variations in plasma carotenoid amounts in both humans and animals.Objectives: We investigated whether BCX feeding inhibits high refined-carbohydrate diet (HRCD)-induced NAFLD, dependent or independent of BCO1/BCO2.Methods: Six-week-old male wild-type (WT) and BCO1-/-/BCO2-/- double knockout (DKO) mice were randomly fed HRCD (66.5% of energy from carbohydrate) with or without BCX (10 mg/kg diet) for 24 wk. Pathological and biochemical variables were analyzed in the liver and mesenteric adipose tissues (MATs). Data were analyzed by 2-factor ANOVA.Results: Compared to their respective HRCD controls, BCX reduced hepatic steatosis severity by 33‒43% and hepatic total cholesterol by 43‒70% in both WT and DKO mice (P < 0.01). Hepatic concentrations of BCX, but not retinol and retinyl palmitate, were 33-fold higher in DKO mice than in WT mice (P < 0.001). BCX feeding increased the hepatic fatty acid oxidation protein peroxisome proliferator-activated receptor-α, and the cholesterol efflux gene ATP-binding cassette transporter5, and suppressed the lipogenesis gene acetyl-CoA carboxylase 1 (Acc1) in the MAT of WT mice but not DKO mice (P < 0.05). BCX feeding decreased the hepatic lipogenesis proteins ACC and stearoyl-CoA desaturase-1 (3-fold and 5-fold) and the cholesterol synthesis genes 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and HMG-CoA synthase 1 (2.7-fold and 1.8-fold) and increased the cholesterol catabolism gene cholesterol 7α-hydroxylase (1.9-fold) in the DKO but not WT mice (P < 0.05). BCX feeding increased hepatic protein sirtuin1 (2.5-fold) and AMP-activated protein kinase (9-fold) and decreased hepatic farnesoid X receptor protein (80%) and the inflammatory cytokine gene Il6 (6-fold) in the MAT of DKO mice but not WT mice (P < 0.05).Conclusion: BCX feeding mitigates HRCD-induced NAFLD in both WT and DKO mice through different mechanisms in the liver-MAT axis, depending on the presence or absence of BCO1/BCO2. [ABSTRACT FROM AUTHOR]

Sirtuin 1 (SIRT1) has been reported to protect against nonalcoholic fatty liver disease (NAFLD) development. The mechanism of how SIRT1 deacetylase activity affects NAFLD has not been well investigated. The current investigation addressed the causal effect of systemic SIRT1 activity on NAFLD development and the underlying mechanism involved in both liver and mesenteric adipose tissue (MAT). Both SIRT1 homozygous mice ablated the catalytic activity (sirt1 Y/Y ) and their corresponding wild type littermates (WT) were fed a high fat diet (HFD, 60% calories from fat) for 34 weeks. Sirt1 Y/Y mice showed significantly higher level of hepatic triglyceride which was accompanied with higher levels of SREBP-1 and SCD1and decreased phosphorylation of LKB1 and AMPK in the liver. Compared with WT mice, mRNA expression of lipogenic genes ( lxrα , srebp-1c , scd1 and fas ) in the MAT increased significantly in sirt1 Y/Y mice. Fatty acid oxidation biomarkers ( acox1 , acox3 , cpt , ucp1 , sirt3 ) in both liver and MAT were comparable between groups. Interestingly, we observed that in sirt1 Y/Y mice, the mRNA level of hormone sensitive lipase ( hsl ), adipose triglyceride lipase ( atgl ) and perilipin-2 ( plin-2 ), all involved in lipolysis, significantly increased in MAT, but not in epididymal adipose tissue. These changes positively correlated with circulating free fatty acid (FFA) concentrations and higher hepatic mRNA expression of cd36 for FFA uptake. The present study has provided novel evidence to suggest that under HFD-induced metabolic surplus, the lack of SIRT1 catalytic activity promotes release of FFA from MAT and escalate NAFLD by interfering with lipid homeostasis in both liver and MAT. [ABSTRACT FROM AUTHOR]

Chronic and excessive alcohol consumption leads to the development of alcoholic liver disease (ALD) and greatly increases the risk of liver cancer. Induction of the cytochrome p450 2E1 (CYP2E1) enzyme by chronic and excessive alcohol intake is known to play a role in the pathogenesis of ALD. High intake of tomatoes, rich in the carotenoid lycopene, is associated with a decreased risk of chronic disease. We investigated the effects of whole tomato (tomato powder, TP), partial tomato (tomato extract, TE), and purified lycopene (LYC) against ALD development in rats. Of the three supplements, only TP reduced the severity of alcohol-induced steatosis, hepatic inflammatory foci, and CYP2E1 protein levels. TE had no effect on these outcomes and LYC greatly increased inflammatory foci in alcohol-fed rats. To further support the protective effect of TP against ALD, TP was supplemented in a carcinogen (diethylnitrosamine, DEN)-initiated alcohol-promoted mouse model. In addition to reduced steatosis and inflammatory foci, TP abolished the presence of preneoplastic foci of altered hepatocytes in DEN-injected mice fed alcohol. These reductions were associated with decreased hepatic CYP2E1 protein levels, restored levels of peroxisome proliferator-activated receptor-α and downstream gene expression, decreased inflammatory gene expression, and reduced endoplasmic reticulum stress markers. These data provide strong evidence for TP as an effective whole food prevention strategy against ALD. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that diet-induced obese mice fed a semi-purified high-fat diet (HFD) had greater liver tumorigenesis than mice fed a non-semi-purified diet. Because ingredients present in standard unpurified diets may elicit potential chemopreventive properties that are not present in semi-purified diets, the present study evaluated hepatic tumorigenic effects of dietary fat by replacing it with refined carbohydrates [digestible saccharides; high-carbohydrate diet (HCD)] in a semi-purified diet without altering other components. Two-wk-old C57Bl/6J male mice were randomly injected i.p. with either the liver-specific carcinogen diethylnitrosamine (25 mg/kg body weight) to induce liver cancer or saline as the nontumor control. At age 6 wk, mice with or without cancer initiation were further randomly assigned to an HFD (26% and 60% energy from carbohydrates and fat, respectively) or an HCD (66% and 12% energy from carbohydrates and fat, respectively) and consumed food ad libitum for 24 wk. Results showed that HCD-fed mice had a comparable degree of hepatic tumorigenesis (tumor number and volume) as HFD-fed mice, despite having significantly reduced body weights. HCD feeding induced greater hepatic endoplasmic reticulum (ER) stress-mediated protein kinase RNA-activated-like kinase (PERK) activation and oncogenic interleukin-6/signal transducer and activator of transcription 3 signaling than HFD feeding. HCD-stimulated PERK signaling was associated with elevated expression of prosurvival markers in tumors, including induced protein kinase B activation, increased extracellular signal-regulated kinases 1/2 phosphorylation, and elevated cyclin D1 protein expression. However, HCD-mediated PERK activation in tumors was also positively associated with markers of proapoptosis, which included elevated CCAAT/enhancer-binding protein homology protein expression and increased cleaved caspase-3. HCD-fed mice had greater severity in hepatic steatosis than HFD-fed mice. HCD-induced steatosis exacerbation was associated with increased expression in hepatic de novo lipogenic markers that can promote ER stress. Together, these data indicated that chronic HCD consumption by mice can produce comparable severity of hepatic tumorigenesis as HFD consumption, potentially through upregulating PERK-mediated ER stress. [ABSTRACT FROM AUTHOR]

Abstract: The accuracy of stated energy contents of reduced-energy restaurant foods and frozen meals purchased from supermarkets was evaluated. Measured energy values of 29 quick-serve and sit-down restaurant foods averaged 18% more than stated values, and measured energy values of 10 frozen meals purchased from supermarkets averaged 8% more than originally stated. These differences substantially exceeded laboratory measurement error but did not achieve statistical significance due to considerable variability in the degree of underreporting. Some individual restaurant items contained up to 200% of stated values and, in addition, free side dishes increased provided energy to an average of 245% of stated values for the entrees they accompanied. These findings suggest that stated energy contents of reduced-energy meals obtained from restaurants and supermarkets are not consistently accurate, and in this study averaged more than measured values, especially when free side dishes were taken into account. If widespread, this phenomenon could hamper efforts to self-monitor energy intake to control weight, and could also reduce the potential benefit of recent policy initiatives to disseminate information on food energy content at the point of purchase. [Copyright &y& Elsevier]

Hepatocyte apoptosis in addition to oxidative stress could be a key component in the pathogenesis of nonalcoholic steatohepatitis (NASH). However, the underlying mechanisms of hepatocellular apoptotic response associated with oxidative stress have not been investigated in high-fat diet (HFD)-induced NASH models. In this study, Sprague-Dawley rats were fed either a Lieber-DeCarli control diet (CD; 35% energy from fat) or a HFD (71% energy from fat) for 6 wk. Pathologic lesions, lipid peroxidation products, and apoptotic hepatocytes in the liver were examined. The expressions of hepatic tumor necrosis factor-alpha (TNFalpha) and protein concentrations of cleaved caspase-3, cytochrome p4502E1 (CYP2E1), phosphorylated c-Jun NH(2)-terminal kinase (JNK), Bax, Bcl-2, and Bcl-xl were measured. Results showed that the key histological features of NASH, including steatosis, inflammatory cell infiltration, and ballooning degeneration of hepatocytes, were induced by HFD feeding, with increased hepatic TNFalpha mRNA expression. HFD-fed rats had elevated lipid peroxidation products and CYP2E1 protein in the liver. The apoptotic hepatocytes were significantly greater in livers of rats fed HFD than in those fed CD, and these were associated with a higher level of cleaved caspase-3. In addition, HFD feeding increased both hepatic phosphorylated JNK and pro-apoptotic Bax but did not affect anti-apoptotic Bcl-2 and Bcl-xl compared with CD feeding. These data indicate that the increased oxidative stress and its associated JNK activation as well as an imbalance of pro- and anti-apoptotic proteins in the Bcl-2 family all contribute to high hepatocyte apoptosis that may play an important role in the pathogenesis of NASH in this model. [ABSTRACT FROM AUTHOR]

Cigarette smoke (CS) is an independent risk factor in development of nonalcoholic steatohepatitis (NASH) and fibrosis. Lycopene, a carotenoid naturally occurring in tomatoes, has been shown to be a protective agent against tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced NASH. In the present study using a ferret model we investigated whether CS promotes NASH and whether dietary lycopene can inhibit CS-promoted NASH development, and if so, what potential mechanisms were involved. Ferrets were divided into 4 groups (n=12-16/group): control, NNK/CS exposed, NNK/CS plus low-dose lycopene (2.2 mg/kg BW/day), and NNK/CS plus high-dose lycopene (6.6 mg/kg BW/day) groups, for 26 weeks. Results showed that hepatic steatosis, infiltrates of inflammatory cells, and the number and size of inflammatory foci in liver, together with key genes involved in hepatic fibrogenesis were higher in the NNK/CS group compared to the control group; a lycopene diet reversed these changes to the levels of the control group. Interestingly, a major lycopene cleavage enzyme, beta-carotene 9',10'-oxygenase (BCO2), which recently has been recognized to play metabolic roles beyond cleavage function, was down-regulated by NNK/CS exposure, but this decrease was prevented by lycopene feeding. NNK/CS exposure also downregulated liver expression of antioxidant enzymes and upregulated oxidative stress marker, which were all prevented by lycopene. In conclusion, our results suggest that CS can promote development of NASH and liver fibrosis in ferrets, which is associated with downregulation of BCO2 and impairment of antioxidant system in liver; dietary lycopene may inhibit CS-promoted NASH by preventing suppression of BCO2 and decline in antioxidant network. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular disease (CVD) does not become clinically manifest until adulthood. However, children and young adults have evidence of atheromatous lesions and fatty streaks in their aortas and coronary vessels. Most longitudinal studies in children are not designed to evaluate the dynamics of change in CVD risk factors. There is a need to describe the trajectory of CVD risk factors as growth processes, to better understand their relationships. This study assesses the associations between dietary variables and blood total cholesterol concentration (BTCC) among children and adolescents aged 8-18 years after adjustment for sexual maturation.Methods: There were 678 boys and girls aged 8, 11, and 14 years at baseline who were followed for up to 4 years, allowing the creation of a synthetic cohort analytically, from ages 8-18 years. Multilevel modeling was used to longitudinally assess BTCC, dietary intake, Tanner stage, and BMI.Results: For every 1-mg/day increase in dietary cholesterol, BTCC increased by 0.012 mg/dL. However, no associations were evident between BTCC and dietary total fat, saturated fatty acids, polyunsaturated fatty acids, or monounsaturated fatty acids. In girls, none of the dietary variables was significantly associated with BTCC after controlling for Tanner stage for breast. In boys, with the exception of dietary cholesterol, no other dietary variable was significantly associated with BTCC after controlling for Tanner stage for genitalia.Conclusions: Sexual maturation exerts a strong influence on BTCC in children and adolescents aged 8-18 years, obscuring most associations between diet and BTCC. The inclusion of sexual maturity stage is important in studies of blood lipids among children and adolescents. [ABSTRACT FROM AUTHOR]