European Journal of Nutrition (v.48, #5)
Lycopene isomerisation and storage in an in vitro model of murine hepatic stellate cells by Anderson J. Teodoro; Daniel Perrone; Renata B. Martucci; Radovan Borojevic (261-268).
Lycopene is a carotenoid whose biological activities and protective effect on prostate and breast cancer have been described, but little is known on its extra-intestinal metabolism and storage. While most alimentary lycopene is in all-trans configuration, in animal and human tissues approximately half of the lycopene is in cis isoforms.Our object was to monitor the capacity of storage, isomerisation, and intracellular localization of all-trans and cis lycopene in hepatic stellate cells, which are the major sites of metabolism and storage of retinoids and carotenoids in the body.We used the GRX cell line representative of murine hepatic stellate cells, incubated with 1–30 μM lycopene in culture medium. Analysis was done by high-performance liquid chromatography.Lycopene was able to induce expression of the lipocyte phenotype and it was internalized into GRX cells. Its cellular release only occurred in presence of albumin with a rapid initial decrease of intracellular lycopene. A corresponding increase in the culture medium was observed at 24 h. All-trans, 13-cis and 9-cis lycopene isoforms were identified in all the cell compartments. The membrane fraction contained the major part of lycopene, followed by the cytoplasmic fraction, lipid droplets and nuclei. The ratio between all-trans and cis isomers was approximately 2/1 in the majority parts of cell compartments.This study identified a novel hepatic cell type able to store and isomerise lycopene. Liver can contribute to the serum and tissue equilibrium of cis/trans isomers of lycopene, and to participate in storage of lycopene under high extracellular concentration such as observed after the alimentary input.
Keywords: Lycopene; Metabolism; Isomerisation; Liver; Hepatic stellate cells
Gastric cancer in relation to the intake of nutrients involved in one-carbon metabolism among MTHFR 677 TT carriers by Marcia V. Galván-Portillo; Alejandra Cantoral; Luis F. Oñate-Ocaña; Jia Chen; Roberto Herrera-Goepfert; Luisa Torres-Sanchez; Raul U. Hernandez-Ramirez; Oswaldo Palma-Coca; Lizbeth López-Carrillo (269-276).
DNA methylation is an important epigenetic process for transcriptional control of human genome including those genes involved in cancer initiation and progression. Clinical studies have suggested that biological explanation to the protective effect of some nutrients could be linked with the DNA methylation. Folate is a primary methyl donor nutrient; it has been shown to play a key role in DNA methylation, repair and synthesis, by acting as co-factors and/or substrates in this metabolic pathway. Likewise, activity of a key enzyme, the methylenetetrahydrofolate reductase (MTHFR) has also been shown to influence DNA methylation. Overall, these findings support the notion that dietary intake as well as genetic factors play a role in one-carbon metabolism.This study is to evaluate the dietary intake of nutrients involved in one-carbon metabolism and the genotype of MTHFR 677 C > T with respect to GC risk.We carried out in January 2004 a population-based case–control study in the metropolitan area of Mexico City. A total of 248 histological confirmed GC patients were recruited from nine tertiary hospitals, along with 478 age and sex-matched controls. Nutrient intake was estimated from food frequency questionnaire; the MTHFR 677C > T genotype was determined by PCR-RFLP analysis.A significant reduction in diffuse GC risk was observed for MTHFR 677 TT genotype among individuals with high consumption of folate (OR = 0.23; 95% CI 0.06–0.84), choline (OR = 0.55; 95% CI 0.33–0.9) and Vitamin B6 (OR = 0.59; 95% CI 0.36–0.96) compared to MTHFR 677 CC + CT carriers. Among subjects with low consumption of methionine, a reduced risk of diffuse GC was also detected (OR = 0.40; 95% CI 0.16–0.97). In contrast, carriers of the MTHFR 677 TT genotype with a low consumption of folate had a significant increased risk of intestinal GC (OR = 1.88 95% CI 1.02–3.47). A folate–MTHFR 677 C > T interaction in the borderline of significance (P = 0.055) was detected.It is probable that GC prevention requires dietary recommendations according to the individual genotype; nevertheless, the available information to this respect is still very limited.
Keywords: Gastric cancer; Diffuse; MTHFR ; Folate; Choline; Vitamin B6; Mexico
Effect of a low dose of sea buckthorn berries on circulating concentrations of cholesterol, triacylglycerols, and flavonols in healthy adults by Petra S. Larmo; Baoru Yang; Saija A. M. Hurme; Jouni A. Alin; Heikki P. Kallio; Eeva K. Salminen; Raija L. Tahvonen (277-282).
Epidemiological studies indicate beneficial effects of flavonoids on cardiovascular disease (CVD) risk.To study the effect of flavonoid-rich sea buckthorn berry (SBB) on circulating lipid markers associated with CVD risk and plasma flavonol concentration. Also investigated was whether changes in the circulating flavonol concentrations correlate with the SBB induced changes in C-reactive protein (CRP) concentration observed previously.In all 229 healthy participants completed the randomized double-blind study and consumed daily 28 g of SBB or placebo for 3 months. Fasting blood samples for the analysis of lipid markers and flavonols were obtained at the beginning and end of the study.Compared to the placebo, the consumption of SBB increased the plasma concentration of the flavonols quercetin and isorhamnetin significantly [treatment differences 3.0 ng/ml (P = 0.03) and 3.9 ng/ml (P < 0.01), respectively]. The increase of kaempferol concentration was not significant [treatment difference 0.7 ng/ml (P = 0.08)]. SBB did not affect the serum total, HDL, LDL cholesterol, or the serum triacylglycerol concentrations. There was no correlation between the changes in flavonol and CRP concentrations of participants.The consumption of SBB significantly increased the fasting plasma concentration of quercetin and isorhamnetin indicating that it is a good dietary source of flavonols. However, this did not convert to affecting the circulating concentrations of lipid markers in healthy, normolipidemic adults having healthy diets.
Keywords: Cholesterol; Flavonol; Hippophaë ; Isorhamnetin; Sea buckthorn
Regulation of expression of apolipoprotein A-I by selenium status in human liver hepatoblastoma cells by Jessica A. Stahle; Hema Vunta; C. Channa Reddy; K. Sandeep Prabhu (283-290).
Cardiomyopathy is common to areas with low selenium (Se) intake and in patients receiving total parenteral nutrition. Although controversial, a few studies have suggested a protective role for Se in coronary heart disease on the basis of modulation of high-density lipoproteins (HDL).In this study, the role of Se as a positive regulator of expression of a key HDL, apolipoprotein A-I (apoA-I), has been evaluated in human hepatoblastoma (HepG2) cell culture model. We further examined if the transcription of apoA-I, driven by the nuclear hormone receptor, peroxisome-proliferator activated receptor, PPARα, was trans-repressed by the presence of the oxidative stress-responsive transcription factor, NF-κB.Modulation of expression of apoA-I and activation of nuclear NF-κB subunit p65 and PPARα by Se status were evaluated by Western blot and luciferase-based assays. Interaction of p65 with PPARα was evaluated by immunoprecipitation.HepG2 cultured in media with Se (100 nM) demonstrated an increase in the expression of apoA-I when compared to Se-deficient cells. A similar trend was also seen in mice that were supplemented with 0.4 ppm of Se as sodium selenite. Treatment of Se-supplemented cells with bacterial lipopolysaccharide (LPS) showed induction of apoA-I. Supplementation of hepatocytes with Se decreased the nuclear levels of p65, which prevented its interaction with PPARα to modulate apoA-I transcription.Our results suggest that supplementation of hepatocytes with Se mitigates oxidative stress-dependent repression of apoA-I expression by suppressing the NF-κB pathway, which allows PPARα to effectively drive the expression of apoA-I.
Keywords: NF-κB; Selenium; HDL-cholesterol; Hepatocytes; Trans-repression
Site-related white adipose tissue lipid-handling response to oleoyl-estrone treatment in overweight male rats by María del Mar Romero; José Antonio Fernández-López; Montserrat Esteve; Marià Alemany (291-299).
Oleoyl-estrone (OE) decreases energy intake while maintaining glucose homeostasis, and energy expenditure at the expense of body fat. White adipose tissue (WAT) depots behave differently under starvation, postprandial state and pharmacologically induced lipolysis.To understand the mechanism of massive lipid loss from WAT elicited by OE treatment.We used overweight male rats. Rats receiving OE (10 nmol/g) gavages were compared with controls and a pair-fed group. Whole fat pads from the mesenteric, retroperitoneal, epididymal and inguinal subcutaneous sites were excised and analyzed for lipid, DNA, mRNA and the expression of lipogenic, fatty acid transporters and lipase genes.In OE and pair-fed rats, WAT weights decreased, with the limited loss of cells. Patterns of gene expression in most WAT sites were similar for OE and PF, suggesting a shared mechanism of fat mobilization, but in mesenteric WAT, PF increased lipogenic and fatty acid transporter gene expressions. However, OE inhibited lipogenic expressions more deeply than PF.White adipose tissue sites showed different expression patterns, hinting at relatively specialized functions in fat storage; thus, single site analyses cannot be extrapolated to whole WAT. Differences between mesenteric and the other sites suggest that ‘visceral fat’ should be reserved for this site only, and not applied to other abdominal fat depots (epididymal, retroperitoneal).
Keywords: White adipose tissue; Obesity; Oleoyl-estrone; Visceral fat; Lipogenesis
Evaluation of milk basic protein supplementation on bone density and bone metabolism in Chinese young women by Zhi-Yong Zou; Xiao-Ming Lin; Xian-Rong Xu; Rui Xu; Le Ma; Ying Li; Ming-Fang Wang (301-306).
Milk is a good source of bioavailable calcium compared with other foods. Recent in vitro and in vivo studies have shown that milk whey protein, especially its basic protein fraction (milk basic protein, MBP), contains several components capable of promoting bone formation and inhibiting bone resorption. The objective of this study was to examine the effects of MBP on bone mineral density (BMD) and bone metabolism of healthy young women.Eighty-four healthy young women were randomly assigned to three groups: control group, whole milk group or MBP group treated with milk containing 40 mg MBP for 8 months. The bone mineral density of total body, the lumbar vertebrae L2–L4 and the left forearm of each subject were measured by dual-energy X-ray absorptiometry (DEXA) at 0 and 8 months of treatment. Serum indexes of bone metabolism were measured at 0, 3, 6 and 8 months. Eighty-one subjects who completed the study in accordance with the protocol were included in the analysis.Total BMD in all groups significantly increased compared with baseline values. However, no significant difference on the mean rate of gain of total BMD was observed among the MBP group (2.19%), the whole milk group (2.63%) and the control group (1.61%). Serum cross-linked N-teleopeptides of type-I collagen (NTx) in MBP group at 8 months and in whole milk group at 6 months were significantly decreased from baseline. There were no significant differences between whole milk group and MBP group; however, after combining the milk groups, NTx had significantly decreased from baseline. No significant increase was observed in serum bone-specific alkaline phosphatase (BAP) in both whole milk group and MBP group.No significant effect of MBP on bone mineral density and bone metabolism was observed, but milk supplementation was effective in suppressing bone resorption.
Keywords: Bone formation; Bone mineral density; Bone resorption; Healthy young women; Milk basic protein
‘Designer oils’ low in n-6:n-3 fatty acid ratio beneficially modifies cardiovascular risks in mice by Natalie D. Riediger; Nazila Azordegan; Sydney Harris-Janz; David W. L. Ma; Miyoung Suh; Mohammed H. Moghadasian (307-314).
Cardiovascular benefits of dietary n-3 fatty acids have been shown. However, benefits of n-3 fatty acids as part of a high fat, low n-6:n-3 fatty acid ratio diet has not been fully characterized. Aim of this study is to investigate cardiovascular and metabolic benefits of ‘designer oils’ containing a low ratio of n-6:n-3 fatty acids in C57BL/6 mice. Three groups of C57BL/6 mice were fed an atherogenic diet supplemented with either a fish oil- or flaxseed oil-based ‘designer oil’ with an approximate n-6:n-3 fatty acid ratio of 2:1 (treated groups, n = 6 each) or with a safflower oil-based formulation with a high ratio (25:1) of n-6:n-3 fatty acids (control group, n = 6) for 6 weeks. Food intake, body weight, and blood lipid levels were monitored regularly. Fatty acid profile of the heart tissues was assessed. Histological assessment of liver samples was conducted. At the end of the study body weight and food intake was significantly higher in the flax group compared to control. The levels of 20:5n-3 and 22:6n-3 was significantly increased in the heart phospholipids in both flax and fish groups compared to control; tissue 20:4n-6 was significantly reduced in the fish group compared to control. Significant liver pathology was observed in the control group only. Lowering dietary ratio of n-6:n-3 fatty acids may significantly reduce cardiovascular and metabolic risks in mice regardless of the source of n-3 fatty acids.
Keywords: α-Linolenic acid; Cardiovascular; Designer oil; Docosahexaenoic acid; Eicosapentaenoic acid
Rheumatoid cachexia, central obesity and malnutrition in patients with low-active rheumatoid arthritis: feasibility of anthropometry, Mini Nutritional Assessment and body composition techniques by Ann-Charlotte Elkan; Inga-Lill Engvall; Tommy Cederholm; Ingiäld Hafström (315-322).
The concurrent decrease in fat free mass (FFM) and increase in fat mass (FM), including central obesity, in patients with rheumatoid arthritis (RA) may be related to increased cardiovascular morbidity as well as to functional decline. The objectives of this study were to evaluate body composition and nutritional status in patients with RA and the feasibility of bioelectrical impedance (BIA) to detect rheumatoid cachexia.Eighty RA outpatients (76% women), mean age 61 (range 22–80) years and with mean disease duration of 6 (range 1–52) years, were assessed by body mass index (BMI), waist circumference (WC), whole-body dual-energy X-ray absorptiometry (DXA), BIA and the Mini Nutritional Assessment (MNA).Fat free mass index (FFMI; kg/m2) was low in 26% of the women and in 21% of the men. About every fifth patient displayed concomitant low FFMI and elevated fat mass index (FMI; kg/m2), i.e. rheumatoid cachexia. BMI and MNA were not able to detect this condition. Sixty-seven percent had increased WC. Reduced FFM was independently related to age (p = 0.022), disease duration (p = 0.027), ESR (p = 0.011) and function trendwise (p = 0.058). There was a good relative agreement between DXA and BIA (FM r 2 = 0.94, FFM r 2 = 0.92; both p < 0.001), but the limits of agreement were wide for each variable, i.e. for FM −3.3 to 7.8 kg; and for FFM −7.9 to 3.7 kg.Rheumatoid cachexia and central obesity were common in patients with RA. Neither BMI nor MNA could detect this properly. There was a good relative agreement between DXA and BIA, but the limits of agreement were wide, which may restrict the utility of BIA in clinical practice.
Keywords: Rheumatoid cachexia; Body composition; Nutritional status; Mini Nutritional Assessment; Bioelectrical impedance