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Department of Biochemistry, Biophysics and Molecular Biology, 3252 Molecular Biology Building, Iowa State University, Ames, IA 50011, USA
Summary
Three all-trans epoxides of b-carotene (b-Car), namely, 5,6-epoxy-b-carotene (5,6-EC), 5,8-epoxy-b-carotene (5,8-EC) and 5,6,5',6'-diepoxy-b-carotene (5,6,5',6'-DEC) were synthesized by treatment of b-carotene with 3-chloroperoxybenzoic acid, were purified chromatographically, and were characterized. The relative potencies (mean ± S.D.) of 1 mM compounds in inducing the differentiation of NB4 cells, a cell line that contains the chromosomal transposition t(15;17) characteristic of acute promyelocytic leukemia, after 4 days of incubation were: RA: 1.35 ± 0.16, 5,6-EC: 0.29 ± 0.01, 5,8-EC: 0.22 ± 0.05, 5,6,5',6'-DEC: 0.11 ± 0.02, bC: 0.09 ± 0.01, and the control: 0.06 ± 0.01. The same order of potencies existed at other concentrations tested and at other incubation times. P values for the differences between the inducing activities of successive pairs of compounds at 1 mM were: RA vs. 5,6-EC, < 0.001; 5,6-EC vs. 5,8-EC, < 0.01; 5,8-EC vs. 5,6,5',6'-DEC, < 0.01; 5,6,5',6'-DEC vs. b-Car, < 0.10; b-Car vs. control, < 0.005. Similar P values were also obtained for studies at other concentrations and at other incubation times. The viable cell mass at 4 days was inversely proportional to the extent of differentiation (rs = 1.0). The inducing activities of all compounds were dose-dependent. Thus, the 5,6-monoepoxide of b-carotene, which has not previously been studied as an inducer, showed higher activity in NB4 cell differentiation than the 5,8-monoepoxide, the 5,6,5',6'-diepoxide, or b-carotene. Possible explanations of these observations are discussed.
Key words
Epoxycarotenoids, b-carotene, retinoic acid, 5,6-epoxyretinoic acid, cell differentiation, viability, NB4 cells
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5 © Verlag Hans Huber AG, Bern
Department of Biological Chemistry and Nutrition, University of Hohenheim, Fruwirthstrasse 12, 70599 Stuttgart, Germany
Summary
For determination of the vitamin status via mass screening, simple and rapid methods are required. Additionally, blood samples should be obtained using simple and low invasive sampling techniques. To fulfill this existing methods have been modified to analyze retinol, tocopherols, b-carotene, vitamin C and homocysteine in 20 ml plasma. Blood samples were obtained via skin punctures. HPLC measurements were carried out with isocratic separation and precolumn derivatization. Intra and interday variation coefficients were below 8% and regression coefficients better than 0.99 for all measurements. The difference between venous and capillary samples were < 5%. In conclusion, the methods employed proved satisfactory for the determination of important nutritional parameters in blood samples obtained via skin punctures. These methods are therefore well suited for mass screening, especially under field conditions in developing countries.
Key words
Plasma, ascorbid acid, retinol, tocopherols, carotenoids, homocysteine, micromethod, skin puncture
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Dipartimento di Biochimica, Università di Bologna, Via Irnerio 48, 40126 Bologna, Italy 2Centro Aterosclerosi, Università di Bologna, Via Massarenti 9, 40126 Bologna, Italy
Summary
Since many connections exist between vitamin B6 and lipid metabolism, we aim to investigate the lipemic effect of different dietary intakes of polyunsaturated fatty acids in rats fed a vitamin B6 deficient diet. Diets were either vitamin B6 deficient (-B6) or vitamin B6 sufficient, pair-fed to the deficient group (PF) and ad libitum (N). The diets were combined with normal lipid (LC: soya bean-coconut-palm oils) and fish oil (FO: soya bean fish oil). The fish oil diet with sufficient vitamin B6 content caused an increase in n-3 long chain polyunsaturated fatty acids and a decrease in arachidonic acid. In the -B6 group fed a normal lipid diet, the arachidonic acid percentage decreased and the linoleic acid percentage increased; in the -B6 group fed fish oil these changes in fatty acid composition, already consequent upon dietary intake of n-3 long chain polyunsaturated fatty acids, did not show further variations. In the dietary condition of vitamin B6 deficiency, plasma cholesterol content increased in rats fed a lipid control diet, whereas no hypocholesterolemic effect was observed in those fed a fish oil diet. Plasma triglyceride contents were not influenced by dietary lipid quality because, in all conditions, the lower food intake of the PF groups caused a decrease and vitamin B6 deficiency caused an elevation in triglyceride contents which reached those of the ad libitum groups. The study highlights the interaction between vitamin B6 and polyunsaturated fatty acids and the opportunity of dietary intake of fish oil to counterbalance some effects of vitamin B6 deficiency.
Key words
Diet, vitamin B6-state, n-3 polyunsaturated fatty acids, fish oil
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1Nelson Institute of Environmental Medicine and Kaplan Comprehensive Cancer Center, New York University School of Medicine, 650 First Avenue 5th Floor, New York, NY 10016, U.S.A.
2Department of Clinical Laboratories, Memorial Sloan Kettering Cancer Center, 1275 York Avenue New York, NY 10021, U.S.A.Summary
Lower serum folate and higher serum homocysteine levels are known risk factors for various conditions. Thus, epidemiologic correlates with these measurements were studied for 256 multivitamin users and 230 non-users who were middle-aged women. Both serum folate and homocysteine levels increased with advancing age in both multivitamin users (P < 0.01 and P < 0.01) and non-users (P = 0.08 and P < 0.01). Among non-users, higher intake of vegetables, fruits, cold cereals and total protein were associated positively with serum folate and inversely with homocysteine levels. There were 2574% increases in serum folate and 1015% decreases in serum homocysteine between 1st and 4th quartiles of intake of these food/nutrients. In addition, 26% lower serum folage and 18% higher serum homocysteine were observed for those smoking 20 or more cigarettes per day compared with non-smokers. Among multivitamin users, body weight was correlated inversely with serum folate (P < 0.01) and positively with serum homocysteine levels (P = 0.04), while no correlates were found among lifestyle factors. Regular use of multivitamins increased serum folate about fourfold and decreased homocysteine twofold. These results suggest that multivitamin use can offset the effects of an unhealthy lifestyle on these serum markers, and that levels of serum folate and homocysteine can also be favorably influenced by healthier diet and abstinence from smoking.
Key words
Folate, homocysteine, age, body weight, diet, smoking
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Laboratoire de Biologie et de Biochimie des Lipides, UPRES-EA2033, Institut de Biologie, Université Montpellier I
2 Ecole Nationale Supérieure d'Agronomie, Département de Technologie des I.A.A. et de Nutrition Humaine, 16200 Alger, Algeria
Summary
The aim was first to examine the differential effects of crude and refined palm oil (CPO and RPO) on the lipid and lipoprotein constants of plasma in rats and to compare the effect of crude palm oil to that of fish oil. Secondarily, it was to know whether one can take advantage from the association of CPO with FO. Twenty-four-day-old weaning rats were divided into five experimental groups, each receiving a purified diet containing 10% oil as either a single oil or an equal amount of two oils. After a feeding period of 36 days, the main results were as follows. As compared to the rats fed the RPO diet, those fed the CPO diet had lower total cholesterol, LDL-C, VLDL-C and apoB and higher HDL-C/LDL-C and apoA1/apoB ratios. Those fed the FO diet had only lower VLDL-C and triglycerides and higher HDL-C and HDL-C/LDL-C ratio. Whereas FO associated with RPO in the same diet had the same effect as FO alone, FO associated with CPO tends to reinforce the effect of CPO. This is particularly true for the effects on apoB and apoA1 which were found to be synergistically depressed and enhanced, respectively. Given the role played by these biological constants as predictors of CVD in humans, and in spite of the fact that these predictors are not relevant in rats, these results would suggest the potential interest of CPO or the association of CPO with FO in human nutrition.
Key words
Palm oil, cholesterol, lipoproteins, triglycerides, tocotrienols, rat
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Research Department, Research and Development Division, Hokuriku Seiyaku Co., Ltd., 37-1-1 Inokuchi, Katsuyama, Fukui 911-8555, Japan
2 Department of Hygiene and Preventive Medicine, Niigata University School of Medicine, Asahimachi-dori 1-757, Niigata City, Niigata 951-8510, Japan
Summary
Male rats were dosed with capsaicin after the administration of olive oil, and the serum was obtained for analysis of triglycerides and free fatty acids (FFAs). The serum triglycerides level was increased at 2 and 4 hours after olive oil treatment. On the other hand, capsaicin significantly lowered this increase after 4 hours of treatment in the dosage of 100 mg/kg. Total FFA level was also lowered which had previously been increased by the administration of olive oil after 2 hours of treatment, solely the increase in oleic acid (C18:1) levels was lowered among the FFA. The present results indicated that capsaicin decreased only the components of the dosed olive oil. Furthermore, elevation of the serum total FFA concentration was significantly inhibited 2 or 4 hours after the treatment but not at 8 hours, suggesting that a single high dose treatment with capsaicin may inhibit the absorption of lipid in the gastrointestinal tract.
Key words
Capsaicin, triglycerides, serum free fatty acid, oleic acid, rats
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Korea Research Institute of Bioscience & Biotechnology, KIST, P.O. Box 115, Yusong, Taejon, 305-606, Korea
2 Chungnam National University School of Pharmacy, Taejon, 305-764, Korea
3 Department of Nutrition and Food Science, Department of Genetic Engineering, Kyungpook, National University, Taegu, 702-701, Korea
Summary
The effects of the citrus bioflavonoid naringin were tested by using it as a supplement in a high-cholesterol diet. Male rats were fed for 42 days with a 1% (wt/wt) high cholesterol diet either with or without naringin-supplementation (0.1%, wt/wt) to study the effect on plasma lipid levels, hepatic lipid contents, hepatic enzyme activity, and the excretion of fecal neutral sterols. Naringin did not significantly alter the levels of plasma triglycerides, however, the levels of plasma cholesterol (3.80 ± 0.31 mmol/L vs. 2.61 ± 0.30 mmol/L, mean ± SE; p < 0.05) and hepatic cholesterol (70.3 ± 4.3 mg/g vs. 54.3 ± 3.8 mg/g, mean ± SD; p < 0.05) were significantly lowered compared to those of the control. HMG-CoA reductase (2487.0 ± 210.0 pmole/min/mg vs. 1879.0 ± 236.0 pmole/min/mg, mean ± SE; p < 0.05) and ACAT (806.0 ± 105.0 pmole/min/mg vs. 643.0 ± 80.0 pmole/ min/mg, mean ± SE; p < 0.05) activities were both substantially lower in the naringin-supplemented group than in the control. The naringin supplementation markedly decreased the excretion of fecal neutral sterols (204.7 ± 28.5 mg/day) compared to the control (521.9 ± 53.9 mg/day). The combination of the inhibited HMG-CoA reductase (24.4%) and ACAT (20.2%) activities as a result of naringin supplementation could account for the decrease of fecal neutral sterols.
Key words
ACAT, HMG-CoA reductase, naringin, cholesterol-lowering effect
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Nutritional Science Center, Bioscience Laboratories, Meiji Seka Kaisha, Ltd., Saitama 350-0289, Japan
2 Department of Nutrition, Faculty of Agriculture, Tokyo University of Agriculture, Tokyo 156-8502, Japan
Summary
Gastrectomized rats exhibit iron deficiency anemia. We observed the effects of dietary heme-iron and short chain frucooligosaccharides (Sc-FOS) in relation to prevention of postgastrectomy anemia in rats. Twelve laparotomized (sham-operated) rats were fed iron-citrate (control) as iron source diet without or with Sc-FOS (75 g/kg of diet) and twenty four totally gastrectomized (Bilroth II) rats, were fed a iron-citrate (control) or heme-iron (heme) as iron source diet without or with Sc-FOS (75 g/kg of diet) for 4 weeks. All rats received an intramuscular injection of vitamin B-12 every two weeks. Tail blood was collected every other week for determination of hematocrit and hemoglobin concentration. At the end of the experiment, the rats were killed and whole blood was collected. The total gastrectomy induced the postgastrectomy anemia. Dietary Sc-FOS increase iron absorption and thereby prevented completely this anemia in gastrectomized rats fed the control diet but this effect of Sc-FOS in rats fed heme diet was not complete. Dietary heme iron could not prevent postgastrectomy anemia itself, but fructooligosaccharides improve bioavailability of not only non-heme iron such as iron-citrate, but also heme-iron in rats.
Key words
Elderly people, nutritional status, dietary intake, biochemical indicators
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern
1 Department of Pharmacy, University of Basel, Totengässlein 3, CH-4051 Basel
2 Max-Planck-Institut für Biochemie, Abteilung Zellbiochemie, D-82152 Martinsried bei München
3 F. Hoffmann-La Roche AG, Department Human and Nutrition Research, CH-4002 Basel
Summary
Many studies and scientific publications report on potentially beneficial effects of the lipophilic antioxidant vitamin E on cellular metabolic pathways. The present work presents data on the influence of tocopherol on different intracellular parameters of intact and living human skin fibroblasts by flow-cytometric measurements. The parameters analysed were the intracellular pH, representing cell metabolism and cell function, intracellular glutathione, representing one of the cell's own radical scavenger enzyme systems, membrane potential and cell viability. In order to cause large numbers of free radicals cells were UVB-irradiated prior to measurement. The results of the flow-cytometric measurements indicate that vitamin E has significant protecting effects on the measured biochemical parameters during oxidative stress. In the presence of the lipophilic radical scavenger a significant stabilizing effect on pH, intracellular glutathion levels and membrane potential could be observed. Furthermore, vitamin E administration was associated with increased cell viability after UVB irradiation.
Key words
Vitamin E, flow cytometry, human skin fibroblasts, cellular viability, intracellular pH, intracellular glutathione, membrane potential, UVB
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 4, © Verlag Hans Huber AG, Bern
Swiss Vitamin Institute Lausanne, chemin des Boveresses, CH-1066 Epalinges
Summary
A microbiological method for the determination of thiamine in biological
fluids and food using 96-well microtitre plates and automatic plate reader,
suitable for using in routine clinical diagnosis is described. Thiamine
was extracted from samples by acid digestion (acetate buffer, pH 4.5) at
110°C for 20 minutes.
Assay recovery and reproducibility were optimally evaluated. Results obtained
from this method were compared with those obtained using traditional microbiological
and HPLC methods. The values resulting from this method were more or less
the same as those of the traditional microbiological method, but much higher
than those of HPLC assay.
However, the new assay presents many advantages: it reduces the use of serum
volume, which is a main benefit for clinical analysis. It lowers also the
reagent costs and increases the number of analyses as well as it is easy
to perform for routine clinical laboratory.
International Journal for Vitamin and Nutrition Research, Band 69, 1999, Heft 5, © Verlag Hans Huber AG, Bern