A method for determining all of the six natural vitamin B6 compounds and pyridoxine-β-glucoside in urine from humans consuming their usual diet was developed. These compounds were specifically converted with 5 enzymes into a high fluorescent 4-pyridoxolactone which was supersensitively determined by an isocratic HPLC. All of the compounds in urine from humans consuming their usual diets were for the first time determined together. The preparation procedure for urine samples was easy without HCl-hydrolysis, and the enzyme reactions took only 2 or 3 h. It required only 5 μL of the urine sample for analysis of one of the compounds. Urine samples from five young Japanese males consuming their usual diet contained pyridoxal, pyridoxamine, and pyridoxine-β-glucoside but not pyridoxine or phosphoester forms. The contents of 4-pyridoxic acid and pyridoxal correlate well with a correlation coefficient of 0.98. On the other hand, the content of pyridoxamine did not correlate with that of 4-pyridoxic acid.
Because trans fatty acids (TFAs) are a potent risk factor for coronary heart disease, it is important to know the amount of TFA consumed. We estimated TFA intakes of Japanese university students by direct measurement. Subjects included 118 students (57 males and 61 females) in two regions of Japan: Kanto (Tokyo area) and Okinawa. A dietary survey was conducted over six consecutive days using dietary records and photographic records. A single-day meal in the survey period was reproduced to measure TFA content by gas chromatography. The median values of TFA intakes (and energy percentage) estimated by the contents of reproduced meals for men were 0.43 g/d (0.22%) in Kanto and 0.30 g/d (0.14%) in Okinawa. Corresponding values for women were 0.49 g/d (0.29%) and 0.73 g/d (0.35%), respectively. Compared to the group with a low TFA intake, the subjects with a high TFA intake consumed significantly more energy from total fat and saturated fatty acids, and had a high ratio of TFA/linoleic acid. In addition, multiple regression analysis showed the intakes of TFA were positively associated with those of saturated fatty acids and groups of nonessential groceries such as cookies, cakes and pastries. In conclusion, the TFA intakes of these survey subjects were relatively lower than the WHO recommended energy ratio (<1%). However, nutritional education on dietary habits seems indispensable for those subjects who are consuming high volumes of TFA.
Our previous study showed that tsao-ko intake can lower plasma and liver triacylglycerol (TG) concentrations and has hypoglycemic and antioxidant activity in mice. This study involved separating two major fractions (A and B) from the methanol extracts (MeX) of tsao-ko using silica gel column chromatography, and then determining the effect of the fractions in vivo and in vitro to clarify the most effective components of tsao-ko. An intake of MeX and A fraction statistically significantly reduced body lipids and plasma thiobarbitutic acid reactive substances (TBARS) concentrations compared with the control and inhibited lipase and α-glucosidase activities. These reductions were not observed in mice fed the B fraction and these inhibitions of B fraction were mild compared with MeX and A fraction. The plasma and liver TG concentrations of each fraction group did not show significant differences compared with the control. The [M−H]+ and maximum UV absorption of the A fraction were 291 m/z and 279 nm, respectively. The peak of A fraction appeared at a similar time to the epicatechin standard in the LC/MS/MS analysis and the MS/MS spectrum of the A fraction was similar to that of the epicatechin standard. It was concluded that the most effective component of tsao-ko for body lipid reduction and hypoglycemic and antioxidant activity was contained in the polar fraction and the evidence suggested that this component could be epicatechin. However, the strongest TG lowering components of tsao-ko may be methanol insoluble.
This study aimed to investigate the effects of physical training, and different levels of protein intake in the diet, on the growth and nutritional status of growing rats. Newly-weaned Wistar rats (n=48) were distributed into six experimental groups; three of them were subjected to physical swim training (1 h per day, 5 d per week, for 4 wk, after 2 wk of familiarization) and the other three were considered as controls (non-trained). Each pair of groups, trained and non-trained, received diets with a different level of protein in their composition: 14%, 21% or 28%. The animals were euthanized at the end of the training period and the following analyses were performed: proteoglycan synthesis as a biomarker of bone and cartilage growth, IGF-I (insulin-like growth factor-I) assay as a biomarker of growth and nutritional status, total RNA and protein concentration and protein synthesis measured in vivo using a large-dose phenylalanine method. As a main finding, increased dietary protein, combined with physical training, was able to improve neither tissue protein synthesis nor muscle growth. In addition, cartilage and bone growth seem to be deteriorated by the lower and the higher levels of protein intake. Our data allow us to conclude that protein enhancement in the diet, combined with physical exercise, does not stimulate tissue protein synthesis or muscle mass growth. Furthermore, physical training, combined with low protein intake, was not favorable to bone development in growing animals.
Physical exercise dramatically increases the energy expenditure of animals. In terms of energy substrate, at the onset of exercise, the contribution of carbohydrates to the energy expenditure is relatively predominant, and decreases gradually with the progression of exercise, while fat consumption increases progressively. The ventromedial hypothalamus (VMH) is a nucleus in the hypothalamus that regulates whole body energy metabolism via the sympathetic nervous system. Some reports have indicated that noradrenergic projections to the VMH are involved in energy metabolism during exercise. However, it is not clear whether exercise influences the activity of noradrenergic projections to the VMH. We hypothesize that during exercise, noradrenergic neurons projecting to the VMH are activated, and play an important part in enhancing fat oxidation. To test this hypothesis, we used in vivo microdialysis to investigate the effect of exercise on the activity of monoaminergic (noradrenaline: NA, dopamine: DA, serotonin: 5-HT) neurons projecting to the VMH of rats. Rats were subjected to running at 15 m/min (incline 3o) for 60 min. During treadmill running, noradrenergic and dopaminergic activities increased significantly in the VMH. Extracellular 5-HT concentrations in the VMH did not change during treadmill running at the exercise intensity. Given the known effects of NA in the VMH on energy metabolism, our results suggest that the increase in noradrenergic activity in the VMH is related to the enhancement of fat oxidation during exercise.
Difructose anhydride III (DFAIII) is an indigestible disaccharide and has been shown to enhance iron absorption in animal studies; however, the effect has not been investigated in anemic subjects. We investigated the efficacy of co-administration of DFAIII with water-insoluble iron in the treatment of iron deficiency anemia in Vietnamese women. One hundred sixty-eight moderately anemic women (80 g/L<hemoglobin (Hb)<120 g/L) participated in a double-blinded, placebo-controlled study with daily supplementation of iron for 6 mo. The volunteers were randomly assigned into four groups, i.e., Group A: received 15 mg Fe as ferric pyrophosphate; Group B: received 15 mg Fe as ferric pyrophosphate and 1.25 g DFAIII; Group C: received 15 mg Fe as ferrous sulfate; Group D: received a placebo. Hb and iron status were measured at baseline and after 2, 4 and 6 mo of intervention. The ratio of transferrin receptor to ferritin was used to estimate stored and functional body iron (BI). One hundred sixteen (69.0%) women completed the trial. After 6 mo, mean (±SE) Hb concentration was higher in Group A (121.6±1.7 g/L), Group B (126.4±1.5 g/L) and Group C (126.8±1.6 g/L) compared to Group D (107.0±1.7 g/L, p<0.0001). Mean change in BI was twofold greater in Group B (5.0±0.5 mg/kg) than that in Group A (2.5±0.6 mg/kg, p=0.008). The percentage of anemia was significantly reduced in Group B (18.8%) compared to Group D (95.8%, p<0.0001) and Group A (39.1%, p=0.033). Co-administration of DFAIII enhances Hb concentration and iron stores more than single administration of water-insoluble iron in anemic Vietnamese women.
We investigated in 30 healthy adults the glycemic index (GI) of five strawberry jams made from various sugar compositions. The jam containing the highest ratio of glucose showed a high GI, while that containing a high ratio of fructose, a jam made from polydextrose, showed a low GI. There was a high correlation (r=0.969, p=0.006) between the GI and the predicted GI calculated from the sugar composition of the jams. Moreover, the influence on postprandial blood glucose response after an intake of only 20 g of jam and one slice of bread with 20 g jam was measured in 8 healthy adults. The blood glucose level after an intake of 20 g of the high GI jam containing the high glucose ratio was higher than that of other jams at 15 min, but there was no significant difference after 30 min. Regardless of whether the GI was low or high, differences in the jams were not observed in the postprandial blood glucose level or the area under the curve after eating either one slice of bread (60 g) or one slice of bread with less than 20 g of jam.
Lutein is one of the major carotenoids in green leafy vegetables (GLVs), which show a marked antioxidant activity. The study was carried out to identify and quantify the carotenoid content of selected Sri Lankan GLVs. RP-HPLC with photodiode array detection method was followed for the separation, identification and quantification of carotenoids. Among the vegetables analyzed, Ipomoea batatas leaves showed the highest β-carotene content (743.9±35.0 μg/g dry weight (DW)) while Syngonium angustatum leaves contained the highest amount of lutein (1,728.2±168.3 μg/g DW). Percentage in vitro bioaccessibility of lutein from cooked GLVs ranged from 10.1 to 48.0% in stir-fried preparations of Centella asiatica and Cucurbita maxima, respectively. Hence these GLVs can be exploited as a rich source of β-carotene and lutein to overcome vitamin A deficiency and age-related macular degeneration.
Effects of chicken collagen hydrolysate (CCH) on atherogenesis in apolipoprotein E-deficient C57BL/6.KOR-ApoEshl mice were investigated in this paper. The mice were fed on either a normal CE-2 diet (control group) or a diet containing 10% CCH (CCH group) for 12 wk. Compared with that of the control, the amount of total plasma cholesterol, total hepatic cholesterol and hepatic triglycerides in the CCH group was reduced by 14.4, 24.7 and 42.8%, respectively. Histological analysis results showed that the abundance of diffuse hepatic lipid droplets and fat vacuoles was decreased in the CCH group. Meanwhile, the concentration of proinflammatory cytokines in the CCH group plasma, including interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), and tumor necrosis factor-α (TNF-α), was downregulated by 43.4, 17.9 and 24.1%, respectively. The present results suggested that CCH treatment might help prevent atherosclerosis through not only its lipid-lowering effects but also inhibiting expression of inflammatory cytokines.
The preventive effects of C-2 epimeric isomers of (−)-epigallocatechin-3-O-gallate (EGCG) and the O-methylated derivative, (−)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3''Me), against ovalbumin-induced type I allergy in male mice were investigated. EGCG and EGCG3''Me exhibited strong antiallergic effects by oral administration at doses of 25 and 50 mg/kg body weight. The antiallergic effects of their C-2 epimers, (−)-gallocatechin-3-O-gallate and (−)-gallocatechin-3-O-(3-O-methyl)gallate (GCG3''Me), on mouse type I allergy were almost equivalent to and/or as strong as those of the corresponding original catechins, respectively. Oral administration of these compounds at a dose of 50 mg/kg body weight tended to suppress the increases in interleukin-4 levels in the abdominal walls of allergic mice and immunoglobulin E levels in the serum of allergic mice. In particular, the administration of GCG3''Me exhibited significant effects on the production and/or release of these parameters stimulating type 2 T helper cells and mast cells in the type I allergic process. These results indicated that C-2 epimerization of tea catechins, which are produced during heat processing at high temperatures, would not be disadvantageous for preventive effects on type I allergy.