We previously showed that the intake of sesamin, a major lignan in sesame seed, decreased lipid peroxidation and elevated tocopherol concentration in rat tissues. In this study, we examined the effect of dietary sesame seed and sesamin on the ascorbic acid concentration in rat tissues. Rats (4-wk-old) were fed either a vitamin E-free diet, or a diet containing 50 mg γ-tocopherol/kg, one containing 2 g sesamin/kg, one containing 50 mg γ-tocopherol/kg and 2 g sesamin/kg, or one containing 200 g sesame seed/kg for 28 d. The dietary sesamin and sesame seed elevated ascorbic acid concentrations in the liver and kidney, and increased urinary excretion in those Wistar rats. The dietary sesamin also elevated the hepatic mRNA levels of cytochrome P450 (CYP) 2B, and UDP-glucuronosyltransferase (UGT) 1A and 2B. In contrast, neither the sesamin nor the sesame seed affected the liver concentration of ascorbic acid in ODS rats with a hereditary defect in ascorbic acid synthesis, though the dietary sesame seed elevated the UGT1A and 2B mRNA levels in the liver. In addition, the sesame seed elevated the γ-tocopherol concentration in the various ODS rat tissues and the ascorbic acid concentrations in the kidney, heart and lung, while reducing the thiobarbituric acid reactive substance concentration in the heart and kidney. These results suggest that dietary sesame seed and its lignan stimulate ascorbic acid synthesis as a result of the induction of UGT1A and the 2B-mediated metabolism of sesame lignan in rats. The data of ODS rat studies also suggest that dietary sesame seed enhances antioxidative activity in the tissues by elevating the levels of two antioxidative vitamins, vitamin C and E.
We have previously reported that sesame seed with the tetrahydrofurofuran type lignans sesamin and sesaminol (SeOH) produced higher tocopherol concentrations, while flaxseed with the dibenzylbutyrolactone type lignans did not cause higher tocopherol concentrations in rats. Sesame seeds also contain the dibenzylbutyrolactone type lignan 7-hydroxymatairesinol (HMR). To clarify whether or not the tocopherol elevating effect is affected by the chemical structure of lignans, the effect of HMR isolated from Norway spruce, was compared with SeOH, isolated from sesame seed. The lignans were added to a low α-tocopherol (10 mg/kg) diet, and rats were maintained on these diets for 8 wk. The experimental diet containing 0.2% SeOH elevated α-tocopherol content in the plasma liver, kidney, and brain, but HMR (0.2% or 0.5%) had no effects. Dietary HMR and SeOH (both in concentrations of 0.2%) were further compared in rats fed on a γ-tocopherol (50 mg/kg) containing diet. SeOH produced significantly higher g-tocopherol content in the plasma and tissues, and significantly lower 2,7,8-trimethyl-2(2'-carboxyethyl)-6-hydroxychroman (γ-CEHC, a γ-tocopherol metabolite) content in the urine. However, HMR did not show such effects. These results suggest that the sesame lignan SeOH increases tocopherol concentrations in animals by suppressing the conversion of γ-tocopherol to γ-CEHC. HMR, a structurally different plant lignan, does not have such properties. Further studies are needed to show the potential health effects associated with an increased tocopherol concentration in the body.
Three percent milled-rice was evaluated for beneficial effect on blood glucose level and serum lipid concentrations in an experiment with Otsuka Long-Evans Tokushima Fatty (OLETF) rats, used as model animals for spontaneously non-insulin-dependent diabetes mellitus. The same experiment was carried out using Long-Evans Tokushima Otsuka (LETO) rats, the control of the OLETF rats. The results obtained from the rats given a diet containing 3% milled-rice (3% MRD) ad libitum were compared with those from rats given polished rice. During the feeding period of 140 d, body weight of the OLETF rats receiving the 3% MRD was significantly lower than that of the rats fed on the diet containing polished rice (PRD) from the 48th to the 124th days. The body weight of the LETO rats during the both periods of 90 to 104 d and 114 to 140 d was lower than that of the rats receiving the PRD. Though food intakes of the rats receiving 3% MRD were significantly lower in the OLETF and LETO rats during the two periods of days 48 to 124 and days 1 to 140 than in the rats of the PRD group, the feed efficiency of the OLETF or LETO rats did not show significant difference between the 3% MRD and the PRD groups during the same experimental periods. The excretion rate of feces of the OLETF rats receiving the 3% MRD was significantly higher than that of the rats receiving the PRD, both on the 126th day and during the period of days 129 to 131. The fasting blood glucose levels were significantly lower in the OLETF rats receiving the 3% MRD than the rats receiving the PRD on the 84th day, the 105th day and the 127th day, and also lower in the LETO rats receiving the 3% MRD on the 84th day and the 105th day. The incremental areas under the curve of blood glucose concentrations (IAUC-Glc) for 120 min after oral administration of glucose on the 133rd day was lower in the OLETF rats receiving 3% MRD than that of the PRD. The ratio of IAUC-Glc in the 3% MRD to PRD group, after ingestion of diets for 1 h after fasting for 18 h on the 138th day, was 0.89 in the OLETF rats, and 0.74 in the LETO rats. Compared with the PRD group, the amounts of cholesterol and bile acid in the feces of the OLETF rats in the 3% MRD group were significantly higher on days 129-131, and the cholesterol excretion was significantly higher on the 84th day in the OLETF rats in the 3% MRD group. The liver weight, the level of total lipids in liver, and the concentrations of triglyceride and total cholesterol in liver and serum of the OLETF rats on the 140th day were significantly lower in the 3% MRD than those of the PRD group. These results indicate that 3% milled-rice has beneficial effects on blood glucose level and serum lipid concentrations in spontaneously non-insulin-dependent diabetic rats.
This cross sectional study was performed to find the adequate amount and combination of dietary protein and energy for maintaining better nutritional status for stable non-diabetic maintenance hemodialysis (MHD) patients. The body composition including body fat, total body water, body cell mass and body protein were measured by multi-frequency bioelectrical impedance analysis in 200 stable MHD patients without diabetes (124 men, 76 women). Dietary energy intake (DEI) and dietary protein intake (DPI) were assessed by a brief self-administered diet history questionnaire (BDHQ), the DPI value being confirmed by calculating the normalized protein equivalent of total nitrogen appearance (nPNA). The nutritional status and the body composition were compared among 4 groups of patients in each gender that were divided by the combination of DEI and DPI; high energy (HE)/high protein (HP), HE/low protein (LP), low energy (LE)/HP and LE/LP groups. The mean DPI ranged between 1.17-1.23 and 0.89-0.95 g/kg IBW/d in the HP and LP groups, respectively for both genders, and the mean DEI was 35-37 and 24-25 kcal/kg IBW/d in HE and LE groups, respectively. BMI and serum albumin concentration were not different among the 4 groups. Body cell mass index (BCMI) was maintained in the HE groups regardless of DPI, and it was significantly higher in the HE/HP group than in the LE/LP group. Multiple regression analysis also showed that the BCMI was more greatly affected by DEI than DPI. These results indicated that a DPI of 0.89-0.95 g/kg IBW/d could be sufficient for maintaining BCMI, if DEI is kept over 35 kcal/kg IBW/d in stable non-diabetic MHD patients. This DPI level is lower than the recommended DPI proposed by dietary guidelines in the US and Japan.
Vitamin K is a cofactor for γ-glutamyl carboxylase (GGCX), which is an essential enzyme for the γ-carboxylation of vitamin K-dependent proteins such as osteocalcin (OC). Associations among dietary vitamin K intake, vitamin K status, and bone metabolism have not been thoroughly investigated. Recently, it has been reported that single nucleotide polymorphisms of GGCX (R325Q, 974G>A) were associated with age-related bone loss and the kinetic affinity for the substrate. In the present study, we investigated the associations among dietary vitamin K intake, the level of serum vitamin K, and the ratio of undercarboxylated OC (ucOC) to intact OC. The subjects were 60 healthy young male volunteers (mean age, 22.6 y; standard deviation, 1.6). Dietary nutrient intake was assessed by consecutive individual 3-d food records taken before the day of blood examinations. Serum concentrations of vitamin K (phylloquinone: PK, menaquinone 4: MK-4, and menaquinone 7: MK-7), ucOC, and intact OC were measured. All subjects were genotyped for polymorphism (R325Q) presence. Dietary vitamin K intake from vegetables was significantly correlated with the level of serum PK, and vitamin K intake from fermented beans, natto, was also significantly correlated with the level of serum MK-7. The ratio of ucOC to intact OC showed a negative association with the total vitamin K intake (r=−0.331, p=0.010) and serum MK-7 (r=−0.394, p=0.002). Interestingly, grouped by the GGCX genotype, a significant interaction between the ratio of ucOC to intact OC with serum MK-7 was observed in 325R homozygotes (r=−0.572, p=0.003), but not in heterozygotes, nor in 325Q homozygotes. This is the first report to suggest the effects of the single nucleotide polymorphism R325Q in the GGCX gene on the correlation between the level of serum MK-7 and γ-carboxylation of serum OC.
Nutritional and hormonal regulation of the expression of uncoupling protein (UCP)-1, -2, and -3 mRNA and protein was investigated in primary cultured adipocytes of rats. The UCP-1, -2, -3 mRNA and protein induction in the adipocytes reached maximal levels at 4 h in the presence of glucose with or without insulin. Moreover, the UCP induction was accelerated by triiodothyronine (T3) or epinephrine, and reached a maximum at 2 h. It appeared that the induction of UCP mRNA and protein was rapid. UCP-1 mRNA expression was stimulated by the presence of T3 or epinephrine in the culture medium. UCP-2 mRNA expression was more markedly increased by glucose, unsaturated fatty acids, insulin and T3 than UCP-1 or -3 mRNA expression. UCP-3 expression was more markedly increased by epinephrine than by T3. The protein expression of the UCPs was induced by glucose and the hormones nearly parallel to the UCP mRNA expression. Thus, UCP-2 expression appears to be stimulated by energy sources such as glucose and fat, and by regulators of thermogenesis and basal metabolic rate such as T3 and insulin, in contrast to UCP-1 and -3 expression.
Bisphenol A (BPA) is used in the production of polycarbonate and epoxy resins. The weak estrogenic activity of BPA has been confirmed by both in vitro and in vivo assays. Retinal acetate has been reported to inhibit the adverse effects of BPA on male mice reproduction. All-trans-retinoic acid (ATRA) is a potent natural derivative of vitamin A and is reported to inhibit the estrogen-induced proliferation of human breast carcinoma cells. In this study, we investigated the possible inhibitory effects of ATRA on the estrogenic activity of BPA by a standard in vivo uterotrophic assay. Proliferated and apoptotic uterine cells were identified by 5-bromo-2'deoxyuridine (BrdU) incorporation and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay. We observed that ATRA supplementation significantly inhibits a BPA-induced uterine weight increase in adult ovariectomized rats. However, there were no significant differences in the increases in the numbers of BrdU-positive cells and TUNEL-positive cells between the BPA and BPA+ATRA groups. These results show that ATRA may have an inhibitory effect on the estrogenic activity of BPA in an in vivo assay.
Objectives: Few national surveys have been conducted on the health and nutrition of disabled people in Japan, and as a result, the actual health and nutritional status of this population group has not been clarified. The aim of the present study is to clarify the following hypotheses: nutritional assessment is not carried out at institutions and schools for individuals with intellectual disabilities (ID) and/or motor disabilities (MD), and there are marked differences in implementation rates and assessment methods (i) between institutions and schools and (ii) among the disability categories. Methods: Questionnaires were sent to 1,080 selected institutions and schools for individuals with ID and/or MD. For each disability category, the implementation rate of blood and urine tests (14 items) was calculated separately for the institutions and schools. Results: A total of 826 responses were obtained (response rate: 76.5%); of these, 822 were valid. For all investigated items, implementation rate was significantly higher for the institutions (0-90.3%) when compared to the schools (0-10.2%). The implementation rate of 13 items at institutions for patients with severe intellectual and motor disabilities (4.8-90.3%) was higher than that for institutions for those with intellectual disabilities (0.4-57.0%) or institutions for those with motor disabilities (0-80.0%). The implementation rate of creatinine urinary excretion/24 h and creatinine height index was lower than that for other examinations. Conclusions: Large differences in implementation rates were apparent between the institutions and schools. The implementation rate of blood and urine laboratory examinations varied considerably among the disability categories.
The effects of various concentrations of the nerve growth factor (NGF) and of dimethylsulfoniopropionate (DMSP) on the outgrowth of neurites from pheochromocytoma (PC12) cells were examined singly or in combination on an RPMI 1640 medium containing 10% horse serum, 5% fetal bovine serum, penicillin and streptomycin in collagen-coated Petri dishes by increasing the incubation times up to 4 d. The results indicated that NGF significantly accelerated the number of neurite-bearing cells, which reached a maximum at concentrations of more than 0.5 ng/mL among the various concentrations of NGF on the 4th day. The combined effects of the various concentrations (10−6 -10−3 M) of DMSP with NGF (5 ng/mL) on the growth and the number of neurite-bearing cells were then examined, which demonstrated that all the concentrations of DMSP restricted the growth of the cells to various extents but that the concentration of DMSP at 10−4 M with the NGF more highly accelerated the number of neurite-bearing cells than did the NGF alone during the experimental period.
Previous studies in our laboratory demonstrated the repressive effect of seaweeds (Laminaria sp., Sargassum fulvellum, Eisenia bicyclis and Gelidium sp.) against D-galactosamine (D-GalN)-induced hepatopathy. However, the mechanism by which these four seaweeds attenuate the D-GalN-hepatopathy has not been completely clarified. This study was carried out to determine the constituents of these seaweeds that protect rats against the D-GalN-hepatopathy. Male Wistar rats were fed for 8 d diets containing 5% seaweeds with or without the antibiotic neomycin (NEO) in experiment 1, and typical seaweed dietary fibers (laminaran, fucoidan, alginate, agar and κ-carrageenan) of these seaweeds in experiment 2. On the 7th day, the rats were treated with D-GalN (1,900 mg in experiment 1 and 800 mg/kg in experiment 2) and then sacrificed 24 h after the injection of D-GalN. Their serum transaminase (aspartate and alanine aminotransferases: AST and ALT) activities were then determined. In experiment 1, the serum AST and ALT levels in the rats fed the four kinds of seaweeds without NEO were significantly low in comparison to that of the control group, but those with NEO were not significantly different among the groups. In experiment 2, the serum AST and ALT levels in the rats fed fucoidan were significantly low in comparison to those of the other groups fed the dietary fibers and the control. These results suggest that the protective effect of the three kinds of brown seaweeds Laminaria sp., Sargassum fulvellum and Eisenia bicyclis against D-GalN-hepatopathy was caused at least in part by fucoidan.
The effect of smoke-dried bonito undigested fraction remaining after microbial protease treatment (SDBR) on a spontaneously occurring mouse model of atopic dermatitis was studied in male 5-wk-old, NC/Nga mice. Smoke-dried bonito, Katsuobushi, is a traditional Japanese food. SDBR contains 2 major components: bonito oil and protease-undigested proteins. Mice were fed a casein diet containing corn oil (C diet) or a diet containing SDBR (SDBR diet) for 18 wk. In comparison with the C diet, the SDBR diet alleviated the increase in skin severity score and plasma IgE concentration in a time-dependent manner, and lowered leucotriene B4 (LTB4)-releasing ability upon calcium ionophore A23187 stimulation. The SDBR diet did not affect scratching time. These results demonstrate that SDBR diet alleviates atopic dermatitis-like skin lesions in NC/Nga mice.