Journal of nutritional science and vitaminology最新文献

Terrestrial green plants are rich in phylloquinone (PK), and their PK content is highly correlated with the chlorophyll content. However, there are few studies on the PK content of algae and its correlation with chlorophyll content. To evaluate the PK content in algae and its correlation with chlorophyll, the PK and chlorophyll contents in algae, including Phaeophyta (18 species), Rhodophyta (17 species), and Chlorophyta (seven species), were determined. Algae, particularly Phaeophyta, contain more functional components than do other green terrestrial plants. Therefore, other components such as carotenoids, polyphenols, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability were analyzed to confirm their correlation with PK. Furthermore, terrestrial plants such as leafy vegetables, other vegetables, and tea powder were evaluated for the same components and compared with the experimental results for algae. This results showed that PK was abundant in Phaeophyta and almost all samples contained more than 100 μg/100 g of dry samples. In particular, Sargassum muticum contained 514.11±11.29 μg/100 g. However, almost all of the Rhodophyta and Chlorophyta contained a little PK. The results also confirmed a positive correlation between the PK and chlorophyll content in Rhodophyta (R²=0.7085), Chlorophyta (R²=0.7264), and terrestrial plants (R²=0.8436). However, no correlation was observed between the PK and chlorophyll content in Phaeophyta (R²=0.1013). In addition, the principal component analysis results showed no correlation between PK and other components, such as carotenoids and polyphenols, and DPPH radical scavenging ability in algae. However, Phaeophyta also contained more functional components, such as carotenoids, polyphenols, and DPPH radical scavenging ability than the other algal groups.

In this study, the effect of calcium alginate (Ca-Alg) on postprandial serum triglycerides (TG) was examined in healthy adults in a placebo-controlled, randomized, double-blind, crossover study. Eight healthy adults were given a fat-loaded food followed by placebo or 1.5 g (300 mg/capsule×5) of Ca-Alg, and serum TG and remnant-like lipoprotein cholesterol (RLP-C) levels were measured before and at various times (2, 3, 4 and 6 h) after consumption of the fat-loaded food. The results showed that TG and RLP-C levels were significantly lower at all time points in the Ca-Alg intake group compared to the control group, starting 2 h after consumption of the fat-loaded food. The area under the time curve (AUC_0-6h) and the highest level observed (C_max) up to 6 h after the food were also significantly lower in the Ca-Alg intake group than in the control group. Furthermore, biochemical analyses revealed that at 6 h after consumption of the fat-loaded food, ΔCa (change in serum calcium concentration) was significantly increased, whereas ΔNa (change in serum sodium concentration) was significantly decreased in the Ca-Alg intake group compared to the control group. These results indicate that Ca-Alg may have broad applications as a supplement that also contributes to the prevention of lifestyle-related diseases such as hyperlipidemia.

We found indigo reductase homolog in Bacillus cohnii gene and succeeded in production of a large amount of the recombinant homolog in Escherichia coli. The homolog exhibited FMN-dependent NADPH-quinone reductase activity, but not indigo-reducing activity. Crystal structure analysis of the enzyme revealed the formation of a binary complex with FMN, 2-propanol, and glycerol, determined at a resolution of 1.57 Å. Notably, the structure of FMN was of particular interest, as the isoalloxazine ring of FMN exhibited a butterfly-like bent conformation, with an angular deviation of approximately 9.4º to 10.9º along the axis between N5 and N10. The reason for FMN adopting a butterfly-like structure was thought that the exposure of the enzyme crystal to X-ray radiation led to the one-electron reduction of FMN, forming the semiquinone radical FMNH^•.

Brazilian green propolis (BGP), produced by honey bees, induces beige adipocyte formation and accelerates whole-body energy metabolism. Artepillin C (ArtC), the major cinnamic acid derivative of BGP, induces beige adipocyte formation and increases thermogenesis in inguinal white adipose tissue. However, the effects of BGP on beige adipocyte formation and energy metabolism remain unclear. Therefore, we aimed to examine the effects of BGP on beige adipocyte formation and thermogenesis. We used in vitro and in vivo approaches, such as cell culture and differentiation, component testing, thermogenesis measurement, and calcium influx assay. First, ArtC was confirmed to be a major BGP component contributing to beige adipocyte formation in vitro and in vivo. BGP-induced interscapular brown adipose tissue (iBAT) thermogenesis was not observed upon ArtC stimulation. Thereafter, inhibitory studies revealed that iBAT thermogenesis could be related to the transient receptor potential vanilloid 1 (TRPV1)-sympathetic nervous system channel. Finally, we identified culifolin, a cinnamic acid derivative of BGP, as an active component of this response, which activates calcium signaling in TRPV1-expressing cells. In addition, culifolin administration significantly increased the mouse iBAT temperature to the same extent as increased by BGP. Thus, BGP has a unique biological function in activating the two distinct pathways of brown-adipocyte and beige-adipocyte thermogenesis, contributing to increased energy expenditure.

This animal experiment aimed to evaluate the efficacy of the extract of pre-germinated brown rice (EP) and γ-oryzanol on non-alcoholic fatty liver disease (NAFLD) and the cardiac complications associated with it. WKY rats were fed high-fructose water (HFW) and high-fat diet (HFD) for 4 wk to induce NAFLD. The other two groups were fed HFW and HFD, while oral administration of EP 200 μL/kg or γ-oryzanol 2 mg/kg every day for 4 wk. NAFLD was successfully induced in as evidenced by clear increases in body, hepatic and cardiac weight as well as by increases in blood pressure and heart rate, hypertriglyceridemia, hyperuricemia, higher liver function index: glutamic pyruvic transaminase (GPT), higher levels of IL-6 and TNF-α in the blood and higher levels TG in the liver. NAFLD rats also had adverse changes the protein expressions of lipid synthesis, inflammation, cardiac fibrosis and hypertrophy. However, when the NAFLD rats were simultaneously fed EP or γ-oryzanol, the development of adverse diet-induced effects, including glutamic oxaloacetic transaminase (GOT), were clearly ameliorated. Specifically, EP could reduce uric acid levels, while γ-oryzanol did not. EP, as well as γ-oryzanol, reversed the increases in levels of lipid synthesis, inflammation, cardiac fibrosis and hypertrophy. We concluded that EP effectively prevented HFW/HFD-induced NAFLD and its associated cardiac complications, which it likely achieved through an improvement of lipid homeostasis and inhibition of inflammation. We believe that EP, like γ-oryzanol, can be developed as a beneficial agent for the prevention and control of NAFLD and associated cardiac dysfunction.

Obesity is known to induce diabetes, hypertension, and dyslipidemia, and reducing obesity is important from the perspective of disease prevention. Oligonol, a standardized oligomerized-polyphenol from Litchi chinensis fruit extract, is expected to have high absorption and body fat reduction. In this study, the effects of Oligonol intake on abdominal fat were examined in overweight Japanese participants. This randomized, double-blind, placebo-controlled trial was performed including 66 overweight adult men and women (body mass index [BMI] of 25 or more and less than 30 kg/m²) who were assigned to receive a daily dose of placebo or 200 mg Oligonol (40 mg as monomers and dimers of flavanols from lychee and tea) for 12 wk. The primary endpoint was a reduction of the visceral fat area (VFA) as quantified by computed tomography scanning after continual intake of test foods for 12 wk. In addition, body weight, BMI, waist circumference, peripheral blood tests, and general urinalysis were performed. Of 66 participants (33 per group), 63 were included in the efficacy analysis (placebo n=32; Oligonol n=31). Intake of 200 mg Oligonol significantly reduced abdominal VFA compared with the placebo group. No clinically relevant adverse events related to the intake of Oligonol were observed. These results indicate that Oligonol had the abdominal visceral fat reduction effect in overweight participants.

Several Japanese cohort studies reported that alcohol consumption was inversely associated with coronary artery disease (CAD). However, these results were inconsistent. We investigated alcohol consumption and CAD in 802 patients undergoing coronary angiography, in whom foods, beverages and alcohol intakes were assessed. Alcohol intake was classified into 4 categories: nondrinkers, light (<23 g/d), moderate (23-45 g/d), and heavy (≥46 g/d) drinkers. Among 583 men, CAD was found in 404, of whom 137 had myocardial infarction (MI). The prevalence of CAD and MI stepwisely decreased on alcohol intake: 80% and 30% in nondrinkers, 65% and 20% in light, 60% and 17% in moderate, and 54% and 16% in heavy drinkers (p<0.001). However, serum γ-GTP levels were higher in heavy drinkers than in nondrinkers. In multivariate analyses, odds ratios for <23 g/d, 23-45 g/d and ≥46 g/d alcohol intakes compared to nondrinkers was 0.53 (95%CI: 0.33-0.85), 0.44 (0.24-0.81), and 0.33 (0.16-0.68) for CAD, and 0.56 (0.34-0.90), 0.62 (0.32-1.20), and 0.43 (0.18-1.01) for MI. Among 219 women, CAD and MI were present in 107 and 36. Compared with nondrinkers, light and moderate to heavy drinkers less often had CAD (52%, 41%, and 29%) and MI (19%, 9%, and 14%), but these differences did not reach statistical significance. In women, no significant association was found between alcohol intake and CAD. Thus, in Japanese men undergoing coronary angiography, alcohol consumption was inversely associated with CAD, but heavy consumption was associated with abnormally high γ-GTP levels. In women, no significant association was found between alcohol consumption and CAD.

The expression of the forkhead box O (FoxO) transcription factor, FoxO, in the skeletal muscle is involved in muscle atrophy caused by disuse, fasting, diabetes, and cachexia. Since inhibition of FoxO activity has been shown to be effective in preventing muscle atrophy in genetically engineered animals, inhibition of FoxO activity by dietary components may contribute to the prevention of muscle atrophy. In this study, 4,006 plant extracts were evaluated for FoxO1 and FoxO3a inhibitory activity using a reporter gene assay system, and the extracts from Cephalotaxus harringtonia showed potent inhibitory activities. These extracts also suppressed dexamethasone-induced expression of FoxO target genes, such as atrogin-1 and cathepsin L in C2C12 myotubes. Furthermore, harringtonine alkaloids, harringtonine and homoharringtonine, contained in Cephalotaxus harringtonia inhibited FoxOs activities and suppressed dexamethasone-induced expression of FoxO target genes in C2C12 myotubes, suggesting that harringtonine alkaloids contributed to the effects observed in C2C12 myotubes treated with Cephalotaxus harringtonia extract. However, these extracts and harringtonine alkaloids did not improve weakness in dexamethasone-atrophic myotubes. In conclusion, harringtonine alkaloids from Cephalotaxus harringtonia suppressed FoxO1 and 3a activity and the expression of their target atrophy genes in C2C12 myotubes, but these alkaloids had no the effect on dexamethasone-induced reduction in muscle contractility.

Epoxyeicosatrienoic acids (EETs), the epoxidation products of arachidonic acid, were shown to have vasodilation and anti-inflammatory activity in many tissues. In the present study, the roles and mechanisms of EETs in the development of inflammation in adipose tissue were investigated in obese mice. Diet-induced obesity models were established on male C57BL/6 mice, and randomly divided into three groups: OB group (saline), EET group (11,12-EET), or EEZE group (14,15-epoxyeicosa-5(Z)-enoicacid). The levels of cytochrome P450 (CYP) 2J6, hypoxia inducible factor (HIF)-1α, 11,12-EET, interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were determined. Angiogenesis was evaluated with platelet endothelial cell adhesion molecule-1 (CD31); Insulin resistance was evaluated with homeostasis model assessment of insulin resistance (HOMA-IR). In diet-induced obese mice, CYP2J6 expression in both mRNA and protein levels was downregulated and 11,12-EET level was reduced, levels of IL-6, IL-1β, TNF-α, and HIF-1α were increased in epididymal adipose tissue and in serum compared with non-obese controls. These changes were attenuated by exogenous 11,12-EET, whereas but aggravated by 14,15-EEZE, an EET antagonist. CD31-positive cells in the epididymal adipose tissue of obese mice were markedly reduced, which was significantly improved by 11,12-EET. HOMA-IR was increased but markedly attenuated by 11,12-EET in obese mice. These findings indicate that dysregulation of the CYP epoxygenases/EETs pathway may contribute to adipose inflammation in diet-induced obese mice. Exogenous EETs may attenuate adipose inflammation through modulation of adipose angiogenesis and hypoxia, which may have a favorable effect on systemic insulin resistance.

Natural disasters have occurred frequently in Japan and are currently the focus of much attention. The objective of this study is to investigate the association between the degree of health and food stockpiling for disasters across Japan. This study conducted an online survey from November 25 to 29, 2022, via a self-administered web-based questionnaire. The sample for this study consisted of 2,000 individuals over the age of 20 who registered with an online survey company. The associations between the degree of health and food stockpiling for disasters were analyzed (n=1,634). Only 11.9% of the participants had a high level of health, whereas 52.5% had a low level. Fewer than half of the participants had a middle level of health (35.6%). A multivariable logistic regression analysis was conducted to examine the association between the degree of health and food stockpiling for disasters. The analysis revealed a significant positive association between the degree of health and food stockpiling behavior for disasters. The levels of health, physical health and social health were significantly positively related to food stockpiling. Therefore, it is crucial to focus on personality traits to promote food stockpiling for disasters. This study emphasized that the degree of health should receive more attention in research, which could help promote food stockpiling for disasters.