Nobiletin suppresses the development of experimental autoimmune encephalomyelitis mediated by modulation of T helper 17 cell differentiation.

Multiple sclerosis is an organ-specific autoimmune disease that targets the myelin antigen in the central nervous system. Nobiletin is a dietary polymethoxylated flavonoid found in citrus fruits. In this study, we investigated how nobiletin affects the disease state and immune responses to myelin oligodendrocyte glycoprotein in experimental autoimmune encephalomyelitis mice. Nobiletin was administered orally from 14 days before immunization until the end of the experiment, and clinical scores were determined. The production levels of interleukin-17A and interferon-γ were measured in a culture supernatant of splenocytes stimulated with myelin oligodendrocyte glycoprotein. In addition, flow cytometric analysis was performed to examine the effect of nobiletin on T cell differentiation in vitro. Admin-istration of nobiletin significantly decreased the clinical score and interleukin-17A production in splenocytes. Furthermore, in vitro analysis showed that nobiletin significantly suppressed Th17 cell differentiation and interleukin-17A production in a dose-dependent manner. The results suggest that nobiletin attenuates experimental autoimmune encephalomyelitis severity through modulation of Th17 cell differentiation.

Associations of dietary diversity with allergic diseases in Japanese workers: a cross-sectional study.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine the associations of dietary diversity with prevalences of allergic diseases. METHODS AND STUDY DESIGN: The participants were 1,317 men and women aged 20 to 63 years who were living in Tokushima Prefecture, Japan during the period 2012-2013. We obtained anthropometric data and information on lifestyle characteristics and current medical histories of allergic diseases using a self-administered questionnaire. Dietary intake was assessed using a food frequency questionnaire, and dietary diversity was determined using the Quantitative Index for Dietary Diversity (QUANTIDD). The ORs and 95% CIs for each of the allergic diseases with a 1 standard deviation (SD) increase in the QUANTIDD score were estimated, controlling for age, family history of allergic diseases, education, smoking, drinking, physical activity, energy intake and BMI. RESULTS: Higher dietary diversity showed significant inverse dose-response relationships with allergic diseases and allergic rhinitis in women. Multivariate-adjusted ORs (95% CI) for allergic diseases and allergic rhinitis with 1 SD increase in the QUANTIDD score were 0.77 (95% CI: 0.60-0.98, p=0.037) and 0.69 (95% CI: 0.53-0.90, p=0.007), respectively, in women. There were no significant associations between dietary diversity and allergic diseases in men. CONCLUSIONS: The results indicate that there is an inverse association between higher dietary diversity and allergic rhinitis in Japanese female workers.

Sudachitin, polymethoxyflavone from Citrus sudachi, enhances antigen-specific cellular and humoral immune responses in BALB/c mice.

Scdachitin is a polymethoxyflavone (5,7,4'-trihydroxy-6,8,3-trimethoxyflavone) that is found in the peel of Citrus sudachi. We examined the effect of sudachitin on immune response in ovalbumin-immunized BALB/c mice. Treatment with sudachitin increased ovalbumin-specific IL-4 and IL-10 productions. In addition, mice that received sudachitin showed higher levels of ovalbumin-specific IgE, IgG1 and IgG l production than did control mice. The antibody response to the thymus-independent antigen 2,4,6-trinitrophenyl Ficoll was not different in the control and sudachitin groups, suggesting that sudachitin does not directly stimulate antibody production. An in vitro study showed that treatment of sudachitin enhanced the ability of antigen presentation in bone marrow-derived dendritic cells. Furthermore, CD11c+ cells that had been treated with sudachitin showed increased expression of co-stimulatory molecules. The results indicate that sudachitin regulates immune function both in vivo and in vitro.

Brazilian Green Propolis Promotes Weight Loss and Reduces Fat Accumulation in C57BL/6 Mice Fed A High-Fat Diet.

Propolis is a bee product with various biological properties. C57BL/6 mice were fed a high-fat diet and treated with propolis for 14 weeks. Body weight in mice treated with 2% propolis was less than that in control mice from 3 weeks after the start of treatment until 14 weeks except for the 7th week. Mice treated with propolis showed significantly lower epididymal fat weight and subcutaneous fat weight. Infiltration of epididymal fat by macrophages and T cells was reduced in the propolis group. Supplementation of propolis increased feces weight and fat content in feces, suggesting that mechanisms of weight reduction by propolis partly include a laxative effect and inhibition of fat absorption.

Effects of polymethoxyflavonoids on T helper 17 cell differentiation in vitro and in vivo.

We examined the effects of polymethoxyflavonoids (PMFs) on T helper (Th) 17 cell differentiation in vitro and in vivo. Five different PMFs including nobiletin (NOB), sudachitin (SUD), demethoxysudachitin, heptamethoxyflavone and natsudaidain were used for the in vitro study, and effects of those flavonoids on Th17 responses were investigated. NOB and heptamethoxyflavone significantly suppressed the proliferation response, but SUD, demethoxysudachitin and natsudaidain did not suppress the proliferation response. All of the five flavonoids decreased IL-17A production. Mice with experimentally induced autoimmune encephalomyelitis were used as an in vivo Th17 differentiation model. We focused on two flavonoids, NOB and SUD, and examined the effects of those flavonoids. NOB significantly suppressed Th17 cell proliferation and cytokine responses, but SUD only decreased proliferation responses. The results suggest that the suppressive effect of NOB on Th17 response in vivo is stronger than that of SUD. J. Med. Invest. 70 : 166-170, February, 2023.

Essential Oil of Citrus sudachi Suppresses T Cell Activation Both In Vitro and In Vivo.

The essential oil of Citrus sudachi (sudachi oil) is extracted from the peel of sudachi, a citrus plant. We investigated the effect of sudachi oil on immune function in both in vitro antigen (Ag) induced lymphocyte activation and in vivo Ag-specific immune response. In the in vitro study, the proliferative activity of splenocytes upon Ag-specific and non-specific stimulation was suppressed by treatment with sudachi oil in a dose-dependent manner. In addition, the expression level of Ag-presentation-related molecules and their Ag-presenting function on dendritic cells were suppressed by sudachi oil. To examine how sudachi oil regulates an Ag-specific immune response in vivo, mice were immunized with ovalbumin and the immune response of the mice was investigated. Ag-specific proliferation response of splenocytes from mice treated with sudachi essential oil was significantly suppressed. The results indicate that sudachi oil suppresses T cell and dendritic cell functions in vitro and Ag-specific T cell induction in vivo.

Dietary deoxynucleic acid induces type 2 T-helper immune response through toll-like receptor 9 in mice.

BACKGROUND: It has been shown that dietary nucleotides modulate immune response. Due to their unique properties in immune responses, nucleotides are used as immunonutrition in the field of clinical nutrition. AIM OF THE STUDY: In this study, we examined the effect of dietary deoxynucleic acid (DNA) on antigen (Ag)-specific immune response in ovalbumin (OVA)-immunized BALB/c mice and determined the mechanism using toll-like receptor 9 (TLR9) knock-out (KO) mice. METHODS: BALB/c or TLR9 KO mice were fed control and 1% DNA diets and immunized with OVA. Spleen cells from OVA-immunized mice were stimulated with OVA in vitro, and the contents of IFN-γ and IL-4 in supernatants were measured by an ex vivo system. CD11c(+) dendritic cells were purified, and ability of cytokine induction to CD4(+) cells was examined. RESULTS: The level of OVA-specific IL-4 production in the DNA group was significantly higher than that in the control group. In contrast, the level of OVA-specific IFN-γ production in the DNA group was lower than that in the control group. The DNA diet decreased Ag-specific IL-4 production and enhanced Ag-specific IFN-γ production in TLR9 KO mice. CD11c(+) DCs from mice fed the DNA diet had a greater ability than CD11c(+) DCs from mice fed the control diet to induce the production of IL-4 from DO11.10 CD4(+) T cells. CONCLUSIONS: Dietary DNA increases Ag-specific IL-4 production and decreases IFN-γ production through a TLR9-dependent pathway. CD11c(+) dendritic cells are target cells in dietary DNA-induced immune regulation.

Soy isoflavone equol perpetuates dextran sulfate sodium-induced acute colitis in mice.

The effects of the soy isoflavones, genistein, daidzein and equol, on experimental colitis were examined. Equol severely perpetrated dextran sulfate sodium (DSS)-induced colitis as evaluated by the weight loss. Production of the anti-inflammatory cytokine, IL-10, from T cells was decreased in the equol-treated mice. The results show that the soy isoflavone, equol, played an important role in the inflammatory response in the gastrointestinal tract.

Suppression of oral tolerance by Lactococcus lactis in mice.

Although oral ovabumin (OVA) administration suppressed the antibody (Ab) response in OVA-immunized mice, Lactococcus lactis increased OVA-specific IgG2a in these mice. L. lactis increased the casein-specific IgG level in NC/Nga mice fed on a casein diet. The percentage of CD4(+)CD25(+) cells was increased in DO11.10 mice orally given OVA, but this increase of CD4(+)CD25(+) cells were suppressed in L. lactis-fed DO11.10 mice.

Dietary phosphorus acutely impairs endothelial function.

Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.

Dietary diversity and characteristics of lifestyle and awareness of health in Japanese workers†:†a cross-sectional study.

The aim of this study was to clarify the characteristics of lifestyle and health awareness according to dietary diversity in a Japanese worksite population. The participants were 1,312 men and women aged 20 to 63 years who were living in Tokushima Prefecture, Japan during the period 2012-2013. We obtained anthropometric data and information on lifestyle characteristics using a self-administered questionnaire. Dietary intake was assessed using a food frequency questionnaire, and dietary diversity was determined using the Quantitative Index for Dietary Diversity (QUANTIDD). The characteristics of lifestyle and health awareness according to quartiles of the QUANTIDD score were assessed using the chi-square test and a general linear model. The higher the QUANTIDD score was, the larger were the proportions of participants who knew the appropriate amount of dietary intake and participants who referred to nutritional component information when choosing and / or buying food. Among participants with higher QUANTIDD scores, the proportion of participants who considered their current diet was good was high in women, whereas the proportion of participants who wanted to improve their diet in the future was high in men. Those results indicate that higher dietary diversity was related to better characteristics of lifestyle and awareness of health. J. Med. Invest. 67 : 255-264, August, 2020.

Associations of marital and parental status and family members living together with health-related behaviors in Japanese young workers : a cross-sectional study.

The aim of this study was to clarify the associations of family members living together with healthrelated behaviors in Japanese young workers. The participants were 300 men and women aged 20-39 years in 2015 who had a job. A web-based self-administered questionnaire on status of partnering and parenting, number of family members living together, dietary habits, drinking habit, smoking habit, self-rated health, employment status, working time and commuting time was conducted through Internet. Multiple logistic regression analysis and general linear models were used to assess the association of family members living together with healthrelated behaviors. The multivariate-adjusted odds ratio (95% confidence interval, p-value) for current drinking in unmarried participants living with their parents compared to unmarried participants living alone was 0.35 (0.13-0.93, p=0.036). The adjusted means of frequency of breakfast skipping and frequency of eating out showed a trend for inverse associations with the presence of a partner and children. However, those associations disappeared after adjustment for age of youngest child. The findings suggest that the presence of parents might affect drinking behavior and that age of youngest child living together might affect the frequency of breakfast skipping in young Japanese workers. J. Med. Invest. 66 : 141-147, February, 2019.

Nobiletin Enhances Induction of Antigen-Specific Immune Responses in BALB/c Mice Immunized with Ovalbumin.

We examined the effect of nobiletin (5,6,7,8,3',4'-hexamethoxyflavone) on immune response in ovalbumin (OVA)-immunized mice. Treatment with nobiletin increased OVA-specific IL-4 and IL-10 production. In addition, mice that received nobiletin showed higher levels of OVA-specific IgE, IgG and IgG1 production than did control mice. The antibody response to the thymus-independent antigen 2,4,6-trinitrophenyl-Ficoll was not different in the control and nobiletin groups, suggesting that nobiletin does not directly stimulate antibody production. An in vitro study showed that treatment with nobiletin enhanced the ability of antigen presentation of bone marrow-derived dendritic cells. The in vivo and in vitro results indicate that nobiletin regulates immune function.

Soy product and isoflavone intake associations with allergic diseases in Japanese workers: rhinitis, dermatitis and asthma.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine the associations of intake of soy products and isoflavones with allergic diseases. METHODS AND STUDY DESIGN: We conducted a cross-sectional study in 1437 participants (aged 20-64 years) who were living in Tokushima Prefecture, Japan during the period 2010- 2011. We obtained anthropometric data and information on life style characteristics including dietary intake and current medical histories of allergic diseases using a structural self-administered questionnaire. Multiple logistic regression models were used to assess the associations of soy products and isoflavones with allergic diseases after controlling for age, family history of allergic diseases, smoking, drinking, physical activity, energy intake, BMI and dietary factors. RESULTS: Intake of soy products showed significant inverse dose-response relationships with allergic rhinitis. The third quartile for soy products had an adjusted OR of 0.56 (95% CI: 0.35-0.91) compared to the reference group (first quartile), though intake of soy products showed no dose-response relationship with atopic dermatitis. Intake of soy isoflavones showed a significant inverse dose-response relationship with atopic dermatitis, though the association between intake of soy isoflavones and atopic dermatitis was U-shaped after adjustments for potential confounders. On the other hand, the associations between intake of soy isoflavones and other allergic diseases were not significant. CONCLUSIONS: The results indicate that higher intake of soy products is associated with reduced risk of allergic rhinitis in Japanese workers. Furthermore, moderate intake amounts of soy products and soy isoflavones are associated with inverse risk of atopic dermatitis.

Associations between intake of dietary fermented soy food and concentrations of inflammatory markers: a cross-sectional study in Japanese workers.

Epidemiological investigations have shown that consumption of soybeans or soy foods reduces the risk of the development of cardiovascular disease, cancer and osteoporosis. The aim of this study was to determine the associations between different soy foods and inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, and IL-18, in Japanese workers. The cross-sectional study included 1,426 Japanese workers (1,053 men and 373 women) aged 20 to 64 years. Intake of 12 soy foods was estimated by a validated food frequency questionnaire. Associations of total soy foods, fermented soy food, non-fermented soy food, soy isoflavone with hs-CRP, IL-6, and IL-18 levels were examined by general linear model regression analysis. We found that total fermented soy food intake was inversely associated with multivariable-adjusted geometric concentration of IL-6 in men (Q1:1.03 pg/mL, Q5:0.94 pg /mL;P for trend = 0.031). Furthermore, it was shown that IL-6 concentrations were inversely associated with miso intake (ß = -0.068;p = 0.034) and soy sauce intake in men (ß = -0.074;p = 0.018). This study suggests that intake of total fermented soy food, miso and soy sauce be associated with IL-6 concentrations in Japanese men. J. Med. Invest. 65:74-80, February, 2018.

Advantage of a low glycemic index and low phosphate diet on diabetic nephropathy and aging-related diseases.

Diabetic nephropathy is the leading cause of end-stage renal disease (ESRD) in Japan and other Westernized countries. Over 50% of the ESRD patients die from cardiovascular events. Cardiovascular disease (CVD) in ESRD patients with diabetes mellitus (DM) are implicated in the endothelial dysfunction caused by hyperglycemia, hyperlipidemia, and hypertension, and in the vascular calcification of intimal and medial arterial blood vessels caused by hyperphosphatemia. Therefore, dietary control of hyperglycemia and hyperphosphatemia should play an important role in the management of ESRD patients with DM. Furthermore, recent findings suggest that high concentrations of serum phosphate, even if within the normal range, may be a risk factor for CVD and mortality. An in vivo study using klotho knockout mice and fibroblast growth factor 23 (FGF-23) knockout mice has revealed that correction of hyperphosphatemia and hypervitaminosis D could ameliorate the premature aging-like phenotype. A low glycemic index and low phosphate diet may provide an advantage in the prevention of aging-related diseases in healthy individuals as well as in those with chronic kidney disease.

Extracts of citrus Sudachi peel attenuate body weight gain in C57BL/6 mice fed a high-fat diet.

Citrus Sudachi is the special local product of Tokushima Prefecture, and over 98% of Sudachi consumed in Japan every year is produced in Tokushima Prefecture. In this study, we evaluated the function of sudachi peel extract (SPE) using an animal model of obesity. C57BL/6 mice were fed a high-fat diet containing 1% SPE powder. Treatment with SPE significantly decreased body weight compared to that of mice fed a high-fat diet. A significant difference in body weight was observed between the control and SPE groups from 7 weeks after the start of the experiment, the significant difference continued until the end of the 14-week experiment. Reduction of blood glucose levels following insulin administration in SPE-treated mice was grater than that in control mice. Determination of mRNA expression in adipose tissue showed that the expression level of TNF-α in the SPE group was significantly decreased compared to that on the control group. These results suggest that SPE potentially has the ability to attenuate body weight gain. J. Med. Invest. 64: 20-23, February, 2017.

Design and synthesis of emodin derivatives as novel inhibitors of ATP-citrate lyase.

Aberrant cellular metabolism drives cancer proliferation and metastasis. ATP citrate lyase (ACL) plays a critical role in generating cytosolic acetyl CoA, a key building block for de novo fatty acid and cholesterol biosynthesis. ACL is overexpressed in cancer cells, and siRNA knockdown of ACL limits cancer cell proliferation and reduces cancer stemness. We characterized a new class of ACL inhibitors bearing the key structural feature of the natural product emodin. Structure-activity relationship (SAR) study led to the identification of 1d as a potent lead that demonstrated dose-dependent inhibition of proliferation and cancer stemness of the A549 lung cancer cell line. Computational modeling indicates this class of inhibitors occupies an allosteric binding site and blocks the entrance of the substrate citrate to its binding site.

Evaluation of anti-stress nutrients in the endothelial cells with fluorescence indicator.

Oxidative stress has emerged as an important pathogenic factor in the development of long-term complications, such as hypertension, atherosclerosis, nephropathy, and cancer. Taking many antioxidants from natural food may be effective to prevent us from those diseases. We have attempted to evaluate the effect of improvement by dietary antioxidants on the endothelial dysfunction induced by hyperglycemia. Fluorescence indicators for reactive oxygen species and nitric oxide were employed to the evaluation. The combination of those fluorescence indicators could be powerful tool to evaluate the effect of anti-stress nutrients on both oxidative stress and endothelial dysfunction.

Vitamin A Deficiency Impairs Induction of Oral Tolerance in Mice.

Oral tolerance is a phenomenon of induction of systemic unresponsiveness to antigens ingested by the oral route and loss of immune response. Studies have shown the importance of vitamin A in oral tolerance in vitro but not in an in vivo experimental model. Therefore, we carried out experiments to determine how vitamin A deficiency affects tolerance induction and the ability of mesenteric lymph node (MLN) CD11c(+) cells to induce regulatory T cells (Tregs). Immunological tolerance was induced by oral ovalbumin (OVA) administration in vitamin A-sufficient mice. OVA-specific antibody and cytokine production were significantly reduced. On the other hand, in vitamin A-deficient mice, both OVA-specific antibody and cytokine production were not suppressed by oral OVA administration. Regarding induction of Tregs, the conversion rate of Foxp3(+) cells from naïve CD4(+) cell by CD11c(+) cells was decreased in vitamin A-deficient mice. Our study indicates that vitamin A deficiency causes the breakdown of oral tolerance in vivo.