The Feeding of .BETA.-Carotene Down-Regulates Serum IgE Levels and Inhibits the Type I Allergic Response in Mice

[ADMET Analysis of Amorphous β-Carotene and Its Usefulness Evaluation]

In recent years, functional foods have attracted increasing attention due to growing health consciousness. When functional food ingredients are poorly water-soluble, they largely fail to be absorbed due to their low solubility in the digestive tract, limiting their ability to exert their functions. To develop poorly water-soluble compounds into viable functional food ingredients, it is important to increase their gastrointestinal absorption so that they can fully exert their functions, and to ensure their safety and efficacy through ADMET research. β-Carotene exerts physiological activities including antioxidant effects, and functions as a source of vitamin A, but it is completely insoluble in water, so it is poorly absorbed from the digestive tract, rendering it difficult to use efficiently as a functional food ingredient. To overcome this problem, we are conducting research on drug delivery system to improve β-carotene solubility and thereby improve its digestive absorption by applying our unique amorphous solid dispersion production technology. To date, we have produced amorphous solid dispersions with dramatically improved water solubility by adding polymers and emulsifiers to β-carotene and kneading these mixtures under heat. The resultant amorphous solid dispersion showed unprecedentedly high gastrointestinal absorption, enhanced inhibition of allergic dermatitis, and enhanced amelioration of cognitive impairment. No major safety issues associated with long-term continuous administration were observed. In this paper, we introduce our efforts to effectively deliver poorly water-soluble compounds such as β-carotene in functional foods.

Activation of Immune and Antiviral Effects by Euglena Extracts: A Review

Influenza is an acute respiratory illness caused by influenza virus infection, which is managed using vaccines and antiviral drugs. Recently, the antiviral effects of plants and foods have gained attention. Euglena is a motile unicellular alga and eukaryotic photosynthetic microorganism. It has secondary chloroplasts and is a mixotroph able to feed by photosynthesis or phagocytosis. This review summarizes the influenza treatment effects of Euglena from the perspective of a functional food that is attracting attention. While it has been reported that Euglena contributes to suppressing blood sugar levels and ameliorates symptoms caused by stress by acting on the autonomic nervous system, the immunostimulatory and antiviral activities of Euglena have also been reported. In this review, I focused on the immunostimulation of antiviral activity via the intestinal environment and the suppression of viral replication in infected cells. The functions of specific components of Euglena, which also serves as the source of a wide range of nutrients such as vitamins, minerals, amino acids, unsaturated fatty acids, and β-1,3-glucan (paramylon), are also reviewed. Euglena has animal and plant properties and natural compounds with a wide range of functions, providing crucial information for improved antiviral strategies.

Examination of dissolution ratio of β-carotene in water for practical application of β-carotene amorphous solid dispersion

β-Carotene (BC) has an antioxidant effect that removes active oxygen in vivo and can reduce the risk of developing various diseases, but it is almost insoluble in water. Therefore, to develop highly effective BC functional food products, it is essential to increase its water solubility, which in turn can improve its absolute bioavailability. Recently, a BC amorphous solid dispersion (BC-SD) prepared using hot melt extruder technology had increased water solubility and improved absorption from the gastrointestinal tract. However, only a part of the BC in BC-SD could be dissolved in water. In this study, we evaluated whether the dissolution ratio of BC in water could be improved by examining the mixing ratio of BC and base materials in BC-SD. Results showed that by reducing the mixing ratio of BC to the base materials, the dissolution ratio of BC in water increased. It was also found that when BC-SD, which has the highest dissolution ratio, was intragastrically administered to rats, its absolute bioavailability was most increased. These results are useful findings that may help in reducing the costs associated with the BC-SD manufacturing process and will be an important part of our strategy for practical use in the future.

Mast Cell Regulation and Irritable Bowel Syndrome: Effects of Food Components with Potential Nutraceutical Use

Mast cells are key actors in inflammatory reactions. Upon activation, they release histamine, heparin and nerve growth factor, among many other mediators that modulate immune response and neuron sensitization. One important feature of mast cells is that their population is usually increased in animal models and biopsies from patients with irritable bowel syndrome (IBS). Therefore, mast cells and mast cell mediators are regarded as key components in IBS pathophysiology. IBS is a common functional gastrointestinal disorder affecting the quality of life of up to 20% of the population worldwide. It is characterized by abdominal pain and altered bowel habits, with heterogeneous phenotypes ranging from constipation to diarrhea, with a mixed subtype and even an unclassified form. Nutrient intake is one of the triggering factors of IBS. In this respect, certain components of the daily food, such as fatty acids, amino acids or plant-derived substances like flavonoids, have been described to modulate mast cells' activity. In this review, we will focus on the effect of these molecules, either stimulatory or inhibitory, on mast cell degranulation, looking for a nutraceutical capable of decreasing IBS symptoms.

Oral administration of β-carotene or lycopene prevents atopic dermatitis-like dermatitis in HR-1 mice

Atopic dermatitis (AD) is a chronic relapsing eczematous skin disease. Certain populations of patients are resistant to standard therapies with topical steroids and/or calcineurin inhibitors, and require systemic medication, such as immunosuppressants. Recently, several reports have shed light on the anti-allergic effects of carotenoids. Therefore, we investigated the effect of p.o. administration of β-carotene or lycopene on AD-like symptoms of HR-1 hairless mice fed with a low zinc/magnesium diet. Mice were divided into four groups: (i) fed with a standard diet (Co group); (ii) low zinc/magnesium diet (HR group); (iii) low zinc/magnesium and β-carotene diet (HR-C group); and (iv) low zinc/magnesium and lycopene diet (HR-L group). They were then fed these diets for 8 weeks. Severities of dermatitis were assessed by their appearance, and histopathological and hematological observations. Mice in the HR group developed AD-like dermatitis both clinically and histologically. HR-C and HR-L group mice also developed xerosis and wrinkle-like skin changes, but they were milder than those of HR group mice. Histological analysis revealed that epidermis thickening and inflammatory cell infiltration in the skin of the HR-C and HR-L groups were both statistically less than those of the HR group. The concentration of thymus and activation regulated chemokine in the skin of the HR-L group and the concentration of CCL27 in the skin of the HR-C group were significantly lower than those of the HR group, respectively. In conclusion, p.o. administration of β-carotene or lycopene prevents AD-like symptoms in association with a suppression of T-helper 2 chemokines in a murine model. Ingestion of carotenoids may be beneficial for patients with AD.

Modulación de la respuesta alérgica por los carotenoides de la dieta

<p>Los carotenoides son pigmentos isoprenoides que están presentes de manera natural y en altas concentraciones en la mayoría de alimentos vegetales —entre ellos, aguacate, papaya, tomate y zanahoria—, pero también encontrados como aditivos y colorantes en diversos productos cárnicos, aceites vegetales, salsas, aderezos, harinas, entre otros. En los últimos años, algunos estudios han descrito que los carotenoides de la dieta participan en varios procesos fisiopatológicos, incluyendo la respuesta inmune de tipo alérgico. Las tasas de prevalencia para este tipo de enfermedades han incrementado de manera alarmante durante las últimas cinco décadas en todo el mundo, a la vez que varios factores e hipótesis se han planteado tratando de explicar este fenómeno: uno de ellos es la hipótesis de la dieta, la cual plantea que la composición de varios micro y macronutrientes de la alimentación, así como los cambios en los patrones dietarios, influirían en tal problemática. Evidencia epidemiológica y básica experimental emergente señala que los carotenoides de la dieta participan en la regulación de la inflamación alérgica, y por ello se postulan como coadyuvantes en la terapia de tales padecimientos. En el presente artículo se revisará el estado del arte en relación a los efectos de los carotenoides de la dieta sobre la patología alérgica.</p>

Astaxanthin, a Carotenoid, Stimulates Immune Responses by Enhancing IFN-γ and IL-2 Secretion in Primary Cultured Lymphocytes in Vitro and ex Vivo

Astaxanthin, a potent antioxidant carotenoid, plays a major role in modulating the immune response. In this study, we examined the immunomodulatory effects of astaxanthin on cytokine production in primary cultured lymphocytes both in vitro and ex vivo. Direct administration of astaxanthin (70-300 nM) did not produce cytotoxicity in lipopolysaccharide (LPS, 100 µg/ mL)- or concanavalin A (Con A, 10 µg/ mL)-activated lymphocytes, whereas astaxanthin alone at 300 nM induced proliferation of splenic lymphocytes (p < 0.05) in vitro. Although astaxanthin, alone or with Con A, had no apparent effect on interferon (INF-γ) and interleukin (IL-2) production in primary cultured lymphocytes, it enhanced LPS-induced INF-γ production. In an ex vivo experiment, oral administration of astaxanthin (0.28, 1.4 and 7 mg/kg/day) for 14 days did not cause alterations in the body or spleen weights of mice and also was not toxic to lymphocyte cells derived from the mice. Moreover, treatment with astaxanthin significantly increased LPS-induced lymphocyte proliferation ex vivo but not Con A-stimulated lymphocyte proliferation ex vivo. Enzyme linked immunosorbent assay (ELISA) analysis revealed that administration of astaxanthin significantly enhanced INF-γ production in response to both LPS and Con A stimulation, whereas IL-2 production increased only in response to Con A stimulation. Also, astaxanthin treatment alone significantly increased IL-2 production in lymphocytes derived from mice, but did not significantly change production of INF-γ. These findings suggest that astaxanthin modulates lymphocytic immune responses in vitro, and that it partly exerts its ex vivo immunomodulatory effects by increasing INF-γ and IL-2 production without inducing cytotoxicity.

Oral administration of Lactobacillus plantarum lysates attenuates the development of atopic dermatitis lesions in mouse models

Lactobacillus plantarum is a well-documented probiotic that has been used in clinical trials for the regulation of the immune system and treatment of gastrointestinal diseases. In this study, we evaluated the effects of L. plantarum cell lysates on the immune regulation through the in vitro and in vivo studies. L. plantarum lysates were prepared by sonication method, and we observed that the repetition of disruption step increased indicator components within the bacterial lysates. Indicator components might affect TNF-α production. L. plantarum lysates did not induce TNF-α production, while LPS-induced TNF-α production was dramatically inhibited in a sonication-dependent manner in THP-1 cells. Oral administration of L. plantarum lysates effectively attenuated the horny layer formation and decreased epidermal thickening in NC/Nga mice skin. The damage to barrier function after the 8 weeks oral administration was reduced by L. plantarum lysates as compared to that in the atopic dermatitis (AD) mice. Further study revealed that L. plantarum lysates polarized Th1 response via induction of IL-12 and IFN-γ production and inhibition of IL-4 and IgE production in NC/Nga mice. Together, our results suggest that L. plantarum lysates are remarkable material for host homeostasis and it could be used for the treatment of inflammatory diseases.

Epigenetic regulation of asthma and allergic disease

Epigenetics of asthma and allergic disease is a field that has expanded greatly in the last decade. Previously thought only in terms of cell differentiation, it is now evident the epigenetics regulate many processes. With T cell activation, commitment toward an allergic phenotype is tightly regulated by DNA methylation and histone modifications at the Th2 locus control region. When normal epigenetic control is disturbed, either experimentally or by environmental exposures, Th1/Th2 balance can be affected. Epigenetic marks are not only transferred to daughter cells with cell replication but they can also be inherited through generations. In animal models, with constant environmental pressure, epigenetically determined phenotypes are amplified through generations and can last up to 2 generations after the environment is back to normal. In this review on the epigenetic regulation of asthma and allergic diseases we review basic epigenetic mechanisms and discuss the epigenetic control of Th2 cells. We then cover the transgenerational inheritance model of epigenetic traits and discuss how this could relate the amplification of asthma and allergic disease prevalence and severity through the last decades. Finally, we discuss recent epigenetic association studies for allergic phenotypes and related environmental risk factors as well as potential underlying mechanisms for these associations.

Feeding with Both β-Carotene and Supplemental α-Tocopherol Enhances Type 1 Helper T Cell Activity among Splenocytes Isolated from DO11.10 Mice

beta-Carotene and/or supplemental alpha-tocopherol were fed to DO11.10 mice to investigate their effect on the immune function of naive splenocytes. A high secretion of interleukin-12 and interferon-gamma in response to the ex vivo primary antigen presentation occurred only when both were fed. This is consistent with the suppressed immunoglobulin E production under the similar condition described in our previous report.

Effects of a Hop Water Extract on the Compound 48/80-Stimulated Vascular Permeability in ICR Mice and Histamine Release from OVA-Sensitized BALB/c Mice

The antiallergic properties of a hop water extract (HWE) were studied by evaluating the Evans blue leakage from ICR mice caused by compound 48/80 stimulation, and the histamine release from ovalbumin (OVA)-sensitized BALB/c mice. An oral administration of HWE significantly inhibited the vascular permeability and histamine release. HWE itself did not have any influence on the total and antigen-specific immunoglobulin E (IgE) production in OVA-sensitized mice. These results indicate that HWE exerted an antiallergic effect by inhibiting the release of chemical mediators from mast cells and basophiles.

Immunomodulation of mast cells by nutrients

In the past decades an increasing prevalence of allergic disorders was observed in industrialized countries. Thus, it is necessary to develop adequate therapeutic and preventive strategies. Many of the conservative strategies possess diverse harmful side effects. Therefore agents with fewer side effects and a better compliance among afflicted patients would be of interest. Especially substances with natural origin acting immunomodulatory on mast cells - the key effector cells of allergic diseases - could be used. Among them there are components of the daily diet such as distinct fatty acids and amino acids as well as a range of secondary plant substances such as carotenoids, flavonoids and spices. These nutritional substances could be applied as nutraceuticals in the therapy of mast cell associated diseases. Many of these substances show inhibitory influences on the release of prestored mast cell mediators such as histamine or de novo expression of mast cell mediators such as cytokines and eicosanoids which are involved in the pathogenesis of mast cell associated inflammatory conditions like allergic reactions.

Immunomodulatory Activity of Lactococcus lactis A17 from Taiwan Fermented Cabbage in OVA-Sensitized BALB/c Mice

From fermented Taiwan foods, we have isolated numerous lactic acid bacteria (LAB) of plant origin and investigated their biological activities. This study aimed to investigate the immunomodulatory effect and mechanism of Lactococcus lactis A17 (A17), isolated from Taiwan fermented cabbage, on ovalbumin (OVA)-sensitized mice. Human peripheral blood mononuclear cells were used to verify immune responses of A17 by IFN-γ production. Live (A17-A) and heat-killed A17 (A17-H) were orally administered to OVA-sensitized BALB/c mice to investigate their effects on immunoglobulin (Ig) and cytokine production. The mRNA expression of Toll-like receptors (TLR) and nucleotide binding oligomerization domain (NOD)-like protein receptors in spleen cells was analyzed by real-time RT-PCR. Both live and heat-killed A17 modulate OVA-induced allergic effects. B-cell response was modulated by diminishing IgE production and raising OVA-specific IgG2a production, while T-cell response was modulated by increasing IFN-γ production and decreasing IL-4 production. The mRNA expression of NOD-1, NOD-2, and TLR-4 was down-regulated by A17 as well. This is the first report to describe a naïve Lactococcus lactis A17 strain as a promising candidate for prophylactic and therapeutic treatments of allergic diseases via oral administration. Our results suggest the ameliorative effects of A17 may be caused by modulating NOD-1 NOD-2, and TLR-4 expression.

Early life precursors, epigenetics, and the development of food allergy

Food allergy (FA), a major clinical and public health concern worldwide, is caused by a complex interplay of environmental exposures, genetic variants, gene-environment interactions, and epigenetic alterations. This review summarizes recent advances surrounding these key factors, with a particular focus on the potential role of epigenetics in the development of FA. Epidemiologic studies have reported a number of nongenetic factors that may influence the risk of FA, such as timing of food introduction and feeding pattern, diet/nutrition, exposure to environmental tobacco smoking, prematurity and low birth weight, microbial exposure, and race/ethnicity. Current studies on the genetics of FA are mainly conducted using candidate gene approaches, which have linked more than 10 genes to the genetic susceptibility of FA. Studies on gene-environment interactions of FA are very limited. Epigenetic alteration has been proposed as one of the mechanisms to mediate the influence of early life environmental exposures and gene-environment interactions on the development of diseases later in life. The role of epigenetics in the regulation of the immune system and the epigenetic effects of some FA-associated environmental exposures are discussed in this review. There is a particular lack of large-scale prospective birth cohort studies that simultaneously assess the interrelationships of early life exposures, genetic susceptibility, epigenomic alterations, and the development of FA. The identification of these key factors and their independent and joint contributions to FA will allow us to gain important insight into the biological mechanisms by which environmental exposures and genetic susceptibility affect the risk of FA and will provide essential information to develop more effective new paradigms in the diagnosis, prevention, and management of FA.

Carotenoids modulate cytokine production in Peyer's patch cells ex vivo

This study investigated the effects of carotenoid and capsaicin constituents of Capsicum on intestinal immune responses in mice. Peyer's patch (PP) cells were isolated from mice orally administered with capsaicin, or one of three carotenoids (beta-carotene, beta-cryptoxanthin, or lycopene), at 5 mg/kg/day for 7 consecutive days. Collagenase-separated PP cells were then cultured in the presence or absence of concanavalin A (Con A). PP cells from mice treated with capsaicin, beta-carotene, or beta-cryptoxanthin all showed significantly enhanced interleukin (IL)-2 and interferon (IFN)-gamma production when costimulated with 5 microg/mL Con A, with capsaicin having the greatest effect (approximately two times greater than in normal mice). No increase in the production of IL-2 or IL-4 was observed when PP cells from mice were cultured without Con A. We further tested the combined efficacy of carotenoids and capsaicin on intestinal T-cell cytokine production. Oral administration of capsaicin with beta-carotene, both at 5 mg/kg/day for 7 days, increased IFN-gamma and IL-2 production in cultured PP cells costimulated with Con A. In contrast, oral administration of beta-cryptoxanthin counteracted the stimulatory effect of capsaicin treatment on T-helper cytokine production. Flow cytometric analysis revealed that the population of IFN-gamma(+) and IL-4(+) cells in PPs from mice administered capsaicin and/or carotenoids did not change, which suggested that the effects of carotenoids and capsaicin on cytokine production were not due to changes in the lymphoid population in PPs. These results indicate that carotenoids and capsaicin, which are common components of foods such as Capsicum, mutually modulate T-cell immune responses to exogenous or endogenous inducers such as antigens in PPs, without changing the lymphoid population. Carotenoids modulate the potentiality of cytokine production in T cells or indirectly activate T cells but have no triggering effect such as Con A.

Dietary carotenoids inhibit oral sensitization and the development of food allergy

Type-I allergic disorders and particularly food hypersensitivities are becoming increasingly common worldwide. This study investigated whether dietary enrichment with carotenoids inhibited oral sensitization to an antigen and the development of food allergies. The effects of a diet high in carotenoids were investigated in B10A mice that were orally sensitized to ovalbumin (OVA). The serum titers of OVA-specific immunoglobulin E (IgE), IgG1, and IgG2a were inhibited in mice fed ad libitum on a diet high in alpha- or beta-carotene compared to the control mice when orally sensitized to OVA. High alpha- and beta-carotene diets inhibited the immediate reduction in body temperature and rise in serum histamine associated with active systemic anaphylaxis in OVA-sensitized B10A mice. After re-stimulation with OVA in vitro, the production of T-helper 2-type cytokines by splenocytes from mice fed a diet high in carotenoids was lower than in control mice. Furthermore, the proportion of CD4(+) CD103(+) T cells in Peyer's patches of mice fed a carotenoid-rich diet was significantly lower than in control mice. These results suggest that an increased oral intake of carotenoids inhibits OVA-specific IgE and IgG1 production and antigen-induced anaphylactic responses by inhibiting specific T-cell activation in the mucosal immune system. A diet high in carotenoids might therefore prevent the development of food allergies.

Consumption of vegetables, fruit, and antioxidants during pregnancy and wheeze and eczema in infants

BACKGROUND

Two previous cohort studies showed inverse relationships between maternal vitamin E and zinc intake during pregnancy and the risk of wheeze and/or asthma in the offspring. We investigated the association between maternal intake of vegetables, fruit, and selected antioxidants during pregnancy and the risk of wheeze and eczema in the offspring aged 16-24 months.

METHODS

Subjects were 763 Japanese mother-child pairs. Data on maternal intake during pregnancy were assessed with a diet history questionnaire. Data on symptoms of wheeze and eczema were based on criteria of the International Study of Asthma and Allergies in Childhood.

RESULTS

Higher maternal intake of green and yellow vegetables, citrus fruit, and beta-carotene during pregnancy was significantly associated with a reduced risk of eczema, but not wheeze, in the offspring {adjusted odds ratios (ORs) between extreme quartiles [95% confidence intervals (CIs)] = 0.41 (0.24-0.71), 0.53 (0.30-0.93), and 0.52 (0.30-0.89), respectively}. Maternal vitamin E consumption during pregnancy was significantly inversely related to the risk of infantile wheeze, but not eczema [adjusted OR (95% CI) = 0.54 (0.32-0.90)]. No statistically significant exposure-response associations were observed between maternal intake of total vegetables, vegetables other than green and yellow vegetables, total fruit, apples, alpha-carotene, vitamin C, or zinc and the risk of wheeze or eczema in the children.

CONCLUSIONS

Higher maternal consumption of green and yellow vegetables, citrus fruit, and beta-carotene during pregnancy may be protective against the development of eczema in the offspring. Higher maternal vitamin E intake during pregnancy may reduce the risk of infantile wheeze.

Dietary antioxidant intake, allergic sensitization and allergic diseases in young children

BACKGROUND

Allergic diseases have risen in prevalence over recent decades. The aetiology remains unclear but is likely to be a result of changing lifestyle and/or environment. A reduction in antioxidant intake, consequent to reduced intake of fresh fruits and vegetables, has been suggested as a possible cause.

OBJECTIVE

To investigate whether dietary antioxidant intake at age 5 was related to atopy at 5 and 8 years of age amongst children in an unselected birth cohort.

METHODS

Children were followed from birth. Parents completed a validated respiratory questionnaire and children were skin prick tested at 5 and 8 years of age. Serum IgE levels were measured at age 5. At age 5, antioxidant intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). A nutrient analysis program computed nutrient intake, and frequency counts of foods high in the antioxidant vitamins A, C and E were assessed.

RESULTS

Eight hundred and sixty-one children completed both the respiratory and FFQ. Beta-carotene intake was associated with reduced risk of allergic sensitization at age 5 [0.80 (0.68-0.93)] and 8 [0.81 (0.70-0.94)]. In addition, beta-carotene intake was negatively associated with total IgE levels (P = 0.002). Vitamin E intake was associated with an increased risk of allergic sensitization [1.19 (1.02-1.39)], only at age 5. There was no association between antioxidant intakes and wheeze or eczema.

CONCLUSION

Increased beta-carotene intake was associated with a reduced risk of allergic sensitization and lower IgE levels, in 5- and 8-year-old children. Dietary antioxidants may play a role in the development of allergic sensitization.

Inhibitory effect of carotenoids on the degranulation of mast cells via suppression of antigen-induced aggregation of high affinity IgE receptors

Carotenoids have been demonstrated to possess antioxidative and anti-inflammatory effects. However, there is no report that the effects of carotenoids on degranulation of mast cell is critical for type I allergy. In this study, we focused on the effect of carotenoids on antigen-induced degranulation of mast cells. Fucoxanthin, astaxanthin, zeaxanthin, and beta-carotene significantly inhibited the antigen-induced release of beta-hexosaminidase in rat basophilic leukemia 2H3 cells and mouse bone marrow-derived mast cells. Those carotenoids also inhibited antigen-induced aggregation of the high affinity IgE receptor (Fc epsilonRI), which is the most upstream of the degranulating signals of mast cells. Furthermore, carotenoids inhibited Fc epsilonRI-mediated intracellular signaling, such as phosphorylation of Lyn kinase and Fyn kinase. It suggests that the inhibitory effect of carotenoids on the degranulation of mast cells were mainly due to suppressing the aggregation of Fc epsilonRI followed by intracellular signaling. In addition, those carotenoids inhibited antigen-induced translocation of Fc epsilonRI to lipid rafts, which are known as platforms of the aggregation of Fc epsilonRI. We assume that carotenoids may modulate the function of lipid rafts and inhibit the translocation of Fc epsilonRI to lipid rafts. This is the first report that focused on the aggregation of Fc epsilonRI to investigate the mechanism of the inhibitory effects on the degranulation of mast cells and evaluated the functional activity of carotenoids associated with lipid rafts.

Suppressive effects of bifidobacterium breve strain M-16V on T-helper type 2 immune responses in a murine model

The Bifidobacterium breve M-16V strain has previously been shown to be effective in infants in improving the symptoms of allergic hypersensitivity to cow's milk and atopic dermatitis. In the current study, we investigated the effect of an oral administration of M-16V on immunoglobulin (Ig) E production in BALB/c mice. Live M-16V was orally administered to ovalbumin (OVA)-immunized mice for 3 weeks at a dose level of 5x10(8) colony-forming unit (cfu)/0.5 ml/d/animal. While M-16V treatment significantly reduced the serum levels of total IgE, OVA-specific IgE and OVA-specific IgG1, as compared to controls, it did not affect the serum level of OVA-specific IgG2a. In M-16V-administered mice, there was a significant decrease in the serum OVA-specific IgG1/IgG2a ratio. In addition, while ex vivo production of interleukin (IL)-4 by the splenocytes from M-16V-administered mice was significantly lower as compared to controls, there was no difference in the production of gamma-interferon (IFN-gamma) and IL-10. We also examined the effect of M-16V on cytokine and IgE production from OVA-sensitized splenocytes via restimulation with OVA in vitro. While M-16V suppressed OVA-induced total IgE and IL-4 production and induced secretion of IFN-gamma and IL-10 in a dose-dependent manner, it was not able to induce IL-12. We concluded that oral administration of M-16V suppressed the T-helper type (Th) 2 immune response and IgE production and modulated the systemic Th1/Th2 balance, and which was at least partially independent of the Th1 cytokine induction. These results suggest that M-16V may potentially have an antiallergic activity.

Immunostimulatory oligodeoxynucleotide containing TTTCGTTT motif from Lactobacillus rhamnosus GG DNA potentially suppresses OVA-specific IgE production in mice

In a previous study of the immunoregulatory properties of commensal bacterial DNA, we identified the strong immunostimulatory oligodeoxynucleotide (ISS-ODN) ID35 in the genomic DNA of Lactobacillus rhamnosus GG (LGG). The observed effects of ID35 are because of the unique TTTCGTTT motif located at the 5' end of the ODN, which is different from the previously identified ISS motifs in humans and mice. In the present study, we used an ovalbumin (OVA)-sensitized mouse model to show that ID35 is a potent suppressor of antigen-specific immunoglobulin E (IgE) production in vivo. This effect was toll-like receptor 9-dependent, as GpC negID35 failed to suppress antigen-specific IgE production. ID35 activated the specific subset of CD11c+CD8a+ dendritic cells, which are associated with T-helper 1 (Th1)-type systemic responses, and effectively induced interferon-gamma (IFN-gamma) production by CD4+ T cells in OVA-challenged mice. These immunoregulatory effects of ID35 were comparable with those induced by the murine prototype ODN 1826. Thus, ID35 is the first ISS-ODN with such a strong immunostimulatory and IgE suppressor activity to be found in immunobiotic bacterial DNA.

Capsicum ethanol extracts and capsaicin enhance interleukin-2 and interferon-gamma production in cultured murine Peyer's patch cells ex vivo

We investigated the effects of red pepper (Capsicum annuum Lin.) extracts (capsicum extract) and its main pungent capsaicin on T helper 1 (Th1) and 2 (Th2) cytokine production in cultured murine Peyer's patch (PP) cells in vitro and ex vivo. Direct administration of capsicum extract (1 and 10 mug/ml) and capsaicin (3 and 30 muM) resulted in suppression of interleukin (IL)-2, interferon (IFN)-gamma, IL-4 and IL-5 production. In an ex vivo experiment using PP cells removed from the mice after oral administration of capsicum extract (10 mg/kg/day for 4 consecutive days), IL-2, IFN-gamma and IL-5 increased in response to concanavalin A (Con A). Oral administration of 3 mg/kg/day capsaicin, one active constituent of the extract, also enhanced IL-2, INF-gamma and IL-4 production in response to Con A stimulation but did not influence the production of IL-5. Orally administered capsazepine (3 mg/kg/day), a selective transient receptor potential vanilloid 1 (TRPV1) antagonist, slightly enhanced IL-2 production also irrespective of Con A stimulation. The capsaicin-induced enhancement of both IL-2 and IFN-gamma production was not reduced by oral administration of capsazepine (3 mg/kg/day), suggesting a TRPV1 receptor-independent mechanism. Flow cytometric analysis revealed that the population of CD3(+) cells in the PP cells was significantly reduced while CD19(+) cells increased after oral administration of capsicum extract (1 and 10 mg/kg/day) and capsaicin (0.3 and 3 mg/kg/day). Capsazepine (3 mg/kg/day) weakly but significantly reversed these effects. Orally administered capsicum extract and capsaicin did not change the T cell subset (CD4(+) and CD8(+)), Th1 (IFN-gamma(+)) and T2 (IL-4(+)) ratio. These findings indicate that capsicum extract and capsaicin modulate T cell-immune responses, and their immunomodulatory effects on murine PP cells are partly due to both TRPV1-dependent and -independent pathway.

Aqueous Extract of Peanut Skin and Its Main Constituent Procyanidin A1 Suppress Serum IgE and IgG1 Levels in Mice-Immunized with Ovalbumin

In this study, we investigated the effects of an aqueous extract of peanut (Arachis hypogaea L.) seed skin (PSE) and its main constituent procyanidin A1 (PA) on the allergic response to allergen ovalbumin (OVA) in a mouse model. Mice immunized interaperitoneally with OVA dramatically increased anti-OVA IgE and total IgG1 levels in serum compared with non-treated control mice. Oral injection of PSE at doses ranging from 10 to 100 mg/kg/d (for 21 consecutive days) decreased anti-OVA IgE and IgG1 levels 21 d after OVA-immunization. OVA-induced increments in spleen weight and peripheral white blood cell count were also suppressed by this PSE administration. Polyphenol-enriched fractions from apple (30 mg/kg) and grape seed (30 mg/kg) also decreased anti-OVA IgE level but did not affect total IgG1 levels. Oral injection of PA (1 to 10 mg/kg/d) purified from PSE resulted in a suppression of IgE and total IgG1 levels in serum. An increment of serum interleukin-4 level in mice that were immunized with OVA was reduced by all tested samples, whereas PSE and PA were the only compounds that could reverse the reduced interferon-gamma level by OVA. These findings suggest that intake of PSE or its main active constituent PA may prevent an allergic reaction by inhibiting immunoglobulin synthesis, and the mechanism of this action of PSE and PA is in part due to their regulation of T helper cytokine production.

Immunostimulatory oligodeoxynucleotide from Bifidobacterium longum suppresses Th2 immune responses in a murine model

We have reported previously that novel immunostimulatory sequence (ISS) oligodeoxynucleotide (ODN) BL07S from a probiotic strain of Bifidobacterium longum inhibited immunoglobulin (Ig) E production in vitro. However, whether ISS-ODNs from probiotics regulate T helper type 2 (Th2)-polarized immune reactions in vivo remains unclear. To evaluate the inhibitory effects of ODN BL07S on type I allergic response, BALB/c mice were injected with or without ODN BL07S in the presence of ovalbumin (OVA) on days 0 and 14. Serum Ig levels (IgE, IgG1 and IgG2a) and cytokine levels (interferon (IFN)-gamma, interleukin (IL)-12, IL-4, IL-5, IL-10 and IL-13) were investigated in splenocyte cultures from days 14-28. Production of OVA-specific and total IgE were significantly suppressed by administration of ODN BL07S, but not by ODN BL06S, a non-ISS-ODN. Compared to controls, ODN BL07S induced significantly lower levels of Th2 cytokines (IL-4 and IL-5) in splenocyte cultures, and significantly higher levels of serum OVA-specific IgG2a. These effects of ODN BL07S on modulation of Th2 immune response were dose-dependent. The present results demonstrate that ODN BL07S from genomic DNA of B. longum BB536 prevents antigen-induced Th2 immune responses in vivo, suggesting that ISS-ODNs from probiotics might be useful in preventing allergic disease.

Chondroitin sulfate intake inhibits the IgE-mediated allergic response by down-regulating Th2 responses in mice

Chondroitin sulfate (CS) was administered orally to BALB/c mice immunized intraperitoneally with ovalbumin (OVA) and/or dinitrophenylated OVA. The titers of antigen-specific IgE and IgG1 in mouse sera were determined. The antigen-specific IgE production by mice fed ad libitum with CS was significantly inhibited. We also examined the effect of feeding CS on immediate-type hypersensitivity. One hour after antigen stimulation, the ears of mice fed with CS swelled less than those of the control mice. Furthermore, the rise in serum histamine in the mice fed with CS under active systemic anaphylaxis was significantly lower than that in the controls. We next examined the pattern of cytokine production by splenocytes from mice followed by re-stimulation with OVA in vitro. The splenocytes from the mice fed with CS produced less interleukin (IL)-5, IL-10, and IL-13 than those from the control group. In contrast, the production of interferon-gamma and IL-2 by the splenocytes of mice fed with CS was not significantly different from those in the control mice. In addition, the production of transforming growth factor-beta from the splenocytes of mice fed with CS was significantly higher than that of the control mice. Furthermore, we showed that the percentages of CD4(+) cells, CD8(+) cells, and CD4(+)CD25(+) cells in the splenocytes of mice fed with CS are significantly higher than those of the control. These findings suggest that oral intake of CS inhibits the specific IgE production and antigen-induced anaphylactic response by up-regulating regulatory T-cell differentiation, followed by down-regulating the Th2 response.