Effects of Dietary Supplementation with Carrot-Derived Rhamnogalacturonan-I (cRG-I) on Accelerated Protective Immune Responses and Quality of Life in Healthy Volunteers Challenged with Rhinovirus in a Randomized Trial.

An adequate and balanced supply of nutrients is essential for maintaining health, and an optimal immune response is fast, contained and properly controlled, curbing infections quickly while minimizing damage. Several micronutrients contribute to normal immune function and certain dietary fibers, for example pectic polysaccharides, can play an important role in educating and regulating immune cell responses. The aim of this paper is to elaborate on our initial findings that dietary supplementation with carrot-derived rhamnogalacturonan-I (cRG-I) accelerates and augments local innate immune and anti-viral interferon response to a rhinovirus-16 (RV16) infection and reduces the severity and duration of symptoms in humans. Dietary intake of cRG-I also enhanced immune responses to this respiratory viral infection as measured by ex vivo stimulation of whole blood with the Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid and NK cell function. Consumption of cRG-I also reduced the negative effects of this common cold infection on quality of life as assessed by individual symptom scores. RG-I from carrot is a safe, sustainable, and economically viable solution that could easily be integrated into food products and dietary supplements aiming to support immune fitness and wellbeing.

Development of an Affordable, Sustainable and Efficacious Plant-Based Immunomodulatory Food Ingredient Based on Bell Pepper or Carrot RG-I Pectic Polysaccharides.

The prevalence of acute respiratory infections and their impact on quality of life underlies the need for efficacious solutions that are safe, sustainable and economically viable. Polysaccharides in several (traditional) plant extracts have been shown to be immunostimulatory, and some studies suggest beneficial effects against respiratory infections. The aim of this study was to (i) identify the active polysaccharide constituents from affordable and renewable crops (bell pepper and carrot) using activity-guided fractionation, (ii) evaluate in vitro effects on innate immune responses (phagocytosis and cytokine secretion), microbiota modulation and production of short chain fatty acids, followed by (iii) the evaluation of effects of a bell pepper extract enriched for the active component in a human proof of concept study. We identified rhamnogalacturonan-I (RG-I) as the nutricophore responsible for the immunostimulatory activity with substantial structural and functional equivalence between bell pepper (bp) and carrot (c). The in vitro studies showed that bpRG-I and cRG-I comprise similar immune- and microbiota modulatory potential and the human study demonstrated that bpRG-I was well tolerated and enhanced innate immune responsiveness in vivo. This is an important step towards testing the efficacy of RG-I from bpRG-I or cRG-I in an infection trial in humans.

The Role of Specific Components of a Plant-Based Diet in Management of Dyslipidemia and the Impact on Cardiovascular Risk.

Convincing evidence supports the intake of specific food components, food groups, or whole dietary patterns to positively influence dyslipidemia and to lower risk of cardiovascular diseases (CVD). Specific macro- and micro-components of a predominantly plant-based dietary pattern are vegetable fats, dietary fibers, and phytonutrients such as phytosterols. This review summarizes the current knowledge regarding effects of these components on lowering blood lipids, i.e., low-density lipoprotein cholesterol (LDL-C) and on reducing CVD risk. The beneficial role of a plant-based diet on cardiovascular (CV) health has increasingly been recognized. Plant-based dietary patterns include a Mediterranean and Nordic diet pattern, the dietary approaches to stop hypertension (DASH), and Portfolio diet, as well as vegetarian- or vegan-type diet patterns. These diets have all been found to lower CVD-related risk factors like blood LDL-C, and observational study evidence supports their role in lowering CVD risk. These diet patterns are not only beneficial for dyslipidemia management and prevention of CVD but further contribute to reducing the impact of food choices on environmental degradation. Hence, the CV health benefits of a predominantly plant-based diet as a healthy and environmentally sustainable eating pattern are today recommended by many food-based dietary as well as clinical practice guidelines.

Environmental enteropathy: new targets for nutritional interventions.

In the developing world major public health issues such as malnutrition and compromised physical development are intimately linked to altered gut morphology and function with underlying chronic inflammatory responses. In these societies the downward spiral of malnutrition and infections does not seem to be remedied by well-informed nutritional interventions that supplement the identified nutrient deficiencies, suggesting that additional strategies are needed. The aim of this scientific opinion paper is to consider how a child from the developing world might benefit, separately and additively, from interventions targeted to impact hygiene, nutritional status, disease resistance and gut function, if successful interventions could be found. A failure to tackle environmental enteropathy (EE) may be a critical limiting factor that can explain the relative lack of success of interventions focussed on micronutrient supplementation so far. Therefore this paper starts with a summary of the aetiology and consequences of EE on child health and the current recommendations aimed at tackling this problem. Then a number of hypotheses will be considered in terms of research strategy to positively affect nutritional status, intestinal health and growth of children with EE, with the aim of inspiring future innovative strategies, for both the food industry and the public health sector, which could benefit millions of children.

Implanted myoblast survival is dependent on the degree of vascularization in a novel delayed implantation/prevascularization tissue engineering model.

In in vivo tissue engineering, many implanted cells die because of hypoxic conditions immediately postimplantation. The aim of this study was to determine whether delayed myoblast implantation, at day 4 or 7, improves myoblast survival compared with implantation at day 0 in an in vivo arterio-venous loop (AB loop) chamber model. In adult inbred Sprague-Dawley rats, an AB loop was inserted into a plastic chamber (day 0). In Group I, day 0, two million DiI-labeled (neonatal inbred) myoblasts were implanted around the AB loop. In Groups II and III, day 0, the AB loop was created and inserted into a novel delayed cell seeding chamber, and 4 (Group II) or 7 days (Group III) later the delay chamber was seeded with 2 million DiI-labeled myoblasts. Constructs were harvested 7-day postmyoblast implantation, for morphometric determination of DiI/DAPI-positive myoblasts/mm(2), and percent vascular volume on Griffonia simplicifolia lectin (endothelial cell marker)-labeled tissue sections. Control (nonmyoblast seeded) and experimental (myoblast seeded) constructs demonstrated similar capillary and tissue growth patterns. DiI/DAPI-labeled myoblasts/mm(2) appeared in similar numbers in constructs implanted at days 0 and 4, but increased markedly in day-7 implanted constructs. The percent vascular volume increased significantly (p = 0.03) over time. A positive correlation existed between myoblast survival and construct vascularity (p = 0.017). In conclusion, delaying myoblast implantation to 7-day postconstruct assembly, when new capillary growth is well established, significantly correlates with increased myoblast survival and indicates that cell seeding in regenerative procedures should always occur into an established vascular bed.

Muscarinic M3-receptors mediate cholinergic synergism of mitogenesis in airway smooth muscle.

Muscarinic receptor agonists have been considered to act synergistically in combination with growth facors on airway smooth muscle growth. Characterization of the proliferative responses and of the receptor subtype(s) involved has not yet been studied. Therefore, we investigated mitogenesis induced by stimulation of muscarinic receptors, alone and in combination with stimulation by platelet-derived growth factor (PDGF). For this purpose, [(3)H]thymidine-incorporation was measured at different culture stages in bovine tracheal smooth muscle cells. Functional muscarinic M(3)-receptors, as measured by formation of inositol phosphates, were present in unpassaged cells, but were lacking in passage 2 cells. Methacholine (10 microM) by itself was not able to induce a proliferative response in both cell culture stages. However, methacholine interacted synergistically with PDGF in a dose-dependent fashion (0.1-10 microM), but only in cells having functional muscarinic M(3)-receptors. This synergism could be suppressed significantly by the selective M(3)-receptor antagonists DAU 5884 (0.1 microM) and 4-DAMP (10 nM), but not at all by the M(2)-subtype selective antagonist gallamine (10 microM). These results show that methacholine potentiates mitogenesis induced by PDGF solely through stimulation of muscarinic M(3)-receptors in bovine tracheal smooth muscle cells.

Functional characterization of serum- and growth factor-induced phenotypic changes in intact bovine tracheal smooth muscle.

1. The present study aims to investigate whether phenotypic changes, reported to occur in cultured isolated airway smooth muscle (ASM) cells, are of relevance to intact ASM. Moreover, we aimed to gain insight into the signalling pathways involved. 2. Culturing of bovine tracheal smooth muscle (BTSM) strips for up to 8 days in the presence of 10% foetal bovine serum caused a time-dependent (t(1/2)=2.8 days) decrease in maximal contraction (E(max)) to methacholine compared to serum-deprived controls (E(max)=74+/-4% at day 8). A reduced E(max) was also found using insulin-like growth factor-1 (30 ng ml(-1)) and platelet-derived growth factor (30 ng ml(-1)), but not using epidermal growth factor (10 ng ml(-1)) (E(max)=83+/-3, 67+/-8, 100+/-4%, respectively). Similar serum and growth factor-induced changes in E(max) were found for KCl-induced contraction (65+/-9, 80+/-7, 64+/-11% and 107+/-2%, respectively). 3. Strong correlations were found between the growth factor-induced reductions in E(max) and their proliferative responses, assessed by [(3)H]-thymidine-incorporation, in BTSM cells. (r=0.97, P=0.002 for methacholine and r=0.93, P=0.007 for KCl). 4. The PDGF-induced reduction in E(max) was inhibited completely by combined treatment with either PD 98059 (30 micro M) or LY 294002 (10 micro M). 5. These results indicate that serum and growth factors may cause a functional shift towards a less contractile phenotype in intact BTSM, which is associated with their proliferative response and dependent on signalling pathways involving the mitogen-activated protein kinase pathway and the phosphatidylinositol-3-kinase pathway.

Increased arginase activity underlies allergen-induced deficiency of cNOS-derived nitric oxide and airway hyperresponsiveness.

1. A deficiency of constitutive nitric oxide synthase (cNOS)-derived nitric oxide (NO), due to reduced availability of L-arginine, importantly contributes to allergen-induced airway hyperresponsiveness (AHR) after the early asthmatic reaction (EAR). Since cNOS and arginase use L-arginine as a common substrate, we hypothesized that increased arginase activity is involved in the allergen-induced NO deficiency and AHR. 2. Using a guinea-pig model of allergic asthma, we addressed this hypothesis by examining the effects of the specific arginase inhibitor N(omega)-hydroxy-nor-L-arginine (nor-NOHA) on the responsiveness to methacholine of isolated perfused tracheae from unchallenged control animals and from animals 6 h after ovalbumin challenge. Arginase activity in these preparations was investigated by measuring the conversion of L-[14C]arginine to [14C]urea. 3. Airways from allergen-challenged animals showed a 2 fold (P<0.001) increase in responsiveness to intraluminal (IL) administration of methacholine compared to controls. A similar hyperresponsiveness (1.8 fold, P<0.01) was observed in control airways incubated with the NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME, 0.1 mM, IL), while L-NAME had no further effect on the airways from challenged animals. 4. Remarkably, 5 microM nor-NOHA (IL) normalized the hyperresponsiveness of challenged airways to basal control (P<0.001), and this effect was fully reversed again by 0.1 mM L-NAME (P<0.05). Moreover, arginase activity in homogenates of the hyperresponsive airways was 3.5 fold (P<0.001) enhanced compared to controls. 5. The results indicate that enhanced arginase activity contributes to allergen-induced deficiency of cNOS-derived NO and AHR after the EAR, presumably by competition with cNOS for the common substrate, L-arginine. This is the first demonstration that arginase is involved in the pathophysiology of asthma.

Autocrine regulation of asthmatic airway inflammation: role of airway smooth muscle.

Chronic airway inflammation is one of the main features of asthma. Release of mediators from infiltrating inflammatory cells in the airway mucosa has been proposed to contribute directly or indirectly to changes in airway structure and function. The airway smooth muscle, which has been regarded as a contractile component of the airways responding to various mediators and neurotransmitters, has recently been recognised as a rich source of pro-inflammatory cytokines, chemokines and growth factors. In this review, we discuss the role of airway smooth muscle cells in the regulation and perpetuation of airway inflammation that contribute to the pathogenesis of asthma.