Dietary Constituents Research Articles

Effects of Undaria pinnatifida (Wakame) on Postprandial Glycemia and Insulin Levels in Humans: a Randomized Crossover Trial.

Postprandial hyperglycemia is a known risk factor for the development of several health disorders, including type 2 diabetes, obesity and cardiovascular disease. This study aimed to investigate the acute effect of Undaria pinnatifida (Wakame), a discriminative constituent of the Japanese diet, on postprandial blood glucose and insulin levels. The study was conducted using a crossover method among 26 subjects. Blood was sampled for glucose and insulin measurements at 0, 30, 60, 90 and 120min after a subject consumed either 200g of rice or 200g rice with 4g of dried wakame. Blood glucose and insulin levels were significantly lower at 30min after consuming rice with wakame than after consuming rice alone. Moreover, the incremental areas under the curves for glucose and insulin were lower when wakame was included. Wakame intake can improve postprandial glucose homeostasis. Wakame intake may offer a simple behavioural strategy that can reduce glycemic excursions in prediabetes. This study was registered with the UMIN Clinical Trial Registry (UMIN000031050).

Dietary Inflammatory Index Is Associated with Risk of All-Cause and Cardiovascular Disease Mortality but Not with Cancer Mortality in Middle-Aged and Older Japanese Adults

The Dietary Inflammatory Index (DII) is a comprehensive, literature-derived index for assessing the effect of dietary constituents on inflammatory biomarkers. Several studies have shown an association between DII score and mortality, but there are limited prospective studies in Asian populations. The aim of this study was to investigate the association between DII score and risk of all-cause, total cardiovascular disease (CVD), stroke, coronary heart disease (CHD), total cancer, digestive cancer, and noncancer/non-CVD mortality in the Japanese population. A total of 58,782 Japanese participants aged 40-79 y who were enrolled in the Japan Collaborative Cohort Study during 1988-1990 were included in the analysis. DII scores were calculated based on a food-frequency questionnaire. HRs and 95% CIs for mortality according to DII quintiles were estimated using Cox proportional hazards models. During the median follow-up period of 19.3 y, a total of 11,693 participants died. The multivariable HR for all-cause mortality for the highest compared with the lowest DII quintiles was 1.13 (95% CI: 1.05, 1.21). For CVD mortality, the highest multivariable HRs were 1.30 (95% CI: 1.13, 1.49), 1.29 (95% CI: 1.05, 1.59), and 1.30 (95% CI: 0.96, 1.76) for total CVD, stroke, and CHD, respectively. No significant associations were observed between DII and risk of total cancer, digestive cancer, and noncancer/non-CVD mortality. Our findings suggest that a higher DII was associated with an increased risk of all-cause and CVD mortality among Japanese adults.

Protein and carbohydrate intakes alter gut microbial community structure in crickets: a Geometric Framework approach.

Proteins and carbohydrates have profound impacts on the ecology of gut microbiota, but disentangling the single and interactive effects of different dietary constituents is challenging. Here, we used a multidimensional approach, the Geometric Framework, to study the interactions between nutrition and bacterial abundances with respect to protein and carbohydrate intakes in field cricket, Teleogryllus oceanicus. Our study revealed that species richness decreased as crickets consumed more macronutrients, and species evenness peaked at high intake of protein-rich diets. Sex and protein:carbohydrate (P:C) ratios in diets were the primary factors influencing the gut bacterial community, but most of the microbial operational taxonomic units (OTUs) that were significantly different between males and females were present in low abundance. In contrast, protein intake had a greater influence than carbohydrate consumption on the relative abundances of the core bacterial taxa, as an increase in dietary protein availability could remove the growth constraint imposed by limited nitrogen. Taken together, the use of the Geometric Framework provides a deeper insight into how nutritional intakes influence the relative abundances of gut microbes, and could be a useful tool to integrate the study of gut microbiome and fitness traits in a host.

Phenethyl isothiocyanate stimulates glucose uptake through the Akt pathway in C2C12 myotubes.

Phenethyl isothiocyanate (PEITC) is an aromatic isothiocyanate present in cruciferous vegetables. Several studies have shown that isothiocyanates regulate various intracellular signaling pathways, and thereby show anti-inflammatory and detoxifying activities. However, little is known about the effects of PEITC on glucose metabolism. In this study, we examined whether PEITC promotes glucose utilization in mouse skeletal muscle cells, C2C12 myotubes. PEITC induced glucose uptake, glucose transporter 4 (Glut4) translocation to the plasma membrane, and activation of Akt and ERK in C2C12 cells. Inhibition of Akt suppressed PEITC-induced Glut4 translocation and glucose uptake, whereas ERK inhibition did not. Furthermore, PEITC increased phosphorylation of ErbB2 and ErbB3. Treatment with a pan-ErbB inhibitor reduced Akt activation and the subsequent glucose uptake induced by PEITC. These results indicate that PEITC promotes glucose utilization through the ErbB/Akt pathway in C2C12 myotubes. PEITC may therefore serve as a dietary constituent with beneficial effects on the carbohydrate metabolism. Abbreviations: PEITC: phenethyl isothiocyanate; Glut4: glucose transporter 4; PI3K: phosphatidylinositide 3-kinase; Nrf2: erythroid-2-related factor; ARE: antioxidant response element; HO-1: heme oxygenase-1; NRG: neuregulin.

Nutrition and Breast Cancer: A Literature Review on Prevention, Treatment and Recurrence.

Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk. However, the effect of dietary factors on BC recurrence and mortality is not clearly understood. Here, we provide an overview of the current evidence obtained from the PubMed databases in the last decade, assessing dietary patterns, as well as the consumption of specific food-stuffs/food-nutrients, in relation to BC incidence, recurrence and survival. Data from the published literature suggest that a healthy dietary pattern characterized by high intake of unrefined cereals, vegetables, fruit, nuts and olive oil, and a moderate/low consumption of saturated fatty acids and red meat, might improve overall survival after diagnosis of BC. BC patients undergoing chemotherapy and/or radiotherapy experience a variety of symptoms that worsen patient quality of life. Studies investigating nutritional interventions during BC treatment have shown that nutritional counselling and supplementation with some dietary constituents, such as EPA and/or DHA, might be useful in limiting drug-induced side effects, as well as in enhancing therapeutic efficacy. Therefore, nutritional intervention in BC patients may be considered an integral part of the multimodal therapeutic approach. However, further research utilizing dietary interventions in large clinical trials is required to definitively establish effective interventions in these patients, to improve long-term survival and quality of life.

Piling on fat with processed foods

Diet Advice about diet agrees that processed foods should be avoided. Their consumption is associated with obese individuals and those with metabolic syndrome. But whether processed foods cause obesity and/or metabolic syndromes is not clear. Emerging data and hypotheses suggest that processed foods promote overeating. Hall et al. sought to test this idea in a small cohort of 20 adults with a normal body mass index. They were offered either ultra-processed or unprocessed meals that were largely matched for dietary constituents, such as calories, fat, and sugar. Individuals on the ultraprocessed diet ate about 450 calories more than those on the unprocessed diet, verifying that eating processed foods causes excessive consumption. So, perhaps the advice is right. Cell Metab. 10.1016/j.cmet.2019.05.008 (2019).

RHOA in Gastric Cancer: Functional Roles and Therapeutic Potential.

The well-known signal mediator and small GTPase family member, RHOA, has now been associated with the progression of specific malignancies. In this review, we appraise the biomedical literature regarding the role of this enzyme in gastric cancer (GC) signaling, suggesting potential clinical significance. To that end, we examined RHOA activity, with regard to second-generation hallmarks of cancer, finding particular association with the hallmark “activation of invasion and metastasis.” Moreover, an abundance of studies show RHOA association with Lauren classification diffuse subtype, in addition to poorly differentiated GC. With regard to therapeutic value, we found RHOA signaling to influence the activity of specific widely used chemotherapeutics, and its possible antagonism by various dietary constituents. We also review currently available targeted therapies for GC. The latter, however, showed a paucity of such agents, underscoring the urgent need for further investigation into treatments for this highly lethal malignancy.

The Health Promoting Bioactivities of Lactuca sativa can be Enhanced by Genetic Modulation of Plant Secondary Metabolites.

Plant secondary metabolites are protective dietary constituents and rol genes evidently increase the synthesis of these versatile phytochemicals. This study subjected a globally important vegetable, lettuce (Lactuca sativa) to a combination of untargeted metabolomics (LC-QTof-MS) and in vitro bioactivity assays. Specifically, we examined the differences between untransformed cultured lettuce (UnT), lettuce transformed with either rolABC (RA) or rolC (RC) and commercially grown (COM) lettuce. Of the 5333 metabolite features aligned, deconvoluted and quantified 3637, 1792 and 3737 significantly differed in RA, RC and COM, respectively, compared with UnT. In all cases the number of downregulated metabolites exceeded the number increased. In vitro bioactivity assays showed that RA and RC (but not COM) significantly improved the ability of L. sativa to inhibit α-glucosidase, inhibit dipeptidyl peptidase-4 (DPP-4) and stimulate GLP-1 secretion. We putatively identified 76 lettuce metabolites (sesquiterpene lactones, non-phenolic and phenolic compounds) some of which were altered by several thousand percent in RA and RC. Ferulic acid levels increased 3033–9777%, aminooxononanoic acid increased 1141–1803% and 2,3,5,4′tetrahydroxystilbene-2-O-β-d-glucoside increased 40,272–48,008%. Compound activities were confirmed using commercially obtained standards. In conclusion, rol gene transformation significantly alters the metabolome of L.sativa and enhances its antidiabetic properties. There is considerable potential to exploit rol genes to modulate secondary metabolite production for the development of novel functional foods. This investigation serves as a new paradigm whereby genetic manipulation, metabolomic analysis and bioactivity techniques can be combined to enable the discovery of novel natural bioactives and determine the functional significance of plant metabolites.

Comparative in vitro hypoglycemic studies of unripe, ripe and overripe fruit extract of Musa paradisiaca (Indian banana)

PurposeIn the Indian system of medicine – Ayurveda, Musa paradisiaca has been mentioned as a remedy for various diseases and ailments. Based on the folkloric use, the purpose of this paper is to verify and compare the hypoglycemic potential of unripe, ripe and overripe fruit extract of Musa paradisiaca.Design/methodology/approachHypoglycemic activity of fruit extracts has been evaluated using various in vitro methods, namely, determination of glucose adsorption capacity, glucose uptake in yeast cells, amylolysis kinetics and glucose diffusion.FindingsThe extracts of unripe, ripe and overripe fruits of Musa paradisiaca adsorbed glucose, and the adsorption of glucose increased remarkably with an increase in glucose concentration. In the amylolysis kinetic experimental model, the rate of glucose diffusion was found to increase with time, and all the extracts of unripe, ripe and overripe fruits of Musa paradisiaca demonstrated significant inhibitory effects on the movement of glucose into external solution across the dialysis membrane as compared to the control. The extracts under study also promoted glucose uptake by the yeast cells in all the five glucose concentrations used in the study.Practical implicationsHere, the authors have verified and compared the hypoglycemic potential of Musa paradisiaca, its unripe fruit extract was found to show a better activity than ripe and overripe fruit extracts.Originality/valueBanana, being an all season readily available fruit, is widely consumed due to its ready availability and low cost. It acts as a complete food for even low socio-economic classes of society, owing to its rich nutritional values. Even in a processed and unprocessed manner, it is an important constituent of diet. The research suggests that instead of consuming ripe and overripe fruit, the unripe fruit will help in management of diabetes.

Precision Nutrition and the Microbiome, Part I: Current State of the Science.

The gut microbiota is a highly complex community which evolves and adapts to its host over a lifetime. It has been described as a virtual organ owing to the myriad of functions it performs, including the production of bioactive metabolites, regulation of immunity, energy homeostasis and protection against pathogens. These activities are dependent on the quantity and quality of the microbiota alongside its metabolic potential, which are dictated by a number of factors, including diet and host genetics. In this regard, the gut microbiome is malleable and varies significantly from host to host. These two features render the gut microbiome a candidate ‘organ’ for the possibility of precision microbiomics—the use of the gut microbiome as a biomarker to predict responsiveness to specific dietary constituents to generate precision diets and interventions for optimal health. With this in mind, this two-part review investigates the current state of the science in terms of the influence of diet and specific dietary components on the gut microbiota and subsequent consequences for health status, along with opportunities to modulate the microbiota for improved health and the potential of the microbiome as a biomarker to predict responsiveness to dietary components. In particular, in Part I, we examine the development of the microbiota from birth and its role in health. We investigate the consequences of poor-quality diet in relation to infection and inflammation and discuss diet-derived microbial metabolites which negatively impact health. We look at the role of diet in shaping the microbiome and the influence of specific dietary components, namely protein, fat and carbohydrates, on gut microbiota composition.

Regulation of Hepatitis C Virus Infection by Cellular Retinoic Acid Binding Proteins through the Modulation of Lipid Droplet Abundance.

Retinoid (vitamin A) is an essential diet constituent that governs a broad range of biological processes. Its biologically active metabolite, all-trans retinoic acid (ATRA), exhibits a potent antiviral property by enhancing both innate and adaptive antiviral immunity against a variety of viral pathogens, such as, but not limited to, HIV, respiratory syncytial virus (RSV), herpes simplex virus (HSV), and measles. Even though the hepatocyte is highly enriched with retinoid and its metabolite ATRA, it supports the establishment of efficient hepatitis C virus (HCV) replication. Here, we demonstrate the hepatocyte-specific cell-intrinsic mechanism by which ATRA exerts either a proviral or antiviral effect, depending on how it engages cellular retinoic acid binding proteins (CRABPs). We found that the engagement of CRABP1 by ATRA potently supported viral infection by promoting the accumulation of lipid droplets (LDs), which robustly enhanced the formation of a replication complex on the LD-associated endoplasmic reticulum (ER) membrane. In contrast, ATRA binding to CRABP2 potently inhibited HCV via suppression of LD accumulation. However, this antiviral effect of CRABP2 was abrogated due to the functional and quantitative predominance of CRABP1 in the hepatocytes. In summary, our study demonstrates that CRABPs serve as an on-off switch that modulates the efficiency of the HCV life cycle and elucidates how HCV evades the antiviral properties of ATRA via the exploitation of CRABP1 functionality.IMPORTANCE ATRA, a biologically active metabolite of vitamin A, exerts pleiotropic biological effects, including the activation of both innate and adaptive immunity, thereby serving as a potent antimicrobial compound against numerous viral pathogens. Despite the enrichment of hepatocytes with vitamin A, HCV still establishes an efficient viral life cycle. Here, we discovered that the hepatocellular response to ATRA creates either a proviral or an antiviral environment depending on its engagement with CRABP1 or -2, respectively. CRABP1 supports the robust replication of HCV, while CRABP2 potently inhibits the efficiency of viral replication. Our biochemical, genetic, and microscopic analyses reveal that the pro- and antiviral effects of CRABPs are mediated by modulation of LD abundance, where HCV establishes the platform for viral replication and assembly on the LD-associated ER membrane. This study uncovered a cell-intrinsic mechanism by which HCV exploits the proviral function of CRABP1 to establish an efficient viral life cycle.

Intraluminal Nutrients Modulate Intracellular Calcium Activity in the Enteric Nervous System of Adult Mice

BackgroundIt has long been hypothesized that enteric neurons are able to detect nutrients present in the intestinal lumen, but direct evidence in intact preparations of the intestine is lacking. Understanding how enteric neurons react to changes in dietary constituents will open new avenues for discoveries on the relation between nutrition, modulation of gut function, and health.AimTo measure neuronal activity in the enteric nervous system in response to luminal nutrients.MethodsWe have designed chambers allowing us to visualize, record and quantify intracellular calcium activity in 3D live‐cell confocal recordings of neurons from intact, whole thickness segments of mouse intestine. Twenty mice expressing the genetically encoded calcium reporter Gcamp6 under the control of the pan‐neuronal Wnt1 promoter were used to record intracellular calcium activity in neurons from the jejunum and colon, while perfusing different nutrients through the lumen. Krebs solution was perfused as control and Ensure®, 10% Intralipid® or 20mM Glucose were used as stimuli. 3D videos of calcium fluorescence in the neuronal network were acquired with a Nikon A1R confocal microscope and calcium dynamics were analyzed using the Imaris software (Bitplane). Results are expressed as relative changes in fluorescence intensity (ΔF/F) ± SEM among the neuronal populations studied.ResultsPerfusion of the intestine with Ensure® (liquid meal replacement) increased the fluorescence intensity in reactive neurons by 670 ± 270% in the jejunum and 403 ± 62% in the colon. Peak amplitude was measured on average 5–6 minutes after the initiation of the nutrient perfusion. Perfusion with 10% Intralipid® (lipid emulsion) increased the fluorescence intensity in reactive neurons by 300 ± 180% in the jejunum and 150 ± 15% in the colon. On the other hand, perfusion of the intestine with Glucose (20mM in Krebs solution) lowered baseline fluorescence intensity in a population of neurons by −91 ± 3% in the jejunum and −80 ± 3% in the colon. The percentage of neurons reacting to intraluminal stimuli was dependent on the stimulus and was different between the jejunum and the colon, indicating that subpopulations of neurons might differentially react to different nutrient stimuli.ConclusionsWe report the existence of slow intracellular calcium changes in the neurons in the intestine that vary depending on the nutrient content of the intestinal lumen. The origin and functional consequences of these changes in intracellular calcium activity as well as the identity of responding neurons are currently under investigation.Support or Funding InformationFunding sources: Canadian institutes of Health Research, Alberta Innovates, Human Frontier Science Program.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Combining alternative processing methods for European soybeans to be used in broiler diets

Locally produced, expeller soybean meal (SBM) may be an important constituent of European broiler diets in the future. In the present trial 4 SBMs were produced from European grown soybeans, using different processing methods; this is the first time that the combination of these methods has been applied. Starter (d0–14) and grower (d15–28) diets were offered to 288 Ross 308 male broilers in a 2 × 2 design: 2 processing methods ((Extrusion-pressing (E) vs Flaking-pressing-cooking (F)) × 2 hulling methods ((with hulls (H) vs no hulls (NH)). Variables measured consisted of average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio, apparent ileal dry matter (DM) and crude protein (CP) digestibility, jejunal histomorphometry at d14 and d28 and ileal digesta viscosity at d28 of age. In addition, carcass and carcass part yield, organ weight, and empty gastrointestinal tract weight and length per small intestinal segment were assessed at d28. Processing method did not affect any of the variables tested. On the other hand, hull presence increased (P < 0.05) ADFI over the starter period, but not over the grower period. Presence of hulls increased proventriculus, gizzard and jejunum weight, and reduced carcass yield at d28 of age, likely due to the higher fibre content. Method of processing and hulling significantly interacted (P < 0.05) for ADFI and ADG at the end of the starter period, being highest for the E/H treatment, but overall broiler performance was similar between dietary treatments. Similarly, small intestinal architecture and DM and CP digestibility were not affected by dietary treatments at either d14 or d28 post hatch. Although there was some variation in soybean protein solubility and trypsin inhibitors amongst SBM products these factors did not appear to affect any of the measured variables. In conclusion, all 4 methods of production resulted in comparable results in relation to performance variables. Hull removal did not confer a significant advantage, aside from increased carcass yield, possibly due to the adaptive growth of the gizzard and proventriculus.

The Human Fecal Microbiota Metabolizes Foodborne Heterocyclic Aromatic Amines by Reuterin Conjugation and Further Transformations.

Heterocyclic aromatic amines (HAAs) are process-induced food contaminants with high mutagenic and/or carcinogenic potential. Although the human gut microbiota is known to affect the metabolism of dietary constituents, its impact on HAA metabolism and toxicity has been little studied. Here, the glycerol-dependent metabolism of seven foodborne HAAs (AαC, Trp-P-1, harman, norharman, PhIP, MeIQx, and MeIQ) by the human fecal microbiota is investigated. As analyzed by HPLC-DAD/FLD, the extent of conversion is strongly dependent on glycerol supplementation and HAA structure. AαC (60-100%) and the 2-aminoimidazoazarenes (up to 58%) are especially prone to microbial conversion. Based on high-resolution MS and/or NMR spectroscopy data, 70 fecal metabolites are identified in total, mainly formed by chemical reactions with one or two molecules of microbially derived reuterin. Moreover, it has been demonstrated that the human fecal microbiota can further transform reuterin adducts by reduction and/or hydroxylation reactions. Upon isolation, some reuterin-induced HAA metabolites appear to be partially unstable, complicating structural identification. The formation of microbial metabolites needs to be incorporated into risk assessment considerations for HAAs in human health. In this study, several HAA metabolites, mainly reuterin-dependent, are identified in vitro, providing the basis for future human studies investigating microbial HAA metabolism.

Hesperetin and Hesperidin Improved β-Carotene Incorporation Efficiency, Intestinal Cell Uptake, and Retinoid Concentrations in Tissues.

Dietary constituents can influence the bioavailability of carotenoids. This study investigated the effect of citrus flavanones on β-carotene (Bc) bioavailability using four experimental models: in vitro digestion procedure, synthetic mixed micelles, Caco-2 cell monolayers, and gavage experiments in mice. The addition of hesperetin (Hes, 25 μM) and hesperidin (Hes-G, 25 μM) standards significantly increased the incorporation efficiency of the Bc standard to 68.7 ± 3.6 and 75.2 ± 7.5% ( p < 0.05), respectively. However, the addition of naringenin (Nar, 25 μM) and naringin (Nar-G, 25 μM) standards significantly reduced the incorporation efficiency of Bc by 23.8 and 26.4%, respectively ( p < 0.05). The increases in scavenger receptor class B type I (SR-BI) expression promoted by citrus flavanones played an important role in Bc cellular absorption in the Caco-2 cell model. Furthermore, after 3 days of gavage, four citrus flavanones (7.5 mg kg-1 day-1) increased the retinoid concentrations in tissues; in contrast, after 7 days of gavage, Nar and Nar-G significantly decreased hepatic retinoid concentrations ( p < 0.05). This finding suggested that the incorporation efficiency into micelles was the main step governing carotenoid bioavailability.

Effect of antibacterial lipids on biofilm formation by Streptococcus mutans

Streptococcus mutans is the major cariogenic organism associated with Dental Caries, a widespread chronic disease of the oral cavity (Muras et al. 2018). It is associated with oral biofilm formation, production of organic acids, and has the capacity to out-compete non-cariogenic commensal species (Lemos et al. 2013). Recent studies carried out on fatty acids demonstrated effective antimicrobial activity against S. mutans (Hughes, 2014). This study will evaluate the activity of lipids on S. mutans biofilm formation and proposes that dietary constituents may be used as a natural therapy to maintain oral hygiene. Clinical isolate S. mutans 3014 D5929 was exposed to various concentrations of lipid for 24 h. Crystal violet assay was performed for quantification of biofilm biomass. Fluorescent microscopy using SYTO® 9 and Alexa Fluor® 647-labelled dextran conjugate was performed to visualise biofilm formation pre- and post-exposure to MCO. Biofilm biomass was reduced for all lipid concentrations. Fluorescent microscopy indicated a significant reduction in bacterial cell number and a lack of structural biofilm upon exposure to fatty acid mixtures when compared to control. The research demonstrated that lipid does have S. mutans based antimicrobial and antibiofilm capabilities.

Environmental sustainability issues in the food-energy-water nexus in the UK vegetables sector: Energy and water consumption

Vegetables are an important constituent of a balanced diet. Nearly 11 million tonnes of vegetables are consumed in the UK annually, 67% of which are purchased as fresh, with the remaining processed into various products. Almost 40% of vegetables are imported, most of them from water-stressed countries. The water and energy demands of different vegetables vary depending on their kind and origin, as well as the type and level of processing. As water and energy are interconnected, it is vital to examine their dependency. Therefore, this work evaluates the environmental impacts of vegetables on the food-energy-water (FEW) nexus. A new methodology has been developed for these purposes, based on a life cycle approach. Eight types of vegetables most consumed in the UK are considered, including fresh and processed products produced domestically and imported. The impacts are considered at both the product and sectoral levels.

The effect of different drying methods on the elemental and nutritional composition of Vernonia amygdalina (bitter leaf)

Vernonia amygdalina (VA) popularly known as bitter leaf is a common and popular vegetable in Nigeria used as a spice in many delicacies and as medicine. Most people believe that when vegetable like bitter leaf is preserved by the drying method, most of the essential minerals are lost. In this study, the effect of air, sun, oven and solar drying methods on the organic and dietary elemental composition of its leaves was evaluated using standard analytical procedures. Drying increased significantly the concentration of all the organic constituents evaluated. The ashed content was markedly enhanced by drying and it range from 2.56% in fresh sample to 11.20% in sun-dried sample, the fibre content range from 1.62% in fresh sample to 4.02% in air-dried sample, also the lipid content from 0.62% in fresh sample to 2.64% in air-dried sample. A significant increase in mineral content was observed upon drying except magnesium and copper whose concentrations were found to be high (48.23 and 0.31 mg/100 g) in fresh sample. The lead content also decreases upon drying, showing a way of reducing the quantity of lead intake. The concentrations of calcium and iron increased upon drying. The results of this study suggest that drying improves the concentration of both organic and dietary elemental constituents and oven–solar drying methods could be useful in preserving VA leaves in a more hygienic way and ensure its all-the-year round availability and possibly elimination of most nutrient deficiencies.

Attraction of Female Aedes aegypti (L.) to Aphid Honeydew.

Plant sugar is an essential dietary constituent for mosquitoes, and hemipteran honeydew is one of the many forms of plant sugar that is important to mosquitoes. Many insects rely on volatile honeydew semiochemicals to locate aphids or honeydew itself. Mosquitoes exploit volatile semiochemicals to locate sources of plant sugar but their attraction to honeydew has not previously been investigated. Here, we report the attraction of female yellow fever mosquitoes, Aedes aegypti, to honeydew odorants from the green peach aphid, Myzus persicae, and the pea aphid, Acyrthosiphon pisum, feeding on fava bean, Vicia faba. We used solid phase micro-extraction and gas chromatography-mass spectrometry to collect and analyze headspace odorants from the honeydew of A. pisum feeding on V. faba. An eight-component synthetic blend of these odorants and synthetic odorant blends of crude and sterile honeydew that we prepared according to literature data all attracted female A. aegypti. The synthetic blend containing microbial odor constituents proved more effective than the blend without these constituents. Our study provides the first evidence for anemotactic attraction of mosquitoes to honeydew and demonstrates a role for microbe-derived odorants in the attraction of mosquitoes to essential plant sugar resources.

A Method for Visualizing Fluorescence of Flavonoid Therapeutics in Vivo in the Model Eukaryote Dictyostelium Discoideum

Naturstoff reagent A (diphenylboric acid 2-aminoethyl ester [DPBA]) has been used historically in plant science to observe polyphenolic pigments, such as flavonoids, whose fluorescence requires enhancement to be visible by microscopy. Flavonoids are common dietary constituents and are the focus of considerable attention because of their potential as novel therapies for numerous diseases. The molecular basis of therapeutic activity is only gradually being established, and one strand of such research is making use of the social amoeba Dictyostelium discoideum. We extended the application of DPBA to flavonoid imaging in these preclinical studies, and report the first method for use of DPBA in this eukaryotic model microbe and its applicability alongside subcellular markers. This in vivo fluorescence imaging provided a useful adjunct to parallel chemical and genetic studies.