Reply to Comments: Comparison of Methods Study between a Photonic Crystal Biosensor and Certified ELISA to Measure Biomarkers of Iron Deficiency in Chronic Kidney Disease Patients.

In this brief note, we respond to the comments made by Dr [...].

Performance Factors Influencing Efficacy and Effectiveness of Iron Fortification Programs of Condiments for Improving Anemia Prevalence and Iron Status in Populations: A Systematic Review.

Iron fortification of staple foods is a common practice around the world to reduce the prevalence of iron-deficiency anemia. More recently, fortified condiments, including salts, sauces, and powders, have been tested in various efficacy trials. However, there is limited information on how nutritional, environmental, and experimental factors affect their efficacy and effectiveness. The purpose of the present work was to systematically review performance factors affecting the efficacy of condiment fortification trials. Three databases were searched using a standardized keyword search and included based on four-point inclusion criteria. Studies were evaluated against a quality assessment tool and effect sizes were calculated. Studies were ranked as low or high performing, based on whether or not they significantly improved iron-deficiency outcomes (hemoglobin, anemia prevalence, and ferritin levels). Of the 955 retrieved studies, 23 were included-of which, nine performed poorly, eight performed highly, and six were classified as neither because they did not meet the criteria of assessing the three iron outcomes. Results showed that unsuccessful trials did not consider environmental factors such as parasitic infections, nutritional factors such as micronutrient deficiencies other than iron, consumer acceptability of the product or experimental factors such as monitoring and adherence to the trials. Two common performing factors identified among those studies performing highly vs. those that did not were the control of sensory changes and monitoring of consumption compliance (i.e., dose delivery). The present work can be used as decision-making support for nutrition policy makers when determining the appropriate implementation of condiment fortification programs.

Do Fruit and Vegetable Policies, Socio-Environmental Factors, and Physical Activity Influence Fruit and Vegetable Intake Among Adolescents?

PURPOSE: Several factors are known to influence the intake of fruits and vegetables (FV) among adolescents. However, few studies have examined the role that FV policies and associated factors (such as availability of food at home, parental support, and physical activity) play on consumption of FV, particularly among adolescents in low- and middle-income countries (LMICs). METHOD: Adolescent data (except for FV policy status) were obtained from the Global School-based Student Health Survey from 2004 to 2013. Information on FV policies was obtained from government ministries, World Health Organization databases, Scopus, and PubMed. Countries were designated as having the policy if the policy was issued at least a year before Global School-based Student Health Survey data collection (n = 13 LMICs). Countries without FV policies were based on the absence of a policy between 2004 and 2013 (n = 11 LMICs). The total analytic sample included 89,843 adolescents from 24 countries. RESULTS: Logistic regression models revealed a positive association between the presence of FV policy and the adequate consumption of FV (adjusted odds ratio [AOR] = 2.04; 95% confidence interval [CI]: 1.74-2.40; p-value < .001). Parental supervision was positively associated with sufficient intake of FV (AOR = 1.62; 95% CI: 1.42-1.84; p-value < .001). Physical activity was also positively associated with adolescents consuming ≥5 servings of FV daily (AOR = 1.30; 95% CI: 1.13-1.50; p-value < .001). CONCLUSION: Adolescents' physical environment (presence of FV policies, unavailability of food), social environment (parental connectedness, supervision, and bonding), and physical activity behavior are all significant predictors of adolescents' intake of FV.

Development of a Paper-Based Sensor Compatible with a Mobile Phone for the Detection of Common Iron Formulas Used in Fortified Foods within Resource-Limited Settings.

A lack of quality control tools limits the enforcement of fortification policies. In alignment with the World Health Organization's ASSURED criteria (affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and deliverable), a paper-based assay that interfaces with a smartphone application for the quantification of iron fortificants is presented. The assay is based on the Ferrozine colorimetric method. The reaction started after deposition of the 5 µL aqueous sample and drying. After developing color, pixel intensity values were obtained using a smartphone camera and image processing software or a mobile application, Nu3px. From these values, the actual iron concentration from ferrous sulfate and ferrous fumarate was calculated. The limits of detection, quantification, linearity, range, and errors (systematic and random) were ascertained. The paper-based values from real samples (wheat flour, nixtamalized corn flour, and infant formula) were compared against atomic emission spectroscopy. The comparison of several concentrations of atomic iron between the spectrophotometric and paper-based assays showed a strong positive linear correlation (y = 47.01x + 126.18; R2 = 0.9932). The dynamic range (5.0-100 µg/mL) and limit of detection (3.691 µg/mL) of the paper-based assay are relevant for fortified food matrices. Random and systematic errors were 15.9% and + 8.65 µg/g food, respectively. The concept can be applied to limited-resource settings to measure iron in fortified foods.

Ultrascalable Multifunctional Nanoengineered Copper and Aluminum for Antiadhesion and Bactericidal Applications.

Biofouling disrupts the surface functionality and integrity of engineered substrates. A variety of natural materials such as plant leaves and insect wings have evolved sophisticated physical mechanisms capable of preventing biofouling. Over the past decade, several reports have pinpointed nanoscale surface topography as an important regulator of surface adhesion and growth of bacteria. Although artificial nanoengineered features have been used to create bactericidal materials that kill adhered bacteria, functional surfaces capable of synergistically providing antiadhesion and bactericidal properties remain to be developed. Furthermore, fundamental questions pertaining to the need for intrinsic hydrophobicity to achieve bactericidal performance and the role of structure length scale (nano vs micro) are still being explored. Here, we demonstrate highly scalable, cost-effective, and efficient nanoengineered multifunctional surfaces that possess both antiadhesion and bactericidal properties on industrially relevant copper (Cu) and aluminum (Al) substrates. We characterize antiadhesion and bactericidal performance using a combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), live/dead bacterial staining and imaging, as well as solution-phase and Petrifilm measurements of bacterial viability. Our results showed that nanostructures created on both Cu and Al were capable of physical deformation of adhered Escherichia coli bacteria. Bacterial viability measurements on both Cu and Al indicated a complex interaction between the antiadhesion and bactericidal nature of these materials and their surface topography, chemistry, and structure. Increased superhydrophobicity greatly decreased bacterial adhesion while not significantly influencing surface bactericidal performance. Furthermore, we observed that more densely packed nanoscale structures improved antiadhesion properties when compared to larger features, even over extended time scales of up to 24 h. Our data suggests that the superhydrophobic Al substrate possesses superior antiadhesion and bactericidal effects, even over long time courses. The techniques and insights presented here will inform future work on antiadhesion and bactericidal multifunctional surfaces and enable their rational design.

Iron Fortification of Spiced Vinegar in the Philippines.

Despite existent fortification initiatives in the Philippines, approximately 50% of the population still suffers from iron deficiency anemia (IDA), mainly in rural areas. Fortification of staple foods has been proved successful in China and Vietnam. Coconut spiced vinegar (SV) is an inexpensive, widely available, and culturally acceptable condiment in Filipino households; however, no technical evidence exists on its potential as fortification vehicle. This study aimed to physicochemically characterize and evaluate the consumer acceptability of SV fortified with ferrous sulfate (FS), ferrous fumarate (FF), or sodium iron ethylenediaminetetraacetate (NaFeEDTA) at 0.2 mg Fe/mL. Iron fortificants were added directly to SV, vortexed, and stored for analysis. A nonfortified SV served as a control. Physicochemical analyses (pH, titratable acidity, color, turbidity, and iron recovery) were conducted from 0 to 6 months postfortification. Consumer acceptability (9-point hedonic scale: color, appearance, aroma, sourness, and overall acceptability) was conducted using 1-month fortified vinegar in 96 students and 27 women. Iron recovery of fortified samples was high and similar (>97%) after 3 days of fortification and remained >87% at 6 months postfortification. All samples had minimum acidity of 5.31% and pH between 3.12 and 3.3. Color difference against the control followed the next order: SV-NaFeEDTA < SV-FS = SV-FF. Among students, acceptability of SV-FS and SV-FF were lower than the control and SV-NaFeEDTA for all attributes (P < 0.05) except aroma. In women, overall acceptability and aroma were not different among samples (P > 0.05). Overall, SV-NaFeEDTA had similar acceptability to the control, and was the most accepted fortified vinegar. SV-NaFeEDTA shows potential (in terms of physicochemical stability and consumer acceptability) to be used as an iron-delivery vehicle to address IDA. PRACTICAL APPLICATION: The present study addresses the technical and organoleptic challenges of fortifying Filipino spiced vinegar with three iron sources. About 50% of the Filipino population (especially women and children) still suffers from iron deficiency, thus, more effective ways to deliver iron are needed. If successful, our study could pose as the base milestone for implementing mass iron fortification of spiced vinegar, given its frequent consumption and reach of all socioeconomic pockets of the Filipino population. Our aim is to improve the overall nutritional health of at-risk populations, and our study is one step closer to achieve this goal.

Functionalization of Lipid-Based Nutrient Supplement with ß-Cyclodextrin Inclusions of Oregano Essential Oil.

Intestinal parasitic infection is one of the main causes of acute undernutrition in children. Oral consumption of oregano essential oil (OEO) can reduce intestinal parasitic infections, however, its addition to therapeutic and supplementary foods is hampered by its undesirable flavor. The objective of this study was to develop a functional lipid-based nutrient supplement (LNS) containing OEO, which is stable, acceptable and provides targeted intestinal delivery of bioactive. ß-cyclodextrin (ß-CyD) inclusion complexes of OEO (ß-CyD-OEO), and carvacrol (ß-CyD-CV) (1:1 molar) were prepared using slurry complexation (-20 °C) method and characterized based on encapsulation efficiency, moisture content, morphology, and 2-phase in vitro digestion stability. Carvacrol (CV) content was measured using reverse phase HPLC-UV. LNS containing ß-CyD-OEO (27.2 mg encapsulate/20 g LNS) was formulated using Indian staples and ingredients. Discriminatory sensory tests (triangle) were performed with college students (n = 58) and low-income women (n = 25), with young children at home (1 to 6 years), living in Mehsana, India to evaluate differences between LNS with and without bioactive ingredient (ß-CyD-OEO only). Moisture of dried complexes ranged 9.1% to 9.7% d.b., whereas water activity 0.35 to 0.412. The complex size and encapsulation efficiency of ß-CyD-OEO and ß-CyD-CV were 1.5 to 7 µm and 4 to 20 µm, and 86.04 ± 4.48% and 81.39 ± 3.34%, respectively. The bioactive complexes were stable through the gastric and intestinal phases. Bioaccessibility of encapsulated CV ranged 6.0% to 7.7%. Sensory tests revealed no differences (P > 0.05) in color, aroma, and taste between LNS with and without ß-CyD-OEO complexes. Functionalization of LNS with ß-CyD-OEO is feasible based on in vitro stability and sensory studies. PRACTICAL APPLICATION: Despite its antiparasitic activities, the addition of oregano essential oil into foods is limited due to its strong flavor and volatility. In this study, we evaluated the encapsulation of oregano essential oil with ß-cyclodextrin and its addition into lipid-based nutrition supplements. The results revealed that complex encapsulation efficiency was above 80%. Also, the bioactive complexes were stable under in vitro gastrointestinal conditions. Sensory evaluation of LNS with and without encapsulated essential oil showed no difference in terms of color, aroma, and taste. The functional LNS can both address nutrient insufficiency as well as parasitic infection among malnourished populations in low-resource settings.

A comparative study of fruit and vegetable consumption and physical activity among adolescents in 49 Low-and-Middle-Income Countries.

Physical inactivity and low consumption of fruits and vegetables (FV) during adolescence may persist through adulthood, putting adolescents at risk of developing chronic diseases. Although studies from high-income countries have reported differences in FV consumption and physical activity (PA) between adolescent boys and girls, few exist from low-and-middle-income countries (LMICs). In this study, we examined patterns of FV consumption and PA among adolescent boys and girls in LMICs. Country selection was based on availability of Global School-Based Student Health Survey (GSHS) data from 2004 to 2013. The total analytic sample was 164,771 adolescents from 49 LMICs. Descriptive statistics were generated to determine adolescents meeting the World Health Organization (WHO) recommendations for FV and PA. A Rao-Scott adjusted chi-square statistic was computed to assess gender differences. Less than 30% of adolescents across all countries met the WHO guidelines for FV consumption or PA. Morocco (29.5%) and India (29.5%) however had the highest percentage of adolescents meeting recommendations for FV and PA, respectively. Adolescent boys were more active than girls, and this difference was more notable in the Middle East and North African region. Adolescents achieving the WHO recommendations for daily consumption of FV and PA were consistently low in all countries.

Effect of oregano essential oil and carvacrol on Cryptosporidium parvum infectivity in HCT-8 cells.

Cryptosporidium parvum is the second leading cause of persistent diarrhea among children in low-resource settings. This study examined the effect of oregano essential oil (OEO) and carvacrol (CV) on inhibition of C. parvum infectivity in vitro. HCT-8 cells were seeded (1×106) in 96-well microtiter plates until confluency. Cell viability and infectivity were assessed by seeding HCT-8 cell monolayers with C. parvum oocysts (1×104) in two modalities: 1) 4h co-culture with bioactive (0-250µg/mL) followed by washing and incubation (48h, 37°C, 5% CO2) in bioactive-free media; and 2) 4h co-culture of C. parvum oocysts followed by washing and treatment with bioactive (0-250µg/mL) during 48-h incubation. Cell viability was tested using Live/Dead™ assay whereas infectivity was measured using C. parvum-specific antibody staining via immunofluorescence detection. Loss of cell viability was observed starting at 125µg/mL and 60µg/mL for OEO and CV, respectively. Neither OEO nor CV modulated the invasion of C. parvum sporozoites in HCT-8 cells. Treatment with bioactive after invasion reduced relative C. parvum infectivity in a dose-dependent manner to 55.6±10.4% and 45.8±4.1% at 60 and 30µg/mL of OEO and CV, respectively. OEO and CV are potential bioactives to counteract C. parvum infection in children.

Comparison of Methods Study between a Photonic Crystal Biosensor and Certified ELISA to Measure Biomarkers of Iron Deficiency in Chronic Kidney Disease Patients.

The total analytical error of a photonic crystal (PC) biosensor in the determination of ferritin and soluble transferrin receptor (sTfR) as biomarkers of iron deficiency anemia in chronic kidney disease (CKD) patients was evaluated against certified ELISAs. Antigens were extracted from sera of CKD patients using functionalized iron-oxide nanoparticles (fAb-IONs) followed by magnetic separation. Immuno-complexes were recognized by complementary detection Ab affixed to the PC biosensor surface, and their signals were followed using the BIND instrument. Quantification was conducted against actual protein standards. Total calculated error (TEcalc) was estimated based on systematic (SE) and random error (RE) and compared against total allowed error (TEa) based on established quality specifications. Both detection platforms showed adequate linearity, specificity, and sensitivity for biomarkers. Means, SD, and CV were similar between biomarkers for both detection platforms. Compared to ELISA, inherent imprecision was higher on the PC biosensor for ferritin, but not for sTfR. High SE or RE in the PC biosensor when measuring either biomarker resulted in TEcalc higher than the TEa. This did not influence the diagnostic ability of the PC biosensor to discriminate CKD patients with low iron stores. The performance of the PC biosensor is similar to certified ELISAs; however, optimization is required to reduce TEcalc.

Profiles of free and bound phenolics extracted from Citrus fruits and their roles in biological systems: content, and antioxidant, anti-diabetic and anti-hypertensive properties.

This study of selected plants of the Rutaceae family was carried out to investigate their phenolic content, antioxidant activity, and the in vitro inhibitory potential of extracted phenolics towards enzymes relevant for hyperglycemia and hypertension. The phenolic content, antioxidant activity and phenolic extract-mediated inhibitory activities for α-glucosidase and α-amylase were evaluated by spectrophotometry. The content of individual phenolics and the angiotensin I-converting enzyme (ACE) inhibitory activity of the phenolic extracts were evaluated by LC/MS-MS and RP-HPLC methods, respectively. A higher percentage of free phenolic content was seen for all the selected plants of the Rutaceae family (85.43-92.82% of the total phenolic content) than of the bound form (7.18-14.57% of total phenolic content). The major predominant bound phenolic in lemon and red blood orange was hesperidin. The major predominant bound phenolic in pummelo, shamouti and clementine was ferulic acid. The highest ACE and α-glucosidase inhibitory activity of the extracted phenolics from lemon was associated with free phenolic extracts obtained at 30 °C with values of 100% inhibition. Red blood orange free phenolic extract (30 °C) elicited the highest α-amylase inhibition activity (32.3%). In contrast, extracted bound phenolics after acid and base hydrolysis from all selected plants from the Citrus species were shown to induce activation of the ACE and α-amylase enzymes.

Stability of Trans-Resveratrol Encapsulated in a Protein Matrix Produced Using Spray Drying to UV Light Stress and Simulated Gastro-Intestinal Digestion.

Trans-resveratrol has demonstrated the potential to provide both therapeutic and preventive activities against chronic diseases such as heart disease and cancer. The incorporation of trans-resveratrol into food products would allow for broader access of this bioactive compound to a larger population. However, this strategy is limited by instability of trans-resveratrol under environmental conditions and within the digestive system leading to isomerization of trans-resveratrol (bioactive form) to cis-resveratrol (bio-inactive form). Studies in the stabilization of trans-resveratrol into protein microparticles are presented. Trans-resveratrol was encapsulated using whey protein concentrate (WPC) or sodium caseinate (SC), with or without anhydrous milk fat (AMF). Binding of resveratrol and aromatic residues in protein was estimated utilizing the Stern-Volmer equation and the number of tryptophan residues. The stability of encapsulated resveratrol was evaluated after exposure to ultraviolet A (UVA) light and 3-stage in vitro digestion. After UVA light exposure, SC-based microcapsules maintained a higher trans:cis resveratrol ratio (0.63, P < 0.05) than WPC-based microcapsules (0.43) and unencapsulated resveratrol (0.49). In addition, encapsulation of resveratrol in both protein microparticles led to an increased digestive stability and bioaccessibility in comparison to unencapsulated resveratrol (47% and 23%, respectively, P < 0.05). SC-based microcapsules provided a higher digestive stability and bioaccessibility (86% and 81%; P < 0.05) compared to WPC-based microcapsules (71% and 68%). The addition of AMF to the microcapsules did not significantly change the in vitro digestion values. In conclusion, SC-based microencapsulation increased the stability of trans-resveratrol to UVA light exposure and simulated digestion conditions. This encapsulation-system-approach can be extended to other labile, bioactive polyphenols.

Enhanced sandwich immunoassay using antibody-functionalized magnetic iron-oxide nanoparticles for extraction and detection of soluble transferrin receptor on a photonic crystal biosensor.

Iron deficiency anemia (IDA) has detrimental effects on individuals and societies worldwide. A standard sandwich assay (SA) for the detection of soluble transferrin receptor (sTfR), a biomarker of IDA, on a photonic crystal (PC) biosensor was established, but it was susceptible to non-specific signals from complex matrixes. In this study, iron-oxide nanoparticles (fAb-IONs) were used as magnetic immuno-probes to bind sTfR and minimize non-specific signals, while enhancing detection on the PC biosensor. This inverse sandwich assay (IA) method completely bound sTfR with low variability (<4% RSD) in buffer and allowed for its accurate and precise detection in sera (Liquichek™ control sera) on the PC biosensor using two certified ELISAs as reference methods. A linear dose-response curve was elicited at the fAb-IONs concentration in which the theoretical binding ratio (sTfR:fAb-IONs) was calculated to be <1 on the IA. The LoDs for sTfR in the SA and IA were similar (P>0.05) at 14 and 21 µg/mL, respectively. The inherent imprecision of the IA and reference ELISAs was σ(δ)=0.45 µg/mL and the mean biases for Liquichek™ 1, 2 and 3 were 0.18, 0.19 and -0.04 µg/mL, respectively. Whereas the inherent imprecision of the SA and reference ELISAs was σ(δ)=0.52 µg/mL and the biases for Liquichek™ 1, 2 and 3 were 0.66, 0.14 and -0.67 µg/mL, respectively. Thus, unlike the SA, the IA method measures sTfR with the same bias as the reference ELISAs. Combined magnetic separation and detection of nutrition biomarkers on PC biosensors represents a facile method for their accurate and reliable quantification in complex matrixes.

The use of mobile apps to improve nutrition outcomes: A systematic literature review.

We conducted a systematic review to determine if the use of nutrition apps resulted in improved outcomes, including knowledge and behavior, among healthy adults. Using app(s), cellular phone, iPads, mobile phone, mobile telephone, smart phone, mobile and mHealth as search terms with diet, food and nutrition as qualifiers we searched PubMed, CINAHL (January 2008-October 2013) and Web of Science (January 2008-January 2014). Inclusion criteria were peer-reviewed randomized controlled trials, non-controlled trials, and cohort studies published in English that used apps to increase nutrition knowledge or improve behavior related to nutrition. Studies that were descriptive, did not include apps, focused on app development, app satisfaction app feasibility, text messaging, or digital photography were excluded. We evaluated article quality using the Academy of Nutrition and Dietetics Evidence Analysis Manual. Data was extracted for knowledge, behavior and weight change. Our initial search identified 12,010 titles from PubMed, 260 from CINAHL and 4762 from Web of Science; of these, only four articles met all search criteria. Positive quality ratings were given to three articles; only one reported knowledge outcomes (non-significant). All four articles evaluated weight loss and suggested an advantage to using nutrition apps. Behavioral changes in reviewed studies included increased adherence to diet monitoring (p < 0.001) and decreased effort to continue diet without app (p = 0.024). Few studies, however, have explored the use of nutrition apps as supportive educational interventions. Most apps focus on weight loss with inconsistent outcomes. We conclude that using apps for education needs additional research which includes behavior theory within the app and improved study design.

Long-term exposure to dietary sources of genistein induces estrogen-independence in the human breast cancer (MCF-7) xenograft model.

SCOPE: The long-term effect of exposure to relevant dietary levels of genistein (GEN) on estrogen receptor-positive (ER+) human breast cancer (MCF-7) progression after GEN withdrawal in athymic mice xenograft model was studied. MATERIALS AND METHODS: Feeding studies were conducted to determine the estrogenic effect of diets on MCF-7 tumor growth: (1) implantation (19 weeks) and withdrawal (6 weeks) of 17ß-estradiol (E2 ); (2) dietary GEN 500 and 750 ppm during treatment/withdrawal for 23/10 and 15/9 weeks, respectively; and, (3) dietary soy protein isolate (SPI) containing GEN 180 ppm for 31/9 weeks of treatment/withdrawal. MCF-7 tumors grew fast in the presence of E2 implantation and abruptly regressed completely after E2 withdrawal. At different rates, dietary GEN alone (500 and 750 ppm) and GEN (180 ppm)-containing SPI stimulated MCF-7 tumor growth. After removal of the stimulus diet, tumors induced by 750 ppm GEN, but not 500 ppm GEN or SPI, regressed completely. The protein expression of epidermal growth factor receptor 2 (HER2) was higher in the GEN- and SPI-induced nonregressing (GINR) tumors compared to MCF-7 and E2 controls. CONCLUSION: Long-term consumption of low GEN doses (≤500 ppm) promotes MCF-7 tumor growth and results in GINR tumors with more aggressive and advanced growth phenotypes.

A photonic crystal biosensor assay for ferritin utilizing iron-oxide nanoparticles.

Iron deficiency anemia afflicts 1 in 3 individuals, mostly women and children worldwide. A novel application using iron-oxide nanoparticles (IONPs) and a photonic crystal (PC) optical biosensor as an immunodiagnostic platform for detection of serum ferritin, a biomarker for iron deficiency, is presented. Human liver ferritin (450 kDa), clinical serum controls, and three commercially available ferritin ELISA tests were used to evaluate the PC biosensor assay in terms of inter- and intra-assay variability, spike-recovery (%), limit of detection (LOD), and matrix effects on binding. For the PC biosensor, signal response from label-free, sandwich with secondary antibody (pAb), and pAb functionalized with iron-oxide nanoparticles (FpAb) assays were detected using the Biomolecular Interaction Detection (BIND) system. Bland-Altman analysis was used to evaluate agreement between expected values for ferritin in control sera and each of the detection platforms. Inter- and intra-assay variability of the PC biosensor were both <10%. Percent mean recovery (±%RSD) of ferritin from two control sera samples were 94.3% (13.1%) and 96.9% (7.6%). Use of FpAb in PC biosensor resulted in two orders of magnitude increase in sensitivity compared to label-free assay; capable of measuring serum ferritin as low as 26 ng/mL. In comparison to ELISA tests, the PC biosensor assay had the lowest bias (-1.26; 95% CI [-3.0-5.5]) and narrower limit of agreement (-11.6-9.1 ng/mL) when determining ferritin concentrations from control sera. These proof-of-concept studies support the use of IONPs to enhance detection sensitivity of PC biosensors for determination of biomarkers of nutritional status.

Is soy consumption good or bad for the breast?

Genistein in soy activates estrogen receptor (ER)-α and ERß and acts as an estradiol in multiple target tissues. Because estrogens increase breast cancer risk and genistein promotes the growth of ER-positive human breast cancer cells, it has remained unclear whether this isoflavone or soy is safe. Results reviewed here suggest that women consuming moderate amounts of soy throughout their life have lower breast cancer risk than women who do not consume soy; however, this protective effect may originate from soy intake early in life. We also review the literature regarding potential risks genistein poses for breast cancer survivors. Findings obtained in 2 recent human studies show that a moderate consumption of diet containing this isoflavone does not increase the risk of breast cancer recurrence in Western women, and Asian breast cancer survivors exhibit better prognosis if they continue consuming a soy diet. The mechanisms explaining the breast cancer risk-reducing effect of early soy intake or the protective effect in Asian breast cancer survivors remain to be established. We propose that the reduction in risk involves epigenetic changes that result in alterations in the expression of genes that regulate mammary epithelial cell fate, i.e. cell proliferation and differentiation. Lifetime soy consumption at a moderate level may prevent breast cancer recurrence through mechanisms that change the biology of tumors; e.g. women who consumed soy during childhood develop breast cancers that express significantly reduced Human epidermal growth factor receptor 2 levels. More research is needed to understand why soy intake during early life may both reduce breast cancer risk and risk of recurrence.

Impact of dietary genistein and aging on executive function in rats.

Genistein is an estrogenic soy isoflavone widely promoted for healthy aging, but its effects on cognitive function are not well-understood. We examined the cognitive effects of once daily oral genistein treatment at two doses (approximately 162 microg/kg/day low dose and a 323 microg/kg/day high dose) in ovariectomized young (7 month), middle-aged (16 month), and old (22 month) Long-Evans rats. Operant tasks including delayed spatial alternation (DSA), differential reinforcement of low rates of responding (DRL), and reversal learning that tap prefrontal cortical function were used to assess working memory, inhibitory control/timing, and strategy shifting, respectively. At the conclusion of cognitive testing, brains were collected and relative densities of D1 and D2 dopamine receptors and dopamine transporter (DAT) were measured in the prefrontal cortex. On the DSA task, the high dose old group performed worse than both the high dose young and middle-aged groups. On the DRL task, the high dose of genistein resulted in a marginally significant impairment in the ratio of reinforced to non-reinforced lever presses. This effect was present across age groups. Age effects were also found as old rats performed more poorly than the young and middle-aged rats on the DSA overall. In contrast, middle-aged and old rats made fewer lever presses on the DRL than did the young rats, a pattern of behavior associated with better performance on this task. Moreover, while DAT levels overall decreased with age, genistein treatment produced an increase in DAT expression in old rats relative to similarly aged control rats. D1 and D2 densities did not differ between genistein dose groups or by age. These results highlight the fact that aspects of executive function are differentially sensitive to both genistein exposure and aging and suggest that altered prefrontal dopamine function could potentially play a role in mediating these effects.

Quercetin blocks airway epithelial cell chemokine expression.

Quercetin (3,3',4',5,7-pentahydroxyflavone), a dietary flavonoid, is an inhibitor of phosphatidylinositol (PI) 3-kinase and potent antioxidant. We hypothesized that quercetin blocks airway epithelial cell chemokine expression via PI 3-kinase-dependent mechanisms. Pretreatment with quercetin and the PI 3-kinase inhibitor LY294002 each reduced TNF-alpha-induced IL-8 and monocyte chemoattractant protein (MCP)-1 (also called CCL2) expression in cultured human airway epithelial cells. Quercetin also inhibited TNF-alpha-induced PI 3-kinase activity, Akt phosphorylation, intracellular H(2)O(2) production, NF-kappaB transactivation, IL-8 promoter activity, and steady-state mRNA levels, consistent with the notion that quercetin inhibits chemokine expression by attenuating NF-kappaB transactivation via a PI 3-kinase/Akt-dependent pathway. Quercetin also reduced TNF-alpha-induced chemokine secretion in the presence of the transcriptional inhibitor actinomycin D, while inducing phosphorylation of eukaryotic translation initiation factor (eIF)-2alpha, suggesting that quercetin attenuates chemokine expression by post-transcriptional as well as transcriptional mechanisms. Finally, we tested the effects of quercetin in cockroach antigen-sensitized and -challenged mice. These mice show MCP-1-dependent airways hyperresponsiveness and inflammation. Quercetin significantly reduced lung MCP-1 and methacholine responsiveness. We conclude that quercetin blocks airway cell chemokine expression via transcriptional and post-transcriptional pathways.