Nutrition & Food Science
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Item Selenium Supranutrition: Are the Potential Benefits of Chemoprevention Outweighed by the Promotion of Diabetes and Insulin Resistance?(MDPI, 2013-04-19) Rocourt, Caroline R. B.; Cheng, Wen-HsingSelenium was considered a toxin until 1957, when this mineral was shown to be essential in the prevention of necrotic liver damage in rats. The hypothesis of selenium chemoprevention is principally formulated by the observations that cancer incidence is inversely associated with selenium status. However, recent clinical and epidemiological studies demonstrate a role for some selenoproteins in exacerbating or promoting other disease states, specifically type 2 diabetes, although other data support a role of selenium in stimulating insulin sensitivity. Therefore, it is clear that our understanding in the role of selenium in glucose metabolism and chemoprevention is inadequate and incomplete. Research exploring the role of selenium in individual healthcare is of upmost importance and possibly will help explain how selenium is a double-edged sword in the pathologies of chronic diseases.Item TCF4 Is a Molecular Target of Resveratrol in the Prevention of Colorectal Cancer(MDPI, 2015-05-07) Jeong, Jin Boo; Lee, Jihye; Lee, Seong-HoThe Wnt/β-catenin pathway plays an essential role in the tumorigenesis of colorectal cancer. T-cell factor-4 (TCF4) is a member of the TCF/LEF (lymphoid enhancer factor) family of transcription factors, and dysregulation of β-catenin is decisive for the initiation and progression of colorectal cancer. However, the role of TCF4 in the transcriptional regulation of its target gene remained poorly understood. Resveratrol is a dietary phytoalexin and present in many plants, including grape skin, nuts and fruits. Although resveratrol has been widely implicated in anti-tumorigenic and pro-apoptotic properties in several cancer models, the underlying cellular mechanisms are only partially understood. The current study was performed to elucidate the molecular mechanism of the anti-cancer activity of resveratrol in human colorectal cancer cells. The treatment of resveratrol and other phytochemicals decreased the expression of TCF4. Resveratrol decreases cellular accumulation of exogenously-introduced TCF4 protein, but did not change the TCF4 transcription. The inhibition of proteasomal degradation using MG132 (carbobenzoxy-Leu-Leu-leucinal) and lactacystin ameliorates resveratrol-stimulated down-regulation of TCF4. The half-life of TCF4 was decreased in the cells exposed to resveratrol. Resveratrol increased phosphorylation of TCF4 at serine/threonine residues through ERK (extracellular signal-regulated kinases) and p38-dependent pathways. The TCF4 knockdown decreased TCF/β-catenin-mediated transcriptional activity and sensitized resveratrol-induced apoptosis. The current study provides a new mechanistic link between resveratrol and TCF4 down-regulation and significant benefits for further preclinical and clinical practice.Item Comparison of Metabolic Syndrome Indicators in Two Samples of Central and South Americans Living in the Washington, D.C. Area in 1993–1994 and 2008–2009: Secular Changes in Metabolic Syndrome in Hispanics(MDPI, 2017-08-05) Gill, Regina; Jackson, Robert T.; Duane, Marguerite; Miner, Allison; Khan, Saira A.The Central and South American populations are growing rapidly in the US; however, there is a paucity of information about their health status. Objectives: we estimated the prevalence of metabolic syndrome (MetS) and its individual components from two cohorts of Central and South Americans. Methods: This cross-sectional, medical record extraction survey sampled 1641 adults from a Washington, D.C clinic. A questionnaire was used to collect socio-demographic, medical history, anthropometric, biochemical, and clinical data. Results: among the 1993–1994 cohort, the MetS prevalence was 19.7%. The most prevalent MetS components were low high-density lipoprotein (HDL) cholesterol (40.4% men and 51.3% women), elevated triglycerides (40.9% men and 33.1% women), and high body mass index (BMI) ≥ 25 kg/m2 (27.6% men and 36.6% women). The overall prevalence of MetS in the 2008–2009 cohort was 28%. The most common abnormal metabolic indicator was an elevated BMI ≥ 25 kg/m2 (75.6%). 43.2% of men and 50.7% of women had HDL levels below normal, while the prevalence of hypertriglyceridemia was 46.5% and 32.5% for men and women, respectively. Conclusion: the prevalence of MetS was significantly greater in 2008–2009 compared with 1993–1994 (p ≤ 0.05). Dyslipidemia and high BMI have increased. Although similar components were identified in both the 1993–1994 and 2008–2009 study populations, the risks of MetS have increased over time.Item Recent Developments in Food Packaging Based on Nanomaterials(MDPI, 2018-10-13) Huang, Yukun; Mei, Lei; Chen, Xianggui; Wang, QinThe increasing demand for high food quality and safety, and concerns of environment sustainable development have been encouraging researchers in the food industry to exploit the robust and green biodegradable nanocomposites, which provide new opportunities and challenges for the development of nanomaterials in the food industry. This review paper aims at summarizing the recent three years of research findings on the new development of nanomaterials for food packaging. Two categories of nanomaterials (i.e., inorganic and organic) are included. The synthetic methods, physical and chemical properties, biological activity, and applications in food systems and safety assessments of each nanomaterial are presented. This review also highlights the possible mechanisms of antimicrobial activity against bacteria of certain active nanomaterials and their health concerns. It concludes with an outlook of the nanomaterials functionalized in food packaging.Item Antimicrobial Nanoparticles Incorporated in Edible Coatings and Films for the Preservation of Fruits and Vegetables(MDPI, 2019-04-30) Xing, Yage; Li, Wenxiu; Wang, Qin; Li, Xuanlin; Xu, Qinglian; Guo, Xunlian; Liu, Xiaocui; Shui, Yuru; Lin, Hongbin; Yang, Hua; Bi, XiufangEdible coatings and films (ECF) are employed as matrixes for incorporating antimicrobial nanoparticles (NPs), and then they are applied on the fruits and vegetables to prolong shelf life and enhance storage quality. This paper provides a comprehensive review on the preparation, antimicrobial properties and mechanisms, surface and physical qualities of ECF containing antimicrobial NPs, and its efficient application to vegetables and fruits as well. Following an introduction on the properties of the main edible coating materials, the preparation technologies of ECF with NPs are summarized. The antimicrobial activity of ECF with NPs against the tested microorganism was observed by many researchers. This might be mainly due to the electrostatic interaction between the cationic polymer or free metal ions and the charged cell membrane, the photocatalytic reaction of NPs, the detachment of free metal ion, and partly due to the antimicrobial activity of edible materials. Moreover, their physical, mechanical and releasing properties are discussed in detail, which might be influenced by the concentration of NPs. The preservation potential on the quality of fruits and vegetables indicates that various ECF with NPs might be used as the ideal materials for food application. Following the introduction on these characteristics, an attempt is made to predict future trends in this field.Item Food-Grade Nanoemulsions: Preparation, Stability and Application in Encapsulation of Bioactive Compounds(MDPI, 2019-11-21) Kiu, Qingqing; Huang, He; Chen, Honghong; Lin, Junfan; Wang, QinNanoemulsions have attracted significant attention in food fields and can increase the functionality of the bioactive compounds contained within them. In this paper, the preparation methods, including low-energy and high-energy methods, were first reviewed. Second, the physical and chemical destabilization mechanisms of nanoemulsions, such as gravitational separation (creaming or sedimentation), flocculation, coalescence, Ostwald ripening, lipid oxidation and so on, were reviewed. Then, the impact of different stabilizers, including emulsifiers, weighting agents, texture modifiers (thickening agents and gelling agents), ripening inhibitors, antioxidants and chelating agents, on the physicochemical stability of nanoemulsions were discussed. Finally, the applications of nanoemulsions for the delivery of functional ingredients, including bioactive lipids, essential oil, flavor compounds, vitamins, phenolic compounds and carotenoids, were summarized. This review can provide some reference for the selection of preparation methods and stabilizers that will improve performance in nanoemulsion-based products and expand their usage.Item Induction of apoptosis in HeLa cells by chloroform fraction of seed extracts of Nigella sativa(Springer Nature, 2009-11-27) Shafi, Gowhar; Munshi, Anjana; Hasan, Tarique N; Alshatwi, Ali A; Jyothy, A; Lei, David KYCancer remains one of the most dreaded diseases causing an astonishingly high death rate, second only to cardiac arrest. The fact that conventional and newly emerging treatment procedures like chemotherapy, catalytic therapy, photodynamic therapy and radiotherapy have not succeeded in reverting the outcome of the disease to any drastic extent, has made researchers investigate alternative treatment options. The extensive repertoire of traditional medicinal knowledge systems from various parts of the world are being re-investigated for their healing properties. This study progresses in the direction of identifying component(s) from Nigella sativa with anti cancer acitivity. In the present study we investigated the efficacy of Organic extracts of Nigella sativa seed powder for its clonogenic inhibition and induction of apoptosis in HeLa cancer cell. Methanolic, n-Hexane and chloroform extracts of Nigella sativa seedz effectively killed HeLa cells. The IC50 values of methanolic, n-hexane, and chloroform extracts of Nigella sativa were 2.28 μg/ml, 2.20 μg/ml and 0.41 ng/ml, respectively. All three extracts induced apoptosis in HeLa cells. Apoptosis was confirmed by DNA fragmentation, western blot and terminal transferase-mediated dUTP-digoxigenin-end labeling (TUNEL) assay. Western Blot and TUNEL results suggested that Nigella sativa seed extracts regulated the expression of pro- and anti- apoptotic genes, indicating its possible development as a potential therapeutic agent for cervical cancer upon further investigation.Item Impact of the shedding level on transmission of persistent infections in Mycobacterium avium subspecies paratuberculosis (MAP)(Springer Nature, 2016-02-29) Slater, Noa; Mitchell, Rebecca Mans; Whitlock, Robert H.; Fyock, Terry; Pradhan, Abani Kumar; Knupfer, Elena; Schukken, Ynte Hein; Louzoun, YoramSuper-shedders are infectious individuals that contribute a disproportionate amount of infectious pathogen load to the environment. A super-shedder host may produce up to 10 000 times more pathogens than other infectious hosts. Super-shedders have been reported for multiple human and animal diseases. If their contribution to infection dynamics was linear to the pathogen load, they would dominate infection dynamics. We here focus on quantifying the effect of super-shedders on the spread of infection in natural environments to test if such an effect actually occurs in Mycobacterium avium subspecies paratuberculosis (MAP). We study a case where the infection dynamics and the bacterial load shed by each host at every point in time are known. Using a maximum likelihood approach, we estimate the parameters of a model with multiple transmission routes, including direct contact, indirect contact and a background infection risk. We use longitudinal data from persistent infections (MAP), where infectious individuals have a wide distribution of infectious loads, ranging upward of three orders of magnitude. We show based on these parameters that the effect of super-shedders for MAP is limited and that the effect of the individual bacterial load is limited and the relationship between bacterial load and the infectiousness is highly concave. A 1000-fold increase in the bacterial contribution is equivalent to up to a 2–3 fold increase in infectiousness.Item Rapid detection of Salmonella in food and feed by coupling loop-mediated isothermal amplification with bioluminescent assay in real-time(Springer Nature, 2016-06-17) Yang, Qianru; Domesle, Kelly J; Wang, Fei; Ge, BeileiSalmonella is among the most significant pathogens causing food and feed safety concerns. This study examined the rapid detection of Salmonella in various types of food and feed samples by coupling loop-mediated isothermal amplification (LAMP) with a novel reporter, bioluminescent assay in real-time (BART). Performance of the LAMP-BART assay was compared to a conventional LAMP and the commercially available 3M Molecular Detection Assay (MDA) Salmonella. The LAMP-BART assay was 100 % specific among 178 strains (151 Salmonella and 27 non-Salmonella) tested. The detection limits were 36 cells per reaction in pure culture and 104 to 106 CFU per 25 g in spiked food and feed samples without enrichment, which were comparable to those of the conventional LAMP and 3M MDA Salmonella but 5–10 min faster. Ground turkey showed a strong inhibition on 3M MDA Salmonella, requiring at least 108 CFU per 25 g for detection. The correlation between Salmonella cell numbers and LAMP-BART signals was high (R 2 = 0.941–0.962), suggesting good quantification capability. After 24 h enrichment, all three assays accurately detected 1 to 3 CFU per 25 g of Salmonella among five types of food (cantaloupe, ground beef, ground turkey, shell eggs, and tomato) and three types of feed (cattle feed, chicken feed, and dry dog food) examined. However, 101 CFU per 25 g was required for cattle feed when tested by 3M MDA Salmonella. The Salmonella LAMP-BART assay was rapid, specific, sensitive, quantitative, and robust. Upon further validation, it may become a valuable tool for routine screening of Salmonella in various types of food and feed samples.Item Assessing the potential for Salmonella growth in rehydrated dry dog food(Springer Nature, 2016-11-18) Oni, Ruth A.; Lambertini, Elisabetta; Buchanan, Robert L.A substantial percentage of dog owners add water to dry dog food to increase its palatability. The recent association of Salmonella contamination of dry pet foods with salmonellosis cases in both dogs and their owners has generated a need to determine the ability of Salmonella to grow in eight commercial brands of rehydrated dry dog food. Eight brands of commercial dry dog food were rehydrated to 20, 35 and 50% added moisture, inoculated with two S. enterica strains (~105 CFU/g) and incubated for 72 h at 18 °C, 22 °C, or 28 °C. Dog food brand, moisture content, and temperature affected pathogen growth/survival patterns. Rehydration to 20% moisture did not support growth of S. enterica, and in general there was a 0.5–2.0 Log decline. At 35% moisture and 28 °C, 4 of 8 brands supported up to 3.4 Log(CFU/g) of growth, while Salmonella levels declined in three brands, and remained unchanged in one. Rehydration to 50% moisture at 28 °C supported increases of up to 4.6 Log(CFU/g) in 5 of 8 brands. Growth kinetics determinations with two of the brands that supported growth had calculated lag times, generation times, and maximum population densities of 4.4 and 2.2 h, 1.4 and 10.8 h, and 7.3 and 6.9 Log(CFU/g) when rehydrated to 35% moisture and held at 30 °C. Results of this study establish that the rehydration of dry dog food with sufficient amounts of water may support the growth of S. enterica. Based on the most rapid observed lag times, growth of Salmonella, if present, in rehydrated dog food could be avoided by discarding or refrigerating uneaten portions within 2–3 h of rehydration. These data allow accidental or intentional rehydration of dry dog food to be factored into predictive microbiology models and exposure assessments.