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Results for “Food, Genetically Modified”

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PubMed1989

Safrole, eugenol and methyleugenol induce intrachromosomal recombination in yeast.

Deletion of an integrated plasmid, a specific type of intrachromosomal recombination, was evaluated for inducibility with the phenylpropenes safrole, eugenol and methyleugenol in the yeast Saccharomyces cerevisiae. These phenylpropenes are found in food products, spices, pharmaceuticals and clove cigarettes. Safrole and eugenol are known carcinogens in animals and methyleugenol is a suspected carcinogen. These phenylpropenes are not detectable by the Ames assay and most other short-term tests used currently in predictive carcinogenesis. Like safrole, which has been shown to be nonmutagenic with the Ames assay, eugenol and methyleugenol were found to be nonmutagenic with the Ames assay. In contrast, with the yeast assays which screen for intra- and inter-chromosomal recombination in logarithmic phase cultures, all 3 compounds gave a positive dose-related response. These results demonstrate further that the yeast system can be modified easily to detect various genetic endpoints and that it deserves serious consideration as a test system for predictive carcinogenesis.

Adenine↗

PubMed2004

Lutein and beta-carotene from lutein-containing yellow carrots are bioavailable in humans.

BACKGROUND: Lutein is a hydroxy-carotenoid constituting the macular pigment of the human retina. Increasing lutein intake from foods could increase the density of this pigment and decrease the risk of developing macular degeneration. Yellow carrots are a novel food source that could increase lutein consumption. OBJECTIVE: We evaluated and compared lutein uptake and clearance in humans from genetically selected lutein-containing yellow carrots fed chronically and from a lutein supplement. DESIGN: Four women and 5 men aged 23-28 y participated in this randomized, blinded, 3 x 3 crossover intervention. Treatments consisted of yellow carrots (YC treatment, 1.7 mg lutein/d), white carrots as a negative control (WC treatment, 0 mg lutein/d), and a lutein supplement in oil as a positive control (LS treatment, 1.7 mg lutein/d). Each treatment lasted 7 d and was followed by a 7-d washout period. RESULTS: Mean (+/- SD) peak changes in serum lutein concentration from baseline were 0.31 +/- 0.08, 0.19 +/- 0.08, and -0.04 +/- 0.04 micromol/L for the LS, YC, and WC treatments, respectively. The areas under the curve for 0-14 d (AUC(0-14d)) differed significantly (P < 0.0001) between treatments. Lutein from the YC treatment was 65% as bioavailable as that from the LS treatment. The AUC(0-14d) for beta-carotene (-0.01 +/- 0.28 micromol.d/L) also showed that the YC treatment maintained peak serum beta-carotene concentrations at 0.35 +/- 0.30 micromol/L, whereas the LS treatment did not (AUC(0-14d) = -0.71 +/- 0.59 micromol.d/L). CONCLUSION: Lutein from this novel food source significantly increases serum lutein concentrations and does not result in the decrease in beta-carotene concentrations that accompanies administration of lutein supplements.

Adult↗

PubMed2000

Protein and energy evaluation of soybean meals processed from genetically modified high-protein soybeans.

A conventional and two genetically modified soybean samples were processed to dehulled soybean meal (SBM) at a pilot plant and were compared with SBM from a commercial processing plant. Crude protein levels (%) of the experimental SBM samples were M700, 52.5; M702, 53.4; and M703, 62.7. The commercial SBM sample (UI) contained 47.5% protein. Amino acid, gross energy, lipid, and fiber analyses were carried out, and true metabolizable energy and true amino acid digestibility were determined with adult cecectomized cockerels. Digestible Lys, Met, Cys, Thr, and Val, and also TMEn, were higher (P < 0.05) and NDF, fat, and phospholipids were lower in M703 than in the other SBM samples. The results of this study indicate that M703 has considerable advantages over conventional SBM as a feed ingredient for broiler chickens.

Amino Acids↗

PubMed2006

Chickpea (Cicer arietinum L.).

Chickpea is one of the most important leguminous, cool-season, food crops, cultivated prevalently in the Asian Pacific region. In spite of its nutritional importance, its area of cultivation has been low, with virtually no increase. Conventional breeding has resulted in several important improvements in this crop, and recent advances in biotechnology such as plant tissue culture and genetic transformation can significantly contribute to better sustainability of this important food crop. Here, we describe an efficient Agrobacterium-mediated transformation protocol for chickpea using axillary meristem explants, which results in a high frequency of genetic transformation (70%) and recovery of valuable transgenic plants. The protocol is significant owing to its high reproducibility and recovery of the transgenics in a relatively short period (90-100 days).

Agrobacterium tumefaciens↗

PubMed1998

Functional food science and the cardiovascular system.

Cardiovascular disease has a multifactorial aetiology, as is illustrated by the existence of numerous risk indicators, many of which can be influenced by dietary means. It should be recalled, however, that only after a cause-and-effect relationship has been established between the disease and a given risk indicator (called a risk factor in that case), can modifying this factor be expected to affect disease morbidity and mortality. In this paper, effects of diet on cardiovascular risk are reviewed, with special emphasis on modification of the plasma lipoprotein profile and of hypertension. In addition, dietary influences on arterial thrombotic processes, immunological interactions, insulin resistance and hyperhomocysteinaemia are discussed. Dietary lipids are able to affect lipoprotein metabolism in a significant way, thereby modifying the risk of cardiovascular disease. However, more research is required concerning the possible interactions between the various dietary fatty acids, and between fatty acids and dietary cholesterol. In addition, more studies are needed with respect to the possible importance of the postprandial state. Although in the aetiology of hypertension the genetic component is definitely stronger than environmental factors, some benefit in terms of the development and coronary complications of atherosclerosis in hypertensive patients can be expected from fatty acids such as alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid. This particularly holds for those subjects where the hypertensive mechanism involves the formation of thromboxane A2 and/or alpha 1-adrenergic activities. However, large-scale trials are required to test this contention. Certain aspects of blood platelet function, blood coagulability, and fibrinolytic activity are associated with cardiovascular risk, but causality has been insufficiently proven. Nonetheless, well-designed intervention studies should be initiated to further evaluate such promising dietary components as the various n-3 and n-6 fatty acids and their combination, antioxidants, fibre, etc. for their effect on processes participating in arterial thrombus formation. Long-chain polyenes of the n-3 family and antioxidants can modify the activity of immunocompetent cells, but we are at an early stage of examining the role of immune function on the development of atherosclerotic plaques. Actually, there is little, if any, evidence that dietary modulation of immune system responses of cells participating in atherogenesis exerts beneficial effects. Although it seems feasible to modulate insulin sensitivity and subsequent cardiovascular risk factors by decreasing the total amount of dietary fat and increasing the proportion of polyunsaturated fatty acids, additional studies on the efficacy of specific fatty acids, dietary fibre, and low-energy diets, as well as on the mechanisms involved are required to understand the real function of these dietary components. Finally, dietary supplements containing folate and vitamins B6 and/or B12 should be tested for their potential to reduce cardiovascular risk by lowering the plasma level of homocysteine.

Blood Coagulation↗

PubMed1997

[Transgenic plants as medicine production systems].

Transgenic plants are emerging as an important system for the expression of many recombinant proteins, especially those intended for therapeutic purpose. The production of foreign proteins in plants has several advantages. In terms of required equipment and cost, mass production in plants is far easier to achieve than techniques involving animal cells. Successful production of several proteins in plants, including human serum albumin, haemoglobin, monoclonal antibodies, viral antigens (vaccines), enkephalin, and trichosanthin, has been reported. Particularly, the demonstration that vaccine antigens can be produced in plants in their native, immunogenic forms opens exciting possibilities for the "bio-farming" of vaccines. If the antigens are orally active, food-based "edible vaccines" could allow economical production. In this review, I will discuss the progress that has been made by several groups in what is now an expanding area of medicine research that utilizes transgenic plants.

Antibodies, Monoclonal↗

PubMed2007

The glutathione antioxidant system is enhanced in growth hormone transgenic coho salmon (Oncorhynchus kisutch).

Insertion of a growth hormone (GH) transgene in coho salmon results in accelerated growth, and increased feeding and metabolic rates. Whether other physiological systems within the fish are adjusted to this accelerated growth has not been well explored. We examined the effects of a GH transgene and feeding level on the antioxidant glutathione and its associated enzymes in various tissues of coho salmon. When transgenic and control salmon were fed to satiation, transgenic fish had increased tissue glutathione, increased hepatic glutathione reductase activity, decreased hepatic activity of the glutathione synthesis enzyme gamma-glutamylcysteine synthetase, and increased intestinal activity of the glutathione catabolic enzyme gamma-glutamyltranspeptidase. However, these differences were mostly abolished by ration restriction and fasting, indicating that upregulation of the glutathione antioxidant system was due to accelerated growth, and not to intrinsic effects of the transgene. Increased food intake and ability to digest potential dietary glutathione, and not increased activity of glutathione synthesis enzymes, likely contributed to the higher levels of glutathione in transgenic fish. Components of the glutathione antioxidant system are likely upregulated to combat potentially higher reactive oxygen species production from increased metabolic rates in GH transgenic salmon.

Animals↗

PubMed2002

A functional antigen in a practical crop: LT-B producing maize protects mice against Escherichia coli heat labile enterotoxin (LT) and cholera toxin (CT).

We have produced a functional heat labile enterotoxin (LT-) B subunit of Escherichia coli in maize. LT-B is a multimeric protein that presents an ideal model for an edible vaccine, displaying stability in the gut and inducing mucosal and systemic immune responses. Transgenic maize was engineered to synthesize the LT-B polypeptides, which assembled into oligomeric structures with affinity for G(M1) gangliosides. We orally immunized BALB/c mice by feeding transgenic maize meal expressing LT-B or non-transgenic maize meal spiked with bacterial LT-B. Both treatments stimulated elevated IgA and IgG antibodies against LT-B and the closely related cholera toxin B subunit (CT-B) in serum, and elevated IgA in fecal pellets. The transgenic maize induced a higher anti-LT-B and anti-CT-B mucosal and serum IgA response compared to the equivalent amount of bacterial LT-B spiked into maize. Following challenge by oral administration of the diarrhea inducing toxins LT and CT, transgenic maize-fed mice displayed reduced fluid accumulation in the gut compared to non-immunized mice. Moreover, the gut to carcass ratio of immunized mice was not significantly different from the PBS (non-toxin) challenged control group. We concluded that maize-synthesized LT-B had features of the native bacterial LT-B such as molecular weight, G(M1) binding ability, and induction of serum and mucosal immunity. We have demonstrated that maize, a major food and feed ingredient, can be efficiently transformed to produce, accumulate, and store a fully assembled and functional candidate vaccine antigen.

Administration, Oral↗

PubMed2003

Vitamin production in transgenic plants.

Plants are a major source of vitamins in the human diet. Due to their significance for human health and development, research has been initiated to understand the biosynthesis of vitamins in plants. The pathways that are furthest advanced in elucidation are those of provitamin A, vitamin C and vitamin E. There is little knowledge about the regulation, storage, sink and degradation of any vitamin made in plants, or the interaction of vitamin biosynthetic pathways with other metabolic pathways. Researchers as well as life science companies have endeavoured to manipulate levels of vitamins in order to create functional food with enhanced health benefits, and even with the goal of achieving levels worth extracting from plant tissues. Thus far, metabolic engineering has resulted in transgenic plants that contain elevated levels of provitamin A, vitamin C and E, respectively. Additional research is necessary to identify all relevant target genes in order to further improve and tailor plants with elevated vitamin contents at will.

Crops, Agricultural↗

PubMed2005

Cancer prevention by phytochemicals.

Information has been accumulated indicating that diets rich in vegetables and fruits can reduce the risk of a number of chronic diseases, including cancer, cardiovascular disease, diabetes and age-related macular degeneration. Phytochemicals (various factors in plant foods), such as carotenoids, antioxidative vitamins, phenolic compounds, terpenoids, steroids, indoles and fibers, have been considered responsible for the risk reduction. Among them, a mixture of natural carotenoids has been studied extensively and proven to show beneficial effects on human cancer prevention.

Animals↗

PubMed2003

Incorporating basic nutrition science into health interventions for cancer prevention.

Increasing evidence points to numerous dietary components that modify cancer incidence as well as the biological behavior of tumors. These inhibitory or stimulatory effects depend not only on the dietary component examined, but on a number of factors including the cellular DNA profile (nutrigenetic and nutrigenomic effects), protein formation and regulation (proteomic effect), and the effective delivery of the active intermediate at specific target sites (metabolomic effect). Unfortunately, the diet and cancer research domain is strewn with studies that were inadequately designed to monitor biological endpoints, used invalid biomarkers, or monitored irrelevant intakes or exposures. The scientific frontiers in health risk prediction and disease prevention strategies will greatly expand with the building of reliable nutrition and cancer biomarker databases that use modeling techniques to integrate information about intakes, effect biomarkers, and susceptibility biomarkers. Fundamental to this database will be the elucidation of the specific molecular sites of action (targets) for the specific dietary component. Clustering techniques that build on either genes or ratios of genetic expressions or their products will be needed to assess the merit of a particular dietary intervention. Models are already surfacing about how dietary-induced fluctuations in genes and their expression products can modify pathways associated with carcinogen activation and detoxification, alter rates of cellular proliferation, influence apoptosis, and modify angiogenesis. Embracing new genomic technologies offers exciting opportunities for advancing nutrition, especially those related to cancer prevention. We must effectively communicate, within a responsible bioethical framework, the potential value of knowledge about genes and gene products.

DNA Methylation↗

PubMed2026

Comparing genome-wide significant and chemosensory variants as instruments for dietary patterns in Mendelian randomization.

BACKGROUND: Diet is a modifiable risk factor for cardiometabolic disease, yet establishing causality remains challenging. Mendelian randomization (MR) leverages genetic variants as instrumental variables (IVs) to enable causal inference. METHOD: Using two-sample MR, we assessed the causal effects of four principal component-derived dietary patterns (DPs)-Unhealthy, Healthy, Meat-based, Pescatarian-on cardiometabolic outcomes including body mass index, coronary artery disease, blood lipids, blood pressures, type 2 diabetes, fasting glucose and insulin, and glycated haemoglobin. Two sets of IVs were employed: conventional genome-wide significant variants associated with each DP, filtered for pleiotropy and directionality; and biologically informed variants in chemosensory receptor genes, given the role of taste and smell perception in food choice. RESULTS: Using conventional IVs, the Pescatarian DP was associated with reduced fasting insulin (βIVW = -0.10 pmol/L per SD increase in the Pescatarian DP score, 95% confidence interval -0.15, -0.04; P = 1.19 × 10-3), surviving multiple sensitivity analyses. Associations between the Unhealthy DP and elevated blood pressure and glycated haemoglobin should be interpreted cautiously; one of the two filtered IVs was strongly associated with caffeine intake, limiting the attribution of these findings to the DP itself. Chemosensory Receptor IVs yielded null findings, reflecting insufficient power. CONCLUSION: Evidence for causal effects of DPs on cardiometabolic traits was limited, with the strongest support for a protective effect of the Pescatarian DP on fasting insulin. Chemosensory IVs demonstrated limited utility for DPs, likely reflecting the heterogeneous and complex sensory profiles of overall diets. Future efforts should consider guideline-based dietary indices to facilitate interpretability and translation.

Humans↗

PubMed2006

Amylinergic control of food intake.

Amylin is a pancreatic B-cell hormone that plays an important role in the regulation of nutrient fluxes. As such, amylin reduces food intake in laboratory animals and man, slows gastric emptying and it reduces postprandial glucagon secretion. Amylin deficiency which occurs concomitantly to insulin deficiency in diabetes mellitus, may therefore contribute to some of the major derangements associated with this disorder (hyperphagia, excessive glucagon secretion, accelerated rate of gastric emptying). The described actions of amylin all seem to depend on a direct effect of amylin on the area postrema (AP). As to amylin's satiating effect, the physiological relevance of this action is underlined by studies involving specific amylin antagonists and amylin-deficient mice. In the AP, amylin seems to modulate the anorectic signal elicited by CCK. Subsequent to AP activation, the amylin signal is conveyed to the forebrain via distinct relay stations. Within the lateral hypothalamic area, amylin diminishes the expression of orexigenic neuropeptides such as orexin and MCH. Whether these effects contribute to amylin's short term satiating action remains to be determined. Recent studies suggest that amylin may also play a role as a long-term, lipostatic signal, especially when other feedback systems to the brain are deficient. Obese, leptin-resistant Zucker rats which are hyperinsulinemic and hyperamylinemic, were chronically infused with the amylin antagonist AC 187. AC 187 significantly elevated food intake in obese Zucker rats while having no effect in lean controls. This indicates that at least under certain conditions, chronic blockade of endogenous amylin action may lead to an increase in food intake and/or body weight. As mentioned, the site and mechanism of action for peripheral amylin to reduce food intake seems to be well established. It is less clear how centrally administered amylin reduces food intake although it is well known that 3rd ventricular administration of amylin produces a very strong and long-lasting anorectic action. Amylin receptors have been described in various hypothalamic nuclei but the endogenous ligand of these receptors remains to be investigated. The same holds true as to the physiological relevance of the anorectic effect seen after central amylin administration.

Adiposity↗

PubMed1996

Lessons from animal models of obesity.

Obesity in animals may result from genetic, dietary, or neuroendocrine perturbations. Study of these models has identified the central systems that regulate food intake and energy expenditure and identified the interdependence of feeding behavior, the autonomic nervous system, and adrenal glucocorticoids in the development of obesity. The animal models of obesity have been influential in showing that adipose tissue is an important secretory tissue. The recent identification of five genes that cause obesity will provide new insight into the physiologic systems that regulate energy balance.

Animals↗

PubMed2004

Composition of grain and forage from corn rootworm-protected corn event MON 863 is equivalent to that of conventional corn (Zea mays l.).

Insect-protected corn hybrids containing event MON 863 protect corn plants against feeding damage from corn rootworm (Diabrotica), a major North American insect pest. Corn event MON 863 contains a gene that expresses an amino acid sequence variant of the wild-type Cry3Bb1 insecticidal protein from Bacillus thuringiensis. The purpose of this study was to compare the composition of corn containing event MON 863 with that of conventional nontransgenic corn. Compositional analyses were conducted to measure proximates, fiber, amino acids, fatty acids, minerals, folic acid, thiamin, riboflavin, vitamin E, antinutrients, and certain secondary metabolites in grain and proximates and fiber content in forage collected from a total of eight field sites in the U.S. and Argentina. Compositional analyses demonstrated that the grain and forage of event MON 863 are comparable in their nutritional content to the control corn hybrid and conventional corn. These comparisons, together with the history of the safe use of corn as a common component of animal feed and human food, support the conclusion that corn event MON 863 is compositionally equivalent to, and as safe and nutritious as, conventional corn hybrids grown commercially today.

Amino Acids↗

PubMed2005

A direct role for dual oxidase in Drosophila gut immunity.

Because the mucosal epithelia are in constant contact with large numbers of microorganisms, these surfaces must be armed with efficient microbial control systems. Here, we show that the Drosophila nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme, dual oxidase (dDuox), is indispensable for gut antimicrobial activities. Adult flies in which dDuox expression is silenced showed a marked increase in mortality rate even after a minor infection through ingestion of microbe-contaminated food. This could be restored by the specific reintroduction of dDuox, demonstrating that this oxidase generates a unique epithelial oxidative burst that limits microbial proliferation in the gut. Thus, oxidant-mediated antimicrobial responses are not restricted to the phagocytes, but rather are used more broadly, including in mucosal barrier epithelia.

Animals↗

PubMed2006

Major advances associated with reproduction in dairy cattle.

The purpose of this overview is to review some of the major advances in reproductive technologies, and how they may be applied to meet the challenge of enhancing reproductive efficiency in the high-producing dairy cow of the 21st century. The current population of high-producing dairy cows is considered to be subfertile, as characterized by low pregnancy rates and high rates of embryonic mortality. Coordinated systems of reproductive management have been developed based upon a thorough understanding of the endocrine, cellular, and molecular factors controlling ovarian and uterine function. These systems will partially restore herd reproductive performance. Advances in other reproductive technologies offer possibilities for wider use of superior germplasm. Technologies such as sexed semen, cloning, transgenesis, and preimplantation genetic diagnosis offer the potential to enhance the influence of superior animals on production of food for human consumption. However, at this time, additional research is needed to counteract the higher rates of embryonic and fetal mortality associated with some of these technologies. Furthermore, use of genomics, proteomics, and bioinformatics in the study of reproduction will undoubtedly provide investigators with a greater understanding of the limitations to efficient reproductive processes in the subfertile lactating dairy cow.

Animals↗

PubMed1999

Food plant-delivered cholera toxin B subunit for vaccination and immunotolerization.

Developments in recombinant DNA technology have enabled molecular biologists to introduce a variety of novel genes into plant species for specific purposes. From crop improvement to vaccine antigen and antibody production, plants are attractive bioreactors for production of recombinant proteins, as their eukaryotic nature often permits appropriate post-translational modification of recombinant proteins to retain native biological activity. The autotrophic growth of plants requires only soil minerals, water, nitrogen, sunlight energy and carbon dioxide for the synthesis of constituent proteins. Furthermore, production of biologically active proteins in food plants provides the advantage of direct delivery through consumption of edible transformed plant tissues. The production of cholera toxin B subunit in potato plants and applications for prevention of infectious and autoimmune disease are explained in this contribution.

Animals↗