FOOD AND AGRICULTURAL IMMUNOLOGY

Comparison of gluten recovery in gluten-incurred buckwheat flour using different commercial test kits
Alvarez PA and Boye JI
Recovery of gluten in buckwheat flour was evaluated as part of an effort to produce wheat-contaminated buckwheat flours that could be used as reference materials (RMs) for testing the presence of gluten in buckwheat. RMs of buckwheat containing 0, 20, 100 and 1000 ppm gluten were created and tested by ELISA. The Gluten-Check kit detected gluten accurately at all levels; RIDASCREEN and Biokits tests were accurate at 20 and 100 ppm levels, but at 1000 ppm both suffered from extraction saturation effect; Veratox kit read 60% higher for the 20 ppm RM (i.e., 31.9 ppm), but close to the target at 100 ppm RM; Veratox R5 kit showed low accuracy with around 30% recovery at 20 and 100 ppm and some 60% at 1000 ppm level. Overall, the results showed variations in recovery among different test kits which could have important implications in the accurate detection of gluten in buckwheat.
Alcohol extracts of Echinacea inhibit production of nitric oxide and tumor necrosis factor-alpha by macrophages in vitro
Zhai Z, Haney D, Wu L, Solco A, Murphy PA, Wurtele ES, Kohut ML and Cunnick JE
It has been suggested that Echinacea has anti-inflammatory activity in vivo. Nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1beta are important mediators in the inflammatory response. The effect of alcohol extracts of E. angustifolia (EA), E. pallida (EPA) and E. purpurea (EP) on the production of these inflammatory mediators in both LPS-stimulated RAW 264.7 macrophages in vitro and murine peritoneal exudate cells (PECs) in vivo were investigated. As macrophages produce these inflammatory mediators in response to pathogenic infection, parallel cultures of macrophages were studied for phagocytosis and intracellular killing of Salmonella enterica. EPA and EP in vitro inhibited NO production and TNF-α release in a dose-dependent manner. RAW 264.7 cells treated with EA or EP showed decreased killing over 24 h, although EA enhanced bacterial phagocytosis. Upon bacterial infection, RAW 264.7 cells produce high levels of NO; however, an Echinacea-mediated decrease in NO production was observed. Echinacea alcohol extracts administered orally at 130 mg/kg per day for seven days had a weak effect on NO production and phagocytosis by LPS-stimulated PECs. The results indicated that all Echinacea species significantly decreased inflammatory mediators in vitro, however, only EA and EP reduced bacterial killing. Oral administration of Echinacea alcohol extracts did not adversely affect the development and anti-bacterial function of inflammatory PECs in vivo, however, NO production was decreased during bacterial infection of PECs.
Selenium supplementation through Se-rich dietary matrices can upregulate the anti-inflammatory responses in lipopolysaccharide-stimulated murine macrophages
Dhanjal NIK, Sharma S, Prabhu KS and Prakash NT
The accessibility of selenium from naturally enriched sources such as cereals crops can potentially be used as selenium supplements to support nutritional requirements. Dietary selenium supplementation, as Se-rich wheat extracts, on RAW264.7 macrophage cells enhanced the antioxidant capacity via augmentation of cellular selenoprotein glutathione peroxidase 1 (GPx-1) expression in the absence or presence of lipopolysaccharide (LPS) treatment. Cells were supplemented with Se in the form of sodium selenite (SS), seleniferous wheat extract (SeW) and seleniferous wheat extract with rMETase treatment (SeW+rMET) at three different concentrations. Cells supplemented with SS and SeW+rMET showed increase in GPx-1 expression as compared to SeW treated cells. SeW+rMET, further, down-regulated the LPS-induced expression of cyclooxygenase-2, microsomal PGE synthase-1 and inducible nitric oxide synthase w.r.t. Se-deficient cells, while the expression of hematopoietic PGD synthase was upregulated. This demonstrates SeSup effectively modulates the expression inflammatory responses, indicating the potential benefits of dietary selenium supplementation.
Antibodies as epidemiological markers of genetically modified crop exposure: detection of Cry1Ab-specific IgG
Razavi A, Malhotra I, Ghosh A, Pusztai-Carey M, Marks J and King C
There has been an increasing concern with the safety of genetically modified (GM) crops. An important modification of GM crops is the expression of (Bt) protein, Cry1Ab. Animal exposure to Cry1Ab indicates that the protein is safe, but that it is immunogenic. Whether Cry1Ab is a human immunogen and whether antibody response to this protein can serve as a marker of high exposure to GM crops is unknown. Here we develop an enzyme-linked immunosorbent assay to detect the presence of Cry1Ab-specific IgG in ~100 individuals living in each of three countries that have varied exposure to GM crops (Papua New Guinea (PNG), low exposure; Kenya, moderate exposure; and the USA, high exposure). Cry1Ab-specific IgG antibodies were detected in individuals living in each region (8%, the USA; 3%, PNG; and 2%, Kenya). Thus, individuals develop anti-Cry1Ab antibodies at a frequency that roughly correlates with the exposure to GM crops expressing this protein.