Evaluation of the safety and nutritional equivalency of maize grain with genetically modified event DP-Ø23211-2

Rodent and broiler feeding studies with maize containing genetically modified event DP-915635-4 show no adverse effects on health or performance

Several regulatory agencies continue to require animal feeding studies to approve new genetically modified crops despite such studies providing little value in the safety assessment. Feeding studies with maize grain containing event DP-915635-4 (DP915635), a new corn rootworm management trait, were conducted to fulfill that requirement. Diets fed to Crl:CD®(SD) rats for 90 days contained up to 50% ground maize grain from DP915635, non-transgenic control, or non-transgenic reference hybrids (P1197, 6158, and 6365). Ross 708 broilers received phase diets containing up to 67% maize grain from each source for 42 days. Growth performance was compared between animals fed DP915635 and control diets; rats were further evaluated for clinical and neurobehavioral measures, ophthalmology, clinical pathology, organ weights, and gross and microscopic pathology, whereas carcass parts and select organ yields were determined for broilers. Reference group inclusion assisted in determining natural variation influence on observed significant differences between DP915635 and control groups. DP915635 maize grain diet consumption did not affect any measure evaluated in either feeding study. Results demonstrated DP-915635-4 maize grain safety and nutritional equivalency when fed in nutritionally adequate diets, adding to the existing literature confirming the lack of significant effects of feeding grain from genetically modified plants.

Fate of transgenic soybean DNA and immune response of broilers fed genetically modified DP-3Ø5423-1 soybean

Increased use of genetically modified (GM) plants in the food and feed industry has raised several concerns about the presence of unwanted genes in the food chain and potential associated health risks. In recent years, several studies have compared the nutrient contents of GM crops to conventional counterparts, and some have also tracked the fate of novel DNA fragments and proteins in the gastrointestinal (GIT) and their presence in several tissues. This study was conducted to investigate the fate of transgenic PHP19340A DNA fragment containing gm-fad2-1 (Soybean Event DP-3Ø5423-1) gene in digestive tract contents, blood, internal organs, and muscle tissues. The effects of feeding DP-3Ø5423-1 full-fat soybean meal (FFSBM) to broiler chickens on immune response and blood profiles were also evaluated on d 35. Day-old Ross 308 birds (n = 480) were randomly allocated to 24 floor pens in a 2 × 2 factorial arrangement with diet and gender as main factors. Birds were fed diets containing 20% of either DP-3Ø5423-1 or non-GM FFSBM for 35 d. Data were subjected to a 2-way ANOVA using the GLM procedure of JMP (Pro13). Based on PCR analysis, transgenic PHP19340A DNA fragment containing gm-fad2-1 gene was degraded throughout the digestive system to reach undetectable level in the cecal digesta. Moreover, there was no transgenic gene translocation to blood, organs, or muscle tissue. Feeding DP-3Ø5423-1 FFSBM to broilers had no effect on mRNA abundance of IL-1β, IL-2, IL-6, IL-12B, IL-17A, IFNγ, TNFα, and NF-κB in the spleen or on blood profile. In conclusion, these findings indicate that the examined transgenic fragment in DP-3Ø5423-1 FFSBM progressively degraded in the GIT and did not translocate into blood or tissues. Along with the immune response and blood profile findings, it can be assumed that DP-3Ø5423-1 soybean is safe and unlikely to pose any health risks to broilers or consumers.

Evaluation of an in vitro experimental platform of human polarized intestinal epithelial monolayers for the hazard assessment of insecticidal proteins

Previous work demonstrated the utility of using human-derived intestinal epithelial cell (IEC) lines cultured as polarized monolayers on Transwell® filters to differentiate between hazardous and non-hazardous proteins. The current study seeks to further resolve appropriate concentrations for evaluating proteins of unknown hazard potential using the IEC experimental platform and leverages these parameters for evaluating the potential toxicity of insecticidal proteins characteristic of those expressed in genetically modified (GM) agricultural biotechnology crops. To establish optimal test protein concentrations, effects of several known hazardous (C. perfringens epsilon toxin, Listeriolysin O, Phaseolus vulgaris erythroagglutinin, E. coli Shiga toxin 1, C. difficile Toxin B and wheat germ agglutinin) and non-hazardous (Ara-h2, β-lactoglobulin, fibronectin and Rubisco) proteins on IEC barrier integrity and cell viability were evaluated at concentration ranges. Two insecticidal proteins (AfIP-1A and AfIP-1B) were evaluated for effects in the IEC assay, a seven-day insecticidal bioassay, and assessed in a high-dose 14-day acute oral toxicity study in mice. The results obtained from the human in vitro IEC assay were consistent with results obtained from an in vivo acute oral toxicity study, both demonstrating that the combination of AfIP-1A and AfIP-1B do not exhibit any identifiable harmful impacts on mammalian cells.