Subchronic feeding study of grain from herbicide-tolerant maize DP-Ø9814Ø-6 in Sprague-Dawley rats

• Published in: Food and chemical toxicology Vol. 47; no. 9; pp. 2269 - 2280
• Main Authors: Appenzeller, Laura M., Munley, Susan M., Hoban, Denise, Sykes, Greg P., Malley, Linda A., Delaney, Bryan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2009
• Subjects: adverse effects; Animal Feed - toxicity; animal models; Animal Nutritional Physiological Phenomena; Animals; Bacillus licheniformis; Behavior, Animal - drug effects; Biotechnology; Blood Chemical Analysis; Body Weight - drug effects; brand name products; corn; diet; Drug Tolerance - genetics; Eating - drug effects; experimental diets; Eye - drug effects; Female; food safety; genetically modified foods; Genetically-modified maize; glyphosate; Glyphosate acetyltransferase; growth and development; health hazards; Hematologic Tests; herbicide resistance; human nutrition; long term experiments; Male; Muscle Strength - drug effects; Nervous System - drug effects; Plants, Genetically Modified - chemistry; Plants, Genetically Modified - genetics; Plants, Genetically Modified - toxicity; Rat; Rats; Rats, Sprague-Dawley; Subchronic; subchronic toxicity; toxicity; Toxicity Tests; Zea mays; Zea mays - genetics; Zea mays - metabolism; Zea mays - toxicity; NAS; Biotechnology; FDA; Subchronic; Rat; GLP; EFSA; SD; Genetically-modified maize; OECD; APHIS; ILSI; EC; US; w/w; WHO; h; Gly/SU; ppm; PMI; AAALAC; Glyphosate acetyltransferase; FAO; DNA; ILAR; EPA; USDA; NRC
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2009.06.014

This 13-week feeding study conducted in Sprague-Dawley rats evaluated the potential health effects from long-term consumption of a rodent diet formulated with grain from genetically modified (GM), herbicide-tolerant maize DP-Ø9814Ø-6 (98140; trade name Optimum® GAT® (Optimum® GAT® is a registered trademark of Pioneer Hi-Bred)). Metabolic inactivation of the herbicidal active ingredient glyphosate was conferred by genomic integration and expression of a gene-shuffled acetylase coding sequence, gat4621, from Bacillus licheniformis; tolerance to acetolactate synthase (ALS) inhibiting herbicides was conferred by overexpression of a modified allele (zm-hra) of the endogenous maize ALS enzyme that is resilient to inactivation. Milled maize grain from untreated (98140) and herbicide-treated (98140+Gly/SU) plants, the conventional non-transgenic, near-isogenic control (091), and three commercial non-transgenic reference hybrids (33J56, 33P66, and 33R77) was substituted at concentrations of 35–38% w/w into a common rodent chow formula (PMI® Nutrition International, LLC Certified Rodent LabDiet® 5002) and fed to rats (12/sex/group) for at least 91 consecutive days. Compared with rats fed diets containing grain from the conventional near-isogenic control maize, no adverse effects were observed in rats fed diets containing grain from 98140 or 98140+Gly/SU maize with respect to standard nutritional performance metrics and OECD 408-compliant toxicological response variables [OECD, 1998. Section 4 (Part 408), Health Effects: Repeated Dose 90-Day Oral Toxicity Study in Rodents, Guideline for the Testing of Chemicals. Organisation of Economic Co-operation and Development, Paris, France]. These results support the comparative safety and nutritional value of maize grain from genetically modified Optimum® GAT® and conventional, non-transgenic hybrid field corn.